neurodegenerative disorders mri approach
TRANSCRIPT
DEGENERATIVE DISORDERS OF BRAIN
Dr Arif khan S
AGING OR SENILE ATROPHY OF BRAIN
normal aging include ventricular and sulcal dilatation owing to cerebral volume loss typically reported as ldquoatrophyrdquo
Sulcal dilatation is a prominent feature
Despite these structural changes cerebral metabolism as measured by positron emission tomography (PET) with the glucose analogues fluorine deoxyglucose (18FDG) and carbon deoxyglucose (11C-2DG) does not decline with age
Neuronal loss is minimal in number and only parenchymal atrophy occurs in most
cerebrospinal fluid (CSF) volume increases approximately twofold
parenchymal volume loss rather than cerebral atrophy
DEMENTIAWide range of pathologies
1 Anatomic abscess tumor subdural hematoma posttraumatic encephalomalacia diffuse axonal injury
2 Metabolic electrolyte imbalance nutritional deficiency endocrinopathy toxic exposure medications
3 psychiatric
4 Degenerative Alzheimers disease [AD]
Parkinsons disease [PD] frontotemporal dementia dementia with Lewybodies) vascular (eg cerebral infarction Binswangers disease CADASIL
5 infectiousinflammatory vasculitis prion disease
6 demyelinating disease multiple sclerosis
7 paraneoplastic phenomena
DISEASES
Alzheimers disease
vascular dementia
Lewy body disease
frontotemporal lobar degeneration
MISCELLANEOUS
Creutzfeldt-Jakob disease
progressive supranuclear palsy (PSP)
multiple system atrophy (MSA)
Huntington disease
corticobasal degeneration
CADASIL
MRI PROTOCOL
Three plane imaging (preferably with the coronal images angled at right angles to the hippocampus) with T1 T2 FLAIR DWI and T2 sequences
T1
sequence volumetric gradient echo eg MPRAGE
eg 09mm reformatted in three planes
Purpose anatomical best for assessing regional volume loss
T2
sequence fast spin echo whole brain or limited to basal ganglia and posterior fossa (thin eg 3mm)
purpose signal intensity of basal ganglia and posterior fossa structures (often less well seen on FLAIR due to flow artefact)
FLAIR
sequence whole brain axial or volumetric
purpose white matter signal abnormality
small vessel ischaemia resulting in multi-infarct dementia and abnormal sulcalsignal in leptomeningeal processes
DWI ADC (or isometric images from optional DTI acquisition)
purpose cortical or deep grey matter restricted diffusion in Creutzfeldt Jakobdisease (CJD) and restriction in demyelination of infarction (eg cerebral vasculitis)
SWI
sequence SWI including phase and magnitude images
purpose microhaemorrhages (eg cerebral amyloid angiopathy (CAA) hypertensive encephalopathy) Mineral deposition in cortex (eg Alzheimers disease amyotrophic lateral sclerosis (ALS)) Loss of low signal in substantianigra (Parkinson disease)
Optional additional sequences
DTI (optional) for tractography
MR Perfusion arterial spin labelling or preferably contrast perfusion
MR spectroscopy
SYSTEMATIC APPROACH
T1 sagittal
AMidlline
corpus callosum
the anterior half of the body should be thicker and certainly not thinner than the posterior half
Upward bowing ndash Hydrocephalus
midbrain shape size and midbrain to pons area ratio
pons shape
should be plump and rounded and about 4 times as large as the midbrain
B Sagittal
medial surfaces of the frontal parietal and occipital lobes
all the sulci should be about the same size
Significant parietal sulcal widening with atrophy of the precuneus and posterior cingulate suggests Alzheimers disease (AD)
anterior to posterior gradient of sulcalsize (bigger anteriorly) seen in frontotemporal lobar degeneration
mamillary bodies
should be about the same size Atrophic or asymmetrical mammillary bodies may imply hippocampal pathology or Wernicke-Korsakoff syndrome
upper cervical spine and cord
Axial FLAIR amp T2
bullgyral atrophy particularly useful for the frontal lobes
bullwidening of the sylvian fissures
bullhippocampal volume and signal
bullposterior fossa morphology
bullMidbrain
bullPons
bullMedulla
bullCerebellum
bullWernicke pattern high T2 signal (ventromedial thalamus mammillary bodies periaqueductal grey matter)
bullCortical white matter changes
T2 axial imaging is often better for basal ganglia structures and posterior fossa Assess for
reversal of normal T2 signal of putamen vs globus pallidus of MSA-P
atrophic caudate heads of Huntingtons disease
size and flow void in aqueduct (usually prominent in NPH)
3 Coronal sequences
bullhippocampal choroidal fissure and temporal horn size
bullsymmetrybull left gt right atrophy favours FTLD
bull equal involvement favours Alzheimers disease
bullanterior to posterior gradientbull anterior atrophy gt posterior atrophy favours FTLD
bullinvolvement of the temporal lobe generally favours FTLD
bullatrophy largely restricted to the hippocampus and parahippocampalgyrus favours Alzheimers disease
bullmammillary body size signal and symmetry
4 T2 sequences
Sequences susceptible to blood products are particularly useful in assessing
bullmicrohaemorrhages
bull peripherally distributed in cerebral amyloid angiopathy which in turn is associate with Alzheimers disease
bullcentrally distributed (basal ganglia pons cerebellum) in chronic hypertensive encephalophathy
5 DWI
DWI has a limited role in the assessment of a patient with a suspected neurodegenerative disease
Crucial particularly for Creutzfeldt-Jakob disease look for cortical basal ganglia and thalamic restricted diffusion
SCORING SYSTEMS AND MEASUREMENTS
bullFazekas scale for white matter lesions the deep white matter component is used in assessing the amount of chronic small vessel ischaemic change
bullposterior atrophy score of parietal atrophy (PA or PCA or Koedam score) useful in atypical (posterior cortical atrophy) or early onset Alzheimers disease
bullmedial temporal lobe atrophy score (MTA score)
bullglobal cortical atrophy scale (GCA scale)
A number of measurements ratios are also useful
midbrain to pons area ratio (for PSP)
magnetic resonance parkinsonism index (MRPI) (for PSP)
ALZHEIMER DISEASE
Alzheimer disease (AD) is a common neurodegenerative disease responsible for the majority of all dementias and imposing a significant burden on developed nations
Most common cause of dementia and accounts for two thirds of cases of dementia in patients aged 60-70 years
Epidemiological risk factor advanced age female gender
apolipoprotein E (APOE) ε4 allele carrier status
current smoking
family history of dementia
Classicaltypical Alzheimer disease
with antegrade episodic memory deficits
Neuropsychiatric symptoms are also common and eventually affect almost all patients These include apathy depression anxiety aggressionagitation and psychosis
Atypicalvariant Alzheimer disease
These entities often recognised clinically well before they were identified to be pathologically identical to Alzheimer disease
slowly progressive focal cortical atrophy with symptoms and signs matched to the affected area
Examples include
posterior cortical atrophy
frontal variant of Alzheimer disease
a minority of cases of semantic dementia
Pathology
Alzheimer disease is characterised by the accumulation of senile (neuritic) plaques neuritic (neurofibrillary) tangles and progressive loss of neurons
The progression of pathology initially involves the transentorhinalregion and then spreads to the hippocampal complex and mesial temporal lobe structures and eventually the temporal lobes and basal forebrain
RADIOGRAPHIC FEATURES
The primary role of MRI (and CT) in the diagnosis of Alzheimer disease is the assessment of volume change in characteristic locations which can yield a diagnostic accuracy of up to 87
The diagnosis should be made on the basis of two features
mesial temporal lobe atrophy
temporoparietal cortical atrophy
MESIAL TEMPORAL LOBE ATROPHY
hippocampal and parahippocampal decrease in volume
Indirectly by examining enlargement of the parahippocampalfissures
The former is more sensitive and specific but ideally requires actual volumetric calculations rather than eye-balling the scan
These measures have been combined in the medial temporal atrophy score which has been shown to be predictive of progression from mild cognitive impairment (MCI) to dementiA
MEDIAL TEMPORAL LOBE ATROPHY SCORE
visual score performed on MRI of the brain using coronal T1 weighted images through the hippocampus at the level of the anterior pons and assesses three features
width of the choroid fissure
width of the temporal horn of the lateral ventricle
height of the hippocampus
These result in a score of 0 to 4
0 = no CSF is visible around the hippocampus
1 = choroid fissure is slightly widened
2 = moderate widening of the choroid fissure mild enlargement of the temporal horn and mild loss of hippocampal height
3 = marked widening of the choroid fissure moderate enlargement of the temporal horn and moderate loss of hippocampal height
4 = marked widening of the choroid fissure marked enlargement of the temporal horn and the hippocampus is markedly atrophied and internal structure is lost
In a patient younger than 75 years of age a score of 2 or more is abnormal
In a patient 75 years or older a score of 3 or more is abnormal
Atrophy has been shown to correlate with likelihood of progression from mild cognitive impairment (MCI) to dementia 4
MRI SPECTROSCOPY
increases in myoinositol (MI) (356 ppm) thought to reflect inhibition of enzyme(s) mediating conversion of MI to phosphatidyl inositol
decreased N-acetyl aspartate (NAA) (202 ppm) indicating decreased neuronal activity
TEMPOROPARIETAL CORTICAL ATROPHY Parietal atrophy particularly relevant to posterior cortical atrophy or early onset Alzheimer disease
the inter-hemispheric surface of the parietal lobe
TREATMENT AND PROGNOSIS
There is no cure for this disease some drugs have been developed trying to improve symptoms or at least temporarily slow down their progression
cholinsterase inhibitors
partial NMDA receptor antagonists
medications for behavioural symptoms
antidepressants
anxiolytics
antiparkinsonian (movement symptoms)
anticonvulsantssedatives (behavioural)
VASCULAR DEMENTIAalso known as vascular cognitive impairment
It is primarily seen in patients with atherosclerosis and chronic hypertension
Results from the accumulation of multiple white matter or cortical infarcts although cerebral haemorrhages can be variably included
strongly correlated with age seen in only 1 of patients over the age of 55 years of age but in over 4 of patients over 71 years of age
It is also possible to divide vascular dementia into subtypes
small vessel dementia (aka Binswanger disease)
cortical vascular dementia roughly equivalent to multi-infarct dementia
strategic infarct dementia
thalamic dementia
RADIOGRAPHIC FEATURES
Both CT and MRI are able to provide evidence of ischaemic damage
MRI is more sensitive especially to white matter small vessel ischaemic change as well as to microhaemorrhages seen in cerebral amyloid angiopathy and chronic hypertensive encephalopathy
bullsmall vessel dementia (aka Binswanger disease)
bullcerebral infarction
bulllacunar infarction
bullintracerebral haemorrhage
CEREBRAL AMYLOID ANGIOPATHY
SMALL VESSEL DEMENTIA
also known as Binswanger disease
Subcortical arteriosclerotic encephalopathy
refers to slowly progressive exclusively white-matter multi-infarct dementia
A genetically transmitted form of the disease is known as familial arteriopathic leukoencephalopathy
or
CADASIL (cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy)
CLINICAL CRITERIA FOR DIAGNOSIS
marked subcortical microangiopathic lesions at MR imaging
a negative family history for strokes early cognitive impairment or psychiatric disorders in first- and second-degree relatives
documented arterial hypertension systolic values higher than 160 mm Hg diastolic values higher than 95 mm Hg or both measured at several occasions 5
MRI
subcortical and periventricular lesions visible on T2 FLAIR T2-weighted and proton-density sequences
commonly grouped around the frontal and occipital horns and in the centrum semi ovale
Moderate generalised cerebral atrophy is invariably present and lacunar infarctsin the basal ganglia and
thalami are common
CT
Diffuse incompletely symmetrical hypodensities are present in deep white matter especially they are prominent in the frontal lobes and the centrum semiovale
CEREBRAL AUTOSOMAL DOMINANT ARTERIOPATHY WITH SUBCORTICAL INFARCTS AND LEUKOENCEPHALOPATHY (CADASIL)
occurs in the absence of hypertension and arteriosclerosis and presents in 71 of cases before the age of 60 years
Imaging features demonstrate severe microvascular changes with multiple subcortical infarcts
Not distinguishable from hypertensive type microvascular disease
DEMENTIA WITH LEWY BODIESPD
Neurodegenerative disease (a synucleinopathy to be specific) related to Parkinsons disease (PD)
Epidemiology
Dementia with Lewy bodies presents in older patients (onset typically in 50-70 years of age) and is sporadic
It is the second most common neurodegenerative cause of dementia in older patients after Alzheimers disease accounting for 15-20 of case
RADIOGRAPHIC FEATURES
MRI
Atrophy in various parts of the brain without a clearly identified unique pattern
Most helpful in distinguishing DLB from other entities resulting in dementia is the absence of features of other diseases
generalised decrease in cerebral volume most marked in
frontal lobes parietotemporal regions
enlargement of the lateral ventricles
relatively focal atrophy
midbrain
hypothalamus
SWALLOW TAIL SIGN
The swallow tail sign describes the normal axial imaging appearance of nigrosome-1 within the substantianigra on high resolution T2SWI weighted MRI
Absence of the sign (absent swallow tail sign) is reported to have a diagnostic accuracy of greater than 90 for Parkinson disease
Nuclear medicine
Occipital hypoperfusion on SPECT PET
May aid in differentiation from other types of dementia especially Alzheimers disease
TREATMENT AND PROGNOSIS
Unlike Parkinsons disease dementia with Lewy bodies respond less readily to L-dopa and also may have severe sensitivity reactions to neuroleptic drugs such as rigidity reduced consciousness pyrexia falling postural hypotension and collapse
Lewy body dementia also responds favourably to acetylcholinesteraseinhibitors
DIFFERENTIAL DIAGNOSISwith strong overlap between
bullAlzheimers diseasebull clinical may occasionally have similar clinical presentation with a frontal type dementia or posterior
cortical atrophy
bull imaging prominent involvement of hippocampi on imaging
bullFronto-temporal lobar degenerationbull clinical usually younger onset absent parkinsonian features absent visual hallucinations
bull imaging more pronounced frontal temporal atrophy L gt R asymmetry
FRONTO-TEMPORAL LOBAR DEGENERATION
Frontotemporal lobar degeneration (FTLD) is the pathological description of a group of neurodegenerative disorders characterised by focal atrophy of the frontal and temporal cortices
rontotemporal lobar degeneration can be divided as follows 3-4
bullbehavioural variant fronto-temporal lobar degeneration dementia (bvFTLD) (aka behavioural variant frontotemporal dementia)1
bulllanguage variant fronto-temporal lobar degeneration (lvFTLD) (aka primary progressive aphasia (PPA)6
bull agrammatic variant primary progressive aphasia (aka progressive non-fluent aphasia (PNFA)
bull semantic variant primary progressive aphasia (aka semantic dementia)
bull logopaenic variant primary progressive aphasia
RADIOGRAPHIC FEATURES
The frontal and temporal lobes are predominantly affected there is often striking asymmetry both of involvement of frontal vs temporal lobes and involvement of left and right hemispheres
In addition the degree of fronto-striatal dysfunction varies between the different FTLD subgroups with behavioural variant frontotemporal dementia (bvFTD) having the greatest involvement
As a result the caudate heads tend to be reduced in size in these patients to a much greater degree than in the language variants of frontotemporal dementia
BEHAVIOURAL VARIANT FRONTO-TEMPORAL LOBAR DEGENERATION (BVFTLD)also referred to as Pick disease
Patients with behavioural variant FTD typically present with a dysexecutive cognitive syndrome associated with changes in personality and social behaviour
As the disease progresses impairments in language and memory may develop and the cognitive phenotype may come to resemble one of the language variants of FTD
RADIOGRAPHIC FEATURES
MRI
typical radiographic finding is atrophy of the frontal lobes and to a lesser extent the temporal lobes
The degree of atrophy can be very asymmetric
Decrease in volume of the caudate heads This indicates loss of both efferent and afferent fibres
CREUTZFELDT-JAKOB DISEASEspongiform encephalopathy
Results in a rapidly progressive dementia
other non-specific neurological features
Three types of Creutzfeldt-Jakob disease have been described
bullsporadic (sCJD) accounts for 85-90 of cases
bullvariant (vCJD)
bullfamilial (fCJD) 10 of cases (these individuals carry a PRPc mutation)
Creutzfeldt-Jakob disease is characterized by rapidly progressive dementia cerebral atrophy myoclonus and death
Patients with vCJD present mostly with sensory and psychiatric symptoms
Patients with sCJD usually present with progressive cognitive impairment and cerebellar symptoms
PATHOLOGY
mediated via (infectious) prions
a type of protein which manifest in sheep as the disease scrapie and in cows as bovine spongiform encephalopathy
Prions are considered infectious in sense that they can alter the structure of neighbouring proteins
CJD leads to spongiform degeneration of the brain
the conversion of normal prion protein to proteinaceous infectious particles that accumulate in and around neurons and lead to cell death
RADIOGRAPHIC FEATURES
MRI
MRI findings may be bilateral or unilateral and symmetric or asymmetric and include
T2 hyperintensity
obasal ganglia (putamen and caudate)
othalamus ( hockey stick sign and pulvinar sign)
ocortex most common early manifestation
owhite matter
persistent restricted diffusion on DWI (considered the most sensitive sign)
Review of sequential studies also typically demonstrates rapidly progressive cerebral atrophy
hypometabolism on 18FDG-PET studies
TREATMENT AND PROGNOSIS
here is currently no curative treatment and the disease is invariably fatal with a mean survival of only 7 months for most cases
PROGRESSIVE SUPRANUCLEARPALSYlso known as the Steele-Richardson-Olszewski syndrome
Progressive supranuclear palsy typically becomes clinically apparent in the 6th decade of life
Progresses to death usually within a decade (2-17 years from diagnosis)
Progressive supranuclear palsy is characterised
decreased cognition
abnormal eye movements (supranuclear vertical gaze palsy)
postural instability and falls
as well as parkinsonian features and speech disturbances
RADIOGRAPHIC FEATURESMRI
midbrain atrophy
reduction of anteroposterior midline midbrain diameter at the level of the superior colliculi on axial imaging (from interpeduncular fossa to the intercolicular groove lt12mm 8) which can give a mickey mouse appearance
reduced area of the midbrain on midline sagittal and reduced midbrain to pons area ratio approx 012 (normal approx 024) on midline sagittal
Loss of the lateral convex margin of the tegmentum of midbrain has been described as the morning glory sign
hummingbird sign also known as the penguin sign The key is a flattening or concave outline to the superior aspect of the midbrain which should be upwardly convex
bullT2 diffuse high-signal lesions in
bull pontine tegmentum
bull tectum of the midbrain
bull inferior olivary nucleus
MICKEY MOUSE APPEARANCE
THE PENGUIN SIGN
MULTIPLE SYSTEM ATROPHY
sporadic neurodegenerative disease
Typically symptoms begin between 40 and 60 years of age
Clinical presentation is variable but typically presents in one of three patterns (initially described as separate entities)
Shy-Drager syndrome is used when autonomic symptoms predominate
striatonigral degeneration shows predominant parkinsonian features
olivopontocerebellar atrophy demonstrates primarily cerebellar dysfunction
MSA has been divided clinically into 2 forms according to the dominant non-autonomic symptoms
MSA-C predominance of cerebellar symptoms (olivopontocerebellar atrophy)
MSA-P predominance of parkinsonian signs and symptoms (striatonigraldegeneration)
RADIOGRAPHIC FEATURES
bullT2 hyperintensities typically present in the pontocerebellar tractsbull pons hot cross bun sign (MSA-C)
bull middle cerebellar peduncles
bull Cerebellum
putaminal findings in MSA-P reduced volume
reduced GRE and T2 signal relative to globus pallidus
reduced GRE and T2 signal relative to red nucleus
abnormal disruption of the normal high T2 linear rim
bullMSA-Cbull disproportionate atrophy of the cerebellum and brainstem (especially olivary nuclei and middle
cerebellar peduncle)
NUCLEAR MEDICINE
SPECT and PET studies tend to demonstrate hypometabolism in the superior parietal and superior frontal areas in the basal ganglia
HUNTINGTON DISEASE
autosomal dominant neurodegenerative disease
a loss of GABAergic neurons of the basal ganglia
especially atrophy of the caudate nucleus and putamen
Huntington disease has a prevalence of 5-10 per 100000 and is typically diagnosed between 30 and 50 years of age
In approximately 1-6 symptoms occur before the age of 20 so-called juvenile form
Presentation is typically with progressive rigidity choreoathetosis dementia psychosis and emotional lability
The juvenile form has a different presentation with cerebellar symptoms rigidity and hypokinesia being prominent
it is a autosomal dominant with complete penetrance and genetic anticipation particularly if inherited mutated allele is paternal
The mutation responsible is on chromosome 4p163 and consists of a CAG trineucleotide repeat
The usual 10-30 copies are amplified to greater than 36 and the greater the number of repeats the earlier the age of onset
RADIOGRAPHIC FEATURES
MRI
The most striking and best known feature is that of caudate head atrophy resulting in enlargement of the frontal horns often giving them a box like configuration
This can be quantified by an number of measurements
bullfrontal horn width to intercaudate distance ratio (FHCC)
bullintercaudate distance to inner table width ratio (CCIT)
Juvenile form
putamen are also atrophied and demonstrate increased T2 signal
basal ganglia may show decrease T2 signal and blooming on SWI in keeping with iron deposition
Generalised age inappropriate cortical volume loss is also recognised
FHCC ratio normal mean 22 to 26 (this ratio decreases with ageing as a result of enlargement of the frontal horns of the lateral ventricles)
CCIT ratio normal mean 009 to 012
AMYOTROPHIC LATERAL SCLEROSISalso known as Lou Gehrig disease or Charcot disease
Primary degeneration of the motor neurons within the brain brain stem and spinal cord
Patients typically present with progressive muscle weakness and limb and truncal atrophy combined with signs of spasticity
Mean age at the time of diagnosis is 55 years
RADIOGRAPHIC FEATURES
MRI
The earliest MR manifestation is hyperintensity on T2WI in the corticospinal tracts seen earliest in the internal capsule
Iron deposition in the cortex is demonstrated as loss of signal most evident on T2 weighted sequences
IS IT ATROPHY OR HYDROCEPHALUS
Abnormal accumulation of CSF in Ventricular system
Results from Structural or functional block to normal flow Of CSF
In effect all are obhstructive
Difficult to differentiate Atrophy from Hydrocephalus gt60yrs
Initially show increased ICT
Later stages may reach Equillibrium and Becomes NP hYdrocephalus
Types
Obstructive
Communicating
NPH ndash seen typically in old patients Diagnosis is more based on clinical feature
Dementia urinary incontinence and gait apraxias + Hydrocephalus = NPH
Radiologically w
1 degeree of ventricular dilatation is more with Thinning and bowing of CC
2 Sulcal effacement is invariable seen Hydrocephalus
3 dilatation or rounding of the Temporal Horns
4 Rounding and enlargement of the frontal horns
5 Enlargement and ballooning of 3rd
ventricle
6 Enlargement of fourth ventricle
SPOTTERS
THANK YOU
AGING OR SENILE ATROPHY OF BRAIN
normal aging include ventricular and sulcal dilatation owing to cerebral volume loss typically reported as ldquoatrophyrdquo
Sulcal dilatation is a prominent feature
Despite these structural changes cerebral metabolism as measured by positron emission tomography (PET) with the glucose analogues fluorine deoxyglucose (18FDG) and carbon deoxyglucose (11C-2DG) does not decline with age
Neuronal loss is minimal in number and only parenchymal atrophy occurs in most
cerebrospinal fluid (CSF) volume increases approximately twofold
parenchymal volume loss rather than cerebral atrophy
DEMENTIAWide range of pathologies
1 Anatomic abscess tumor subdural hematoma posttraumatic encephalomalacia diffuse axonal injury
2 Metabolic electrolyte imbalance nutritional deficiency endocrinopathy toxic exposure medications
3 psychiatric
4 Degenerative Alzheimers disease [AD]
Parkinsons disease [PD] frontotemporal dementia dementia with Lewybodies) vascular (eg cerebral infarction Binswangers disease CADASIL
5 infectiousinflammatory vasculitis prion disease
6 demyelinating disease multiple sclerosis
7 paraneoplastic phenomena
DISEASES
Alzheimers disease
vascular dementia
Lewy body disease
frontotemporal lobar degeneration
MISCELLANEOUS
Creutzfeldt-Jakob disease
progressive supranuclear palsy (PSP)
multiple system atrophy (MSA)
Huntington disease
corticobasal degeneration
CADASIL
MRI PROTOCOL
Three plane imaging (preferably with the coronal images angled at right angles to the hippocampus) with T1 T2 FLAIR DWI and T2 sequences
T1
sequence volumetric gradient echo eg MPRAGE
eg 09mm reformatted in three planes
Purpose anatomical best for assessing regional volume loss
T2
sequence fast spin echo whole brain or limited to basal ganglia and posterior fossa (thin eg 3mm)
purpose signal intensity of basal ganglia and posterior fossa structures (often less well seen on FLAIR due to flow artefact)
FLAIR
sequence whole brain axial or volumetric
purpose white matter signal abnormality
small vessel ischaemia resulting in multi-infarct dementia and abnormal sulcalsignal in leptomeningeal processes
DWI ADC (or isometric images from optional DTI acquisition)
purpose cortical or deep grey matter restricted diffusion in Creutzfeldt Jakobdisease (CJD) and restriction in demyelination of infarction (eg cerebral vasculitis)
SWI
sequence SWI including phase and magnitude images
purpose microhaemorrhages (eg cerebral amyloid angiopathy (CAA) hypertensive encephalopathy) Mineral deposition in cortex (eg Alzheimers disease amyotrophic lateral sclerosis (ALS)) Loss of low signal in substantianigra (Parkinson disease)
Optional additional sequences
DTI (optional) for tractography
MR Perfusion arterial spin labelling or preferably contrast perfusion
MR spectroscopy
SYSTEMATIC APPROACH
T1 sagittal
AMidlline
corpus callosum
the anterior half of the body should be thicker and certainly not thinner than the posterior half
Upward bowing ndash Hydrocephalus
midbrain shape size and midbrain to pons area ratio
pons shape
should be plump and rounded and about 4 times as large as the midbrain
B Sagittal
medial surfaces of the frontal parietal and occipital lobes
all the sulci should be about the same size
Significant parietal sulcal widening with atrophy of the precuneus and posterior cingulate suggests Alzheimers disease (AD)
anterior to posterior gradient of sulcalsize (bigger anteriorly) seen in frontotemporal lobar degeneration
mamillary bodies
should be about the same size Atrophic or asymmetrical mammillary bodies may imply hippocampal pathology or Wernicke-Korsakoff syndrome
upper cervical spine and cord
Axial FLAIR amp T2
bullgyral atrophy particularly useful for the frontal lobes
bullwidening of the sylvian fissures
bullhippocampal volume and signal
bullposterior fossa morphology
bullMidbrain
bullPons
bullMedulla
bullCerebellum
bullWernicke pattern high T2 signal (ventromedial thalamus mammillary bodies periaqueductal grey matter)
bullCortical white matter changes
T2 axial imaging is often better for basal ganglia structures and posterior fossa Assess for
reversal of normal T2 signal of putamen vs globus pallidus of MSA-P
atrophic caudate heads of Huntingtons disease
size and flow void in aqueduct (usually prominent in NPH)
3 Coronal sequences
bullhippocampal choroidal fissure and temporal horn size
bullsymmetrybull left gt right atrophy favours FTLD
bull equal involvement favours Alzheimers disease
bullanterior to posterior gradientbull anterior atrophy gt posterior atrophy favours FTLD
bullinvolvement of the temporal lobe generally favours FTLD
bullatrophy largely restricted to the hippocampus and parahippocampalgyrus favours Alzheimers disease
bullmammillary body size signal and symmetry
4 T2 sequences
Sequences susceptible to blood products are particularly useful in assessing
bullmicrohaemorrhages
bull peripherally distributed in cerebral amyloid angiopathy which in turn is associate with Alzheimers disease
bullcentrally distributed (basal ganglia pons cerebellum) in chronic hypertensive encephalophathy
5 DWI
DWI has a limited role in the assessment of a patient with a suspected neurodegenerative disease
Crucial particularly for Creutzfeldt-Jakob disease look for cortical basal ganglia and thalamic restricted diffusion
SCORING SYSTEMS AND MEASUREMENTS
bullFazekas scale for white matter lesions the deep white matter component is used in assessing the amount of chronic small vessel ischaemic change
bullposterior atrophy score of parietal atrophy (PA or PCA or Koedam score) useful in atypical (posterior cortical atrophy) or early onset Alzheimers disease
bullmedial temporal lobe atrophy score (MTA score)
bullglobal cortical atrophy scale (GCA scale)
A number of measurements ratios are also useful
midbrain to pons area ratio (for PSP)
magnetic resonance parkinsonism index (MRPI) (for PSP)
ALZHEIMER DISEASE
Alzheimer disease (AD) is a common neurodegenerative disease responsible for the majority of all dementias and imposing a significant burden on developed nations
Most common cause of dementia and accounts for two thirds of cases of dementia in patients aged 60-70 years
Epidemiological risk factor advanced age female gender
apolipoprotein E (APOE) ε4 allele carrier status
current smoking
family history of dementia
Classicaltypical Alzheimer disease
with antegrade episodic memory deficits
Neuropsychiatric symptoms are also common and eventually affect almost all patients These include apathy depression anxiety aggressionagitation and psychosis
Atypicalvariant Alzheimer disease
These entities often recognised clinically well before they were identified to be pathologically identical to Alzheimer disease
slowly progressive focal cortical atrophy with symptoms and signs matched to the affected area
Examples include
posterior cortical atrophy
frontal variant of Alzheimer disease
a minority of cases of semantic dementia
Pathology
Alzheimer disease is characterised by the accumulation of senile (neuritic) plaques neuritic (neurofibrillary) tangles and progressive loss of neurons
The progression of pathology initially involves the transentorhinalregion and then spreads to the hippocampal complex and mesial temporal lobe structures and eventually the temporal lobes and basal forebrain
RADIOGRAPHIC FEATURES
The primary role of MRI (and CT) in the diagnosis of Alzheimer disease is the assessment of volume change in characteristic locations which can yield a diagnostic accuracy of up to 87
The diagnosis should be made on the basis of two features
mesial temporal lobe atrophy
temporoparietal cortical atrophy
MESIAL TEMPORAL LOBE ATROPHY
hippocampal and parahippocampal decrease in volume
Indirectly by examining enlargement of the parahippocampalfissures
The former is more sensitive and specific but ideally requires actual volumetric calculations rather than eye-balling the scan
These measures have been combined in the medial temporal atrophy score which has been shown to be predictive of progression from mild cognitive impairment (MCI) to dementiA
MEDIAL TEMPORAL LOBE ATROPHY SCORE
visual score performed on MRI of the brain using coronal T1 weighted images through the hippocampus at the level of the anterior pons and assesses three features
width of the choroid fissure
width of the temporal horn of the lateral ventricle
height of the hippocampus
These result in a score of 0 to 4
0 = no CSF is visible around the hippocampus
1 = choroid fissure is slightly widened
2 = moderate widening of the choroid fissure mild enlargement of the temporal horn and mild loss of hippocampal height
3 = marked widening of the choroid fissure moderate enlargement of the temporal horn and moderate loss of hippocampal height
4 = marked widening of the choroid fissure marked enlargement of the temporal horn and the hippocampus is markedly atrophied and internal structure is lost
In a patient younger than 75 years of age a score of 2 or more is abnormal
In a patient 75 years or older a score of 3 or more is abnormal
Atrophy has been shown to correlate with likelihood of progression from mild cognitive impairment (MCI) to dementia 4
MRI SPECTROSCOPY
increases in myoinositol (MI) (356 ppm) thought to reflect inhibition of enzyme(s) mediating conversion of MI to phosphatidyl inositol
decreased N-acetyl aspartate (NAA) (202 ppm) indicating decreased neuronal activity
TEMPOROPARIETAL CORTICAL ATROPHY Parietal atrophy particularly relevant to posterior cortical atrophy or early onset Alzheimer disease
the inter-hemispheric surface of the parietal lobe
TREATMENT AND PROGNOSIS
There is no cure for this disease some drugs have been developed trying to improve symptoms or at least temporarily slow down their progression
cholinsterase inhibitors
partial NMDA receptor antagonists
medications for behavioural symptoms
antidepressants
anxiolytics
antiparkinsonian (movement symptoms)
anticonvulsantssedatives (behavioural)
VASCULAR DEMENTIAalso known as vascular cognitive impairment
It is primarily seen in patients with atherosclerosis and chronic hypertension
Results from the accumulation of multiple white matter or cortical infarcts although cerebral haemorrhages can be variably included
strongly correlated with age seen in only 1 of patients over the age of 55 years of age but in over 4 of patients over 71 years of age
It is also possible to divide vascular dementia into subtypes
small vessel dementia (aka Binswanger disease)
cortical vascular dementia roughly equivalent to multi-infarct dementia
strategic infarct dementia
thalamic dementia
RADIOGRAPHIC FEATURES
Both CT and MRI are able to provide evidence of ischaemic damage
MRI is more sensitive especially to white matter small vessel ischaemic change as well as to microhaemorrhages seen in cerebral amyloid angiopathy and chronic hypertensive encephalopathy
bullsmall vessel dementia (aka Binswanger disease)
bullcerebral infarction
bulllacunar infarction
bullintracerebral haemorrhage
CEREBRAL AMYLOID ANGIOPATHY
SMALL VESSEL DEMENTIA
also known as Binswanger disease
Subcortical arteriosclerotic encephalopathy
refers to slowly progressive exclusively white-matter multi-infarct dementia
A genetically transmitted form of the disease is known as familial arteriopathic leukoencephalopathy
or
CADASIL (cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy)
CLINICAL CRITERIA FOR DIAGNOSIS
marked subcortical microangiopathic lesions at MR imaging
a negative family history for strokes early cognitive impairment or psychiatric disorders in first- and second-degree relatives
documented arterial hypertension systolic values higher than 160 mm Hg diastolic values higher than 95 mm Hg or both measured at several occasions 5
MRI
subcortical and periventricular lesions visible on T2 FLAIR T2-weighted and proton-density sequences
commonly grouped around the frontal and occipital horns and in the centrum semi ovale
Moderate generalised cerebral atrophy is invariably present and lacunar infarctsin the basal ganglia and
thalami are common
CT
Diffuse incompletely symmetrical hypodensities are present in deep white matter especially they are prominent in the frontal lobes and the centrum semiovale
CEREBRAL AUTOSOMAL DOMINANT ARTERIOPATHY WITH SUBCORTICAL INFARCTS AND LEUKOENCEPHALOPATHY (CADASIL)
occurs in the absence of hypertension and arteriosclerosis and presents in 71 of cases before the age of 60 years
Imaging features demonstrate severe microvascular changes with multiple subcortical infarcts
Not distinguishable from hypertensive type microvascular disease
DEMENTIA WITH LEWY BODIESPD
Neurodegenerative disease (a synucleinopathy to be specific) related to Parkinsons disease (PD)
Epidemiology
Dementia with Lewy bodies presents in older patients (onset typically in 50-70 years of age) and is sporadic
It is the second most common neurodegenerative cause of dementia in older patients after Alzheimers disease accounting for 15-20 of case
RADIOGRAPHIC FEATURES
MRI
Atrophy in various parts of the brain without a clearly identified unique pattern
Most helpful in distinguishing DLB from other entities resulting in dementia is the absence of features of other diseases
generalised decrease in cerebral volume most marked in
frontal lobes parietotemporal regions
enlargement of the lateral ventricles
relatively focal atrophy
midbrain
hypothalamus
SWALLOW TAIL SIGN
The swallow tail sign describes the normal axial imaging appearance of nigrosome-1 within the substantianigra on high resolution T2SWI weighted MRI
Absence of the sign (absent swallow tail sign) is reported to have a diagnostic accuracy of greater than 90 for Parkinson disease
Nuclear medicine
Occipital hypoperfusion on SPECT PET
May aid in differentiation from other types of dementia especially Alzheimers disease
TREATMENT AND PROGNOSIS
Unlike Parkinsons disease dementia with Lewy bodies respond less readily to L-dopa and also may have severe sensitivity reactions to neuroleptic drugs such as rigidity reduced consciousness pyrexia falling postural hypotension and collapse
Lewy body dementia also responds favourably to acetylcholinesteraseinhibitors
DIFFERENTIAL DIAGNOSISwith strong overlap between
bullAlzheimers diseasebull clinical may occasionally have similar clinical presentation with a frontal type dementia or posterior
cortical atrophy
bull imaging prominent involvement of hippocampi on imaging
bullFronto-temporal lobar degenerationbull clinical usually younger onset absent parkinsonian features absent visual hallucinations
bull imaging more pronounced frontal temporal atrophy L gt R asymmetry
FRONTO-TEMPORAL LOBAR DEGENERATION
Frontotemporal lobar degeneration (FTLD) is the pathological description of a group of neurodegenerative disorders characterised by focal atrophy of the frontal and temporal cortices
rontotemporal lobar degeneration can be divided as follows 3-4
bullbehavioural variant fronto-temporal lobar degeneration dementia (bvFTLD) (aka behavioural variant frontotemporal dementia)1
bulllanguage variant fronto-temporal lobar degeneration (lvFTLD) (aka primary progressive aphasia (PPA)6
bull agrammatic variant primary progressive aphasia (aka progressive non-fluent aphasia (PNFA)
bull semantic variant primary progressive aphasia (aka semantic dementia)
bull logopaenic variant primary progressive aphasia
RADIOGRAPHIC FEATURES
The frontal and temporal lobes are predominantly affected there is often striking asymmetry both of involvement of frontal vs temporal lobes and involvement of left and right hemispheres
In addition the degree of fronto-striatal dysfunction varies between the different FTLD subgroups with behavioural variant frontotemporal dementia (bvFTD) having the greatest involvement
As a result the caudate heads tend to be reduced in size in these patients to a much greater degree than in the language variants of frontotemporal dementia
BEHAVIOURAL VARIANT FRONTO-TEMPORAL LOBAR DEGENERATION (BVFTLD)also referred to as Pick disease
Patients with behavioural variant FTD typically present with a dysexecutive cognitive syndrome associated with changes in personality and social behaviour
As the disease progresses impairments in language and memory may develop and the cognitive phenotype may come to resemble one of the language variants of FTD
RADIOGRAPHIC FEATURES
MRI
typical radiographic finding is atrophy of the frontal lobes and to a lesser extent the temporal lobes
The degree of atrophy can be very asymmetric
Decrease in volume of the caudate heads This indicates loss of both efferent and afferent fibres
CREUTZFELDT-JAKOB DISEASEspongiform encephalopathy
Results in a rapidly progressive dementia
other non-specific neurological features
Three types of Creutzfeldt-Jakob disease have been described
bullsporadic (sCJD) accounts for 85-90 of cases
bullvariant (vCJD)
bullfamilial (fCJD) 10 of cases (these individuals carry a PRPc mutation)
Creutzfeldt-Jakob disease is characterized by rapidly progressive dementia cerebral atrophy myoclonus and death
Patients with vCJD present mostly with sensory and psychiatric symptoms
Patients with sCJD usually present with progressive cognitive impairment and cerebellar symptoms
PATHOLOGY
mediated via (infectious) prions
a type of protein which manifest in sheep as the disease scrapie and in cows as bovine spongiform encephalopathy
Prions are considered infectious in sense that they can alter the structure of neighbouring proteins
CJD leads to spongiform degeneration of the brain
the conversion of normal prion protein to proteinaceous infectious particles that accumulate in and around neurons and lead to cell death
RADIOGRAPHIC FEATURES
MRI
MRI findings may be bilateral or unilateral and symmetric or asymmetric and include
T2 hyperintensity
obasal ganglia (putamen and caudate)
othalamus ( hockey stick sign and pulvinar sign)
ocortex most common early manifestation
owhite matter
persistent restricted diffusion on DWI (considered the most sensitive sign)
Review of sequential studies also typically demonstrates rapidly progressive cerebral atrophy
hypometabolism on 18FDG-PET studies
TREATMENT AND PROGNOSIS
here is currently no curative treatment and the disease is invariably fatal with a mean survival of only 7 months for most cases
PROGRESSIVE SUPRANUCLEARPALSYlso known as the Steele-Richardson-Olszewski syndrome
Progressive supranuclear palsy typically becomes clinically apparent in the 6th decade of life
Progresses to death usually within a decade (2-17 years from diagnosis)
Progressive supranuclear palsy is characterised
decreased cognition
abnormal eye movements (supranuclear vertical gaze palsy)
postural instability and falls
as well as parkinsonian features and speech disturbances
RADIOGRAPHIC FEATURESMRI
midbrain atrophy
reduction of anteroposterior midline midbrain diameter at the level of the superior colliculi on axial imaging (from interpeduncular fossa to the intercolicular groove lt12mm 8) which can give a mickey mouse appearance
reduced area of the midbrain on midline sagittal and reduced midbrain to pons area ratio approx 012 (normal approx 024) on midline sagittal
Loss of the lateral convex margin of the tegmentum of midbrain has been described as the morning glory sign
hummingbird sign also known as the penguin sign The key is a flattening or concave outline to the superior aspect of the midbrain which should be upwardly convex
bullT2 diffuse high-signal lesions in
bull pontine tegmentum
bull tectum of the midbrain
bull inferior olivary nucleus
MICKEY MOUSE APPEARANCE
THE PENGUIN SIGN
MULTIPLE SYSTEM ATROPHY
sporadic neurodegenerative disease
Typically symptoms begin between 40 and 60 years of age
Clinical presentation is variable but typically presents in one of three patterns (initially described as separate entities)
Shy-Drager syndrome is used when autonomic symptoms predominate
striatonigral degeneration shows predominant parkinsonian features
olivopontocerebellar atrophy demonstrates primarily cerebellar dysfunction
MSA has been divided clinically into 2 forms according to the dominant non-autonomic symptoms
MSA-C predominance of cerebellar symptoms (olivopontocerebellar atrophy)
MSA-P predominance of parkinsonian signs and symptoms (striatonigraldegeneration)
RADIOGRAPHIC FEATURES
bullT2 hyperintensities typically present in the pontocerebellar tractsbull pons hot cross bun sign (MSA-C)
bull middle cerebellar peduncles
bull Cerebellum
putaminal findings in MSA-P reduced volume
reduced GRE and T2 signal relative to globus pallidus
reduced GRE and T2 signal relative to red nucleus
abnormal disruption of the normal high T2 linear rim
bullMSA-Cbull disproportionate atrophy of the cerebellum and brainstem (especially olivary nuclei and middle
cerebellar peduncle)
NUCLEAR MEDICINE
SPECT and PET studies tend to demonstrate hypometabolism in the superior parietal and superior frontal areas in the basal ganglia
HUNTINGTON DISEASE
autosomal dominant neurodegenerative disease
a loss of GABAergic neurons of the basal ganglia
especially atrophy of the caudate nucleus and putamen
Huntington disease has a prevalence of 5-10 per 100000 and is typically diagnosed between 30 and 50 years of age
In approximately 1-6 symptoms occur before the age of 20 so-called juvenile form
Presentation is typically with progressive rigidity choreoathetosis dementia psychosis and emotional lability
The juvenile form has a different presentation with cerebellar symptoms rigidity and hypokinesia being prominent
it is a autosomal dominant with complete penetrance and genetic anticipation particularly if inherited mutated allele is paternal
The mutation responsible is on chromosome 4p163 and consists of a CAG trineucleotide repeat
The usual 10-30 copies are amplified to greater than 36 and the greater the number of repeats the earlier the age of onset
RADIOGRAPHIC FEATURES
MRI
The most striking and best known feature is that of caudate head atrophy resulting in enlargement of the frontal horns often giving them a box like configuration
This can be quantified by an number of measurements
bullfrontal horn width to intercaudate distance ratio (FHCC)
bullintercaudate distance to inner table width ratio (CCIT)
Juvenile form
putamen are also atrophied and demonstrate increased T2 signal
basal ganglia may show decrease T2 signal and blooming on SWI in keeping with iron deposition
Generalised age inappropriate cortical volume loss is also recognised
FHCC ratio normal mean 22 to 26 (this ratio decreases with ageing as a result of enlargement of the frontal horns of the lateral ventricles)
CCIT ratio normal mean 009 to 012
AMYOTROPHIC LATERAL SCLEROSISalso known as Lou Gehrig disease or Charcot disease
Primary degeneration of the motor neurons within the brain brain stem and spinal cord
Patients typically present with progressive muscle weakness and limb and truncal atrophy combined with signs of spasticity
Mean age at the time of diagnosis is 55 years
RADIOGRAPHIC FEATURES
MRI
The earliest MR manifestation is hyperintensity on T2WI in the corticospinal tracts seen earliest in the internal capsule
Iron deposition in the cortex is demonstrated as loss of signal most evident on T2 weighted sequences
IS IT ATROPHY OR HYDROCEPHALUS
Abnormal accumulation of CSF in Ventricular system
Results from Structural or functional block to normal flow Of CSF
In effect all are obhstructive
Difficult to differentiate Atrophy from Hydrocephalus gt60yrs
Initially show increased ICT
Later stages may reach Equillibrium and Becomes NP hYdrocephalus
Types
Obstructive
Communicating
NPH ndash seen typically in old patients Diagnosis is more based on clinical feature
Dementia urinary incontinence and gait apraxias + Hydrocephalus = NPH
Radiologically w
1 degeree of ventricular dilatation is more with Thinning and bowing of CC
2 Sulcal effacement is invariable seen Hydrocephalus
3 dilatation or rounding of the Temporal Horns
4 Rounding and enlargement of the frontal horns
5 Enlargement and ballooning of 3rd
ventricle
6 Enlargement of fourth ventricle
SPOTTERS
THANK YOU
DEMENTIAWide range of pathologies
1 Anatomic abscess tumor subdural hematoma posttraumatic encephalomalacia diffuse axonal injury
2 Metabolic electrolyte imbalance nutritional deficiency endocrinopathy toxic exposure medications
3 psychiatric
4 Degenerative Alzheimers disease [AD]
Parkinsons disease [PD] frontotemporal dementia dementia with Lewybodies) vascular (eg cerebral infarction Binswangers disease CADASIL
5 infectiousinflammatory vasculitis prion disease
6 demyelinating disease multiple sclerosis
7 paraneoplastic phenomena
DISEASES
Alzheimers disease
vascular dementia
Lewy body disease
frontotemporal lobar degeneration
MISCELLANEOUS
Creutzfeldt-Jakob disease
progressive supranuclear palsy (PSP)
multiple system atrophy (MSA)
Huntington disease
corticobasal degeneration
CADASIL
MRI PROTOCOL
Three plane imaging (preferably with the coronal images angled at right angles to the hippocampus) with T1 T2 FLAIR DWI and T2 sequences
T1
sequence volumetric gradient echo eg MPRAGE
eg 09mm reformatted in three planes
Purpose anatomical best for assessing regional volume loss
T2
sequence fast spin echo whole brain or limited to basal ganglia and posterior fossa (thin eg 3mm)
purpose signal intensity of basal ganglia and posterior fossa structures (often less well seen on FLAIR due to flow artefact)
FLAIR
sequence whole brain axial or volumetric
purpose white matter signal abnormality
small vessel ischaemia resulting in multi-infarct dementia and abnormal sulcalsignal in leptomeningeal processes
DWI ADC (or isometric images from optional DTI acquisition)
purpose cortical or deep grey matter restricted diffusion in Creutzfeldt Jakobdisease (CJD) and restriction in demyelination of infarction (eg cerebral vasculitis)
SWI
sequence SWI including phase and magnitude images
purpose microhaemorrhages (eg cerebral amyloid angiopathy (CAA) hypertensive encephalopathy) Mineral deposition in cortex (eg Alzheimers disease amyotrophic lateral sclerosis (ALS)) Loss of low signal in substantianigra (Parkinson disease)
Optional additional sequences
DTI (optional) for tractography
MR Perfusion arterial spin labelling or preferably contrast perfusion
MR spectroscopy
SYSTEMATIC APPROACH
T1 sagittal
AMidlline
corpus callosum
the anterior half of the body should be thicker and certainly not thinner than the posterior half
Upward bowing ndash Hydrocephalus
midbrain shape size and midbrain to pons area ratio
pons shape
should be plump and rounded and about 4 times as large as the midbrain
B Sagittal
medial surfaces of the frontal parietal and occipital lobes
all the sulci should be about the same size
Significant parietal sulcal widening with atrophy of the precuneus and posterior cingulate suggests Alzheimers disease (AD)
anterior to posterior gradient of sulcalsize (bigger anteriorly) seen in frontotemporal lobar degeneration
mamillary bodies
should be about the same size Atrophic or asymmetrical mammillary bodies may imply hippocampal pathology or Wernicke-Korsakoff syndrome
upper cervical spine and cord
Axial FLAIR amp T2
bullgyral atrophy particularly useful for the frontal lobes
bullwidening of the sylvian fissures
bullhippocampal volume and signal
bullposterior fossa morphology
bullMidbrain
bullPons
bullMedulla
bullCerebellum
bullWernicke pattern high T2 signal (ventromedial thalamus mammillary bodies periaqueductal grey matter)
bullCortical white matter changes
T2 axial imaging is often better for basal ganglia structures and posterior fossa Assess for
reversal of normal T2 signal of putamen vs globus pallidus of MSA-P
atrophic caudate heads of Huntingtons disease
size and flow void in aqueduct (usually prominent in NPH)
3 Coronal sequences
bullhippocampal choroidal fissure and temporal horn size
bullsymmetrybull left gt right atrophy favours FTLD
bull equal involvement favours Alzheimers disease
bullanterior to posterior gradientbull anterior atrophy gt posterior atrophy favours FTLD
bullinvolvement of the temporal lobe generally favours FTLD
bullatrophy largely restricted to the hippocampus and parahippocampalgyrus favours Alzheimers disease
bullmammillary body size signal and symmetry
4 T2 sequences
Sequences susceptible to blood products are particularly useful in assessing
bullmicrohaemorrhages
bull peripherally distributed in cerebral amyloid angiopathy which in turn is associate with Alzheimers disease
bullcentrally distributed (basal ganglia pons cerebellum) in chronic hypertensive encephalophathy
5 DWI
DWI has a limited role in the assessment of a patient with a suspected neurodegenerative disease
Crucial particularly for Creutzfeldt-Jakob disease look for cortical basal ganglia and thalamic restricted diffusion
SCORING SYSTEMS AND MEASUREMENTS
bullFazekas scale for white matter lesions the deep white matter component is used in assessing the amount of chronic small vessel ischaemic change
bullposterior atrophy score of parietal atrophy (PA or PCA or Koedam score) useful in atypical (posterior cortical atrophy) or early onset Alzheimers disease
bullmedial temporal lobe atrophy score (MTA score)
bullglobal cortical atrophy scale (GCA scale)
A number of measurements ratios are also useful
midbrain to pons area ratio (for PSP)
magnetic resonance parkinsonism index (MRPI) (for PSP)
ALZHEIMER DISEASE
Alzheimer disease (AD) is a common neurodegenerative disease responsible for the majority of all dementias and imposing a significant burden on developed nations
Most common cause of dementia and accounts for two thirds of cases of dementia in patients aged 60-70 years
Epidemiological risk factor advanced age female gender
apolipoprotein E (APOE) ε4 allele carrier status
current smoking
family history of dementia
Classicaltypical Alzheimer disease
with antegrade episodic memory deficits
Neuropsychiatric symptoms are also common and eventually affect almost all patients These include apathy depression anxiety aggressionagitation and psychosis
Atypicalvariant Alzheimer disease
These entities often recognised clinically well before they were identified to be pathologically identical to Alzheimer disease
slowly progressive focal cortical atrophy with symptoms and signs matched to the affected area
Examples include
posterior cortical atrophy
frontal variant of Alzheimer disease
a minority of cases of semantic dementia
Pathology
Alzheimer disease is characterised by the accumulation of senile (neuritic) plaques neuritic (neurofibrillary) tangles and progressive loss of neurons
The progression of pathology initially involves the transentorhinalregion and then spreads to the hippocampal complex and mesial temporal lobe structures and eventually the temporal lobes and basal forebrain
RADIOGRAPHIC FEATURES
The primary role of MRI (and CT) in the diagnosis of Alzheimer disease is the assessment of volume change in characteristic locations which can yield a diagnostic accuracy of up to 87
The diagnosis should be made on the basis of two features
mesial temporal lobe atrophy
temporoparietal cortical atrophy
MESIAL TEMPORAL LOBE ATROPHY
hippocampal and parahippocampal decrease in volume
Indirectly by examining enlargement of the parahippocampalfissures
The former is more sensitive and specific but ideally requires actual volumetric calculations rather than eye-balling the scan
These measures have been combined in the medial temporal atrophy score which has been shown to be predictive of progression from mild cognitive impairment (MCI) to dementiA
MEDIAL TEMPORAL LOBE ATROPHY SCORE
visual score performed on MRI of the brain using coronal T1 weighted images through the hippocampus at the level of the anterior pons and assesses three features
width of the choroid fissure
width of the temporal horn of the lateral ventricle
height of the hippocampus
These result in a score of 0 to 4
0 = no CSF is visible around the hippocampus
1 = choroid fissure is slightly widened
2 = moderate widening of the choroid fissure mild enlargement of the temporal horn and mild loss of hippocampal height
3 = marked widening of the choroid fissure moderate enlargement of the temporal horn and moderate loss of hippocampal height
4 = marked widening of the choroid fissure marked enlargement of the temporal horn and the hippocampus is markedly atrophied and internal structure is lost
In a patient younger than 75 years of age a score of 2 or more is abnormal
In a patient 75 years or older a score of 3 or more is abnormal
Atrophy has been shown to correlate with likelihood of progression from mild cognitive impairment (MCI) to dementia 4
MRI SPECTROSCOPY
increases in myoinositol (MI) (356 ppm) thought to reflect inhibition of enzyme(s) mediating conversion of MI to phosphatidyl inositol
decreased N-acetyl aspartate (NAA) (202 ppm) indicating decreased neuronal activity
TEMPOROPARIETAL CORTICAL ATROPHY Parietal atrophy particularly relevant to posterior cortical atrophy or early onset Alzheimer disease
the inter-hemispheric surface of the parietal lobe
TREATMENT AND PROGNOSIS
There is no cure for this disease some drugs have been developed trying to improve symptoms or at least temporarily slow down their progression
cholinsterase inhibitors
partial NMDA receptor antagonists
medications for behavioural symptoms
antidepressants
anxiolytics
antiparkinsonian (movement symptoms)
anticonvulsantssedatives (behavioural)
VASCULAR DEMENTIAalso known as vascular cognitive impairment
It is primarily seen in patients with atherosclerosis and chronic hypertension
Results from the accumulation of multiple white matter or cortical infarcts although cerebral haemorrhages can be variably included
strongly correlated with age seen in only 1 of patients over the age of 55 years of age but in over 4 of patients over 71 years of age
It is also possible to divide vascular dementia into subtypes
small vessel dementia (aka Binswanger disease)
cortical vascular dementia roughly equivalent to multi-infarct dementia
strategic infarct dementia
thalamic dementia
RADIOGRAPHIC FEATURES
Both CT and MRI are able to provide evidence of ischaemic damage
MRI is more sensitive especially to white matter small vessel ischaemic change as well as to microhaemorrhages seen in cerebral amyloid angiopathy and chronic hypertensive encephalopathy
bullsmall vessel dementia (aka Binswanger disease)
bullcerebral infarction
bulllacunar infarction
bullintracerebral haemorrhage
CEREBRAL AMYLOID ANGIOPATHY
SMALL VESSEL DEMENTIA
also known as Binswanger disease
Subcortical arteriosclerotic encephalopathy
refers to slowly progressive exclusively white-matter multi-infarct dementia
A genetically transmitted form of the disease is known as familial arteriopathic leukoencephalopathy
or
CADASIL (cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy)
CLINICAL CRITERIA FOR DIAGNOSIS
marked subcortical microangiopathic lesions at MR imaging
a negative family history for strokes early cognitive impairment or psychiatric disorders in first- and second-degree relatives
documented arterial hypertension systolic values higher than 160 mm Hg diastolic values higher than 95 mm Hg or both measured at several occasions 5
MRI
subcortical and periventricular lesions visible on T2 FLAIR T2-weighted and proton-density sequences
commonly grouped around the frontal and occipital horns and in the centrum semi ovale
Moderate generalised cerebral atrophy is invariably present and lacunar infarctsin the basal ganglia and
thalami are common
CT
Diffuse incompletely symmetrical hypodensities are present in deep white matter especially they are prominent in the frontal lobes and the centrum semiovale
CEREBRAL AUTOSOMAL DOMINANT ARTERIOPATHY WITH SUBCORTICAL INFARCTS AND LEUKOENCEPHALOPATHY (CADASIL)
occurs in the absence of hypertension and arteriosclerosis and presents in 71 of cases before the age of 60 years
Imaging features demonstrate severe microvascular changes with multiple subcortical infarcts
Not distinguishable from hypertensive type microvascular disease
DEMENTIA WITH LEWY BODIESPD
Neurodegenerative disease (a synucleinopathy to be specific) related to Parkinsons disease (PD)
Epidemiology
Dementia with Lewy bodies presents in older patients (onset typically in 50-70 years of age) and is sporadic
It is the second most common neurodegenerative cause of dementia in older patients after Alzheimers disease accounting for 15-20 of case
RADIOGRAPHIC FEATURES
MRI
Atrophy in various parts of the brain without a clearly identified unique pattern
Most helpful in distinguishing DLB from other entities resulting in dementia is the absence of features of other diseases
generalised decrease in cerebral volume most marked in
frontal lobes parietotemporal regions
enlargement of the lateral ventricles
relatively focal atrophy
midbrain
hypothalamus
SWALLOW TAIL SIGN
The swallow tail sign describes the normal axial imaging appearance of nigrosome-1 within the substantianigra on high resolution T2SWI weighted MRI
Absence of the sign (absent swallow tail sign) is reported to have a diagnostic accuracy of greater than 90 for Parkinson disease
Nuclear medicine
Occipital hypoperfusion on SPECT PET
May aid in differentiation from other types of dementia especially Alzheimers disease
TREATMENT AND PROGNOSIS
Unlike Parkinsons disease dementia with Lewy bodies respond less readily to L-dopa and also may have severe sensitivity reactions to neuroleptic drugs such as rigidity reduced consciousness pyrexia falling postural hypotension and collapse
Lewy body dementia also responds favourably to acetylcholinesteraseinhibitors
DIFFERENTIAL DIAGNOSISwith strong overlap between
bullAlzheimers diseasebull clinical may occasionally have similar clinical presentation with a frontal type dementia or posterior
cortical atrophy
bull imaging prominent involvement of hippocampi on imaging
bullFronto-temporal lobar degenerationbull clinical usually younger onset absent parkinsonian features absent visual hallucinations
bull imaging more pronounced frontal temporal atrophy L gt R asymmetry
FRONTO-TEMPORAL LOBAR DEGENERATION
Frontotemporal lobar degeneration (FTLD) is the pathological description of a group of neurodegenerative disorders characterised by focal atrophy of the frontal and temporal cortices
rontotemporal lobar degeneration can be divided as follows 3-4
bullbehavioural variant fronto-temporal lobar degeneration dementia (bvFTLD) (aka behavioural variant frontotemporal dementia)1
bulllanguage variant fronto-temporal lobar degeneration (lvFTLD) (aka primary progressive aphasia (PPA)6
bull agrammatic variant primary progressive aphasia (aka progressive non-fluent aphasia (PNFA)
bull semantic variant primary progressive aphasia (aka semantic dementia)
bull logopaenic variant primary progressive aphasia
RADIOGRAPHIC FEATURES
The frontal and temporal lobes are predominantly affected there is often striking asymmetry both of involvement of frontal vs temporal lobes and involvement of left and right hemispheres
In addition the degree of fronto-striatal dysfunction varies between the different FTLD subgroups with behavioural variant frontotemporal dementia (bvFTD) having the greatest involvement
As a result the caudate heads tend to be reduced in size in these patients to a much greater degree than in the language variants of frontotemporal dementia
BEHAVIOURAL VARIANT FRONTO-TEMPORAL LOBAR DEGENERATION (BVFTLD)also referred to as Pick disease
Patients with behavioural variant FTD typically present with a dysexecutive cognitive syndrome associated with changes in personality and social behaviour
As the disease progresses impairments in language and memory may develop and the cognitive phenotype may come to resemble one of the language variants of FTD
RADIOGRAPHIC FEATURES
MRI
typical radiographic finding is atrophy of the frontal lobes and to a lesser extent the temporal lobes
The degree of atrophy can be very asymmetric
Decrease in volume of the caudate heads This indicates loss of both efferent and afferent fibres
CREUTZFELDT-JAKOB DISEASEspongiform encephalopathy
Results in a rapidly progressive dementia
other non-specific neurological features
Three types of Creutzfeldt-Jakob disease have been described
bullsporadic (sCJD) accounts for 85-90 of cases
bullvariant (vCJD)
bullfamilial (fCJD) 10 of cases (these individuals carry a PRPc mutation)
Creutzfeldt-Jakob disease is characterized by rapidly progressive dementia cerebral atrophy myoclonus and death
Patients with vCJD present mostly with sensory and psychiatric symptoms
Patients with sCJD usually present with progressive cognitive impairment and cerebellar symptoms
PATHOLOGY
mediated via (infectious) prions
a type of protein which manifest in sheep as the disease scrapie and in cows as bovine spongiform encephalopathy
Prions are considered infectious in sense that they can alter the structure of neighbouring proteins
CJD leads to spongiform degeneration of the brain
the conversion of normal prion protein to proteinaceous infectious particles that accumulate in and around neurons and lead to cell death
RADIOGRAPHIC FEATURES
MRI
MRI findings may be bilateral or unilateral and symmetric or asymmetric and include
T2 hyperintensity
obasal ganglia (putamen and caudate)
othalamus ( hockey stick sign and pulvinar sign)
ocortex most common early manifestation
owhite matter
persistent restricted diffusion on DWI (considered the most sensitive sign)
Review of sequential studies also typically demonstrates rapidly progressive cerebral atrophy
hypometabolism on 18FDG-PET studies
TREATMENT AND PROGNOSIS
here is currently no curative treatment and the disease is invariably fatal with a mean survival of only 7 months for most cases
PROGRESSIVE SUPRANUCLEARPALSYlso known as the Steele-Richardson-Olszewski syndrome
Progressive supranuclear palsy typically becomes clinically apparent in the 6th decade of life
Progresses to death usually within a decade (2-17 years from diagnosis)
Progressive supranuclear palsy is characterised
decreased cognition
abnormal eye movements (supranuclear vertical gaze palsy)
postural instability and falls
as well as parkinsonian features and speech disturbances
RADIOGRAPHIC FEATURESMRI
midbrain atrophy
reduction of anteroposterior midline midbrain diameter at the level of the superior colliculi on axial imaging (from interpeduncular fossa to the intercolicular groove lt12mm 8) which can give a mickey mouse appearance
reduced area of the midbrain on midline sagittal and reduced midbrain to pons area ratio approx 012 (normal approx 024) on midline sagittal
Loss of the lateral convex margin of the tegmentum of midbrain has been described as the morning glory sign
hummingbird sign also known as the penguin sign The key is a flattening or concave outline to the superior aspect of the midbrain which should be upwardly convex
bullT2 diffuse high-signal lesions in
bull pontine tegmentum
bull tectum of the midbrain
bull inferior olivary nucleus
MICKEY MOUSE APPEARANCE
THE PENGUIN SIGN
MULTIPLE SYSTEM ATROPHY
sporadic neurodegenerative disease
Typically symptoms begin between 40 and 60 years of age
Clinical presentation is variable but typically presents in one of three patterns (initially described as separate entities)
Shy-Drager syndrome is used when autonomic symptoms predominate
striatonigral degeneration shows predominant parkinsonian features
olivopontocerebellar atrophy demonstrates primarily cerebellar dysfunction
MSA has been divided clinically into 2 forms according to the dominant non-autonomic symptoms
MSA-C predominance of cerebellar symptoms (olivopontocerebellar atrophy)
MSA-P predominance of parkinsonian signs and symptoms (striatonigraldegeneration)
RADIOGRAPHIC FEATURES
bullT2 hyperintensities typically present in the pontocerebellar tractsbull pons hot cross bun sign (MSA-C)
bull middle cerebellar peduncles
bull Cerebellum
putaminal findings in MSA-P reduced volume
reduced GRE and T2 signal relative to globus pallidus
reduced GRE and T2 signal relative to red nucleus
abnormal disruption of the normal high T2 linear rim
bullMSA-Cbull disproportionate atrophy of the cerebellum and brainstem (especially olivary nuclei and middle
cerebellar peduncle)
NUCLEAR MEDICINE
SPECT and PET studies tend to demonstrate hypometabolism in the superior parietal and superior frontal areas in the basal ganglia
HUNTINGTON DISEASE
autosomal dominant neurodegenerative disease
a loss of GABAergic neurons of the basal ganglia
especially atrophy of the caudate nucleus and putamen
Huntington disease has a prevalence of 5-10 per 100000 and is typically diagnosed between 30 and 50 years of age
In approximately 1-6 symptoms occur before the age of 20 so-called juvenile form
Presentation is typically with progressive rigidity choreoathetosis dementia psychosis and emotional lability
The juvenile form has a different presentation with cerebellar symptoms rigidity and hypokinesia being prominent
it is a autosomal dominant with complete penetrance and genetic anticipation particularly if inherited mutated allele is paternal
The mutation responsible is on chromosome 4p163 and consists of a CAG trineucleotide repeat
The usual 10-30 copies are amplified to greater than 36 and the greater the number of repeats the earlier the age of onset
RADIOGRAPHIC FEATURES
MRI
The most striking and best known feature is that of caudate head atrophy resulting in enlargement of the frontal horns often giving them a box like configuration
This can be quantified by an number of measurements
bullfrontal horn width to intercaudate distance ratio (FHCC)
bullintercaudate distance to inner table width ratio (CCIT)
Juvenile form
putamen are also atrophied and demonstrate increased T2 signal
basal ganglia may show decrease T2 signal and blooming on SWI in keeping with iron deposition
Generalised age inappropriate cortical volume loss is also recognised
FHCC ratio normal mean 22 to 26 (this ratio decreases with ageing as a result of enlargement of the frontal horns of the lateral ventricles)
CCIT ratio normal mean 009 to 012
AMYOTROPHIC LATERAL SCLEROSISalso known as Lou Gehrig disease or Charcot disease
Primary degeneration of the motor neurons within the brain brain stem and spinal cord
Patients typically present with progressive muscle weakness and limb and truncal atrophy combined with signs of spasticity
Mean age at the time of diagnosis is 55 years
RADIOGRAPHIC FEATURES
MRI
The earliest MR manifestation is hyperintensity on T2WI in the corticospinal tracts seen earliest in the internal capsule
Iron deposition in the cortex is demonstrated as loss of signal most evident on T2 weighted sequences
IS IT ATROPHY OR HYDROCEPHALUS
Abnormal accumulation of CSF in Ventricular system
Results from Structural or functional block to normal flow Of CSF
In effect all are obhstructive
Difficult to differentiate Atrophy from Hydrocephalus gt60yrs
Initially show increased ICT
Later stages may reach Equillibrium and Becomes NP hYdrocephalus
Types
Obstructive
Communicating
NPH ndash seen typically in old patients Diagnosis is more based on clinical feature
Dementia urinary incontinence and gait apraxias + Hydrocephalus = NPH
Radiologically w
1 degeree of ventricular dilatation is more with Thinning and bowing of CC
2 Sulcal effacement is invariable seen Hydrocephalus
3 dilatation or rounding of the Temporal Horns
4 Rounding and enlargement of the frontal horns
5 Enlargement and ballooning of 3rd
ventricle
6 Enlargement of fourth ventricle
SPOTTERS
THANK YOU
DISEASES
Alzheimers disease
vascular dementia
Lewy body disease
frontotemporal lobar degeneration
MISCELLANEOUS
Creutzfeldt-Jakob disease
progressive supranuclear palsy (PSP)
multiple system atrophy (MSA)
Huntington disease
corticobasal degeneration
CADASIL
MRI PROTOCOL
Three plane imaging (preferably with the coronal images angled at right angles to the hippocampus) with T1 T2 FLAIR DWI and T2 sequences
T1
sequence volumetric gradient echo eg MPRAGE
eg 09mm reformatted in three planes
Purpose anatomical best for assessing regional volume loss
T2
sequence fast spin echo whole brain or limited to basal ganglia and posterior fossa (thin eg 3mm)
purpose signal intensity of basal ganglia and posterior fossa structures (often less well seen on FLAIR due to flow artefact)
FLAIR
sequence whole brain axial or volumetric
purpose white matter signal abnormality
small vessel ischaemia resulting in multi-infarct dementia and abnormal sulcalsignal in leptomeningeal processes
DWI ADC (or isometric images from optional DTI acquisition)
purpose cortical or deep grey matter restricted diffusion in Creutzfeldt Jakobdisease (CJD) and restriction in demyelination of infarction (eg cerebral vasculitis)
SWI
sequence SWI including phase and magnitude images
purpose microhaemorrhages (eg cerebral amyloid angiopathy (CAA) hypertensive encephalopathy) Mineral deposition in cortex (eg Alzheimers disease amyotrophic lateral sclerosis (ALS)) Loss of low signal in substantianigra (Parkinson disease)
Optional additional sequences
DTI (optional) for tractography
MR Perfusion arterial spin labelling or preferably contrast perfusion
MR spectroscopy
SYSTEMATIC APPROACH
T1 sagittal
AMidlline
corpus callosum
the anterior half of the body should be thicker and certainly not thinner than the posterior half
Upward bowing ndash Hydrocephalus
midbrain shape size and midbrain to pons area ratio
pons shape
should be plump and rounded and about 4 times as large as the midbrain
B Sagittal
medial surfaces of the frontal parietal and occipital lobes
all the sulci should be about the same size
Significant parietal sulcal widening with atrophy of the precuneus and posterior cingulate suggests Alzheimers disease (AD)
anterior to posterior gradient of sulcalsize (bigger anteriorly) seen in frontotemporal lobar degeneration
mamillary bodies
should be about the same size Atrophic or asymmetrical mammillary bodies may imply hippocampal pathology or Wernicke-Korsakoff syndrome
upper cervical spine and cord
Axial FLAIR amp T2
bullgyral atrophy particularly useful for the frontal lobes
bullwidening of the sylvian fissures
bullhippocampal volume and signal
bullposterior fossa morphology
bullMidbrain
bullPons
bullMedulla
bullCerebellum
bullWernicke pattern high T2 signal (ventromedial thalamus mammillary bodies periaqueductal grey matter)
bullCortical white matter changes
T2 axial imaging is often better for basal ganglia structures and posterior fossa Assess for
reversal of normal T2 signal of putamen vs globus pallidus of MSA-P
atrophic caudate heads of Huntingtons disease
size and flow void in aqueduct (usually prominent in NPH)
3 Coronal sequences
bullhippocampal choroidal fissure and temporal horn size
bullsymmetrybull left gt right atrophy favours FTLD
bull equal involvement favours Alzheimers disease
bullanterior to posterior gradientbull anterior atrophy gt posterior atrophy favours FTLD
bullinvolvement of the temporal lobe generally favours FTLD
bullatrophy largely restricted to the hippocampus and parahippocampalgyrus favours Alzheimers disease
bullmammillary body size signal and symmetry
4 T2 sequences
Sequences susceptible to blood products are particularly useful in assessing
bullmicrohaemorrhages
bull peripherally distributed in cerebral amyloid angiopathy which in turn is associate with Alzheimers disease
bullcentrally distributed (basal ganglia pons cerebellum) in chronic hypertensive encephalophathy
5 DWI
DWI has a limited role in the assessment of a patient with a suspected neurodegenerative disease
Crucial particularly for Creutzfeldt-Jakob disease look for cortical basal ganglia and thalamic restricted diffusion
SCORING SYSTEMS AND MEASUREMENTS
bullFazekas scale for white matter lesions the deep white matter component is used in assessing the amount of chronic small vessel ischaemic change
bullposterior atrophy score of parietal atrophy (PA or PCA or Koedam score) useful in atypical (posterior cortical atrophy) or early onset Alzheimers disease
bullmedial temporal lobe atrophy score (MTA score)
bullglobal cortical atrophy scale (GCA scale)
A number of measurements ratios are also useful
midbrain to pons area ratio (for PSP)
magnetic resonance parkinsonism index (MRPI) (for PSP)
ALZHEIMER DISEASE
Alzheimer disease (AD) is a common neurodegenerative disease responsible for the majority of all dementias and imposing a significant burden on developed nations
Most common cause of dementia and accounts for two thirds of cases of dementia in patients aged 60-70 years
Epidemiological risk factor advanced age female gender
apolipoprotein E (APOE) ε4 allele carrier status
current smoking
family history of dementia
Classicaltypical Alzheimer disease
with antegrade episodic memory deficits
Neuropsychiatric symptoms are also common and eventually affect almost all patients These include apathy depression anxiety aggressionagitation and psychosis
Atypicalvariant Alzheimer disease
These entities often recognised clinically well before they were identified to be pathologically identical to Alzheimer disease
slowly progressive focal cortical atrophy with symptoms and signs matched to the affected area
Examples include
posterior cortical atrophy
frontal variant of Alzheimer disease
a minority of cases of semantic dementia
Pathology
Alzheimer disease is characterised by the accumulation of senile (neuritic) plaques neuritic (neurofibrillary) tangles and progressive loss of neurons
The progression of pathology initially involves the transentorhinalregion and then spreads to the hippocampal complex and mesial temporal lobe structures and eventually the temporal lobes and basal forebrain
RADIOGRAPHIC FEATURES
The primary role of MRI (and CT) in the diagnosis of Alzheimer disease is the assessment of volume change in characteristic locations which can yield a diagnostic accuracy of up to 87
The diagnosis should be made on the basis of two features
mesial temporal lobe atrophy
temporoparietal cortical atrophy
MESIAL TEMPORAL LOBE ATROPHY
hippocampal and parahippocampal decrease in volume
Indirectly by examining enlargement of the parahippocampalfissures
The former is more sensitive and specific but ideally requires actual volumetric calculations rather than eye-balling the scan
These measures have been combined in the medial temporal atrophy score which has been shown to be predictive of progression from mild cognitive impairment (MCI) to dementiA
MEDIAL TEMPORAL LOBE ATROPHY SCORE
visual score performed on MRI of the brain using coronal T1 weighted images through the hippocampus at the level of the anterior pons and assesses three features
width of the choroid fissure
width of the temporal horn of the lateral ventricle
height of the hippocampus
These result in a score of 0 to 4
0 = no CSF is visible around the hippocampus
1 = choroid fissure is slightly widened
2 = moderate widening of the choroid fissure mild enlargement of the temporal horn and mild loss of hippocampal height
3 = marked widening of the choroid fissure moderate enlargement of the temporal horn and moderate loss of hippocampal height
4 = marked widening of the choroid fissure marked enlargement of the temporal horn and the hippocampus is markedly atrophied and internal structure is lost
In a patient younger than 75 years of age a score of 2 or more is abnormal
In a patient 75 years or older a score of 3 or more is abnormal
Atrophy has been shown to correlate with likelihood of progression from mild cognitive impairment (MCI) to dementia 4
MRI SPECTROSCOPY
increases in myoinositol (MI) (356 ppm) thought to reflect inhibition of enzyme(s) mediating conversion of MI to phosphatidyl inositol
decreased N-acetyl aspartate (NAA) (202 ppm) indicating decreased neuronal activity
TEMPOROPARIETAL CORTICAL ATROPHY Parietal atrophy particularly relevant to posterior cortical atrophy or early onset Alzheimer disease
the inter-hemispheric surface of the parietal lobe
TREATMENT AND PROGNOSIS
There is no cure for this disease some drugs have been developed trying to improve symptoms or at least temporarily slow down their progression
cholinsterase inhibitors
partial NMDA receptor antagonists
medications for behavioural symptoms
antidepressants
anxiolytics
antiparkinsonian (movement symptoms)
anticonvulsantssedatives (behavioural)
VASCULAR DEMENTIAalso known as vascular cognitive impairment
It is primarily seen in patients with atherosclerosis and chronic hypertension
Results from the accumulation of multiple white matter or cortical infarcts although cerebral haemorrhages can be variably included
strongly correlated with age seen in only 1 of patients over the age of 55 years of age but in over 4 of patients over 71 years of age
It is also possible to divide vascular dementia into subtypes
small vessel dementia (aka Binswanger disease)
cortical vascular dementia roughly equivalent to multi-infarct dementia
strategic infarct dementia
thalamic dementia
RADIOGRAPHIC FEATURES
Both CT and MRI are able to provide evidence of ischaemic damage
MRI is more sensitive especially to white matter small vessel ischaemic change as well as to microhaemorrhages seen in cerebral amyloid angiopathy and chronic hypertensive encephalopathy
bullsmall vessel dementia (aka Binswanger disease)
bullcerebral infarction
bulllacunar infarction
bullintracerebral haemorrhage
CEREBRAL AMYLOID ANGIOPATHY
SMALL VESSEL DEMENTIA
also known as Binswanger disease
Subcortical arteriosclerotic encephalopathy
refers to slowly progressive exclusively white-matter multi-infarct dementia
A genetically transmitted form of the disease is known as familial arteriopathic leukoencephalopathy
or
CADASIL (cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy)
CLINICAL CRITERIA FOR DIAGNOSIS
marked subcortical microangiopathic lesions at MR imaging
a negative family history for strokes early cognitive impairment or psychiatric disorders in first- and second-degree relatives
documented arterial hypertension systolic values higher than 160 mm Hg diastolic values higher than 95 mm Hg or both measured at several occasions 5
MRI
subcortical and periventricular lesions visible on T2 FLAIR T2-weighted and proton-density sequences
commonly grouped around the frontal and occipital horns and in the centrum semi ovale
Moderate generalised cerebral atrophy is invariably present and lacunar infarctsin the basal ganglia and
thalami are common
CT
Diffuse incompletely symmetrical hypodensities are present in deep white matter especially they are prominent in the frontal lobes and the centrum semiovale
CEREBRAL AUTOSOMAL DOMINANT ARTERIOPATHY WITH SUBCORTICAL INFARCTS AND LEUKOENCEPHALOPATHY (CADASIL)
occurs in the absence of hypertension and arteriosclerosis and presents in 71 of cases before the age of 60 years
Imaging features demonstrate severe microvascular changes with multiple subcortical infarcts
Not distinguishable from hypertensive type microvascular disease
DEMENTIA WITH LEWY BODIESPD
Neurodegenerative disease (a synucleinopathy to be specific) related to Parkinsons disease (PD)
Epidemiology
Dementia with Lewy bodies presents in older patients (onset typically in 50-70 years of age) and is sporadic
It is the second most common neurodegenerative cause of dementia in older patients after Alzheimers disease accounting for 15-20 of case
RADIOGRAPHIC FEATURES
MRI
Atrophy in various parts of the brain without a clearly identified unique pattern
Most helpful in distinguishing DLB from other entities resulting in dementia is the absence of features of other diseases
generalised decrease in cerebral volume most marked in
frontal lobes parietotemporal regions
enlargement of the lateral ventricles
relatively focal atrophy
midbrain
hypothalamus
SWALLOW TAIL SIGN
The swallow tail sign describes the normal axial imaging appearance of nigrosome-1 within the substantianigra on high resolution T2SWI weighted MRI
Absence of the sign (absent swallow tail sign) is reported to have a diagnostic accuracy of greater than 90 for Parkinson disease
Nuclear medicine
Occipital hypoperfusion on SPECT PET
May aid in differentiation from other types of dementia especially Alzheimers disease
TREATMENT AND PROGNOSIS
Unlike Parkinsons disease dementia with Lewy bodies respond less readily to L-dopa and also may have severe sensitivity reactions to neuroleptic drugs such as rigidity reduced consciousness pyrexia falling postural hypotension and collapse
Lewy body dementia also responds favourably to acetylcholinesteraseinhibitors
DIFFERENTIAL DIAGNOSISwith strong overlap between
bullAlzheimers diseasebull clinical may occasionally have similar clinical presentation with a frontal type dementia or posterior
cortical atrophy
bull imaging prominent involvement of hippocampi on imaging
bullFronto-temporal lobar degenerationbull clinical usually younger onset absent parkinsonian features absent visual hallucinations
bull imaging more pronounced frontal temporal atrophy L gt R asymmetry
FRONTO-TEMPORAL LOBAR DEGENERATION
Frontotemporal lobar degeneration (FTLD) is the pathological description of a group of neurodegenerative disorders characterised by focal atrophy of the frontal and temporal cortices
rontotemporal lobar degeneration can be divided as follows 3-4
bullbehavioural variant fronto-temporal lobar degeneration dementia (bvFTLD) (aka behavioural variant frontotemporal dementia)1
bulllanguage variant fronto-temporal lobar degeneration (lvFTLD) (aka primary progressive aphasia (PPA)6
bull agrammatic variant primary progressive aphasia (aka progressive non-fluent aphasia (PNFA)
bull semantic variant primary progressive aphasia (aka semantic dementia)
bull logopaenic variant primary progressive aphasia
RADIOGRAPHIC FEATURES
The frontal and temporal lobes are predominantly affected there is often striking asymmetry both of involvement of frontal vs temporal lobes and involvement of left and right hemispheres
In addition the degree of fronto-striatal dysfunction varies between the different FTLD subgroups with behavioural variant frontotemporal dementia (bvFTD) having the greatest involvement
As a result the caudate heads tend to be reduced in size in these patients to a much greater degree than in the language variants of frontotemporal dementia
BEHAVIOURAL VARIANT FRONTO-TEMPORAL LOBAR DEGENERATION (BVFTLD)also referred to as Pick disease
Patients with behavioural variant FTD typically present with a dysexecutive cognitive syndrome associated with changes in personality and social behaviour
As the disease progresses impairments in language and memory may develop and the cognitive phenotype may come to resemble one of the language variants of FTD
RADIOGRAPHIC FEATURES
MRI
typical radiographic finding is atrophy of the frontal lobes and to a lesser extent the temporal lobes
The degree of atrophy can be very asymmetric
Decrease in volume of the caudate heads This indicates loss of both efferent and afferent fibres
CREUTZFELDT-JAKOB DISEASEspongiform encephalopathy
Results in a rapidly progressive dementia
other non-specific neurological features
Three types of Creutzfeldt-Jakob disease have been described
bullsporadic (sCJD) accounts for 85-90 of cases
bullvariant (vCJD)
bullfamilial (fCJD) 10 of cases (these individuals carry a PRPc mutation)
Creutzfeldt-Jakob disease is characterized by rapidly progressive dementia cerebral atrophy myoclonus and death
Patients with vCJD present mostly with sensory and psychiatric symptoms
Patients with sCJD usually present with progressive cognitive impairment and cerebellar symptoms
PATHOLOGY
mediated via (infectious) prions
a type of protein which manifest in sheep as the disease scrapie and in cows as bovine spongiform encephalopathy
Prions are considered infectious in sense that they can alter the structure of neighbouring proteins
CJD leads to spongiform degeneration of the brain
the conversion of normal prion protein to proteinaceous infectious particles that accumulate in and around neurons and lead to cell death
RADIOGRAPHIC FEATURES
MRI
MRI findings may be bilateral or unilateral and symmetric or asymmetric and include
T2 hyperintensity
obasal ganglia (putamen and caudate)
othalamus ( hockey stick sign and pulvinar sign)
ocortex most common early manifestation
owhite matter
persistent restricted diffusion on DWI (considered the most sensitive sign)
Review of sequential studies also typically demonstrates rapidly progressive cerebral atrophy
hypometabolism on 18FDG-PET studies
TREATMENT AND PROGNOSIS
here is currently no curative treatment and the disease is invariably fatal with a mean survival of only 7 months for most cases
PROGRESSIVE SUPRANUCLEARPALSYlso known as the Steele-Richardson-Olszewski syndrome
Progressive supranuclear palsy typically becomes clinically apparent in the 6th decade of life
Progresses to death usually within a decade (2-17 years from diagnosis)
Progressive supranuclear palsy is characterised
decreased cognition
abnormal eye movements (supranuclear vertical gaze palsy)
postural instability and falls
as well as parkinsonian features and speech disturbances
RADIOGRAPHIC FEATURESMRI
midbrain atrophy
reduction of anteroposterior midline midbrain diameter at the level of the superior colliculi on axial imaging (from interpeduncular fossa to the intercolicular groove lt12mm 8) which can give a mickey mouse appearance
reduced area of the midbrain on midline sagittal and reduced midbrain to pons area ratio approx 012 (normal approx 024) on midline sagittal
Loss of the lateral convex margin of the tegmentum of midbrain has been described as the morning glory sign
hummingbird sign also known as the penguin sign The key is a flattening or concave outline to the superior aspect of the midbrain which should be upwardly convex
bullT2 diffuse high-signal lesions in
bull pontine tegmentum
bull tectum of the midbrain
bull inferior olivary nucleus
MICKEY MOUSE APPEARANCE
THE PENGUIN SIGN
MULTIPLE SYSTEM ATROPHY
sporadic neurodegenerative disease
Typically symptoms begin between 40 and 60 years of age
Clinical presentation is variable but typically presents in one of three patterns (initially described as separate entities)
Shy-Drager syndrome is used when autonomic symptoms predominate
striatonigral degeneration shows predominant parkinsonian features
olivopontocerebellar atrophy demonstrates primarily cerebellar dysfunction
MSA has been divided clinically into 2 forms according to the dominant non-autonomic symptoms
MSA-C predominance of cerebellar symptoms (olivopontocerebellar atrophy)
MSA-P predominance of parkinsonian signs and symptoms (striatonigraldegeneration)
RADIOGRAPHIC FEATURES
bullT2 hyperintensities typically present in the pontocerebellar tractsbull pons hot cross bun sign (MSA-C)
bull middle cerebellar peduncles
bull Cerebellum
putaminal findings in MSA-P reduced volume
reduced GRE and T2 signal relative to globus pallidus
reduced GRE and T2 signal relative to red nucleus
abnormal disruption of the normal high T2 linear rim
bullMSA-Cbull disproportionate atrophy of the cerebellum and brainstem (especially olivary nuclei and middle
cerebellar peduncle)
NUCLEAR MEDICINE
SPECT and PET studies tend to demonstrate hypometabolism in the superior parietal and superior frontal areas in the basal ganglia
HUNTINGTON DISEASE
autosomal dominant neurodegenerative disease
a loss of GABAergic neurons of the basal ganglia
especially atrophy of the caudate nucleus and putamen
Huntington disease has a prevalence of 5-10 per 100000 and is typically diagnosed between 30 and 50 years of age
In approximately 1-6 symptoms occur before the age of 20 so-called juvenile form
Presentation is typically with progressive rigidity choreoathetosis dementia psychosis and emotional lability
The juvenile form has a different presentation with cerebellar symptoms rigidity and hypokinesia being prominent
it is a autosomal dominant with complete penetrance and genetic anticipation particularly if inherited mutated allele is paternal
The mutation responsible is on chromosome 4p163 and consists of a CAG trineucleotide repeat
The usual 10-30 copies are amplified to greater than 36 and the greater the number of repeats the earlier the age of onset
RADIOGRAPHIC FEATURES
MRI
The most striking and best known feature is that of caudate head atrophy resulting in enlargement of the frontal horns often giving them a box like configuration
This can be quantified by an number of measurements
bullfrontal horn width to intercaudate distance ratio (FHCC)
bullintercaudate distance to inner table width ratio (CCIT)
Juvenile form
putamen are also atrophied and demonstrate increased T2 signal
basal ganglia may show decrease T2 signal and blooming on SWI in keeping with iron deposition
Generalised age inappropriate cortical volume loss is also recognised
FHCC ratio normal mean 22 to 26 (this ratio decreases with ageing as a result of enlargement of the frontal horns of the lateral ventricles)
CCIT ratio normal mean 009 to 012
AMYOTROPHIC LATERAL SCLEROSISalso known as Lou Gehrig disease or Charcot disease
Primary degeneration of the motor neurons within the brain brain stem and spinal cord
Patients typically present with progressive muscle weakness and limb and truncal atrophy combined with signs of spasticity
Mean age at the time of diagnosis is 55 years
RADIOGRAPHIC FEATURES
MRI
The earliest MR manifestation is hyperintensity on T2WI in the corticospinal tracts seen earliest in the internal capsule
Iron deposition in the cortex is demonstrated as loss of signal most evident on T2 weighted sequences
IS IT ATROPHY OR HYDROCEPHALUS
Abnormal accumulation of CSF in Ventricular system
Results from Structural or functional block to normal flow Of CSF
In effect all are obhstructive
Difficult to differentiate Atrophy from Hydrocephalus gt60yrs
Initially show increased ICT
Later stages may reach Equillibrium and Becomes NP hYdrocephalus
Types
Obstructive
Communicating
NPH ndash seen typically in old patients Diagnosis is more based on clinical feature
Dementia urinary incontinence and gait apraxias + Hydrocephalus = NPH
Radiologically w
1 degeree of ventricular dilatation is more with Thinning and bowing of CC
2 Sulcal effacement is invariable seen Hydrocephalus
3 dilatation or rounding of the Temporal Horns
4 Rounding and enlargement of the frontal horns
5 Enlargement and ballooning of 3rd
ventricle
6 Enlargement of fourth ventricle
SPOTTERS
THANK YOU
MRI PROTOCOL
Three plane imaging (preferably with the coronal images angled at right angles to the hippocampus) with T1 T2 FLAIR DWI and T2 sequences
T1
sequence volumetric gradient echo eg MPRAGE
eg 09mm reformatted in three planes
Purpose anatomical best for assessing regional volume loss
T2
sequence fast spin echo whole brain or limited to basal ganglia and posterior fossa (thin eg 3mm)
purpose signal intensity of basal ganglia and posterior fossa structures (often less well seen on FLAIR due to flow artefact)
FLAIR
sequence whole brain axial or volumetric
purpose white matter signal abnormality
small vessel ischaemia resulting in multi-infarct dementia and abnormal sulcalsignal in leptomeningeal processes
DWI ADC (or isometric images from optional DTI acquisition)
purpose cortical or deep grey matter restricted diffusion in Creutzfeldt Jakobdisease (CJD) and restriction in demyelination of infarction (eg cerebral vasculitis)
SWI
sequence SWI including phase and magnitude images
purpose microhaemorrhages (eg cerebral amyloid angiopathy (CAA) hypertensive encephalopathy) Mineral deposition in cortex (eg Alzheimers disease amyotrophic lateral sclerosis (ALS)) Loss of low signal in substantianigra (Parkinson disease)
Optional additional sequences
DTI (optional) for tractography
MR Perfusion arterial spin labelling or preferably contrast perfusion
MR spectroscopy
SYSTEMATIC APPROACH
T1 sagittal
AMidlline
corpus callosum
the anterior half of the body should be thicker and certainly not thinner than the posterior half
Upward bowing ndash Hydrocephalus
midbrain shape size and midbrain to pons area ratio
pons shape
should be plump and rounded and about 4 times as large as the midbrain
B Sagittal
medial surfaces of the frontal parietal and occipital lobes
all the sulci should be about the same size
Significant parietal sulcal widening with atrophy of the precuneus and posterior cingulate suggests Alzheimers disease (AD)
anterior to posterior gradient of sulcalsize (bigger anteriorly) seen in frontotemporal lobar degeneration
mamillary bodies
should be about the same size Atrophic or asymmetrical mammillary bodies may imply hippocampal pathology or Wernicke-Korsakoff syndrome
upper cervical spine and cord
Axial FLAIR amp T2
bullgyral atrophy particularly useful for the frontal lobes
bullwidening of the sylvian fissures
bullhippocampal volume and signal
bullposterior fossa morphology
bullMidbrain
bullPons
bullMedulla
bullCerebellum
bullWernicke pattern high T2 signal (ventromedial thalamus mammillary bodies periaqueductal grey matter)
bullCortical white matter changes
T2 axial imaging is often better for basal ganglia structures and posterior fossa Assess for
reversal of normal T2 signal of putamen vs globus pallidus of MSA-P
atrophic caudate heads of Huntingtons disease
size and flow void in aqueduct (usually prominent in NPH)
3 Coronal sequences
bullhippocampal choroidal fissure and temporal horn size
bullsymmetrybull left gt right atrophy favours FTLD
bull equal involvement favours Alzheimers disease
bullanterior to posterior gradientbull anterior atrophy gt posterior atrophy favours FTLD
bullinvolvement of the temporal lobe generally favours FTLD
bullatrophy largely restricted to the hippocampus and parahippocampalgyrus favours Alzheimers disease
bullmammillary body size signal and symmetry
4 T2 sequences
Sequences susceptible to blood products are particularly useful in assessing
bullmicrohaemorrhages
bull peripherally distributed in cerebral amyloid angiopathy which in turn is associate with Alzheimers disease
bullcentrally distributed (basal ganglia pons cerebellum) in chronic hypertensive encephalophathy
5 DWI
DWI has a limited role in the assessment of a patient with a suspected neurodegenerative disease
Crucial particularly for Creutzfeldt-Jakob disease look for cortical basal ganglia and thalamic restricted diffusion
SCORING SYSTEMS AND MEASUREMENTS
bullFazekas scale for white matter lesions the deep white matter component is used in assessing the amount of chronic small vessel ischaemic change
bullposterior atrophy score of parietal atrophy (PA or PCA or Koedam score) useful in atypical (posterior cortical atrophy) or early onset Alzheimers disease
bullmedial temporal lobe atrophy score (MTA score)
bullglobal cortical atrophy scale (GCA scale)
A number of measurements ratios are also useful
midbrain to pons area ratio (for PSP)
magnetic resonance parkinsonism index (MRPI) (for PSP)
ALZHEIMER DISEASE
Alzheimer disease (AD) is a common neurodegenerative disease responsible for the majority of all dementias and imposing a significant burden on developed nations
Most common cause of dementia and accounts for two thirds of cases of dementia in patients aged 60-70 years
Epidemiological risk factor advanced age female gender
apolipoprotein E (APOE) ε4 allele carrier status
current smoking
family history of dementia
Classicaltypical Alzheimer disease
with antegrade episodic memory deficits
Neuropsychiatric symptoms are also common and eventually affect almost all patients These include apathy depression anxiety aggressionagitation and psychosis
Atypicalvariant Alzheimer disease
These entities often recognised clinically well before they were identified to be pathologically identical to Alzheimer disease
slowly progressive focal cortical atrophy with symptoms and signs matched to the affected area
Examples include
posterior cortical atrophy
frontal variant of Alzheimer disease
a minority of cases of semantic dementia
Pathology
Alzheimer disease is characterised by the accumulation of senile (neuritic) plaques neuritic (neurofibrillary) tangles and progressive loss of neurons
The progression of pathology initially involves the transentorhinalregion and then spreads to the hippocampal complex and mesial temporal lobe structures and eventually the temporal lobes and basal forebrain
RADIOGRAPHIC FEATURES
The primary role of MRI (and CT) in the diagnosis of Alzheimer disease is the assessment of volume change in characteristic locations which can yield a diagnostic accuracy of up to 87
The diagnosis should be made on the basis of two features
mesial temporal lobe atrophy
temporoparietal cortical atrophy
MESIAL TEMPORAL LOBE ATROPHY
hippocampal and parahippocampal decrease in volume
Indirectly by examining enlargement of the parahippocampalfissures
The former is more sensitive and specific but ideally requires actual volumetric calculations rather than eye-balling the scan
These measures have been combined in the medial temporal atrophy score which has been shown to be predictive of progression from mild cognitive impairment (MCI) to dementiA
MEDIAL TEMPORAL LOBE ATROPHY SCORE
visual score performed on MRI of the brain using coronal T1 weighted images through the hippocampus at the level of the anterior pons and assesses three features
width of the choroid fissure
width of the temporal horn of the lateral ventricle
height of the hippocampus
These result in a score of 0 to 4
0 = no CSF is visible around the hippocampus
1 = choroid fissure is slightly widened
2 = moderate widening of the choroid fissure mild enlargement of the temporal horn and mild loss of hippocampal height
3 = marked widening of the choroid fissure moderate enlargement of the temporal horn and moderate loss of hippocampal height
4 = marked widening of the choroid fissure marked enlargement of the temporal horn and the hippocampus is markedly atrophied and internal structure is lost
In a patient younger than 75 years of age a score of 2 or more is abnormal
In a patient 75 years or older a score of 3 or more is abnormal
Atrophy has been shown to correlate with likelihood of progression from mild cognitive impairment (MCI) to dementia 4
MRI SPECTROSCOPY
increases in myoinositol (MI) (356 ppm) thought to reflect inhibition of enzyme(s) mediating conversion of MI to phosphatidyl inositol
decreased N-acetyl aspartate (NAA) (202 ppm) indicating decreased neuronal activity
TEMPOROPARIETAL CORTICAL ATROPHY Parietal atrophy particularly relevant to posterior cortical atrophy or early onset Alzheimer disease
the inter-hemispheric surface of the parietal lobe
TREATMENT AND PROGNOSIS
There is no cure for this disease some drugs have been developed trying to improve symptoms or at least temporarily slow down their progression
cholinsterase inhibitors
partial NMDA receptor antagonists
medications for behavioural symptoms
antidepressants
anxiolytics
antiparkinsonian (movement symptoms)
anticonvulsantssedatives (behavioural)
VASCULAR DEMENTIAalso known as vascular cognitive impairment
It is primarily seen in patients with atherosclerosis and chronic hypertension
Results from the accumulation of multiple white matter or cortical infarcts although cerebral haemorrhages can be variably included
strongly correlated with age seen in only 1 of patients over the age of 55 years of age but in over 4 of patients over 71 years of age
It is also possible to divide vascular dementia into subtypes
small vessel dementia (aka Binswanger disease)
cortical vascular dementia roughly equivalent to multi-infarct dementia
strategic infarct dementia
thalamic dementia
RADIOGRAPHIC FEATURES
Both CT and MRI are able to provide evidence of ischaemic damage
MRI is more sensitive especially to white matter small vessel ischaemic change as well as to microhaemorrhages seen in cerebral amyloid angiopathy and chronic hypertensive encephalopathy
bullsmall vessel dementia (aka Binswanger disease)
bullcerebral infarction
bulllacunar infarction
bullintracerebral haemorrhage
CEREBRAL AMYLOID ANGIOPATHY
SMALL VESSEL DEMENTIA
also known as Binswanger disease
Subcortical arteriosclerotic encephalopathy
refers to slowly progressive exclusively white-matter multi-infarct dementia
A genetically transmitted form of the disease is known as familial arteriopathic leukoencephalopathy
or
CADASIL (cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy)
CLINICAL CRITERIA FOR DIAGNOSIS
marked subcortical microangiopathic lesions at MR imaging
a negative family history for strokes early cognitive impairment or psychiatric disorders in first- and second-degree relatives
documented arterial hypertension systolic values higher than 160 mm Hg diastolic values higher than 95 mm Hg or both measured at several occasions 5
MRI
subcortical and periventricular lesions visible on T2 FLAIR T2-weighted and proton-density sequences
commonly grouped around the frontal and occipital horns and in the centrum semi ovale
Moderate generalised cerebral atrophy is invariably present and lacunar infarctsin the basal ganglia and
thalami are common
CT
Diffuse incompletely symmetrical hypodensities are present in deep white matter especially they are prominent in the frontal lobes and the centrum semiovale
CEREBRAL AUTOSOMAL DOMINANT ARTERIOPATHY WITH SUBCORTICAL INFARCTS AND LEUKOENCEPHALOPATHY (CADASIL)
occurs in the absence of hypertension and arteriosclerosis and presents in 71 of cases before the age of 60 years
Imaging features demonstrate severe microvascular changes with multiple subcortical infarcts
Not distinguishable from hypertensive type microvascular disease
DEMENTIA WITH LEWY BODIESPD
Neurodegenerative disease (a synucleinopathy to be specific) related to Parkinsons disease (PD)
Epidemiology
Dementia with Lewy bodies presents in older patients (onset typically in 50-70 years of age) and is sporadic
It is the second most common neurodegenerative cause of dementia in older patients after Alzheimers disease accounting for 15-20 of case
RADIOGRAPHIC FEATURES
MRI
Atrophy in various parts of the brain without a clearly identified unique pattern
Most helpful in distinguishing DLB from other entities resulting in dementia is the absence of features of other diseases
generalised decrease in cerebral volume most marked in
frontal lobes parietotemporal regions
enlargement of the lateral ventricles
relatively focal atrophy
midbrain
hypothalamus
SWALLOW TAIL SIGN
The swallow tail sign describes the normal axial imaging appearance of nigrosome-1 within the substantianigra on high resolution T2SWI weighted MRI
Absence of the sign (absent swallow tail sign) is reported to have a diagnostic accuracy of greater than 90 for Parkinson disease
Nuclear medicine
Occipital hypoperfusion on SPECT PET
May aid in differentiation from other types of dementia especially Alzheimers disease
TREATMENT AND PROGNOSIS
Unlike Parkinsons disease dementia with Lewy bodies respond less readily to L-dopa and also may have severe sensitivity reactions to neuroleptic drugs such as rigidity reduced consciousness pyrexia falling postural hypotension and collapse
Lewy body dementia also responds favourably to acetylcholinesteraseinhibitors
DIFFERENTIAL DIAGNOSISwith strong overlap between
bullAlzheimers diseasebull clinical may occasionally have similar clinical presentation with a frontal type dementia or posterior
cortical atrophy
bull imaging prominent involvement of hippocampi on imaging
bullFronto-temporal lobar degenerationbull clinical usually younger onset absent parkinsonian features absent visual hallucinations
bull imaging more pronounced frontal temporal atrophy L gt R asymmetry
FRONTO-TEMPORAL LOBAR DEGENERATION
Frontotemporal lobar degeneration (FTLD) is the pathological description of a group of neurodegenerative disorders characterised by focal atrophy of the frontal and temporal cortices
rontotemporal lobar degeneration can be divided as follows 3-4
bullbehavioural variant fronto-temporal lobar degeneration dementia (bvFTLD) (aka behavioural variant frontotemporal dementia)1
bulllanguage variant fronto-temporal lobar degeneration (lvFTLD) (aka primary progressive aphasia (PPA)6
bull agrammatic variant primary progressive aphasia (aka progressive non-fluent aphasia (PNFA)
bull semantic variant primary progressive aphasia (aka semantic dementia)
bull logopaenic variant primary progressive aphasia
RADIOGRAPHIC FEATURES
The frontal and temporal lobes are predominantly affected there is often striking asymmetry both of involvement of frontal vs temporal lobes and involvement of left and right hemispheres
In addition the degree of fronto-striatal dysfunction varies between the different FTLD subgroups with behavioural variant frontotemporal dementia (bvFTD) having the greatest involvement
As a result the caudate heads tend to be reduced in size in these patients to a much greater degree than in the language variants of frontotemporal dementia
BEHAVIOURAL VARIANT FRONTO-TEMPORAL LOBAR DEGENERATION (BVFTLD)also referred to as Pick disease
Patients with behavioural variant FTD typically present with a dysexecutive cognitive syndrome associated with changes in personality and social behaviour
As the disease progresses impairments in language and memory may develop and the cognitive phenotype may come to resemble one of the language variants of FTD
RADIOGRAPHIC FEATURES
MRI
typical radiographic finding is atrophy of the frontal lobes and to a lesser extent the temporal lobes
The degree of atrophy can be very asymmetric
Decrease in volume of the caudate heads This indicates loss of both efferent and afferent fibres
CREUTZFELDT-JAKOB DISEASEspongiform encephalopathy
Results in a rapidly progressive dementia
other non-specific neurological features
Three types of Creutzfeldt-Jakob disease have been described
bullsporadic (sCJD) accounts for 85-90 of cases
bullvariant (vCJD)
bullfamilial (fCJD) 10 of cases (these individuals carry a PRPc mutation)
Creutzfeldt-Jakob disease is characterized by rapidly progressive dementia cerebral atrophy myoclonus and death
Patients with vCJD present mostly with sensory and psychiatric symptoms
Patients with sCJD usually present with progressive cognitive impairment and cerebellar symptoms
PATHOLOGY
mediated via (infectious) prions
a type of protein which manifest in sheep as the disease scrapie and in cows as bovine spongiform encephalopathy
Prions are considered infectious in sense that they can alter the structure of neighbouring proteins
CJD leads to spongiform degeneration of the brain
the conversion of normal prion protein to proteinaceous infectious particles that accumulate in and around neurons and lead to cell death
RADIOGRAPHIC FEATURES
MRI
MRI findings may be bilateral or unilateral and symmetric or asymmetric and include
T2 hyperintensity
obasal ganglia (putamen and caudate)
othalamus ( hockey stick sign and pulvinar sign)
ocortex most common early manifestation
owhite matter
persistent restricted diffusion on DWI (considered the most sensitive sign)
Review of sequential studies also typically demonstrates rapidly progressive cerebral atrophy
hypometabolism on 18FDG-PET studies
TREATMENT AND PROGNOSIS
here is currently no curative treatment and the disease is invariably fatal with a mean survival of only 7 months for most cases
PROGRESSIVE SUPRANUCLEARPALSYlso known as the Steele-Richardson-Olszewski syndrome
Progressive supranuclear palsy typically becomes clinically apparent in the 6th decade of life
Progresses to death usually within a decade (2-17 years from diagnosis)
Progressive supranuclear palsy is characterised
decreased cognition
abnormal eye movements (supranuclear vertical gaze palsy)
postural instability and falls
as well as parkinsonian features and speech disturbances
RADIOGRAPHIC FEATURESMRI
midbrain atrophy
reduction of anteroposterior midline midbrain diameter at the level of the superior colliculi on axial imaging (from interpeduncular fossa to the intercolicular groove lt12mm 8) which can give a mickey mouse appearance
reduced area of the midbrain on midline sagittal and reduced midbrain to pons area ratio approx 012 (normal approx 024) on midline sagittal
Loss of the lateral convex margin of the tegmentum of midbrain has been described as the morning glory sign
hummingbird sign also known as the penguin sign The key is a flattening or concave outline to the superior aspect of the midbrain which should be upwardly convex
bullT2 diffuse high-signal lesions in
bull pontine tegmentum
bull tectum of the midbrain
bull inferior olivary nucleus
MICKEY MOUSE APPEARANCE
THE PENGUIN SIGN
MULTIPLE SYSTEM ATROPHY
sporadic neurodegenerative disease
Typically symptoms begin between 40 and 60 years of age
Clinical presentation is variable but typically presents in one of three patterns (initially described as separate entities)
Shy-Drager syndrome is used when autonomic symptoms predominate
striatonigral degeneration shows predominant parkinsonian features
olivopontocerebellar atrophy demonstrates primarily cerebellar dysfunction
MSA has been divided clinically into 2 forms according to the dominant non-autonomic symptoms
MSA-C predominance of cerebellar symptoms (olivopontocerebellar atrophy)
MSA-P predominance of parkinsonian signs and symptoms (striatonigraldegeneration)
RADIOGRAPHIC FEATURES
bullT2 hyperintensities typically present in the pontocerebellar tractsbull pons hot cross bun sign (MSA-C)
bull middle cerebellar peduncles
bull Cerebellum
putaminal findings in MSA-P reduced volume
reduced GRE and T2 signal relative to globus pallidus
reduced GRE and T2 signal relative to red nucleus
abnormal disruption of the normal high T2 linear rim
bullMSA-Cbull disproportionate atrophy of the cerebellum and brainstem (especially olivary nuclei and middle
cerebellar peduncle)
NUCLEAR MEDICINE
SPECT and PET studies tend to demonstrate hypometabolism in the superior parietal and superior frontal areas in the basal ganglia
HUNTINGTON DISEASE
autosomal dominant neurodegenerative disease
a loss of GABAergic neurons of the basal ganglia
especially atrophy of the caudate nucleus and putamen
Huntington disease has a prevalence of 5-10 per 100000 and is typically diagnosed between 30 and 50 years of age
In approximately 1-6 symptoms occur before the age of 20 so-called juvenile form
Presentation is typically with progressive rigidity choreoathetosis dementia psychosis and emotional lability
The juvenile form has a different presentation with cerebellar symptoms rigidity and hypokinesia being prominent
it is a autosomal dominant with complete penetrance and genetic anticipation particularly if inherited mutated allele is paternal
The mutation responsible is on chromosome 4p163 and consists of a CAG trineucleotide repeat
The usual 10-30 copies are amplified to greater than 36 and the greater the number of repeats the earlier the age of onset
RADIOGRAPHIC FEATURES
MRI
The most striking and best known feature is that of caudate head atrophy resulting in enlargement of the frontal horns often giving them a box like configuration
This can be quantified by an number of measurements
bullfrontal horn width to intercaudate distance ratio (FHCC)
bullintercaudate distance to inner table width ratio (CCIT)
Juvenile form
putamen are also atrophied and demonstrate increased T2 signal
basal ganglia may show decrease T2 signal and blooming on SWI in keeping with iron deposition
Generalised age inappropriate cortical volume loss is also recognised
FHCC ratio normal mean 22 to 26 (this ratio decreases with ageing as a result of enlargement of the frontal horns of the lateral ventricles)
CCIT ratio normal mean 009 to 012
AMYOTROPHIC LATERAL SCLEROSISalso known as Lou Gehrig disease or Charcot disease
Primary degeneration of the motor neurons within the brain brain stem and spinal cord
Patients typically present with progressive muscle weakness and limb and truncal atrophy combined with signs of spasticity
Mean age at the time of diagnosis is 55 years
RADIOGRAPHIC FEATURES
MRI
The earliest MR manifestation is hyperintensity on T2WI in the corticospinal tracts seen earliest in the internal capsule
Iron deposition in the cortex is demonstrated as loss of signal most evident on T2 weighted sequences
IS IT ATROPHY OR HYDROCEPHALUS
Abnormal accumulation of CSF in Ventricular system
Results from Structural or functional block to normal flow Of CSF
In effect all are obhstructive
Difficult to differentiate Atrophy from Hydrocephalus gt60yrs
Initially show increased ICT
Later stages may reach Equillibrium and Becomes NP hYdrocephalus
Types
Obstructive
Communicating
NPH ndash seen typically in old patients Diagnosis is more based on clinical feature
Dementia urinary incontinence and gait apraxias + Hydrocephalus = NPH
Radiologically w
1 degeree of ventricular dilatation is more with Thinning and bowing of CC
2 Sulcal effacement is invariable seen Hydrocephalus
3 dilatation or rounding of the Temporal Horns
4 Rounding and enlargement of the frontal horns
5 Enlargement and ballooning of 3rd
ventricle
6 Enlargement of fourth ventricle
SPOTTERS
THANK YOU
FLAIR
sequence whole brain axial or volumetric
purpose white matter signal abnormality
small vessel ischaemia resulting in multi-infarct dementia and abnormal sulcalsignal in leptomeningeal processes
DWI ADC (or isometric images from optional DTI acquisition)
purpose cortical or deep grey matter restricted diffusion in Creutzfeldt Jakobdisease (CJD) and restriction in demyelination of infarction (eg cerebral vasculitis)
SWI
sequence SWI including phase and magnitude images
purpose microhaemorrhages (eg cerebral amyloid angiopathy (CAA) hypertensive encephalopathy) Mineral deposition in cortex (eg Alzheimers disease amyotrophic lateral sclerosis (ALS)) Loss of low signal in substantianigra (Parkinson disease)
Optional additional sequences
DTI (optional) for tractography
MR Perfusion arterial spin labelling or preferably contrast perfusion
MR spectroscopy
SYSTEMATIC APPROACH
T1 sagittal
AMidlline
corpus callosum
the anterior half of the body should be thicker and certainly not thinner than the posterior half
Upward bowing ndash Hydrocephalus
midbrain shape size and midbrain to pons area ratio
pons shape
should be plump and rounded and about 4 times as large as the midbrain
B Sagittal
medial surfaces of the frontal parietal and occipital lobes
all the sulci should be about the same size
Significant parietal sulcal widening with atrophy of the precuneus and posterior cingulate suggests Alzheimers disease (AD)
anterior to posterior gradient of sulcalsize (bigger anteriorly) seen in frontotemporal lobar degeneration
mamillary bodies
should be about the same size Atrophic or asymmetrical mammillary bodies may imply hippocampal pathology or Wernicke-Korsakoff syndrome
upper cervical spine and cord
Axial FLAIR amp T2
bullgyral atrophy particularly useful for the frontal lobes
bullwidening of the sylvian fissures
bullhippocampal volume and signal
bullposterior fossa morphology
bullMidbrain
bullPons
bullMedulla
bullCerebellum
bullWernicke pattern high T2 signal (ventromedial thalamus mammillary bodies periaqueductal grey matter)
bullCortical white matter changes
T2 axial imaging is often better for basal ganglia structures and posterior fossa Assess for
reversal of normal T2 signal of putamen vs globus pallidus of MSA-P
atrophic caudate heads of Huntingtons disease
size and flow void in aqueduct (usually prominent in NPH)
3 Coronal sequences
bullhippocampal choroidal fissure and temporal horn size
bullsymmetrybull left gt right atrophy favours FTLD
bull equal involvement favours Alzheimers disease
bullanterior to posterior gradientbull anterior atrophy gt posterior atrophy favours FTLD
bullinvolvement of the temporal lobe generally favours FTLD
bullatrophy largely restricted to the hippocampus and parahippocampalgyrus favours Alzheimers disease
bullmammillary body size signal and symmetry
4 T2 sequences
Sequences susceptible to blood products are particularly useful in assessing
bullmicrohaemorrhages
bull peripherally distributed in cerebral amyloid angiopathy which in turn is associate with Alzheimers disease
bullcentrally distributed (basal ganglia pons cerebellum) in chronic hypertensive encephalophathy
5 DWI
DWI has a limited role in the assessment of a patient with a suspected neurodegenerative disease
Crucial particularly for Creutzfeldt-Jakob disease look for cortical basal ganglia and thalamic restricted diffusion
SCORING SYSTEMS AND MEASUREMENTS
bullFazekas scale for white matter lesions the deep white matter component is used in assessing the amount of chronic small vessel ischaemic change
bullposterior atrophy score of parietal atrophy (PA or PCA or Koedam score) useful in atypical (posterior cortical atrophy) or early onset Alzheimers disease
bullmedial temporal lobe atrophy score (MTA score)
bullglobal cortical atrophy scale (GCA scale)
A number of measurements ratios are also useful
midbrain to pons area ratio (for PSP)
magnetic resonance parkinsonism index (MRPI) (for PSP)
ALZHEIMER DISEASE
Alzheimer disease (AD) is a common neurodegenerative disease responsible for the majority of all dementias and imposing a significant burden on developed nations
Most common cause of dementia and accounts for two thirds of cases of dementia in patients aged 60-70 years
Epidemiological risk factor advanced age female gender
apolipoprotein E (APOE) ε4 allele carrier status
current smoking
family history of dementia
Classicaltypical Alzheimer disease
with antegrade episodic memory deficits
Neuropsychiatric symptoms are also common and eventually affect almost all patients These include apathy depression anxiety aggressionagitation and psychosis
Atypicalvariant Alzheimer disease
These entities often recognised clinically well before they were identified to be pathologically identical to Alzheimer disease
slowly progressive focal cortical atrophy with symptoms and signs matched to the affected area
Examples include
posterior cortical atrophy
frontal variant of Alzheimer disease
a minority of cases of semantic dementia
Pathology
Alzheimer disease is characterised by the accumulation of senile (neuritic) plaques neuritic (neurofibrillary) tangles and progressive loss of neurons
The progression of pathology initially involves the transentorhinalregion and then spreads to the hippocampal complex and mesial temporal lobe structures and eventually the temporal lobes and basal forebrain
RADIOGRAPHIC FEATURES
The primary role of MRI (and CT) in the diagnosis of Alzheimer disease is the assessment of volume change in characteristic locations which can yield a diagnostic accuracy of up to 87
The diagnosis should be made on the basis of two features
mesial temporal lobe atrophy
temporoparietal cortical atrophy
MESIAL TEMPORAL LOBE ATROPHY
hippocampal and parahippocampal decrease in volume
Indirectly by examining enlargement of the parahippocampalfissures
The former is more sensitive and specific but ideally requires actual volumetric calculations rather than eye-balling the scan
These measures have been combined in the medial temporal atrophy score which has been shown to be predictive of progression from mild cognitive impairment (MCI) to dementiA
MEDIAL TEMPORAL LOBE ATROPHY SCORE
visual score performed on MRI of the brain using coronal T1 weighted images through the hippocampus at the level of the anterior pons and assesses three features
width of the choroid fissure
width of the temporal horn of the lateral ventricle
height of the hippocampus
These result in a score of 0 to 4
0 = no CSF is visible around the hippocampus
1 = choroid fissure is slightly widened
2 = moderate widening of the choroid fissure mild enlargement of the temporal horn and mild loss of hippocampal height
3 = marked widening of the choroid fissure moderate enlargement of the temporal horn and moderate loss of hippocampal height
4 = marked widening of the choroid fissure marked enlargement of the temporal horn and the hippocampus is markedly atrophied and internal structure is lost
In a patient younger than 75 years of age a score of 2 or more is abnormal
In a patient 75 years or older a score of 3 or more is abnormal
Atrophy has been shown to correlate with likelihood of progression from mild cognitive impairment (MCI) to dementia 4
MRI SPECTROSCOPY
increases in myoinositol (MI) (356 ppm) thought to reflect inhibition of enzyme(s) mediating conversion of MI to phosphatidyl inositol
decreased N-acetyl aspartate (NAA) (202 ppm) indicating decreased neuronal activity
TEMPOROPARIETAL CORTICAL ATROPHY Parietal atrophy particularly relevant to posterior cortical atrophy or early onset Alzheimer disease
the inter-hemispheric surface of the parietal lobe
TREATMENT AND PROGNOSIS
There is no cure for this disease some drugs have been developed trying to improve symptoms or at least temporarily slow down their progression
cholinsterase inhibitors
partial NMDA receptor antagonists
medications for behavioural symptoms
antidepressants
anxiolytics
antiparkinsonian (movement symptoms)
anticonvulsantssedatives (behavioural)
VASCULAR DEMENTIAalso known as vascular cognitive impairment
It is primarily seen in patients with atherosclerosis and chronic hypertension
Results from the accumulation of multiple white matter or cortical infarcts although cerebral haemorrhages can be variably included
strongly correlated with age seen in only 1 of patients over the age of 55 years of age but in over 4 of patients over 71 years of age
It is also possible to divide vascular dementia into subtypes
small vessel dementia (aka Binswanger disease)
cortical vascular dementia roughly equivalent to multi-infarct dementia
strategic infarct dementia
thalamic dementia
RADIOGRAPHIC FEATURES
Both CT and MRI are able to provide evidence of ischaemic damage
MRI is more sensitive especially to white matter small vessel ischaemic change as well as to microhaemorrhages seen in cerebral amyloid angiopathy and chronic hypertensive encephalopathy
bullsmall vessel dementia (aka Binswanger disease)
bullcerebral infarction
bulllacunar infarction
bullintracerebral haemorrhage
CEREBRAL AMYLOID ANGIOPATHY
SMALL VESSEL DEMENTIA
also known as Binswanger disease
Subcortical arteriosclerotic encephalopathy
refers to slowly progressive exclusively white-matter multi-infarct dementia
A genetically transmitted form of the disease is known as familial arteriopathic leukoencephalopathy
or
CADASIL (cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy)
CLINICAL CRITERIA FOR DIAGNOSIS
marked subcortical microangiopathic lesions at MR imaging
a negative family history for strokes early cognitive impairment or psychiatric disorders in first- and second-degree relatives
documented arterial hypertension systolic values higher than 160 mm Hg diastolic values higher than 95 mm Hg or both measured at several occasions 5
MRI
subcortical and periventricular lesions visible on T2 FLAIR T2-weighted and proton-density sequences
commonly grouped around the frontal and occipital horns and in the centrum semi ovale
Moderate generalised cerebral atrophy is invariably present and lacunar infarctsin the basal ganglia and
thalami are common
CT
Diffuse incompletely symmetrical hypodensities are present in deep white matter especially they are prominent in the frontal lobes and the centrum semiovale
CEREBRAL AUTOSOMAL DOMINANT ARTERIOPATHY WITH SUBCORTICAL INFARCTS AND LEUKOENCEPHALOPATHY (CADASIL)
occurs in the absence of hypertension and arteriosclerosis and presents in 71 of cases before the age of 60 years
Imaging features demonstrate severe microvascular changes with multiple subcortical infarcts
Not distinguishable from hypertensive type microvascular disease
DEMENTIA WITH LEWY BODIESPD
Neurodegenerative disease (a synucleinopathy to be specific) related to Parkinsons disease (PD)
Epidemiology
Dementia with Lewy bodies presents in older patients (onset typically in 50-70 years of age) and is sporadic
It is the second most common neurodegenerative cause of dementia in older patients after Alzheimers disease accounting for 15-20 of case
RADIOGRAPHIC FEATURES
MRI
Atrophy in various parts of the brain without a clearly identified unique pattern
Most helpful in distinguishing DLB from other entities resulting in dementia is the absence of features of other diseases
generalised decrease in cerebral volume most marked in
frontal lobes parietotemporal regions
enlargement of the lateral ventricles
relatively focal atrophy
midbrain
hypothalamus
SWALLOW TAIL SIGN
The swallow tail sign describes the normal axial imaging appearance of nigrosome-1 within the substantianigra on high resolution T2SWI weighted MRI
Absence of the sign (absent swallow tail sign) is reported to have a diagnostic accuracy of greater than 90 for Parkinson disease
Nuclear medicine
Occipital hypoperfusion on SPECT PET
May aid in differentiation from other types of dementia especially Alzheimers disease
TREATMENT AND PROGNOSIS
Unlike Parkinsons disease dementia with Lewy bodies respond less readily to L-dopa and also may have severe sensitivity reactions to neuroleptic drugs such as rigidity reduced consciousness pyrexia falling postural hypotension and collapse
Lewy body dementia also responds favourably to acetylcholinesteraseinhibitors
DIFFERENTIAL DIAGNOSISwith strong overlap between
bullAlzheimers diseasebull clinical may occasionally have similar clinical presentation with a frontal type dementia or posterior
cortical atrophy
bull imaging prominent involvement of hippocampi on imaging
bullFronto-temporal lobar degenerationbull clinical usually younger onset absent parkinsonian features absent visual hallucinations
bull imaging more pronounced frontal temporal atrophy L gt R asymmetry
FRONTO-TEMPORAL LOBAR DEGENERATION
Frontotemporal lobar degeneration (FTLD) is the pathological description of a group of neurodegenerative disorders characterised by focal atrophy of the frontal and temporal cortices
rontotemporal lobar degeneration can be divided as follows 3-4
bullbehavioural variant fronto-temporal lobar degeneration dementia (bvFTLD) (aka behavioural variant frontotemporal dementia)1
bulllanguage variant fronto-temporal lobar degeneration (lvFTLD) (aka primary progressive aphasia (PPA)6
bull agrammatic variant primary progressive aphasia (aka progressive non-fluent aphasia (PNFA)
bull semantic variant primary progressive aphasia (aka semantic dementia)
bull logopaenic variant primary progressive aphasia
RADIOGRAPHIC FEATURES
The frontal and temporal lobes are predominantly affected there is often striking asymmetry both of involvement of frontal vs temporal lobes and involvement of left and right hemispheres
In addition the degree of fronto-striatal dysfunction varies between the different FTLD subgroups with behavioural variant frontotemporal dementia (bvFTD) having the greatest involvement
As a result the caudate heads tend to be reduced in size in these patients to a much greater degree than in the language variants of frontotemporal dementia
BEHAVIOURAL VARIANT FRONTO-TEMPORAL LOBAR DEGENERATION (BVFTLD)also referred to as Pick disease
Patients with behavioural variant FTD typically present with a dysexecutive cognitive syndrome associated with changes in personality and social behaviour
As the disease progresses impairments in language and memory may develop and the cognitive phenotype may come to resemble one of the language variants of FTD
RADIOGRAPHIC FEATURES
MRI
typical radiographic finding is atrophy of the frontal lobes and to a lesser extent the temporal lobes
The degree of atrophy can be very asymmetric
Decrease in volume of the caudate heads This indicates loss of both efferent and afferent fibres
CREUTZFELDT-JAKOB DISEASEspongiform encephalopathy
Results in a rapidly progressive dementia
other non-specific neurological features
Three types of Creutzfeldt-Jakob disease have been described
bullsporadic (sCJD) accounts for 85-90 of cases
bullvariant (vCJD)
bullfamilial (fCJD) 10 of cases (these individuals carry a PRPc mutation)
Creutzfeldt-Jakob disease is characterized by rapidly progressive dementia cerebral atrophy myoclonus and death
Patients with vCJD present mostly with sensory and psychiatric symptoms
Patients with sCJD usually present with progressive cognitive impairment and cerebellar symptoms
PATHOLOGY
mediated via (infectious) prions
a type of protein which manifest in sheep as the disease scrapie and in cows as bovine spongiform encephalopathy
Prions are considered infectious in sense that they can alter the structure of neighbouring proteins
CJD leads to spongiform degeneration of the brain
the conversion of normal prion protein to proteinaceous infectious particles that accumulate in and around neurons and lead to cell death
RADIOGRAPHIC FEATURES
MRI
MRI findings may be bilateral or unilateral and symmetric or asymmetric and include
T2 hyperintensity
obasal ganglia (putamen and caudate)
othalamus ( hockey stick sign and pulvinar sign)
ocortex most common early manifestation
owhite matter
persistent restricted diffusion on DWI (considered the most sensitive sign)
Review of sequential studies also typically demonstrates rapidly progressive cerebral atrophy
hypometabolism on 18FDG-PET studies
TREATMENT AND PROGNOSIS
here is currently no curative treatment and the disease is invariably fatal with a mean survival of only 7 months for most cases
PROGRESSIVE SUPRANUCLEARPALSYlso known as the Steele-Richardson-Olszewski syndrome
Progressive supranuclear palsy typically becomes clinically apparent in the 6th decade of life
Progresses to death usually within a decade (2-17 years from diagnosis)
Progressive supranuclear palsy is characterised
decreased cognition
abnormal eye movements (supranuclear vertical gaze palsy)
postural instability and falls
as well as parkinsonian features and speech disturbances
RADIOGRAPHIC FEATURESMRI
midbrain atrophy
reduction of anteroposterior midline midbrain diameter at the level of the superior colliculi on axial imaging (from interpeduncular fossa to the intercolicular groove lt12mm 8) which can give a mickey mouse appearance
reduced area of the midbrain on midline sagittal and reduced midbrain to pons area ratio approx 012 (normal approx 024) on midline sagittal
Loss of the lateral convex margin of the tegmentum of midbrain has been described as the morning glory sign
hummingbird sign also known as the penguin sign The key is a flattening or concave outline to the superior aspect of the midbrain which should be upwardly convex
bullT2 diffuse high-signal lesions in
bull pontine tegmentum
bull tectum of the midbrain
bull inferior olivary nucleus
MICKEY MOUSE APPEARANCE
THE PENGUIN SIGN
MULTIPLE SYSTEM ATROPHY
sporadic neurodegenerative disease
Typically symptoms begin between 40 and 60 years of age
Clinical presentation is variable but typically presents in one of three patterns (initially described as separate entities)
Shy-Drager syndrome is used when autonomic symptoms predominate
striatonigral degeneration shows predominant parkinsonian features
olivopontocerebellar atrophy demonstrates primarily cerebellar dysfunction
MSA has been divided clinically into 2 forms according to the dominant non-autonomic symptoms
MSA-C predominance of cerebellar symptoms (olivopontocerebellar atrophy)
MSA-P predominance of parkinsonian signs and symptoms (striatonigraldegeneration)
RADIOGRAPHIC FEATURES
bullT2 hyperintensities typically present in the pontocerebellar tractsbull pons hot cross bun sign (MSA-C)
bull middle cerebellar peduncles
bull Cerebellum
putaminal findings in MSA-P reduced volume
reduced GRE and T2 signal relative to globus pallidus
reduced GRE and T2 signal relative to red nucleus
abnormal disruption of the normal high T2 linear rim
bullMSA-Cbull disproportionate atrophy of the cerebellum and brainstem (especially olivary nuclei and middle
cerebellar peduncle)
NUCLEAR MEDICINE
SPECT and PET studies tend to demonstrate hypometabolism in the superior parietal and superior frontal areas in the basal ganglia
HUNTINGTON DISEASE
autosomal dominant neurodegenerative disease
a loss of GABAergic neurons of the basal ganglia
especially atrophy of the caudate nucleus and putamen
Huntington disease has a prevalence of 5-10 per 100000 and is typically diagnosed between 30 and 50 years of age
In approximately 1-6 symptoms occur before the age of 20 so-called juvenile form
Presentation is typically with progressive rigidity choreoathetosis dementia psychosis and emotional lability
The juvenile form has a different presentation with cerebellar symptoms rigidity and hypokinesia being prominent
it is a autosomal dominant with complete penetrance and genetic anticipation particularly if inherited mutated allele is paternal
The mutation responsible is on chromosome 4p163 and consists of a CAG trineucleotide repeat
The usual 10-30 copies are amplified to greater than 36 and the greater the number of repeats the earlier the age of onset
RADIOGRAPHIC FEATURES
MRI
The most striking and best known feature is that of caudate head atrophy resulting in enlargement of the frontal horns often giving them a box like configuration
This can be quantified by an number of measurements
bullfrontal horn width to intercaudate distance ratio (FHCC)
bullintercaudate distance to inner table width ratio (CCIT)
Juvenile form
putamen are also atrophied and demonstrate increased T2 signal
basal ganglia may show decrease T2 signal and blooming on SWI in keeping with iron deposition
Generalised age inappropriate cortical volume loss is also recognised
FHCC ratio normal mean 22 to 26 (this ratio decreases with ageing as a result of enlargement of the frontal horns of the lateral ventricles)
CCIT ratio normal mean 009 to 012
AMYOTROPHIC LATERAL SCLEROSISalso known as Lou Gehrig disease or Charcot disease
Primary degeneration of the motor neurons within the brain brain stem and spinal cord
Patients typically present with progressive muscle weakness and limb and truncal atrophy combined with signs of spasticity
Mean age at the time of diagnosis is 55 years
RADIOGRAPHIC FEATURES
MRI
The earliest MR manifestation is hyperintensity on T2WI in the corticospinal tracts seen earliest in the internal capsule
Iron deposition in the cortex is demonstrated as loss of signal most evident on T2 weighted sequences
IS IT ATROPHY OR HYDROCEPHALUS
Abnormal accumulation of CSF in Ventricular system
Results from Structural or functional block to normal flow Of CSF
In effect all are obhstructive
Difficult to differentiate Atrophy from Hydrocephalus gt60yrs
Initially show increased ICT
Later stages may reach Equillibrium and Becomes NP hYdrocephalus
Types
Obstructive
Communicating
NPH ndash seen typically in old patients Diagnosis is more based on clinical feature
Dementia urinary incontinence and gait apraxias + Hydrocephalus = NPH
Radiologically w
1 degeree of ventricular dilatation is more with Thinning and bowing of CC
2 Sulcal effacement is invariable seen Hydrocephalus
3 dilatation or rounding of the Temporal Horns
4 Rounding and enlargement of the frontal horns
5 Enlargement and ballooning of 3rd
ventricle
6 Enlargement of fourth ventricle
SPOTTERS
THANK YOU
Optional additional sequences
DTI (optional) for tractography
MR Perfusion arterial spin labelling or preferably contrast perfusion
MR spectroscopy
SYSTEMATIC APPROACH
T1 sagittal
AMidlline
corpus callosum
the anterior half of the body should be thicker and certainly not thinner than the posterior half
Upward bowing ndash Hydrocephalus
midbrain shape size and midbrain to pons area ratio
pons shape
should be plump and rounded and about 4 times as large as the midbrain
B Sagittal
medial surfaces of the frontal parietal and occipital lobes
all the sulci should be about the same size
Significant parietal sulcal widening with atrophy of the precuneus and posterior cingulate suggests Alzheimers disease (AD)
anterior to posterior gradient of sulcalsize (bigger anteriorly) seen in frontotemporal lobar degeneration
mamillary bodies
should be about the same size Atrophic or asymmetrical mammillary bodies may imply hippocampal pathology or Wernicke-Korsakoff syndrome
upper cervical spine and cord
Axial FLAIR amp T2
bullgyral atrophy particularly useful for the frontal lobes
bullwidening of the sylvian fissures
bullhippocampal volume and signal
bullposterior fossa morphology
bullMidbrain
bullPons
bullMedulla
bullCerebellum
bullWernicke pattern high T2 signal (ventromedial thalamus mammillary bodies periaqueductal grey matter)
bullCortical white matter changes
T2 axial imaging is often better for basal ganglia structures and posterior fossa Assess for
reversal of normal T2 signal of putamen vs globus pallidus of MSA-P
atrophic caudate heads of Huntingtons disease
size and flow void in aqueduct (usually prominent in NPH)
3 Coronal sequences
bullhippocampal choroidal fissure and temporal horn size
bullsymmetrybull left gt right atrophy favours FTLD
bull equal involvement favours Alzheimers disease
bullanterior to posterior gradientbull anterior atrophy gt posterior atrophy favours FTLD
bullinvolvement of the temporal lobe generally favours FTLD
bullatrophy largely restricted to the hippocampus and parahippocampalgyrus favours Alzheimers disease
bullmammillary body size signal and symmetry
4 T2 sequences
Sequences susceptible to blood products are particularly useful in assessing
bullmicrohaemorrhages
bull peripherally distributed in cerebral amyloid angiopathy which in turn is associate with Alzheimers disease
bullcentrally distributed (basal ganglia pons cerebellum) in chronic hypertensive encephalophathy
5 DWI
DWI has a limited role in the assessment of a patient with a suspected neurodegenerative disease
Crucial particularly for Creutzfeldt-Jakob disease look for cortical basal ganglia and thalamic restricted diffusion
SCORING SYSTEMS AND MEASUREMENTS
bullFazekas scale for white matter lesions the deep white matter component is used in assessing the amount of chronic small vessel ischaemic change
bullposterior atrophy score of parietal atrophy (PA or PCA or Koedam score) useful in atypical (posterior cortical atrophy) or early onset Alzheimers disease
bullmedial temporal lobe atrophy score (MTA score)
bullglobal cortical atrophy scale (GCA scale)
A number of measurements ratios are also useful
midbrain to pons area ratio (for PSP)
magnetic resonance parkinsonism index (MRPI) (for PSP)
ALZHEIMER DISEASE
Alzheimer disease (AD) is a common neurodegenerative disease responsible for the majority of all dementias and imposing a significant burden on developed nations
Most common cause of dementia and accounts for two thirds of cases of dementia in patients aged 60-70 years
Epidemiological risk factor advanced age female gender
apolipoprotein E (APOE) ε4 allele carrier status
current smoking
family history of dementia
Classicaltypical Alzheimer disease
with antegrade episodic memory deficits
Neuropsychiatric symptoms are also common and eventually affect almost all patients These include apathy depression anxiety aggressionagitation and psychosis
Atypicalvariant Alzheimer disease
These entities often recognised clinically well before they were identified to be pathologically identical to Alzheimer disease
slowly progressive focal cortical atrophy with symptoms and signs matched to the affected area
Examples include
posterior cortical atrophy
frontal variant of Alzheimer disease
a minority of cases of semantic dementia
Pathology
Alzheimer disease is characterised by the accumulation of senile (neuritic) plaques neuritic (neurofibrillary) tangles and progressive loss of neurons
The progression of pathology initially involves the transentorhinalregion and then spreads to the hippocampal complex and mesial temporal lobe structures and eventually the temporal lobes and basal forebrain
RADIOGRAPHIC FEATURES
The primary role of MRI (and CT) in the diagnosis of Alzheimer disease is the assessment of volume change in characteristic locations which can yield a diagnostic accuracy of up to 87
The diagnosis should be made on the basis of two features
mesial temporal lobe atrophy
temporoparietal cortical atrophy
MESIAL TEMPORAL LOBE ATROPHY
hippocampal and parahippocampal decrease in volume
Indirectly by examining enlargement of the parahippocampalfissures
The former is more sensitive and specific but ideally requires actual volumetric calculations rather than eye-balling the scan
These measures have been combined in the medial temporal atrophy score which has been shown to be predictive of progression from mild cognitive impairment (MCI) to dementiA
MEDIAL TEMPORAL LOBE ATROPHY SCORE
visual score performed on MRI of the brain using coronal T1 weighted images through the hippocampus at the level of the anterior pons and assesses three features
width of the choroid fissure
width of the temporal horn of the lateral ventricle
height of the hippocampus
These result in a score of 0 to 4
0 = no CSF is visible around the hippocampus
1 = choroid fissure is slightly widened
2 = moderate widening of the choroid fissure mild enlargement of the temporal horn and mild loss of hippocampal height
3 = marked widening of the choroid fissure moderate enlargement of the temporal horn and moderate loss of hippocampal height
4 = marked widening of the choroid fissure marked enlargement of the temporal horn and the hippocampus is markedly atrophied and internal structure is lost
In a patient younger than 75 years of age a score of 2 or more is abnormal
In a patient 75 years or older a score of 3 or more is abnormal
Atrophy has been shown to correlate with likelihood of progression from mild cognitive impairment (MCI) to dementia 4
MRI SPECTROSCOPY
increases in myoinositol (MI) (356 ppm) thought to reflect inhibition of enzyme(s) mediating conversion of MI to phosphatidyl inositol
decreased N-acetyl aspartate (NAA) (202 ppm) indicating decreased neuronal activity
TEMPOROPARIETAL CORTICAL ATROPHY Parietal atrophy particularly relevant to posterior cortical atrophy or early onset Alzheimer disease
the inter-hemispheric surface of the parietal lobe
TREATMENT AND PROGNOSIS
There is no cure for this disease some drugs have been developed trying to improve symptoms or at least temporarily slow down their progression
cholinsterase inhibitors
partial NMDA receptor antagonists
medications for behavioural symptoms
antidepressants
anxiolytics
antiparkinsonian (movement symptoms)
anticonvulsantssedatives (behavioural)
VASCULAR DEMENTIAalso known as vascular cognitive impairment
It is primarily seen in patients with atherosclerosis and chronic hypertension
Results from the accumulation of multiple white matter or cortical infarcts although cerebral haemorrhages can be variably included
strongly correlated with age seen in only 1 of patients over the age of 55 years of age but in over 4 of patients over 71 years of age
It is also possible to divide vascular dementia into subtypes
small vessel dementia (aka Binswanger disease)
cortical vascular dementia roughly equivalent to multi-infarct dementia
strategic infarct dementia
thalamic dementia
RADIOGRAPHIC FEATURES
Both CT and MRI are able to provide evidence of ischaemic damage
MRI is more sensitive especially to white matter small vessel ischaemic change as well as to microhaemorrhages seen in cerebral amyloid angiopathy and chronic hypertensive encephalopathy
bullsmall vessel dementia (aka Binswanger disease)
bullcerebral infarction
bulllacunar infarction
bullintracerebral haemorrhage
CEREBRAL AMYLOID ANGIOPATHY
SMALL VESSEL DEMENTIA
also known as Binswanger disease
Subcortical arteriosclerotic encephalopathy
refers to slowly progressive exclusively white-matter multi-infarct dementia
A genetically transmitted form of the disease is known as familial arteriopathic leukoencephalopathy
or
CADASIL (cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy)
CLINICAL CRITERIA FOR DIAGNOSIS
marked subcortical microangiopathic lesions at MR imaging
a negative family history for strokes early cognitive impairment or psychiatric disorders in first- and second-degree relatives
documented arterial hypertension systolic values higher than 160 mm Hg diastolic values higher than 95 mm Hg or both measured at several occasions 5
MRI
subcortical and periventricular lesions visible on T2 FLAIR T2-weighted and proton-density sequences
commonly grouped around the frontal and occipital horns and in the centrum semi ovale
Moderate generalised cerebral atrophy is invariably present and lacunar infarctsin the basal ganglia and
thalami are common
CT
Diffuse incompletely symmetrical hypodensities are present in deep white matter especially they are prominent in the frontal lobes and the centrum semiovale
CEREBRAL AUTOSOMAL DOMINANT ARTERIOPATHY WITH SUBCORTICAL INFARCTS AND LEUKOENCEPHALOPATHY (CADASIL)
occurs in the absence of hypertension and arteriosclerosis and presents in 71 of cases before the age of 60 years
Imaging features demonstrate severe microvascular changes with multiple subcortical infarcts
Not distinguishable from hypertensive type microvascular disease
DEMENTIA WITH LEWY BODIESPD
Neurodegenerative disease (a synucleinopathy to be specific) related to Parkinsons disease (PD)
Epidemiology
Dementia with Lewy bodies presents in older patients (onset typically in 50-70 years of age) and is sporadic
It is the second most common neurodegenerative cause of dementia in older patients after Alzheimers disease accounting for 15-20 of case
RADIOGRAPHIC FEATURES
MRI
Atrophy in various parts of the brain without a clearly identified unique pattern
Most helpful in distinguishing DLB from other entities resulting in dementia is the absence of features of other diseases
generalised decrease in cerebral volume most marked in
frontal lobes parietotemporal regions
enlargement of the lateral ventricles
relatively focal atrophy
midbrain
hypothalamus
SWALLOW TAIL SIGN
The swallow tail sign describes the normal axial imaging appearance of nigrosome-1 within the substantianigra on high resolution T2SWI weighted MRI
Absence of the sign (absent swallow tail sign) is reported to have a diagnostic accuracy of greater than 90 for Parkinson disease
Nuclear medicine
Occipital hypoperfusion on SPECT PET
May aid in differentiation from other types of dementia especially Alzheimers disease
TREATMENT AND PROGNOSIS
Unlike Parkinsons disease dementia with Lewy bodies respond less readily to L-dopa and also may have severe sensitivity reactions to neuroleptic drugs such as rigidity reduced consciousness pyrexia falling postural hypotension and collapse
Lewy body dementia also responds favourably to acetylcholinesteraseinhibitors
DIFFERENTIAL DIAGNOSISwith strong overlap between
bullAlzheimers diseasebull clinical may occasionally have similar clinical presentation with a frontal type dementia or posterior
cortical atrophy
bull imaging prominent involvement of hippocampi on imaging
bullFronto-temporal lobar degenerationbull clinical usually younger onset absent parkinsonian features absent visual hallucinations
bull imaging more pronounced frontal temporal atrophy L gt R asymmetry
FRONTO-TEMPORAL LOBAR DEGENERATION
Frontotemporal lobar degeneration (FTLD) is the pathological description of a group of neurodegenerative disorders characterised by focal atrophy of the frontal and temporal cortices
rontotemporal lobar degeneration can be divided as follows 3-4
bullbehavioural variant fronto-temporal lobar degeneration dementia (bvFTLD) (aka behavioural variant frontotemporal dementia)1
bulllanguage variant fronto-temporal lobar degeneration (lvFTLD) (aka primary progressive aphasia (PPA)6
bull agrammatic variant primary progressive aphasia (aka progressive non-fluent aphasia (PNFA)
bull semantic variant primary progressive aphasia (aka semantic dementia)
bull logopaenic variant primary progressive aphasia
RADIOGRAPHIC FEATURES
The frontal and temporal lobes are predominantly affected there is often striking asymmetry both of involvement of frontal vs temporal lobes and involvement of left and right hemispheres
In addition the degree of fronto-striatal dysfunction varies between the different FTLD subgroups with behavioural variant frontotemporal dementia (bvFTD) having the greatest involvement
As a result the caudate heads tend to be reduced in size in these patients to a much greater degree than in the language variants of frontotemporal dementia
BEHAVIOURAL VARIANT FRONTO-TEMPORAL LOBAR DEGENERATION (BVFTLD)also referred to as Pick disease
Patients with behavioural variant FTD typically present with a dysexecutive cognitive syndrome associated with changes in personality and social behaviour
As the disease progresses impairments in language and memory may develop and the cognitive phenotype may come to resemble one of the language variants of FTD
RADIOGRAPHIC FEATURES
MRI
typical radiographic finding is atrophy of the frontal lobes and to a lesser extent the temporal lobes
The degree of atrophy can be very asymmetric
Decrease in volume of the caudate heads This indicates loss of both efferent and afferent fibres
CREUTZFELDT-JAKOB DISEASEspongiform encephalopathy
Results in a rapidly progressive dementia
other non-specific neurological features
Three types of Creutzfeldt-Jakob disease have been described
bullsporadic (sCJD) accounts for 85-90 of cases
bullvariant (vCJD)
bullfamilial (fCJD) 10 of cases (these individuals carry a PRPc mutation)
Creutzfeldt-Jakob disease is characterized by rapidly progressive dementia cerebral atrophy myoclonus and death
Patients with vCJD present mostly with sensory and psychiatric symptoms
Patients with sCJD usually present with progressive cognitive impairment and cerebellar symptoms
PATHOLOGY
mediated via (infectious) prions
a type of protein which manifest in sheep as the disease scrapie and in cows as bovine spongiform encephalopathy
Prions are considered infectious in sense that they can alter the structure of neighbouring proteins
CJD leads to spongiform degeneration of the brain
the conversion of normal prion protein to proteinaceous infectious particles that accumulate in and around neurons and lead to cell death
RADIOGRAPHIC FEATURES
MRI
MRI findings may be bilateral or unilateral and symmetric or asymmetric and include
T2 hyperintensity
obasal ganglia (putamen and caudate)
othalamus ( hockey stick sign and pulvinar sign)
ocortex most common early manifestation
owhite matter
persistent restricted diffusion on DWI (considered the most sensitive sign)
Review of sequential studies also typically demonstrates rapidly progressive cerebral atrophy
hypometabolism on 18FDG-PET studies
TREATMENT AND PROGNOSIS
here is currently no curative treatment and the disease is invariably fatal with a mean survival of only 7 months for most cases
PROGRESSIVE SUPRANUCLEARPALSYlso known as the Steele-Richardson-Olszewski syndrome
Progressive supranuclear palsy typically becomes clinically apparent in the 6th decade of life
Progresses to death usually within a decade (2-17 years from diagnosis)
Progressive supranuclear palsy is characterised
decreased cognition
abnormal eye movements (supranuclear vertical gaze palsy)
postural instability and falls
as well as parkinsonian features and speech disturbances
RADIOGRAPHIC FEATURESMRI
midbrain atrophy
reduction of anteroposterior midline midbrain diameter at the level of the superior colliculi on axial imaging (from interpeduncular fossa to the intercolicular groove lt12mm 8) which can give a mickey mouse appearance
reduced area of the midbrain on midline sagittal and reduced midbrain to pons area ratio approx 012 (normal approx 024) on midline sagittal
Loss of the lateral convex margin of the tegmentum of midbrain has been described as the morning glory sign
hummingbird sign also known as the penguin sign The key is a flattening or concave outline to the superior aspect of the midbrain which should be upwardly convex
bullT2 diffuse high-signal lesions in
bull pontine tegmentum
bull tectum of the midbrain
bull inferior olivary nucleus
MICKEY MOUSE APPEARANCE
THE PENGUIN SIGN
MULTIPLE SYSTEM ATROPHY
sporadic neurodegenerative disease
Typically symptoms begin between 40 and 60 years of age
Clinical presentation is variable but typically presents in one of three patterns (initially described as separate entities)
Shy-Drager syndrome is used when autonomic symptoms predominate
striatonigral degeneration shows predominant parkinsonian features
olivopontocerebellar atrophy demonstrates primarily cerebellar dysfunction
MSA has been divided clinically into 2 forms according to the dominant non-autonomic symptoms
MSA-C predominance of cerebellar symptoms (olivopontocerebellar atrophy)
MSA-P predominance of parkinsonian signs and symptoms (striatonigraldegeneration)
RADIOGRAPHIC FEATURES
bullT2 hyperintensities typically present in the pontocerebellar tractsbull pons hot cross bun sign (MSA-C)
bull middle cerebellar peduncles
bull Cerebellum
putaminal findings in MSA-P reduced volume
reduced GRE and T2 signal relative to globus pallidus
reduced GRE and T2 signal relative to red nucleus
abnormal disruption of the normal high T2 linear rim
bullMSA-Cbull disproportionate atrophy of the cerebellum and brainstem (especially olivary nuclei and middle
cerebellar peduncle)
NUCLEAR MEDICINE
SPECT and PET studies tend to demonstrate hypometabolism in the superior parietal and superior frontal areas in the basal ganglia
HUNTINGTON DISEASE
autosomal dominant neurodegenerative disease
a loss of GABAergic neurons of the basal ganglia
especially atrophy of the caudate nucleus and putamen
Huntington disease has a prevalence of 5-10 per 100000 and is typically diagnosed between 30 and 50 years of age
In approximately 1-6 symptoms occur before the age of 20 so-called juvenile form
Presentation is typically with progressive rigidity choreoathetosis dementia psychosis and emotional lability
The juvenile form has a different presentation with cerebellar symptoms rigidity and hypokinesia being prominent
it is a autosomal dominant with complete penetrance and genetic anticipation particularly if inherited mutated allele is paternal
The mutation responsible is on chromosome 4p163 and consists of a CAG trineucleotide repeat
The usual 10-30 copies are amplified to greater than 36 and the greater the number of repeats the earlier the age of onset
RADIOGRAPHIC FEATURES
MRI
The most striking and best known feature is that of caudate head atrophy resulting in enlargement of the frontal horns often giving them a box like configuration
This can be quantified by an number of measurements
bullfrontal horn width to intercaudate distance ratio (FHCC)
bullintercaudate distance to inner table width ratio (CCIT)
Juvenile form
putamen are also atrophied and demonstrate increased T2 signal
basal ganglia may show decrease T2 signal and blooming on SWI in keeping with iron deposition
Generalised age inappropriate cortical volume loss is also recognised
FHCC ratio normal mean 22 to 26 (this ratio decreases with ageing as a result of enlargement of the frontal horns of the lateral ventricles)
CCIT ratio normal mean 009 to 012
AMYOTROPHIC LATERAL SCLEROSISalso known as Lou Gehrig disease or Charcot disease
Primary degeneration of the motor neurons within the brain brain stem and spinal cord
Patients typically present with progressive muscle weakness and limb and truncal atrophy combined with signs of spasticity
Mean age at the time of diagnosis is 55 years
RADIOGRAPHIC FEATURES
MRI
The earliest MR manifestation is hyperintensity on T2WI in the corticospinal tracts seen earliest in the internal capsule
Iron deposition in the cortex is demonstrated as loss of signal most evident on T2 weighted sequences
IS IT ATROPHY OR HYDROCEPHALUS
Abnormal accumulation of CSF in Ventricular system
Results from Structural or functional block to normal flow Of CSF
In effect all are obhstructive
Difficult to differentiate Atrophy from Hydrocephalus gt60yrs
Initially show increased ICT
Later stages may reach Equillibrium and Becomes NP hYdrocephalus
Types
Obstructive
Communicating
NPH ndash seen typically in old patients Diagnosis is more based on clinical feature
Dementia urinary incontinence and gait apraxias + Hydrocephalus = NPH
Radiologically w
1 degeree of ventricular dilatation is more with Thinning and bowing of CC
2 Sulcal effacement is invariable seen Hydrocephalus
3 dilatation or rounding of the Temporal Horns
4 Rounding and enlargement of the frontal horns
5 Enlargement and ballooning of 3rd
ventricle
6 Enlargement of fourth ventricle
SPOTTERS
THANK YOU
SYSTEMATIC APPROACH
T1 sagittal
AMidlline
corpus callosum
the anterior half of the body should be thicker and certainly not thinner than the posterior half
Upward bowing ndash Hydrocephalus
midbrain shape size and midbrain to pons area ratio
pons shape
should be plump and rounded and about 4 times as large as the midbrain
B Sagittal
medial surfaces of the frontal parietal and occipital lobes
all the sulci should be about the same size
Significant parietal sulcal widening with atrophy of the precuneus and posterior cingulate suggests Alzheimers disease (AD)
anterior to posterior gradient of sulcalsize (bigger anteriorly) seen in frontotemporal lobar degeneration
mamillary bodies
should be about the same size Atrophic or asymmetrical mammillary bodies may imply hippocampal pathology or Wernicke-Korsakoff syndrome
upper cervical spine and cord
Axial FLAIR amp T2
bullgyral atrophy particularly useful for the frontal lobes
bullwidening of the sylvian fissures
bullhippocampal volume and signal
bullposterior fossa morphology
bullMidbrain
bullPons
bullMedulla
bullCerebellum
bullWernicke pattern high T2 signal (ventromedial thalamus mammillary bodies periaqueductal grey matter)
bullCortical white matter changes
T2 axial imaging is often better for basal ganglia structures and posterior fossa Assess for
reversal of normal T2 signal of putamen vs globus pallidus of MSA-P
atrophic caudate heads of Huntingtons disease
size and flow void in aqueduct (usually prominent in NPH)
3 Coronal sequences
bullhippocampal choroidal fissure and temporal horn size
bullsymmetrybull left gt right atrophy favours FTLD
bull equal involvement favours Alzheimers disease
bullanterior to posterior gradientbull anterior atrophy gt posterior atrophy favours FTLD
bullinvolvement of the temporal lobe generally favours FTLD
bullatrophy largely restricted to the hippocampus and parahippocampalgyrus favours Alzheimers disease
bullmammillary body size signal and symmetry
4 T2 sequences
Sequences susceptible to blood products are particularly useful in assessing
bullmicrohaemorrhages
bull peripherally distributed in cerebral amyloid angiopathy which in turn is associate with Alzheimers disease
bullcentrally distributed (basal ganglia pons cerebellum) in chronic hypertensive encephalophathy
5 DWI
DWI has a limited role in the assessment of a patient with a suspected neurodegenerative disease
Crucial particularly for Creutzfeldt-Jakob disease look for cortical basal ganglia and thalamic restricted diffusion
SCORING SYSTEMS AND MEASUREMENTS
bullFazekas scale for white matter lesions the deep white matter component is used in assessing the amount of chronic small vessel ischaemic change
bullposterior atrophy score of parietal atrophy (PA or PCA or Koedam score) useful in atypical (posterior cortical atrophy) or early onset Alzheimers disease
bullmedial temporal lobe atrophy score (MTA score)
bullglobal cortical atrophy scale (GCA scale)
A number of measurements ratios are also useful
midbrain to pons area ratio (for PSP)
magnetic resonance parkinsonism index (MRPI) (for PSP)
ALZHEIMER DISEASE
Alzheimer disease (AD) is a common neurodegenerative disease responsible for the majority of all dementias and imposing a significant burden on developed nations
Most common cause of dementia and accounts for two thirds of cases of dementia in patients aged 60-70 years
Epidemiological risk factor advanced age female gender
apolipoprotein E (APOE) ε4 allele carrier status
current smoking
family history of dementia
Classicaltypical Alzheimer disease
with antegrade episodic memory deficits
Neuropsychiatric symptoms are also common and eventually affect almost all patients These include apathy depression anxiety aggressionagitation and psychosis
Atypicalvariant Alzheimer disease
These entities often recognised clinically well before they were identified to be pathologically identical to Alzheimer disease
slowly progressive focal cortical atrophy with symptoms and signs matched to the affected area
Examples include
posterior cortical atrophy
frontal variant of Alzheimer disease
a minority of cases of semantic dementia
Pathology
Alzheimer disease is characterised by the accumulation of senile (neuritic) plaques neuritic (neurofibrillary) tangles and progressive loss of neurons
The progression of pathology initially involves the transentorhinalregion and then spreads to the hippocampal complex and mesial temporal lobe structures and eventually the temporal lobes and basal forebrain
RADIOGRAPHIC FEATURES
The primary role of MRI (and CT) in the diagnosis of Alzheimer disease is the assessment of volume change in characteristic locations which can yield a diagnostic accuracy of up to 87
The diagnosis should be made on the basis of two features
mesial temporal lobe atrophy
temporoparietal cortical atrophy
MESIAL TEMPORAL LOBE ATROPHY
hippocampal and parahippocampal decrease in volume
Indirectly by examining enlargement of the parahippocampalfissures
The former is more sensitive and specific but ideally requires actual volumetric calculations rather than eye-balling the scan
These measures have been combined in the medial temporal atrophy score which has been shown to be predictive of progression from mild cognitive impairment (MCI) to dementiA
MEDIAL TEMPORAL LOBE ATROPHY SCORE
visual score performed on MRI of the brain using coronal T1 weighted images through the hippocampus at the level of the anterior pons and assesses three features
width of the choroid fissure
width of the temporal horn of the lateral ventricle
height of the hippocampus
These result in a score of 0 to 4
0 = no CSF is visible around the hippocampus
1 = choroid fissure is slightly widened
2 = moderate widening of the choroid fissure mild enlargement of the temporal horn and mild loss of hippocampal height
3 = marked widening of the choroid fissure moderate enlargement of the temporal horn and moderate loss of hippocampal height
4 = marked widening of the choroid fissure marked enlargement of the temporal horn and the hippocampus is markedly atrophied and internal structure is lost
In a patient younger than 75 years of age a score of 2 or more is abnormal
In a patient 75 years or older a score of 3 or more is abnormal
Atrophy has been shown to correlate with likelihood of progression from mild cognitive impairment (MCI) to dementia 4
MRI SPECTROSCOPY
increases in myoinositol (MI) (356 ppm) thought to reflect inhibition of enzyme(s) mediating conversion of MI to phosphatidyl inositol
decreased N-acetyl aspartate (NAA) (202 ppm) indicating decreased neuronal activity
TEMPOROPARIETAL CORTICAL ATROPHY Parietal atrophy particularly relevant to posterior cortical atrophy or early onset Alzheimer disease
the inter-hemispheric surface of the parietal lobe
TREATMENT AND PROGNOSIS
There is no cure for this disease some drugs have been developed trying to improve symptoms or at least temporarily slow down their progression
cholinsterase inhibitors
partial NMDA receptor antagonists
medications for behavioural symptoms
antidepressants
anxiolytics
antiparkinsonian (movement symptoms)
anticonvulsantssedatives (behavioural)
VASCULAR DEMENTIAalso known as vascular cognitive impairment
It is primarily seen in patients with atherosclerosis and chronic hypertension
Results from the accumulation of multiple white matter or cortical infarcts although cerebral haemorrhages can be variably included
strongly correlated with age seen in only 1 of patients over the age of 55 years of age but in over 4 of patients over 71 years of age
It is also possible to divide vascular dementia into subtypes
small vessel dementia (aka Binswanger disease)
cortical vascular dementia roughly equivalent to multi-infarct dementia
strategic infarct dementia
thalamic dementia
RADIOGRAPHIC FEATURES
Both CT and MRI are able to provide evidence of ischaemic damage
MRI is more sensitive especially to white matter small vessel ischaemic change as well as to microhaemorrhages seen in cerebral amyloid angiopathy and chronic hypertensive encephalopathy
bullsmall vessel dementia (aka Binswanger disease)
bullcerebral infarction
bulllacunar infarction
bullintracerebral haemorrhage
CEREBRAL AMYLOID ANGIOPATHY
SMALL VESSEL DEMENTIA
also known as Binswanger disease
Subcortical arteriosclerotic encephalopathy
refers to slowly progressive exclusively white-matter multi-infarct dementia
A genetically transmitted form of the disease is known as familial arteriopathic leukoencephalopathy
or
CADASIL (cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy)
CLINICAL CRITERIA FOR DIAGNOSIS
marked subcortical microangiopathic lesions at MR imaging
a negative family history for strokes early cognitive impairment or psychiatric disorders in first- and second-degree relatives
documented arterial hypertension systolic values higher than 160 mm Hg diastolic values higher than 95 mm Hg or both measured at several occasions 5
MRI
subcortical and periventricular lesions visible on T2 FLAIR T2-weighted and proton-density sequences
commonly grouped around the frontal and occipital horns and in the centrum semi ovale
Moderate generalised cerebral atrophy is invariably present and lacunar infarctsin the basal ganglia and
thalami are common
CT
Diffuse incompletely symmetrical hypodensities are present in deep white matter especially they are prominent in the frontal lobes and the centrum semiovale
CEREBRAL AUTOSOMAL DOMINANT ARTERIOPATHY WITH SUBCORTICAL INFARCTS AND LEUKOENCEPHALOPATHY (CADASIL)
occurs in the absence of hypertension and arteriosclerosis and presents in 71 of cases before the age of 60 years
Imaging features demonstrate severe microvascular changes with multiple subcortical infarcts
Not distinguishable from hypertensive type microvascular disease
DEMENTIA WITH LEWY BODIESPD
Neurodegenerative disease (a synucleinopathy to be specific) related to Parkinsons disease (PD)
Epidemiology
Dementia with Lewy bodies presents in older patients (onset typically in 50-70 years of age) and is sporadic
It is the second most common neurodegenerative cause of dementia in older patients after Alzheimers disease accounting for 15-20 of case
RADIOGRAPHIC FEATURES
MRI
Atrophy in various parts of the brain without a clearly identified unique pattern
Most helpful in distinguishing DLB from other entities resulting in dementia is the absence of features of other diseases
generalised decrease in cerebral volume most marked in
frontal lobes parietotemporal regions
enlargement of the lateral ventricles
relatively focal atrophy
midbrain
hypothalamus
SWALLOW TAIL SIGN
The swallow tail sign describes the normal axial imaging appearance of nigrosome-1 within the substantianigra on high resolution T2SWI weighted MRI
Absence of the sign (absent swallow tail sign) is reported to have a diagnostic accuracy of greater than 90 for Parkinson disease
Nuclear medicine
Occipital hypoperfusion on SPECT PET
May aid in differentiation from other types of dementia especially Alzheimers disease
TREATMENT AND PROGNOSIS
Unlike Parkinsons disease dementia with Lewy bodies respond less readily to L-dopa and also may have severe sensitivity reactions to neuroleptic drugs such as rigidity reduced consciousness pyrexia falling postural hypotension and collapse
Lewy body dementia also responds favourably to acetylcholinesteraseinhibitors
DIFFERENTIAL DIAGNOSISwith strong overlap between
bullAlzheimers diseasebull clinical may occasionally have similar clinical presentation with a frontal type dementia or posterior
cortical atrophy
bull imaging prominent involvement of hippocampi on imaging
bullFronto-temporal lobar degenerationbull clinical usually younger onset absent parkinsonian features absent visual hallucinations
bull imaging more pronounced frontal temporal atrophy L gt R asymmetry
FRONTO-TEMPORAL LOBAR DEGENERATION
Frontotemporal lobar degeneration (FTLD) is the pathological description of a group of neurodegenerative disorders characterised by focal atrophy of the frontal and temporal cortices
rontotemporal lobar degeneration can be divided as follows 3-4
bullbehavioural variant fronto-temporal lobar degeneration dementia (bvFTLD) (aka behavioural variant frontotemporal dementia)1
bulllanguage variant fronto-temporal lobar degeneration (lvFTLD) (aka primary progressive aphasia (PPA)6
bull agrammatic variant primary progressive aphasia (aka progressive non-fluent aphasia (PNFA)
bull semantic variant primary progressive aphasia (aka semantic dementia)
bull logopaenic variant primary progressive aphasia
RADIOGRAPHIC FEATURES
The frontal and temporal lobes are predominantly affected there is often striking asymmetry both of involvement of frontal vs temporal lobes and involvement of left and right hemispheres
In addition the degree of fronto-striatal dysfunction varies between the different FTLD subgroups with behavioural variant frontotemporal dementia (bvFTD) having the greatest involvement
As a result the caudate heads tend to be reduced in size in these patients to a much greater degree than in the language variants of frontotemporal dementia
BEHAVIOURAL VARIANT FRONTO-TEMPORAL LOBAR DEGENERATION (BVFTLD)also referred to as Pick disease
Patients with behavioural variant FTD typically present with a dysexecutive cognitive syndrome associated with changes in personality and social behaviour
As the disease progresses impairments in language and memory may develop and the cognitive phenotype may come to resemble one of the language variants of FTD
RADIOGRAPHIC FEATURES
MRI
typical radiographic finding is atrophy of the frontal lobes and to a lesser extent the temporal lobes
The degree of atrophy can be very asymmetric
Decrease in volume of the caudate heads This indicates loss of both efferent and afferent fibres
CREUTZFELDT-JAKOB DISEASEspongiform encephalopathy
Results in a rapidly progressive dementia
other non-specific neurological features
Three types of Creutzfeldt-Jakob disease have been described
bullsporadic (sCJD) accounts for 85-90 of cases
bullvariant (vCJD)
bullfamilial (fCJD) 10 of cases (these individuals carry a PRPc mutation)
Creutzfeldt-Jakob disease is characterized by rapidly progressive dementia cerebral atrophy myoclonus and death
Patients with vCJD present mostly with sensory and psychiatric symptoms
Patients with sCJD usually present with progressive cognitive impairment and cerebellar symptoms
PATHOLOGY
mediated via (infectious) prions
a type of protein which manifest in sheep as the disease scrapie and in cows as bovine spongiform encephalopathy
Prions are considered infectious in sense that they can alter the structure of neighbouring proteins
CJD leads to spongiform degeneration of the brain
the conversion of normal prion protein to proteinaceous infectious particles that accumulate in and around neurons and lead to cell death
RADIOGRAPHIC FEATURES
MRI
MRI findings may be bilateral or unilateral and symmetric or asymmetric and include
T2 hyperintensity
obasal ganglia (putamen and caudate)
othalamus ( hockey stick sign and pulvinar sign)
ocortex most common early manifestation
owhite matter
persistent restricted diffusion on DWI (considered the most sensitive sign)
Review of sequential studies also typically demonstrates rapidly progressive cerebral atrophy
hypometabolism on 18FDG-PET studies
TREATMENT AND PROGNOSIS
here is currently no curative treatment and the disease is invariably fatal with a mean survival of only 7 months for most cases
PROGRESSIVE SUPRANUCLEARPALSYlso known as the Steele-Richardson-Olszewski syndrome
Progressive supranuclear palsy typically becomes clinically apparent in the 6th decade of life
Progresses to death usually within a decade (2-17 years from diagnosis)
Progressive supranuclear palsy is characterised
decreased cognition
abnormal eye movements (supranuclear vertical gaze palsy)
postural instability and falls
as well as parkinsonian features and speech disturbances
RADIOGRAPHIC FEATURESMRI
midbrain atrophy
reduction of anteroposterior midline midbrain diameter at the level of the superior colliculi on axial imaging (from interpeduncular fossa to the intercolicular groove lt12mm 8) which can give a mickey mouse appearance
reduced area of the midbrain on midline sagittal and reduced midbrain to pons area ratio approx 012 (normal approx 024) on midline sagittal
Loss of the lateral convex margin of the tegmentum of midbrain has been described as the morning glory sign
hummingbird sign also known as the penguin sign The key is a flattening or concave outline to the superior aspect of the midbrain which should be upwardly convex
bullT2 diffuse high-signal lesions in
bull pontine tegmentum
bull tectum of the midbrain
bull inferior olivary nucleus
MICKEY MOUSE APPEARANCE
THE PENGUIN SIGN
MULTIPLE SYSTEM ATROPHY
sporadic neurodegenerative disease
Typically symptoms begin between 40 and 60 years of age
Clinical presentation is variable but typically presents in one of three patterns (initially described as separate entities)
Shy-Drager syndrome is used when autonomic symptoms predominate
striatonigral degeneration shows predominant parkinsonian features
olivopontocerebellar atrophy demonstrates primarily cerebellar dysfunction
MSA has been divided clinically into 2 forms according to the dominant non-autonomic symptoms
MSA-C predominance of cerebellar symptoms (olivopontocerebellar atrophy)
MSA-P predominance of parkinsonian signs and symptoms (striatonigraldegeneration)
RADIOGRAPHIC FEATURES
bullT2 hyperintensities typically present in the pontocerebellar tractsbull pons hot cross bun sign (MSA-C)
bull middle cerebellar peduncles
bull Cerebellum
putaminal findings in MSA-P reduced volume
reduced GRE and T2 signal relative to globus pallidus
reduced GRE and T2 signal relative to red nucleus
abnormal disruption of the normal high T2 linear rim
bullMSA-Cbull disproportionate atrophy of the cerebellum and brainstem (especially olivary nuclei and middle
cerebellar peduncle)
NUCLEAR MEDICINE
SPECT and PET studies tend to demonstrate hypometabolism in the superior parietal and superior frontal areas in the basal ganglia
HUNTINGTON DISEASE
autosomal dominant neurodegenerative disease
a loss of GABAergic neurons of the basal ganglia
especially atrophy of the caudate nucleus and putamen
Huntington disease has a prevalence of 5-10 per 100000 and is typically diagnosed between 30 and 50 years of age
In approximately 1-6 symptoms occur before the age of 20 so-called juvenile form
Presentation is typically with progressive rigidity choreoathetosis dementia psychosis and emotional lability
The juvenile form has a different presentation with cerebellar symptoms rigidity and hypokinesia being prominent
it is a autosomal dominant with complete penetrance and genetic anticipation particularly if inherited mutated allele is paternal
The mutation responsible is on chromosome 4p163 and consists of a CAG trineucleotide repeat
The usual 10-30 copies are amplified to greater than 36 and the greater the number of repeats the earlier the age of onset
RADIOGRAPHIC FEATURES
MRI
The most striking and best known feature is that of caudate head atrophy resulting in enlargement of the frontal horns often giving them a box like configuration
This can be quantified by an number of measurements
bullfrontal horn width to intercaudate distance ratio (FHCC)
bullintercaudate distance to inner table width ratio (CCIT)
Juvenile form
putamen are also atrophied and demonstrate increased T2 signal
basal ganglia may show decrease T2 signal and blooming on SWI in keeping with iron deposition
Generalised age inappropriate cortical volume loss is also recognised
FHCC ratio normal mean 22 to 26 (this ratio decreases with ageing as a result of enlargement of the frontal horns of the lateral ventricles)
CCIT ratio normal mean 009 to 012
AMYOTROPHIC LATERAL SCLEROSISalso known as Lou Gehrig disease or Charcot disease
Primary degeneration of the motor neurons within the brain brain stem and spinal cord
Patients typically present with progressive muscle weakness and limb and truncal atrophy combined with signs of spasticity
Mean age at the time of diagnosis is 55 years
RADIOGRAPHIC FEATURES
MRI
The earliest MR manifestation is hyperintensity on T2WI in the corticospinal tracts seen earliest in the internal capsule
Iron deposition in the cortex is demonstrated as loss of signal most evident on T2 weighted sequences
IS IT ATROPHY OR HYDROCEPHALUS
Abnormal accumulation of CSF in Ventricular system
Results from Structural or functional block to normal flow Of CSF
In effect all are obhstructive
Difficult to differentiate Atrophy from Hydrocephalus gt60yrs
Initially show increased ICT
Later stages may reach Equillibrium and Becomes NP hYdrocephalus
Types
Obstructive
Communicating
NPH ndash seen typically in old patients Diagnosis is more based on clinical feature
Dementia urinary incontinence and gait apraxias + Hydrocephalus = NPH
Radiologically w
1 degeree of ventricular dilatation is more with Thinning and bowing of CC
2 Sulcal effacement is invariable seen Hydrocephalus
3 dilatation or rounding of the Temporal Horns
4 Rounding and enlargement of the frontal horns
5 Enlargement and ballooning of 3rd
ventricle
6 Enlargement of fourth ventricle
SPOTTERS
THANK YOU
B Sagittal
medial surfaces of the frontal parietal and occipital lobes
all the sulci should be about the same size
Significant parietal sulcal widening with atrophy of the precuneus and posterior cingulate suggests Alzheimers disease (AD)
anterior to posterior gradient of sulcalsize (bigger anteriorly) seen in frontotemporal lobar degeneration
mamillary bodies
should be about the same size Atrophic or asymmetrical mammillary bodies may imply hippocampal pathology or Wernicke-Korsakoff syndrome
upper cervical spine and cord
Axial FLAIR amp T2
bullgyral atrophy particularly useful for the frontal lobes
bullwidening of the sylvian fissures
bullhippocampal volume and signal
bullposterior fossa morphology
bullMidbrain
bullPons
bullMedulla
bullCerebellum
bullWernicke pattern high T2 signal (ventromedial thalamus mammillary bodies periaqueductal grey matter)
bullCortical white matter changes
T2 axial imaging is often better for basal ganglia structures and posterior fossa Assess for
reversal of normal T2 signal of putamen vs globus pallidus of MSA-P
atrophic caudate heads of Huntingtons disease
size and flow void in aqueduct (usually prominent in NPH)
3 Coronal sequences
bullhippocampal choroidal fissure and temporal horn size
bullsymmetrybull left gt right atrophy favours FTLD
bull equal involvement favours Alzheimers disease
bullanterior to posterior gradientbull anterior atrophy gt posterior atrophy favours FTLD
bullinvolvement of the temporal lobe generally favours FTLD
bullatrophy largely restricted to the hippocampus and parahippocampalgyrus favours Alzheimers disease
bullmammillary body size signal and symmetry
4 T2 sequences
Sequences susceptible to blood products are particularly useful in assessing
bullmicrohaemorrhages
bull peripherally distributed in cerebral amyloid angiopathy which in turn is associate with Alzheimers disease
bullcentrally distributed (basal ganglia pons cerebellum) in chronic hypertensive encephalophathy
5 DWI
DWI has a limited role in the assessment of a patient with a suspected neurodegenerative disease
Crucial particularly for Creutzfeldt-Jakob disease look for cortical basal ganglia and thalamic restricted diffusion
SCORING SYSTEMS AND MEASUREMENTS
bullFazekas scale for white matter lesions the deep white matter component is used in assessing the amount of chronic small vessel ischaemic change
bullposterior atrophy score of parietal atrophy (PA or PCA or Koedam score) useful in atypical (posterior cortical atrophy) or early onset Alzheimers disease
bullmedial temporal lobe atrophy score (MTA score)
bullglobal cortical atrophy scale (GCA scale)
A number of measurements ratios are also useful
midbrain to pons area ratio (for PSP)
magnetic resonance parkinsonism index (MRPI) (for PSP)
ALZHEIMER DISEASE
Alzheimer disease (AD) is a common neurodegenerative disease responsible for the majority of all dementias and imposing a significant burden on developed nations
Most common cause of dementia and accounts for two thirds of cases of dementia in patients aged 60-70 years
Epidemiological risk factor advanced age female gender
apolipoprotein E (APOE) ε4 allele carrier status
current smoking
family history of dementia
Classicaltypical Alzheimer disease
with antegrade episodic memory deficits
Neuropsychiatric symptoms are also common and eventually affect almost all patients These include apathy depression anxiety aggressionagitation and psychosis
Atypicalvariant Alzheimer disease
These entities often recognised clinically well before they were identified to be pathologically identical to Alzheimer disease
slowly progressive focal cortical atrophy with symptoms and signs matched to the affected area
Examples include
posterior cortical atrophy
frontal variant of Alzheimer disease
a minority of cases of semantic dementia
Pathology
Alzheimer disease is characterised by the accumulation of senile (neuritic) plaques neuritic (neurofibrillary) tangles and progressive loss of neurons
The progression of pathology initially involves the transentorhinalregion and then spreads to the hippocampal complex and mesial temporal lobe structures and eventually the temporal lobes and basal forebrain
RADIOGRAPHIC FEATURES
The primary role of MRI (and CT) in the diagnosis of Alzheimer disease is the assessment of volume change in characteristic locations which can yield a diagnostic accuracy of up to 87
The diagnosis should be made on the basis of two features
mesial temporal lobe atrophy
temporoparietal cortical atrophy
MESIAL TEMPORAL LOBE ATROPHY
hippocampal and parahippocampal decrease in volume
Indirectly by examining enlargement of the parahippocampalfissures
The former is more sensitive and specific but ideally requires actual volumetric calculations rather than eye-balling the scan
These measures have been combined in the medial temporal atrophy score which has been shown to be predictive of progression from mild cognitive impairment (MCI) to dementiA
MEDIAL TEMPORAL LOBE ATROPHY SCORE
visual score performed on MRI of the brain using coronal T1 weighted images through the hippocampus at the level of the anterior pons and assesses three features
width of the choroid fissure
width of the temporal horn of the lateral ventricle
height of the hippocampus
These result in a score of 0 to 4
0 = no CSF is visible around the hippocampus
1 = choroid fissure is slightly widened
2 = moderate widening of the choroid fissure mild enlargement of the temporal horn and mild loss of hippocampal height
3 = marked widening of the choroid fissure moderate enlargement of the temporal horn and moderate loss of hippocampal height
4 = marked widening of the choroid fissure marked enlargement of the temporal horn and the hippocampus is markedly atrophied and internal structure is lost
In a patient younger than 75 years of age a score of 2 or more is abnormal
In a patient 75 years or older a score of 3 or more is abnormal
Atrophy has been shown to correlate with likelihood of progression from mild cognitive impairment (MCI) to dementia 4
MRI SPECTROSCOPY
increases in myoinositol (MI) (356 ppm) thought to reflect inhibition of enzyme(s) mediating conversion of MI to phosphatidyl inositol
decreased N-acetyl aspartate (NAA) (202 ppm) indicating decreased neuronal activity
TEMPOROPARIETAL CORTICAL ATROPHY Parietal atrophy particularly relevant to posterior cortical atrophy or early onset Alzheimer disease
the inter-hemispheric surface of the parietal lobe
TREATMENT AND PROGNOSIS
There is no cure for this disease some drugs have been developed trying to improve symptoms or at least temporarily slow down their progression
cholinsterase inhibitors
partial NMDA receptor antagonists
medications for behavioural symptoms
antidepressants
anxiolytics
antiparkinsonian (movement symptoms)
anticonvulsantssedatives (behavioural)
VASCULAR DEMENTIAalso known as vascular cognitive impairment
It is primarily seen in patients with atherosclerosis and chronic hypertension
Results from the accumulation of multiple white matter or cortical infarcts although cerebral haemorrhages can be variably included
strongly correlated with age seen in only 1 of patients over the age of 55 years of age but in over 4 of patients over 71 years of age
It is also possible to divide vascular dementia into subtypes
small vessel dementia (aka Binswanger disease)
cortical vascular dementia roughly equivalent to multi-infarct dementia
strategic infarct dementia
thalamic dementia
RADIOGRAPHIC FEATURES
Both CT and MRI are able to provide evidence of ischaemic damage
MRI is more sensitive especially to white matter small vessel ischaemic change as well as to microhaemorrhages seen in cerebral amyloid angiopathy and chronic hypertensive encephalopathy
bullsmall vessel dementia (aka Binswanger disease)
bullcerebral infarction
bulllacunar infarction
bullintracerebral haemorrhage
CEREBRAL AMYLOID ANGIOPATHY
SMALL VESSEL DEMENTIA
also known as Binswanger disease
Subcortical arteriosclerotic encephalopathy
refers to slowly progressive exclusively white-matter multi-infarct dementia
A genetically transmitted form of the disease is known as familial arteriopathic leukoencephalopathy
or
CADASIL (cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy)
CLINICAL CRITERIA FOR DIAGNOSIS
marked subcortical microangiopathic lesions at MR imaging
a negative family history for strokes early cognitive impairment or psychiatric disorders in first- and second-degree relatives
documented arterial hypertension systolic values higher than 160 mm Hg diastolic values higher than 95 mm Hg or both measured at several occasions 5
MRI
subcortical and periventricular lesions visible on T2 FLAIR T2-weighted and proton-density sequences
commonly grouped around the frontal and occipital horns and in the centrum semi ovale
Moderate generalised cerebral atrophy is invariably present and lacunar infarctsin the basal ganglia and
thalami are common
CT
Diffuse incompletely symmetrical hypodensities are present in deep white matter especially they are prominent in the frontal lobes and the centrum semiovale
CEREBRAL AUTOSOMAL DOMINANT ARTERIOPATHY WITH SUBCORTICAL INFARCTS AND LEUKOENCEPHALOPATHY (CADASIL)
occurs in the absence of hypertension and arteriosclerosis and presents in 71 of cases before the age of 60 years
Imaging features demonstrate severe microvascular changes with multiple subcortical infarcts
Not distinguishable from hypertensive type microvascular disease
DEMENTIA WITH LEWY BODIESPD
Neurodegenerative disease (a synucleinopathy to be specific) related to Parkinsons disease (PD)
Epidemiology
Dementia with Lewy bodies presents in older patients (onset typically in 50-70 years of age) and is sporadic
It is the second most common neurodegenerative cause of dementia in older patients after Alzheimers disease accounting for 15-20 of case
RADIOGRAPHIC FEATURES
MRI
Atrophy in various parts of the brain without a clearly identified unique pattern
Most helpful in distinguishing DLB from other entities resulting in dementia is the absence of features of other diseases
generalised decrease in cerebral volume most marked in
frontal lobes parietotemporal regions
enlargement of the lateral ventricles
relatively focal atrophy
midbrain
hypothalamus
SWALLOW TAIL SIGN
The swallow tail sign describes the normal axial imaging appearance of nigrosome-1 within the substantianigra on high resolution T2SWI weighted MRI
Absence of the sign (absent swallow tail sign) is reported to have a diagnostic accuracy of greater than 90 for Parkinson disease
Nuclear medicine
Occipital hypoperfusion on SPECT PET
May aid in differentiation from other types of dementia especially Alzheimers disease
TREATMENT AND PROGNOSIS
Unlike Parkinsons disease dementia with Lewy bodies respond less readily to L-dopa and also may have severe sensitivity reactions to neuroleptic drugs such as rigidity reduced consciousness pyrexia falling postural hypotension and collapse
Lewy body dementia also responds favourably to acetylcholinesteraseinhibitors
DIFFERENTIAL DIAGNOSISwith strong overlap between
bullAlzheimers diseasebull clinical may occasionally have similar clinical presentation with a frontal type dementia or posterior
cortical atrophy
bull imaging prominent involvement of hippocampi on imaging
bullFronto-temporal lobar degenerationbull clinical usually younger onset absent parkinsonian features absent visual hallucinations
bull imaging more pronounced frontal temporal atrophy L gt R asymmetry
FRONTO-TEMPORAL LOBAR DEGENERATION
Frontotemporal lobar degeneration (FTLD) is the pathological description of a group of neurodegenerative disorders characterised by focal atrophy of the frontal and temporal cortices
rontotemporal lobar degeneration can be divided as follows 3-4
bullbehavioural variant fronto-temporal lobar degeneration dementia (bvFTLD) (aka behavioural variant frontotemporal dementia)1
bulllanguage variant fronto-temporal lobar degeneration (lvFTLD) (aka primary progressive aphasia (PPA)6
bull agrammatic variant primary progressive aphasia (aka progressive non-fluent aphasia (PNFA)
bull semantic variant primary progressive aphasia (aka semantic dementia)
bull logopaenic variant primary progressive aphasia
RADIOGRAPHIC FEATURES
The frontal and temporal lobes are predominantly affected there is often striking asymmetry both of involvement of frontal vs temporal lobes and involvement of left and right hemispheres
In addition the degree of fronto-striatal dysfunction varies between the different FTLD subgroups with behavioural variant frontotemporal dementia (bvFTD) having the greatest involvement
As a result the caudate heads tend to be reduced in size in these patients to a much greater degree than in the language variants of frontotemporal dementia
BEHAVIOURAL VARIANT FRONTO-TEMPORAL LOBAR DEGENERATION (BVFTLD)also referred to as Pick disease
Patients with behavioural variant FTD typically present with a dysexecutive cognitive syndrome associated with changes in personality and social behaviour
As the disease progresses impairments in language and memory may develop and the cognitive phenotype may come to resemble one of the language variants of FTD
RADIOGRAPHIC FEATURES
MRI
typical radiographic finding is atrophy of the frontal lobes and to a lesser extent the temporal lobes
The degree of atrophy can be very asymmetric
Decrease in volume of the caudate heads This indicates loss of both efferent and afferent fibres
CREUTZFELDT-JAKOB DISEASEspongiform encephalopathy
Results in a rapidly progressive dementia
other non-specific neurological features
Three types of Creutzfeldt-Jakob disease have been described
bullsporadic (sCJD) accounts for 85-90 of cases
bullvariant (vCJD)
bullfamilial (fCJD) 10 of cases (these individuals carry a PRPc mutation)
Creutzfeldt-Jakob disease is characterized by rapidly progressive dementia cerebral atrophy myoclonus and death
Patients with vCJD present mostly with sensory and psychiatric symptoms
Patients with sCJD usually present with progressive cognitive impairment and cerebellar symptoms
PATHOLOGY
mediated via (infectious) prions
a type of protein which manifest in sheep as the disease scrapie and in cows as bovine spongiform encephalopathy
Prions are considered infectious in sense that they can alter the structure of neighbouring proteins
CJD leads to spongiform degeneration of the brain
the conversion of normal prion protein to proteinaceous infectious particles that accumulate in and around neurons and lead to cell death
RADIOGRAPHIC FEATURES
MRI
MRI findings may be bilateral or unilateral and symmetric or asymmetric and include
T2 hyperintensity
obasal ganglia (putamen and caudate)
othalamus ( hockey stick sign and pulvinar sign)
ocortex most common early manifestation
owhite matter
persistent restricted diffusion on DWI (considered the most sensitive sign)
Review of sequential studies also typically demonstrates rapidly progressive cerebral atrophy
hypometabolism on 18FDG-PET studies
TREATMENT AND PROGNOSIS
here is currently no curative treatment and the disease is invariably fatal with a mean survival of only 7 months for most cases
PROGRESSIVE SUPRANUCLEARPALSYlso known as the Steele-Richardson-Olszewski syndrome
Progressive supranuclear palsy typically becomes clinically apparent in the 6th decade of life
Progresses to death usually within a decade (2-17 years from diagnosis)
Progressive supranuclear palsy is characterised
decreased cognition
abnormal eye movements (supranuclear vertical gaze palsy)
postural instability and falls
as well as parkinsonian features and speech disturbances
RADIOGRAPHIC FEATURESMRI
midbrain atrophy
reduction of anteroposterior midline midbrain diameter at the level of the superior colliculi on axial imaging (from interpeduncular fossa to the intercolicular groove lt12mm 8) which can give a mickey mouse appearance
reduced area of the midbrain on midline sagittal and reduced midbrain to pons area ratio approx 012 (normal approx 024) on midline sagittal
Loss of the lateral convex margin of the tegmentum of midbrain has been described as the morning glory sign
hummingbird sign also known as the penguin sign The key is a flattening or concave outline to the superior aspect of the midbrain which should be upwardly convex
bullT2 diffuse high-signal lesions in
bull pontine tegmentum
bull tectum of the midbrain
bull inferior olivary nucleus
MICKEY MOUSE APPEARANCE
THE PENGUIN SIGN
MULTIPLE SYSTEM ATROPHY
sporadic neurodegenerative disease
Typically symptoms begin between 40 and 60 years of age
Clinical presentation is variable but typically presents in one of three patterns (initially described as separate entities)
Shy-Drager syndrome is used when autonomic symptoms predominate
striatonigral degeneration shows predominant parkinsonian features
olivopontocerebellar atrophy demonstrates primarily cerebellar dysfunction
MSA has been divided clinically into 2 forms according to the dominant non-autonomic symptoms
MSA-C predominance of cerebellar symptoms (olivopontocerebellar atrophy)
MSA-P predominance of parkinsonian signs and symptoms (striatonigraldegeneration)
RADIOGRAPHIC FEATURES
bullT2 hyperintensities typically present in the pontocerebellar tractsbull pons hot cross bun sign (MSA-C)
bull middle cerebellar peduncles
bull Cerebellum
putaminal findings in MSA-P reduced volume
reduced GRE and T2 signal relative to globus pallidus
reduced GRE and T2 signal relative to red nucleus
abnormal disruption of the normal high T2 linear rim
bullMSA-Cbull disproportionate atrophy of the cerebellum and brainstem (especially olivary nuclei and middle
cerebellar peduncle)
NUCLEAR MEDICINE
SPECT and PET studies tend to demonstrate hypometabolism in the superior parietal and superior frontal areas in the basal ganglia
HUNTINGTON DISEASE
autosomal dominant neurodegenerative disease
a loss of GABAergic neurons of the basal ganglia
especially atrophy of the caudate nucleus and putamen
Huntington disease has a prevalence of 5-10 per 100000 and is typically diagnosed between 30 and 50 years of age
In approximately 1-6 symptoms occur before the age of 20 so-called juvenile form
Presentation is typically with progressive rigidity choreoathetosis dementia psychosis and emotional lability
The juvenile form has a different presentation with cerebellar symptoms rigidity and hypokinesia being prominent
it is a autosomal dominant with complete penetrance and genetic anticipation particularly if inherited mutated allele is paternal
The mutation responsible is on chromosome 4p163 and consists of a CAG trineucleotide repeat
The usual 10-30 copies are amplified to greater than 36 and the greater the number of repeats the earlier the age of onset
RADIOGRAPHIC FEATURES
MRI
The most striking and best known feature is that of caudate head atrophy resulting in enlargement of the frontal horns often giving them a box like configuration
This can be quantified by an number of measurements
bullfrontal horn width to intercaudate distance ratio (FHCC)
bullintercaudate distance to inner table width ratio (CCIT)
Juvenile form
putamen are also atrophied and demonstrate increased T2 signal
basal ganglia may show decrease T2 signal and blooming on SWI in keeping with iron deposition
Generalised age inappropriate cortical volume loss is also recognised
FHCC ratio normal mean 22 to 26 (this ratio decreases with ageing as a result of enlargement of the frontal horns of the lateral ventricles)
CCIT ratio normal mean 009 to 012
AMYOTROPHIC LATERAL SCLEROSISalso known as Lou Gehrig disease or Charcot disease
Primary degeneration of the motor neurons within the brain brain stem and spinal cord
Patients typically present with progressive muscle weakness and limb and truncal atrophy combined with signs of spasticity
Mean age at the time of diagnosis is 55 years
RADIOGRAPHIC FEATURES
MRI
The earliest MR manifestation is hyperintensity on T2WI in the corticospinal tracts seen earliest in the internal capsule
Iron deposition in the cortex is demonstrated as loss of signal most evident on T2 weighted sequences
IS IT ATROPHY OR HYDROCEPHALUS
Abnormal accumulation of CSF in Ventricular system
Results from Structural or functional block to normal flow Of CSF
In effect all are obhstructive
Difficult to differentiate Atrophy from Hydrocephalus gt60yrs
Initially show increased ICT
Later stages may reach Equillibrium and Becomes NP hYdrocephalus
Types
Obstructive
Communicating
NPH ndash seen typically in old patients Diagnosis is more based on clinical feature
Dementia urinary incontinence and gait apraxias + Hydrocephalus = NPH
Radiologically w
1 degeree of ventricular dilatation is more with Thinning and bowing of CC
2 Sulcal effacement is invariable seen Hydrocephalus
3 dilatation or rounding of the Temporal Horns
4 Rounding and enlargement of the frontal horns
5 Enlargement and ballooning of 3rd
ventricle
6 Enlargement of fourth ventricle
SPOTTERS
THANK YOU
Axial FLAIR amp T2
bullgyral atrophy particularly useful for the frontal lobes
bullwidening of the sylvian fissures
bullhippocampal volume and signal
bullposterior fossa morphology
bullMidbrain
bullPons
bullMedulla
bullCerebellum
bullWernicke pattern high T2 signal (ventromedial thalamus mammillary bodies periaqueductal grey matter)
bullCortical white matter changes
T2 axial imaging is often better for basal ganglia structures and posterior fossa Assess for
reversal of normal T2 signal of putamen vs globus pallidus of MSA-P
atrophic caudate heads of Huntingtons disease
size and flow void in aqueduct (usually prominent in NPH)
3 Coronal sequences
bullhippocampal choroidal fissure and temporal horn size
bullsymmetrybull left gt right atrophy favours FTLD
bull equal involvement favours Alzheimers disease
bullanterior to posterior gradientbull anterior atrophy gt posterior atrophy favours FTLD
bullinvolvement of the temporal lobe generally favours FTLD
bullatrophy largely restricted to the hippocampus and parahippocampalgyrus favours Alzheimers disease
bullmammillary body size signal and symmetry
4 T2 sequences
Sequences susceptible to blood products are particularly useful in assessing
bullmicrohaemorrhages
bull peripherally distributed in cerebral amyloid angiopathy which in turn is associate with Alzheimers disease
bullcentrally distributed (basal ganglia pons cerebellum) in chronic hypertensive encephalophathy
5 DWI
DWI has a limited role in the assessment of a patient with a suspected neurodegenerative disease
Crucial particularly for Creutzfeldt-Jakob disease look for cortical basal ganglia and thalamic restricted diffusion
SCORING SYSTEMS AND MEASUREMENTS
bullFazekas scale for white matter lesions the deep white matter component is used in assessing the amount of chronic small vessel ischaemic change
bullposterior atrophy score of parietal atrophy (PA or PCA or Koedam score) useful in atypical (posterior cortical atrophy) or early onset Alzheimers disease
bullmedial temporal lobe atrophy score (MTA score)
bullglobal cortical atrophy scale (GCA scale)
A number of measurements ratios are also useful
midbrain to pons area ratio (for PSP)
magnetic resonance parkinsonism index (MRPI) (for PSP)
ALZHEIMER DISEASE
Alzheimer disease (AD) is a common neurodegenerative disease responsible for the majority of all dementias and imposing a significant burden on developed nations
Most common cause of dementia and accounts for two thirds of cases of dementia in patients aged 60-70 years
Epidemiological risk factor advanced age female gender
apolipoprotein E (APOE) ε4 allele carrier status
current smoking
family history of dementia
Classicaltypical Alzheimer disease
with antegrade episodic memory deficits
Neuropsychiatric symptoms are also common and eventually affect almost all patients These include apathy depression anxiety aggressionagitation and psychosis
Atypicalvariant Alzheimer disease
These entities often recognised clinically well before they were identified to be pathologically identical to Alzheimer disease
slowly progressive focal cortical atrophy with symptoms and signs matched to the affected area
Examples include
posterior cortical atrophy
frontal variant of Alzheimer disease
a minority of cases of semantic dementia
Pathology
Alzheimer disease is characterised by the accumulation of senile (neuritic) plaques neuritic (neurofibrillary) tangles and progressive loss of neurons
The progression of pathology initially involves the transentorhinalregion and then spreads to the hippocampal complex and mesial temporal lobe structures and eventually the temporal lobes and basal forebrain
RADIOGRAPHIC FEATURES
The primary role of MRI (and CT) in the diagnosis of Alzheimer disease is the assessment of volume change in characteristic locations which can yield a diagnostic accuracy of up to 87
The diagnosis should be made on the basis of two features
mesial temporal lobe atrophy
temporoparietal cortical atrophy
MESIAL TEMPORAL LOBE ATROPHY
hippocampal and parahippocampal decrease in volume
Indirectly by examining enlargement of the parahippocampalfissures
The former is more sensitive and specific but ideally requires actual volumetric calculations rather than eye-balling the scan
These measures have been combined in the medial temporal atrophy score which has been shown to be predictive of progression from mild cognitive impairment (MCI) to dementiA
MEDIAL TEMPORAL LOBE ATROPHY SCORE
visual score performed on MRI of the brain using coronal T1 weighted images through the hippocampus at the level of the anterior pons and assesses three features
width of the choroid fissure
width of the temporal horn of the lateral ventricle
height of the hippocampus
These result in a score of 0 to 4
0 = no CSF is visible around the hippocampus
1 = choroid fissure is slightly widened
2 = moderate widening of the choroid fissure mild enlargement of the temporal horn and mild loss of hippocampal height
3 = marked widening of the choroid fissure moderate enlargement of the temporal horn and moderate loss of hippocampal height
4 = marked widening of the choroid fissure marked enlargement of the temporal horn and the hippocampus is markedly atrophied and internal structure is lost
In a patient younger than 75 years of age a score of 2 or more is abnormal
In a patient 75 years or older a score of 3 or more is abnormal
Atrophy has been shown to correlate with likelihood of progression from mild cognitive impairment (MCI) to dementia 4
MRI SPECTROSCOPY
increases in myoinositol (MI) (356 ppm) thought to reflect inhibition of enzyme(s) mediating conversion of MI to phosphatidyl inositol
decreased N-acetyl aspartate (NAA) (202 ppm) indicating decreased neuronal activity
TEMPOROPARIETAL CORTICAL ATROPHY Parietal atrophy particularly relevant to posterior cortical atrophy or early onset Alzheimer disease
the inter-hemispheric surface of the parietal lobe
TREATMENT AND PROGNOSIS
There is no cure for this disease some drugs have been developed trying to improve symptoms or at least temporarily slow down their progression
cholinsterase inhibitors
partial NMDA receptor antagonists
medications for behavioural symptoms
antidepressants
anxiolytics
antiparkinsonian (movement symptoms)
anticonvulsantssedatives (behavioural)
VASCULAR DEMENTIAalso known as vascular cognitive impairment
It is primarily seen in patients with atherosclerosis and chronic hypertension
Results from the accumulation of multiple white matter or cortical infarcts although cerebral haemorrhages can be variably included
strongly correlated with age seen in only 1 of patients over the age of 55 years of age but in over 4 of patients over 71 years of age
It is also possible to divide vascular dementia into subtypes
small vessel dementia (aka Binswanger disease)
cortical vascular dementia roughly equivalent to multi-infarct dementia
strategic infarct dementia
thalamic dementia
RADIOGRAPHIC FEATURES
Both CT and MRI are able to provide evidence of ischaemic damage
MRI is more sensitive especially to white matter small vessel ischaemic change as well as to microhaemorrhages seen in cerebral amyloid angiopathy and chronic hypertensive encephalopathy
bullsmall vessel dementia (aka Binswanger disease)
bullcerebral infarction
bulllacunar infarction
bullintracerebral haemorrhage
CEREBRAL AMYLOID ANGIOPATHY
SMALL VESSEL DEMENTIA
also known as Binswanger disease
Subcortical arteriosclerotic encephalopathy
refers to slowly progressive exclusively white-matter multi-infarct dementia
A genetically transmitted form of the disease is known as familial arteriopathic leukoencephalopathy
or
CADASIL (cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy)
CLINICAL CRITERIA FOR DIAGNOSIS
marked subcortical microangiopathic lesions at MR imaging
a negative family history for strokes early cognitive impairment or psychiatric disorders in first- and second-degree relatives
documented arterial hypertension systolic values higher than 160 mm Hg diastolic values higher than 95 mm Hg or both measured at several occasions 5
MRI
subcortical and periventricular lesions visible on T2 FLAIR T2-weighted and proton-density sequences
commonly grouped around the frontal and occipital horns and in the centrum semi ovale
Moderate generalised cerebral atrophy is invariably present and lacunar infarctsin the basal ganglia and
thalami are common
CT
Diffuse incompletely symmetrical hypodensities are present in deep white matter especially they are prominent in the frontal lobes and the centrum semiovale
CEREBRAL AUTOSOMAL DOMINANT ARTERIOPATHY WITH SUBCORTICAL INFARCTS AND LEUKOENCEPHALOPATHY (CADASIL)
occurs in the absence of hypertension and arteriosclerosis and presents in 71 of cases before the age of 60 years
Imaging features demonstrate severe microvascular changes with multiple subcortical infarcts
Not distinguishable from hypertensive type microvascular disease
DEMENTIA WITH LEWY BODIESPD
Neurodegenerative disease (a synucleinopathy to be specific) related to Parkinsons disease (PD)
Epidemiology
Dementia with Lewy bodies presents in older patients (onset typically in 50-70 years of age) and is sporadic
It is the second most common neurodegenerative cause of dementia in older patients after Alzheimers disease accounting for 15-20 of case
RADIOGRAPHIC FEATURES
MRI
Atrophy in various parts of the brain without a clearly identified unique pattern
Most helpful in distinguishing DLB from other entities resulting in dementia is the absence of features of other diseases
generalised decrease in cerebral volume most marked in
frontal lobes parietotemporal regions
enlargement of the lateral ventricles
relatively focal atrophy
midbrain
hypothalamus
SWALLOW TAIL SIGN
The swallow tail sign describes the normal axial imaging appearance of nigrosome-1 within the substantianigra on high resolution T2SWI weighted MRI
Absence of the sign (absent swallow tail sign) is reported to have a diagnostic accuracy of greater than 90 for Parkinson disease
Nuclear medicine
Occipital hypoperfusion on SPECT PET
May aid in differentiation from other types of dementia especially Alzheimers disease
TREATMENT AND PROGNOSIS
Unlike Parkinsons disease dementia with Lewy bodies respond less readily to L-dopa and also may have severe sensitivity reactions to neuroleptic drugs such as rigidity reduced consciousness pyrexia falling postural hypotension and collapse
Lewy body dementia also responds favourably to acetylcholinesteraseinhibitors
DIFFERENTIAL DIAGNOSISwith strong overlap between
bullAlzheimers diseasebull clinical may occasionally have similar clinical presentation with a frontal type dementia or posterior
cortical atrophy
bull imaging prominent involvement of hippocampi on imaging
bullFronto-temporal lobar degenerationbull clinical usually younger onset absent parkinsonian features absent visual hallucinations
bull imaging more pronounced frontal temporal atrophy L gt R asymmetry
FRONTO-TEMPORAL LOBAR DEGENERATION
Frontotemporal lobar degeneration (FTLD) is the pathological description of a group of neurodegenerative disorders characterised by focal atrophy of the frontal and temporal cortices
rontotemporal lobar degeneration can be divided as follows 3-4
bullbehavioural variant fronto-temporal lobar degeneration dementia (bvFTLD) (aka behavioural variant frontotemporal dementia)1
bulllanguage variant fronto-temporal lobar degeneration (lvFTLD) (aka primary progressive aphasia (PPA)6
bull agrammatic variant primary progressive aphasia (aka progressive non-fluent aphasia (PNFA)
bull semantic variant primary progressive aphasia (aka semantic dementia)
bull logopaenic variant primary progressive aphasia
RADIOGRAPHIC FEATURES
The frontal and temporal lobes are predominantly affected there is often striking asymmetry both of involvement of frontal vs temporal lobes and involvement of left and right hemispheres
In addition the degree of fronto-striatal dysfunction varies between the different FTLD subgroups with behavioural variant frontotemporal dementia (bvFTD) having the greatest involvement
As a result the caudate heads tend to be reduced in size in these patients to a much greater degree than in the language variants of frontotemporal dementia
BEHAVIOURAL VARIANT FRONTO-TEMPORAL LOBAR DEGENERATION (BVFTLD)also referred to as Pick disease
Patients with behavioural variant FTD typically present with a dysexecutive cognitive syndrome associated with changes in personality and social behaviour
As the disease progresses impairments in language and memory may develop and the cognitive phenotype may come to resemble one of the language variants of FTD
RADIOGRAPHIC FEATURES
MRI
typical radiographic finding is atrophy of the frontal lobes and to a lesser extent the temporal lobes
The degree of atrophy can be very asymmetric
Decrease in volume of the caudate heads This indicates loss of both efferent and afferent fibres
CREUTZFELDT-JAKOB DISEASEspongiform encephalopathy
Results in a rapidly progressive dementia
other non-specific neurological features
Three types of Creutzfeldt-Jakob disease have been described
bullsporadic (sCJD) accounts for 85-90 of cases
bullvariant (vCJD)
bullfamilial (fCJD) 10 of cases (these individuals carry a PRPc mutation)
Creutzfeldt-Jakob disease is characterized by rapidly progressive dementia cerebral atrophy myoclonus and death
Patients with vCJD present mostly with sensory and psychiatric symptoms
Patients with sCJD usually present with progressive cognitive impairment and cerebellar symptoms
PATHOLOGY
mediated via (infectious) prions
a type of protein which manifest in sheep as the disease scrapie and in cows as bovine spongiform encephalopathy
Prions are considered infectious in sense that they can alter the structure of neighbouring proteins
CJD leads to spongiform degeneration of the brain
the conversion of normal prion protein to proteinaceous infectious particles that accumulate in and around neurons and lead to cell death
RADIOGRAPHIC FEATURES
MRI
MRI findings may be bilateral or unilateral and symmetric or asymmetric and include
T2 hyperintensity
obasal ganglia (putamen and caudate)
othalamus ( hockey stick sign and pulvinar sign)
ocortex most common early manifestation
owhite matter
persistent restricted diffusion on DWI (considered the most sensitive sign)
Review of sequential studies also typically demonstrates rapidly progressive cerebral atrophy
hypometabolism on 18FDG-PET studies
TREATMENT AND PROGNOSIS
here is currently no curative treatment and the disease is invariably fatal with a mean survival of only 7 months for most cases
PROGRESSIVE SUPRANUCLEARPALSYlso known as the Steele-Richardson-Olszewski syndrome
Progressive supranuclear palsy typically becomes clinically apparent in the 6th decade of life
Progresses to death usually within a decade (2-17 years from diagnosis)
Progressive supranuclear palsy is characterised
decreased cognition
abnormal eye movements (supranuclear vertical gaze palsy)
postural instability and falls
as well as parkinsonian features and speech disturbances
RADIOGRAPHIC FEATURESMRI
midbrain atrophy
reduction of anteroposterior midline midbrain diameter at the level of the superior colliculi on axial imaging (from interpeduncular fossa to the intercolicular groove lt12mm 8) which can give a mickey mouse appearance
reduced area of the midbrain on midline sagittal and reduced midbrain to pons area ratio approx 012 (normal approx 024) on midline sagittal
Loss of the lateral convex margin of the tegmentum of midbrain has been described as the morning glory sign
hummingbird sign also known as the penguin sign The key is a flattening or concave outline to the superior aspect of the midbrain which should be upwardly convex
bullT2 diffuse high-signal lesions in
bull pontine tegmentum
bull tectum of the midbrain
bull inferior olivary nucleus
MICKEY MOUSE APPEARANCE
THE PENGUIN SIGN
MULTIPLE SYSTEM ATROPHY
sporadic neurodegenerative disease
Typically symptoms begin between 40 and 60 years of age
Clinical presentation is variable but typically presents in one of three patterns (initially described as separate entities)
Shy-Drager syndrome is used when autonomic symptoms predominate
striatonigral degeneration shows predominant parkinsonian features
olivopontocerebellar atrophy demonstrates primarily cerebellar dysfunction
MSA has been divided clinically into 2 forms according to the dominant non-autonomic symptoms
MSA-C predominance of cerebellar symptoms (olivopontocerebellar atrophy)
MSA-P predominance of parkinsonian signs and symptoms (striatonigraldegeneration)
RADIOGRAPHIC FEATURES
bullT2 hyperintensities typically present in the pontocerebellar tractsbull pons hot cross bun sign (MSA-C)
bull middle cerebellar peduncles
bull Cerebellum
putaminal findings in MSA-P reduced volume
reduced GRE and T2 signal relative to globus pallidus
reduced GRE and T2 signal relative to red nucleus
abnormal disruption of the normal high T2 linear rim
bullMSA-Cbull disproportionate atrophy of the cerebellum and brainstem (especially olivary nuclei and middle
cerebellar peduncle)
NUCLEAR MEDICINE
SPECT and PET studies tend to demonstrate hypometabolism in the superior parietal and superior frontal areas in the basal ganglia
HUNTINGTON DISEASE
autosomal dominant neurodegenerative disease
a loss of GABAergic neurons of the basal ganglia
especially atrophy of the caudate nucleus and putamen
Huntington disease has a prevalence of 5-10 per 100000 and is typically diagnosed between 30 and 50 years of age
In approximately 1-6 symptoms occur before the age of 20 so-called juvenile form
Presentation is typically with progressive rigidity choreoathetosis dementia psychosis and emotional lability
The juvenile form has a different presentation with cerebellar symptoms rigidity and hypokinesia being prominent
it is a autosomal dominant with complete penetrance and genetic anticipation particularly if inherited mutated allele is paternal
The mutation responsible is on chromosome 4p163 and consists of a CAG trineucleotide repeat
The usual 10-30 copies are amplified to greater than 36 and the greater the number of repeats the earlier the age of onset
RADIOGRAPHIC FEATURES
MRI
The most striking and best known feature is that of caudate head atrophy resulting in enlargement of the frontal horns often giving them a box like configuration
This can be quantified by an number of measurements
bullfrontal horn width to intercaudate distance ratio (FHCC)
bullintercaudate distance to inner table width ratio (CCIT)
Juvenile form
putamen are also atrophied and demonstrate increased T2 signal
basal ganglia may show decrease T2 signal and blooming on SWI in keeping with iron deposition
Generalised age inappropriate cortical volume loss is also recognised
FHCC ratio normal mean 22 to 26 (this ratio decreases with ageing as a result of enlargement of the frontal horns of the lateral ventricles)
CCIT ratio normal mean 009 to 012
AMYOTROPHIC LATERAL SCLEROSISalso known as Lou Gehrig disease or Charcot disease
Primary degeneration of the motor neurons within the brain brain stem and spinal cord
Patients typically present with progressive muscle weakness and limb and truncal atrophy combined with signs of spasticity
Mean age at the time of diagnosis is 55 years
RADIOGRAPHIC FEATURES
MRI
The earliest MR manifestation is hyperintensity on T2WI in the corticospinal tracts seen earliest in the internal capsule
Iron deposition in the cortex is demonstrated as loss of signal most evident on T2 weighted sequences
IS IT ATROPHY OR HYDROCEPHALUS
Abnormal accumulation of CSF in Ventricular system
Results from Structural or functional block to normal flow Of CSF
In effect all are obhstructive
Difficult to differentiate Atrophy from Hydrocephalus gt60yrs
Initially show increased ICT
Later stages may reach Equillibrium and Becomes NP hYdrocephalus
Types
Obstructive
Communicating
NPH ndash seen typically in old patients Diagnosis is more based on clinical feature
Dementia urinary incontinence and gait apraxias + Hydrocephalus = NPH
Radiologically w
1 degeree of ventricular dilatation is more with Thinning and bowing of CC
2 Sulcal effacement is invariable seen Hydrocephalus
3 dilatation or rounding of the Temporal Horns
4 Rounding and enlargement of the frontal horns
5 Enlargement and ballooning of 3rd
ventricle
6 Enlargement of fourth ventricle
SPOTTERS
THANK YOU
T2 axial imaging is often better for basal ganglia structures and posterior fossa Assess for
reversal of normal T2 signal of putamen vs globus pallidus of MSA-P
atrophic caudate heads of Huntingtons disease
size and flow void in aqueduct (usually prominent in NPH)
3 Coronal sequences
bullhippocampal choroidal fissure and temporal horn size
bullsymmetrybull left gt right atrophy favours FTLD
bull equal involvement favours Alzheimers disease
bullanterior to posterior gradientbull anterior atrophy gt posterior atrophy favours FTLD
bullinvolvement of the temporal lobe generally favours FTLD
bullatrophy largely restricted to the hippocampus and parahippocampalgyrus favours Alzheimers disease
bullmammillary body size signal and symmetry
4 T2 sequences
Sequences susceptible to blood products are particularly useful in assessing
bullmicrohaemorrhages
bull peripherally distributed in cerebral amyloid angiopathy which in turn is associate with Alzheimers disease
bullcentrally distributed (basal ganglia pons cerebellum) in chronic hypertensive encephalophathy
5 DWI
DWI has a limited role in the assessment of a patient with a suspected neurodegenerative disease
Crucial particularly for Creutzfeldt-Jakob disease look for cortical basal ganglia and thalamic restricted diffusion
SCORING SYSTEMS AND MEASUREMENTS
bullFazekas scale for white matter lesions the deep white matter component is used in assessing the amount of chronic small vessel ischaemic change
bullposterior atrophy score of parietal atrophy (PA or PCA or Koedam score) useful in atypical (posterior cortical atrophy) or early onset Alzheimers disease
bullmedial temporal lobe atrophy score (MTA score)
bullglobal cortical atrophy scale (GCA scale)
A number of measurements ratios are also useful
midbrain to pons area ratio (for PSP)
magnetic resonance parkinsonism index (MRPI) (for PSP)
ALZHEIMER DISEASE
Alzheimer disease (AD) is a common neurodegenerative disease responsible for the majority of all dementias and imposing a significant burden on developed nations
Most common cause of dementia and accounts for two thirds of cases of dementia in patients aged 60-70 years
Epidemiological risk factor advanced age female gender
apolipoprotein E (APOE) ε4 allele carrier status
current smoking
family history of dementia
Classicaltypical Alzheimer disease
with antegrade episodic memory deficits
Neuropsychiatric symptoms are also common and eventually affect almost all patients These include apathy depression anxiety aggressionagitation and psychosis
Atypicalvariant Alzheimer disease
These entities often recognised clinically well before they were identified to be pathologically identical to Alzheimer disease
slowly progressive focal cortical atrophy with symptoms and signs matched to the affected area
Examples include
posterior cortical atrophy
frontal variant of Alzheimer disease
a minority of cases of semantic dementia
Pathology
Alzheimer disease is characterised by the accumulation of senile (neuritic) plaques neuritic (neurofibrillary) tangles and progressive loss of neurons
The progression of pathology initially involves the transentorhinalregion and then spreads to the hippocampal complex and mesial temporal lobe structures and eventually the temporal lobes and basal forebrain
RADIOGRAPHIC FEATURES
The primary role of MRI (and CT) in the diagnosis of Alzheimer disease is the assessment of volume change in characteristic locations which can yield a diagnostic accuracy of up to 87
The diagnosis should be made on the basis of two features
mesial temporal lobe atrophy
temporoparietal cortical atrophy
MESIAL TEMPORAL LOBE ATROPHY
hippocampal and parahippocampal decrease in volume
Indirectly by examining enlargement of the parahippocampalfissures
The former is more sensitive and specific but ideally requires actual volumetric calculations rather than eye-balling the scan
These measures have been combined in the medial temporal atrophy score which has been shown to be predictive of progression from mild cognitive impairment (MCI) to dementiA
MEDIAL TEMPORAL LOBE ATROPHY SCORE
visual score performed on MRI of the brain using coronal T1 weighted images through the hippocampus at the level of the anterior pons and assesses three features
width of the choroid fissure
width of the temporal horn of the lateral ventricle
height of the hippocampus
These result in a score of 0 to 4
0 = no CSF is visible around the hippocampus
1 = choroid fissure is slightly widened
2 = moderate widening of the choroid fissure mild enlargement of the temporal horn and mild loss of hippocampal height
3 = marked widening of the choroid fissure moderate enlargement of the temporal horn and moderate loss of hippocampal height
4 = marked widening of the choroid fissure marked enlargement of the temporal horn and the hippocampus is markedly atrophied and internal structure is lost
In a patient younger than 75 years of age a score of 2 or more is abnormal
In a patient 75 years or older a score of 3 or more is abnormal
Atrophy has been shown to correlate with likelihood of progression from mild cognitive impairment (MCI) to dementia 4
MRI SPECTROSCOPY
increases in myoinositol (MI) (356 ppm) thought to reflect inhibition of enzyme(s) mediating conversion of MI to phosphatidyl inositol
decreased N-acetyl aspartate (NAA) (202 ppm) indicating decreased neuronal activity
TEMPOROPARIETAL CORTICAL ATROPHY Parietal atrophy particularly relevant to posterior cortical atrophy or early onset Alzheimer disease
the inter-hemispheric surface of the parietal lobe
TREATMENT AND PROGNOSIS
There is no cure for this disease some drugs have been developed trying to improve symptoms or at least temporarily slow down their progression
cholinsterase inhibitors
partial NMDA receptor antagonists
medications for behavioural symptoms
antidepressants
anxiolytics
antiparkinsonian (movement symptoms)
anticonvulsantssedatives (behavioural)
VASCULAR DEMENTIAalso known as vascular cognitive impairment
It is primarily seen in patients with atherosclerosis and chronic hypertension
Results from the accumulation of multiple white matter or cortical infarcts although cerebral haemorrhages can be variably included
strongly correlated with age seen in only 1 of patients over the age of 55 years of age but in over 4 of patients over 71 years of age
It is also possible to divide vascular dementia into subtypes
small vessel dementia (aka Binswanger disease)
cortical vascular dementia roughly equivalent to multi-infarct dementia
strategic infarct dementia
thalamic dementia
RADIOGRAPHIC FEATURES
Both CT and MRI are able to provide evidence of ischaemic damage
MRI is more sensitive especially to white matter small vessel ischaemic change as well as to microhaemorrhages seen in cerebral amyloid angiopathy and chronic hypertensive encephalopathy
bullsmall vessel dementia (aka Binswanger disease)
bullcerebral infarction
bulllacunar infarction
bullintracerebral haemorrhage
CEREBRAL AMYLOID ANGIOPATHY
SMALL VESSEL DEMENTIA
also known as Binswanger disease
Subcortical arteriosclerotic encephalopathy
refers to slowly progressive exclusively white-matter multi-infarct dementia
A genetically transmitted form of the disease is known as familial arteriopathic leukoencephalopathy
or
CADASIL (cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy)
CLINICAL CRITERIA FOR DIAGNOSIS
marked subcortical microangiopathic lesions at MR imaging
a negative family history for strokes early cognitive impairment or psychiatric disorders in first- and second-degree relatives
documented arterial hypertension systolic values higher than 160 mm Hg diastolic values higher than 95 mm Hg or both measured at several occasions 5
MRI
subcortical and periventricular lesions visible on T2 FLAIR T2-weighted and proton-density sequences
commonly grouped around the frontal and occipital horns and in the centrum semi ovale
Moderate generalised cerebral atrophy is invariably present and lacunar infarctsin the basal ganglia and
thalami are common
CT
Diffuse incompletely symmetrical hypodensities are present in deep white matter especially they are prominent in the frontal lobes and the centrum semiovale
CEREBRAL AUTOSOMAL DOMINANT ARTERIOPATHY WITH SUBCORTICAL INFARCTS AND LEUKOENCEPHALOPATHY (CADASIL)
occurs in the absence of hypertension and arteriosclerosis and presents in 71 of cases before the age of 60 years
Imaging features demonstrate severe microvascular changes with multiple subcortical infarcts
Not distinguishable from hypertensive type microvascular disease
DEMENTIA WITH LEWY BODIESPD
Neurodegenerative disease (a synucleinopathy to be specific) related to Parkinsons disease (PD)
Epidemiology
Dementia with Lewy bodies presents in older patients (onset typically in 50-70 years of age) and is sporadic
It is the second most common neurodegenerative cause of dementia in older patients after Alzheimers disease accounting for 15-20 of case
RADIOGRAPHIC FEATURES
MRI
Atrophy in various parts of the brain without a clearly identified unique pattern
Most helpful in distinguishing DLB from other entities resulting in dementia is the absence of features of other diseases
generalised decrease in cerebral volume most marked in
frontal lobes parietotemporal regions
enlargement of the lateral ventricles
relatively focal atrophy
midbrain
hypothalamus
SWALLOW TAIL SIGN
The swallow tail sign describes the normal axial imaging appearance of nigrosome-1 within the substantianigra on high resolution T2SWI weighted MRI
Absence of the sign (absent swallow tail sign) is reported to have a diagnostic accuracy of greater than 90 for Parkinson disease
Nuclear medicine
Occipital hypoperfusion on SPECT PET
May aid in differentiation from other types of dementia especially Alzheimers disease
TREATMENT AND PROGNOSIS
Unlike Parkinsons disease dementia with Lewy bodies respond less readily to L-dopa and also may have severe sensitivity reactions to neuroleptic drugs such as rigidity reduced consciousness pyrexia falling postural hypotension and collapse
Lewy body dementia also responds favourably to acetylcholinesteraseinhibitors
DIFFERENTIAL DIAGNOSISwith strong overlap between
bullAlzheimers diseasebull clinical may occasionally have similar clinical presentation with a frontal type dementia or posterior
cortical atrophy
bull imaging prominent involvement of hippocampi on imaging
bullFronto-temporal lobar degenerationbull clinical usually younger onset absent parkinsonian features absent visual hallucinations
bull imaging more pronounced frontal temporal atrophy L gt R asymmetry
FRONTO-TEMPORAL LOBAR DEGENERATION
Frontotemporal lobar degeneration (FTLD) is the pathological description of a group of neurodegenerative disorders characterised by focal atrophy of the frontal and temporal cortices
rontotemporal lobar degeneration can be divided as follows 3-4
bullbehavioural variant fronto-temporal lobar degeneration dementia (bvFTLD) (aka behavioural variant frontotemporal dementia)1
bulllanguage variant fronto-temporal lobar degeneration (lvFTLD) (aka primary progressive aphasia (PPA)6
bull agrammatic variant primary progressive aphasia (aka progressive non-fluent aphasia (PNFA)
bull semantic variant primary progressive aphasia (aka semantic dementia)
bull logopaenic variant primary progressive aphasia
RADIOGRAPHIC FEATURES
The frontal and temporal lobes are predominantly affected there is often striking asymmetry both of involvement of frontal vs temporal lobes and involvement of left and right hemispheres
In addition the degree of fronto-striatal dysfunction varies between the different FTLD subgroups with behavioural variant frontotemporal dementia (bvFTD) having the greatest involvement
As a result the caudate heads tend to be reduced in size in these patients to a much greater degree than in the language variants of frontotemporal dementia
BEHAVIOURAL VARIANT FRONTO-TEMPORAL LOBAR DEGENERATION (BVFTLD)also referred to as Pick disease
Patients with behavioural variant FTD typically present with a dysexecutive cognitive syndrome associated with changes in personality and social behaviour
As the disease progresses impairments in language and memory may develop and the cognitive phenotype may come to resemble one of the language variants of FTD
RADIOGRAPHIC FEATURES
MRI
typical radiographic finding is atrophy of the frontal lobes and to a lesser extent the temporal lobes
The degree of atrophy can be very asymmetric
Decrease in volume of the caudate heads This indicates loss of both efferent and afferent fibres
CREUTZFELDT-JAKOB DISEASEspongiform encephalopathy
Results in a rapidly progressive dementia
other non-specific neurological features
Three types of Creutzfeldt-Jakob disease have been described
bullsporadic (sCJD) accounts for 85-90 of cases
bullvariant (vCJD)
bullfamilial (fCJD) 10 of cases (these individuals carry a PRPc mutation)
Creutzfeldt-Jakob disease is characterized by rapidly progressive dementia cerebral atrophy myoclonus and death
Patients with vCJD present mostly with sensory and psychiatric symptoms
Patients with sCJD usually present with progressive cognitive impairment and cerebellar symptoms
PATHOLOGY
mediated via (infectious) prions
a type of protein which manifest in sheep as the disease scrapie and in cows as bovine spongiform encephalopathy
Prions are considered infectious in sense that they can alter the structure of neighbouring proteins
CJD leads to spongiform degeneration of the brain
the conversion of normal prion protein to proteinaceous infectious particles that accumulate in and around neurons and lead to cell death
RADIOGRAPHIC FEATURES
MRI
MRI findings may be bilateral or unilateral and symmetric or asymmetric and include
T2 hyperintensity
obasal ganglia (putamen and caudate)
othalamus ( hockey stick sign and pulvinar sign)
ocortex most common early manifestation
owhite matter
persistent restricted diffusion on DWI (considered the most sensitive sign)
Review of sequential studies also typically demonstrates rapidly progressive cerebral atrophy
hypometabolism on 18FDG-PET studies
TREATMENT AND PROGNOSIS
here is currently no curative treatment and the disease is invariably fatal with a mean survival of only 7 months for most cases
PROGRESSIVE SUPRANUCLEARPALSYlso known as the Steele-Richardson-Olszewski syndrome
Progressive supranuclear palsy typically becomes clinically apparent in the 6th decade of life
Progresses to death usually within a decade (2-17 years from diagnosis)
Progressive supranuclear palsy is characterised
decreased cognition
abnormal eye movements (supranuclear vertical gaze palsy)
postural instability and falls
as well as parkinsonian features and speech disturbances
RADIOGRAPHIC FEATURESMRI
midbrain atrophy
reduction of anteroposterior midline midbrain diameter at the level of the superior colliculi on axial imaging (from interpeduncular fossa to the intercolicular groove lt12mm 8) which can give a mickey mouse appearance
reduced area of the midbrain on midline sagittal and reduced midbrain to pons area ratio approx 012 (normal approx 024) on midline sagittal
Loss of the lateral convex margin of the tegmentum of midbrain has been described as the morning glory sign
hummingbird sign also known as the penguin sign The key is a flattening or concave outline to the superior aspect of the midbrain which should be upwardly convex
bullT2 diffuse high-signal lesions in
bull pontine tegmentum
bull tectum of the midbrain
bull inferior olivary nucleus
MICKEY MOUSE APPEARANCE
THE PENGUIN SIGN
MULTIPLE SYSTEM ATROPHY
sporadic neurodegenerative disease
Typically symptoms begin between 40 and 60 years of age
Clinical presentation is variable but typically presents in one of three patterns (initially described as separate entities)
Shy-Drager syndrome is used when autonomic symptoms predominate
striatonigral degeneration shows predominant parkinsonian features
olivopontocerebellar atrophy demonstrates primarily cerebellar dysfunction
MSA has been divided clinically into 2 forms according to the dominant non-autonomic symptoms
MSA-C predominance of cerebellar symptoms (olivopontocerebellar atrophy)
MSA-P predominance of parkinsonian signs and symptoms (striatonigraldegeneration)
RADIOGRAPHIC FEATURES
bullT2 hyperintensities typically present in the pontocerebellar tractsbull pons hot cross bun sign (MSA-C)
bull middle cerebellar peduncles
bull Cerebellum
putaminal findings in MSA-P reduced volume
reduced GRE and T2 signal relative to globus pallidus
reduced GRE and T2 signal relative to red nucleus
abnormal disruption of the normal high T2 linear rim
bullMSA-Cbull disproportionate atrophy of the cerebellum and brainstem (especially olivary nuclei and middle
cerebellar peduncle)
NUCLEAR MEDICINE
SPECT and PET studies tend to demonstrate hypometabolism in the superior parietal and superior frontal areas in the basal ganglia
HUNTINGTON DISEASE
autosomal dominant neurodegenerative disease
a loss of GABAergic neurons of the basal ganglia
especially atrophy of the caudate nucleus and putamen
Huntington disease has a prevalence of 5-10 per 100000 and is typically diagnosed between 30 and 50 years of age
In approximately 1-6 symptoms occur before the age of 20 so-called juvenile form
Presentation is typically with progressive rigidity choreoathetosis dementia psychosis and emotional lability
The juvenile form has a different presentation with cerebellar symptoms rigidity and hypokinesia being prominent
it is a autosomal dominant with complete penetrance and genetic anticipation particularly if inherited mutated allele is paternal
The mutation responsible is on chromosome 4p163 and consists of a CAG trineucleotide repeat
The usual 10-30 copies are amplified to greater than 36 and the greater the number of repeats the earlier the age of onset
RADIOGRAPHIC FEATURES
MRI
The most striking and best known feature is that of caudate head atrophy resulting in enlargement of the frontal horns often giving them a box like configuration
This can be quantified by an number of measurements
bullfrontal horn width to intercaudate distance ratio (FHCC)
bullintercaudate distance to inner table width ratio (CCIT)
Juvenile form
putamen are also atrophied and demonstrate increased T2 signal
basal ganglia may show decrease T2 signal and blooming on SWI in keeping with iron deposition
Generalised age inappropriate cortical volume loss is also recognised
FHCC ratio normal mean 22 to 26 (this ratio decreases with ageing as a result of enlargement of the frontal horns of the lateral ventricles)
CCIT ratio normal mean 009 to 012
AMYOTROPHIC LATERAL SCLEROSISalso known as Lou Gehrig disease or Charcot disease
Primary degeneration of the motor neurons within the brain brain stem and spinal cord
Patients typically present with progressive muscle weakness and limb and truncal atrophy combined with signs of spasticity
Mean age at the time of diagnosis is 55 years
RADIOGRAPHIC FEATURES
MRI
The earliest MR manifestation is hyperintensity on T2WI in the corticospinal tracts seen earliest in the internal capsule
Iron deposition in the cortex is demonstrated as loss of signal most evident on T2 weighted sequences
IS IT ATROPHY OR HYDROCEPHALUS
Abnormal accumulation of CSF in Ventricular system
Results from Structural or functional block to normal flow Of CSF
In effect all are obhstructive
Difficult to differentiate Atrophy from Hydrocephalus gt60yrs
Initially show increased ICT
Later stages may reach Equillibrium and Becomes NP hYdrocephalus
Types
Obstructive
Communicating
NPH ndash seen typically in old patients Diagnosis is more based on clinical feature
Dementia urinary incontinence and gait apraxias + Hydrocephalus = NPH
Radiologically w
1 degeree of ventricular dilatation is more with Thinning and bowing of CC
2 Sulcal effacement is invariable seen Hydrocephalus
3 dilatation or rounding of the Temporal Horns
4 Rounding and enlargement of the frontal horns
5 Enlargement and ballooning of 3rd
ventricle
6 Enlargement of fourth ventricle
SPOTTERS
THANK YOU
3 Coronal sequences
bullhippocampal choroidal fissure and temporal horn size
bullsymmetrybull left gt right atrophy favours FTLD
bull equal involvement favours Alzheimers disease
bullanterior to posterior gradientbull anterior atrophy gt posterior atrophy favours FTLD
bullinvolvement of the temporal lobe generally favours FTLD
bullatrophy largely restricted to the hippocampus and parahippocampalgyrus favours Alzheimers disease
bullmammillary body size signal and symmetry
4 T2 sequences
Sequences susceptible to blood products are particularly useful in assessing
bullmicrohaemorrhages
bull peripherally distributed in cerebral amyloid angiopathy which in turn is associate with Alzheimers disease
bullcentrally distributed (basal ganglia pons cerebellum) in chronic hypertensive encephalophathy
5 DWI
DWI has a limited role in the assessment of a patient with a suspected neurodegenerative disease
Crucial particularly for Creutzfeldt-Jakob disease look for cortical basal ganglia and thalamic restricted diffusion
SCORING SYSTEMS AND MEASUREMENTS
bullFazekas scale for white matter lesions the deep white matter component is used in assessing the amount of chronic small vessel ischaemic change
bullposterior atrophy score of parietal atrophy (PA or PCA or Koedam score) useful in atypical (posterior cortical atrophy) or early onset Alzheimers disease
bullmedial temporal lobe atrophy score (MTA score)
bullglobal cortical atrophy scale (GCA scale)
A number of measurements ratios are also useful
midbrain to pons area ratio (for PSP)
magnetic resonance parkinsonism index (MRPI) (for PSP)
ALZHEIMER DISEASE
Alzheimer disease (AD) is a common neurodegenerative disease responsible for the majority of all dementias and imposing a significant burden on developed nations
Most common cause of dementia and accounts for two thirds of cases of dementia in patients aged 60-70 years
Epidemiological risk factor advanced age female gender
apolipoprotein E (APOE) ε4 allele carrier status
current smoking
family history of dementia
Classicaltypical Alzheimer disease
with antegrade episodic memory deficits
Neuropsychiatric symptoms are also common and eventually affect almost all patients These include apathy depression anxiety aggressionagitation and psychosis
Atypicalvariant Alzheimer disease
These entities often recognised clinically well before they were identified to be pathologically identical to Alzheimer disease
slowly progressive focal cortical atrophy with symptoms and signs matched to the affected area
Examples include
posterior cortical atrophy
frontal variant of Alzheimer disease
a minority of cases of semantic dementia
Pathology
Alzheimer disease is characterised by the accumulation of senile (neuritic) plaques neuritic (neurofibrillary) tangles and progressive loss of neurons
The progression of pathology initially involves the transentorhinalregion and then spreads to the hippocampal complex and mesial temporal lobe structures and eventually the temporal lobes and basal forebrain
RADIOGRAPHIC FEATURES
The primary role of MRI (and CT) in the diagnosis of Alzheimer disease is the assessment of volume change in characteristic locations which can yield a diagnostic accuracy of up to 87
The diagnosis should be made on the basis of two features
mesial temporal lobe atrophy
temporoparietal cortical atrophy
MESIAL TEMPORAL LOBE ATROPHY
hippocampal and parahippocampal decrease in volume
Indirectly by examining enlargement of the parahippocampalfissures
The former is more sensitive and specific but ideally requires actual volumetric calculations rather than eye-balling the scan
These measures have been combined in the medial temporal atrophy score which has been shown to be predictive of progression from mild cognitive impairment (MCI) to dementiA
MEDIAL TEMPORAL LOBE ATROPHY SCORE
visual score performed on MRI of the brain using coronal T1 weighted images through the hippocampus at the level of the anterior pons and assesses three features
width of the choroid fissure
width of the temporal horn of the lateral ventricle
height of the hippocampus
These result in a score of 0 to 4
0 = no CSF is visible around the hippocampus
1 = choroid fissure is slightly widened
2 = moderate widening of the choroid fissure mild enlargement of the temporal horn and mild loss of hippocampal height
3 = marked widening of the choroid fissure moderate enlargement of the temporal horn and moderate loss of hippocampal height
4 = marked widening of the choroid fissure marked enlargement of the temporal horn and the hippocampus is markedly atrophied and internal structure is lost
In a patient younger than 75 years of age a score of 2 or more is abnormal
In a patient 75 years or older a score of 3 or more is abnormal
Atrophy has been shown to correlate with likelihood of progression from mild cognitive impairment (MCI) to dementia 4
MRI SPECTROSCOPY
increases in myoinositol (MI) (356 ppm) thought to reflect inhibition of enzyme(s) mediating conversion of MI to phosphatidyl inositol
decreased N-acetyl aspartate (NAA) (202 ppm) indicating decreased neuronal activity
TEMPOROPARIETAL CORTICAL ATROPHY Parietal atrophy particularly relevant to posterior cortical atrophy or early onset Alzheimer disease
the inter-hemispheric surface of the parietal lobe
TREATMENT AND PROGNOSIS
There is no cure for this disease some drugs have been developed trying to improve symptoms or at least temporarily slow down their progression
cholinsterase inhibitors
partial NMDA receptor antagonists
medications for behavioural symptoms
antidepressants
anxiolytics
antiparkinsonian (movement symptoms)
anticonvulsantssedatives (behavioural)
VASCULAR DEMENTIAalso known as vascular cognitive impairment
It is primarily seen in patients with atherosclerosis and chronic hypertension
Results from the accumulation of multiple white matter or cortical infarcts although cerebral haemorrhages can be variably included
strongly correlated with age seen in only 1 of patients over the age of 55 years of age but in over 4 of patients over 71 years of age
It is also possible to divide vascular dementia into subtypes
small vessel dementia (aka Binswanger disease)
cortical vascular dementia roughly equivalent to multi-infarct dementia
strategic infarct dementia
thalamic dementia
RADIOGRAPHIC FEATURES
Both CT and MRI are able to provide evidence of ischaemic damage
MRI is more sensitive especially to white matter small vessel ischaemic change as well as to microhaemorrhages seen in cerebral amyloid angiopathy and chronic hypertensive encephalopathy
bullsmall vessel dementia (aka Binswanger disease)
bullcerebral infarction
bulllacunar infarction
bullintracerebral haemorrhage
CEREBRAL AMYLOID ANGIOPATHY
SMALL VESSEL DEMENTIA
also known as Binswanger disease
Subcortical arteriosclerotic encephalopathy
refers to slowly progressive exclusively white-matter multi-infarct dementia
A genetically transmitted form of the disease is known as familial arteriopathic leukoencephalopathy
or
CADASIL (cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy)
CLINICAL CRITERIA FOR DIAGNOSIS
marked subcortical microangiopathic lesions at MR imaging
a negative family history for strokes early cognitive impairment or psychiatric disorders in first- and second-degree relatives
documented arterial hypertension systolic values higher than 160 mm Hg diastolic values higher than 95 mm Hg or both measured at several occasions 5
MRI
subcortical and periventricular lesions visible on T2 FLAIR T2-weighted and proton-density sequences
commonly grouped around the frontal and occipital horns and in the centrum semi ovale
Moderate generalised cerebral atrophy is invariably present and lacunar infarctsin the basal ganglia and
thalami are common
CT
Diffuse incompletely symmetrical hypodensities are present in deep white matter especially they are prominent in the frontal lobes and the centrum semiovale
CEREBRAL AUTOSOMAL DOMINANT ARTERIOPATHY WITH SUBCORTICAL INFARCTS AND LEUKOENCEPHALOPATHY (CADASIL)
occurs in the absence of hypertension and arteriosclerosis and presents in 71 of cases before the age of 60 years
Imaging features demonstrate severe microvascular changes with multiple subcortical infarcts
Not distinguishable from hypertensive type microvascular disease
DEMENTIA WITH LEWY BODIESPD
Neurodegenerative disease (a synucleinopathy to be specific) related to Parkinsons disease (PD)
Epidemiology
Dementia with Lewy bodies presents in older patients (onset typically in 50-70 years of age) and is sporadic
It is the second most common neurodegenerative cause of dementia in older patients after Alzheimers disease accounting for 15-20 of case
RADIOGRAPHIC FEATURES
MRI
Atrophy in various parts of the brain without a clearly identified unique pattern
Most helpful in distinguishing DLB from other entities resulting in dementia is the absence of features of other diseases
generalised decrease in cerebral volume most marked in
frontal lobes parietotemporal regions
enlargement of the lateral ventricles
relatively focal atrophy
midbrain
hypothalamus
SWALLOW TAIL SIGN
The swallow tail sign describes the normal axial imaging appearance of nigrosome-1 within the substantianigra on high resolution T2SWI weighted MRI
Absence of the sign (absent swallow tail sign) is reported to have a diagnostic accuracy of greater than 90 for Parkinson disease
Nuclear medicine
Occipital hypoperfusion on SPECT PET
May aid in differentiation from other types of dementia especially Alzheimers disease
TREATMENT AND PROGNOSIS
Unlike Parkinsons disease dementia with Lewy bodies respond less readily to L-dopa and also may have severe sensitivity reactions to neuroleptic drugs such as rigidity reduced consciousness pyrexia falling postural hypotension and collapse
Lewy body dementia also responds favourably to acetylcholinesteraseinhibitors
DIFFERENTIAL DIAGNOSISwith strong overlap between
bullAlzheimers diseasebull clinical may occasionally have similar clinical presentation with a frontal type dementia or posterior
cortical atrophy
bull imaging prominent involvement of hippocampi on imaging
bullFronto-temporal lobar degenerationbull clinical usually younger onset absent parkinsonian features absent visual hallucinations
bull imaging more pronounced frontal temporal atrophy L gt R asymmetry
FRONTO-TEMPORAL LOBAR DEGENERATION
Frontotemporal lobar degeneration (FTLD) is the pathological description of a group of neurodegenerative disorders characterised by focal atrophy of the frontal and temporal cortices
rontotemporal lobar degeneration can be divided as follows 3-4
bullbehavioural variant fronto-temporal lobar degeneration dementia (bvFTLD) (aka behavioural variant frontotemporal dementia)1
bulllanguage variant fronto-temporal lobar degeneration (lvFTLD) (aka primary progressive aphasia (PPA)6
bull agrammatic variant primary progressive aphasia (aka progressive non-fluent aphasia (PNFA)
bull semantic variant primary progressive aphasia (aka semantic dementia)
bull logopaenic variant primary progressive aphasia
RADIOGRAPHIC FEATURES
The frontal and temporal lobes are predominantly affected there is often striking asymmetry both of involvement of frontal vs temporal lobes and involvement of left and right hemispheres
In addition the degree of fronto-striatal dysfunction varies between the different FTLD subgroups with behavioural variant frontotemporal dementia (bvFTD) having the greatest involvement
As a result the caudate heads tend to be reduced in size in these patients to a much greater degree than in the language variants of frontotemporal dementia
BEHAVIOURAL VARIANT FRONTO-TEMPORAL LOBAR DEGENERATION (BVFTLD)also referred to as Pick disease
Patients with behavioural variant FTD typically present with a dysexecutive cognitive syndrome associated with changes in personality and social behaviour
As the disease progresses impairments in language and memory may develop and the cognitive phenotype may come to resemble one of the language variants of FTD
RADIOGRAPHIC FEATURES
MRI
typical radiographic finding is atrophy of the frontal lobes and to a lesser extent the temporal lobes
The degree of atrophy can be very asymmetric
Decrease in volume of the caudate heads This indicates loss of both efferent and afferent fibres
CREUTZFELDT-JAKOB DISEASEspongiform encephalopathy
Results in a rapidly progressive dementia
other non-specific neurological features
Three types of Creutzfeldt-Jakob disease have been described
bullsporadic (sCJD) accounts for 85-90 of cases
bullvariant (vCJD)
bullfamilial (fCJD) 10 of cases (these individuals carry a PRPc mutation)
Creutzfeldt-Jakob disease is characterized by rapidly progressive dementia cerebral atrophy myoclonus and death
Patients with vCJD present mostly with sensory and psychiatric symptoms
Patients with sCJD usually present with progressive cognitive impairment and cerebellar symptoms
PATHOLOGY
mediated via (infectious) prions
a type of protein which manifest in sheep as the disease scrapie and in cows as bovine spongiform encephalopathy
Prions are considered infectious in sense that they can alter the structure of neighbouring proteins
CJD leads to spongiform degeneration of the brain
the conversion of normal prion protein to proteinaceous infectious particles that accumulate in and around neurons and lead to cell death
RADIOGRAPHIC FEATURES
MRI
MRI findings may be bilateral or unilateral and symmetric or asymmetric and include
T2 hyperintensity
obasal ganglia (putamen and caudate)
othalamus ( hockey stick sign and pulvinar sign)
ocortex most common early manifestation
owhite matter
persistent restricted diffusion on DWI (considered the most sensitive sign)
Review of sequential studies also typically demonstrates rapidly progressive cerebral atrophy
hypometabolism on 18FDG-PET studies
TREATMENT AND PROGNOSIS
here is currently no curative treatment and the disease is invariably fatal with a mean survival of only 7 months for most cases
PROGRESSIVE SUPRANUCLEARPALSYlso known as the Steele-Richardson-Olszewski syndrome
Progressive supranuclear palsy typically becomes clinically apparent in the 6th decade of life
Progresses to death usually within a decade (2-17 years from diagnosis)
Progressive supranuclear palsy is characterised
decreased cognition
abnormal eye movements (supranuclear vertical gaze palsy)
postural instability and falls
as well as parkinsonian features and speech disturbances
RADIOGRAPHIC FEATURESMRI
midbrain atrophy
reduction of anteroposterior midline midbrain diameter at the level of the superior colliculi on axial imaging (from interpeduncular fossa to the intercolicular groove lt12mm 8) which can give a mickey mouse appearance
reduced area of the midbrain on midline sagittal and reduced midbrain to pons area ratio approx 012 (normal approx 024) on midline sagittal
Loss of the lateral convex margin of the tegmentum of midbrain has been described as the morning glory sign
hummingbird sign also known as the penguin sign The key is a flattening or concave outline to the superior aspect of the midbrain which should be upwardly convex
bullT2 diffuse high-signal lesions in
bull pontine tegmentum
bull tectum of the midbrain
bull inferior olivary nucleus
MICKEY MOUSE APPEARANCE
THE PENGUIN SIGN
MULTIPLE SYSTEM ATROPHY
sporadic neurodegenerative disease
Typically symptoms begin between 40 and 60 years of age
Clinical presentation is variable but typically presents in one of three patterns (initially described as separate entities)
Shy-Drager syndrome is used when autonomic symptoms predominate
striatonigral degeneration shows predominant parkinsonian features
olivopontocerebellar atrophy demonstrates primarily cerebellar dysfunction
MSA has been divided clinically into 2 forms according to the dominant non-autonomic symptoms
MSA-C predominance of cerebellar symptoms (olivopontocerebellar atrophy)
MSA-P predominance of parkinsonian signs and symptoms (striatonigraldegeneration)
RADIOGRAPHIC FEATURES
bullT2 hyperintensities typically present in the pontocerebellar tractsbull pons hot cross bun sign (MSA-C)
bull middle cerebellar peduncles
bull Cerebellum
putaminal findings in MSA-P reduced volume
reduced GRE and T2 signal relative to globus pallidus
reduced GRE and T2 signal relative to red nucleus
abnormal disruption of the normal high T2 linear rim
bullMSA-Cbull disproportionate atrophy of the cerebellum and brainstem (especially olivary nuclei and middle
cerebellar peduncle)
NUCLEAR MEDICINE
SPECT and PET studies tend to demonstrate hypometabolism in the superior parietal and superior frontal areas in the basal ganglia
HUNTINGTON DISEASE
autosomal dominant neurodegenerative disease
a loss of GABAergic neurons of the basal ganglia
especially atrophy of the caudate nucleus and putamen
Huntington disease has a prevalence of 5-10 per 100000 and is typically diagnosed between 30 and 50 years of age
In approximately 1-6 symptoms occur before the age of 20 so-called juvenile form
Presentation is typically with progressive rigidity choreoathetosis dementia psychosis and emotional lability
The juvenile form has a different presentation with cerebellar symptoms rigidity and hypokinesia being prominent
it is a autosomal dominant with complete penetrance and genetic anticipation particularly if inherited mutated allele is paternal
The mutation responsible is on chromosome 4p163 and consists of a CAG trineucleotide repeat
The usual 10-30 copies are amplified to greater than 36 and the greater the number of repeats the earlier the age of onset
RADIOGRAPHIC FEATURES
MRI
The most striking and best known feature is that of caudate head atrophy resulting in enlargement of the frontal horns often giving them a box like configuration
This can be quantified by an number of measurements
bullfrontal horn width to intercaudate distance ratio (FHCC)
bullintercaudate distance to inner table width ratio (CCIT)
Juvenile form
putamen are also atrophied and demonstrate increased T2 signal
basal ganglia may show decrease T2 signal and blooming on SWI in keeping with iron deposition
Generalised age inappropriate cortical volume loss is also recognised
FHCC ratio normal mean 22 to 26 (this ratio decreases with ageing as a result of enlargement of the frontal horns of the lateral ventricles)
CCIT ratio normal mean 009 to 012
AMYOTROPHIC LATERAL SCLEROSISalso known as Lou Gehrig disease or Charcot disease
Primary degeneration of the motor neurons within the brain brain stem and spinal cord
Patients typically present with progressive muscle weakness and limb and truncal atrophy combined with signs of spasticity
Mean age at the time of diagnosis is 55 years
RADIOGRAPHIC FEATURES
MRI
The earliest MR manifestation is hyperintensity on T2WI in the corticospinal tracts seen earliest in the internal capsule
Iron deposition in the cortex is demonstrated as loss of signal most evident on T2 weighted sequences
IS IT ATROPHY OR HYDROCEPHALUS
Abnormal accumulation of CSF in Ventricular system
Results from Structural or functional block to normal flow Of CSF
In effect all are obhstructive
Difficult to differentiate Atrophy from Hydrocephalus gt60yrs
Initially show increased ICT
Later stages may reach Equillibrium and Becomes NP hYdrocephalus
Types
Obstructive
Communicating
NPH ndash seen typically in old patients Diagnosis is more based on clinical feature
Dementia urinary incontinence and gait apraxias + Hydrocephalus = NPH
Radiologically w
1 degeree of ventricular dilatation is more with Thinning and bowing of CC
2 Sulcal effacement is invariable seen Hydrocephalus
3 dilatation or rounding of the Temporal Horns
4 Rounding and enlargement of the frontal horns
5 Enlargement and ballooning of 3rd
ventricle
6 Enlargement of fourth ventricle
SPOTTERS
THANK YOU
4 T2 sequences
Sequences susceptible to blood products are particularly useful in assessing
bullmicrohaemorrhages
bull peripherally distributed in cerebral amyloid angiopathy which in turn is associate with Alzheimers disease
bullcentrally distributed (basal ganglia pons cerebellum) in chronic hypertensive encephalophathy
5 DWI
DWI has a limited role in the assessment of a patient with a suspected neurodegenerative disease
Crucial particularly for Creutzfeldt-Jakob disease look for cortical basal ganglia and thalamic restricted diffusion
SCORING SYSTEMS AND MEASUREMENTS
bullFazekas scale for white matter lesions the deep white matter component is used in assessing the amount of chronic small vessel ischaemic change
bullposterior atrophy score of parietal atrophy (PA or PCA or Koedam score) useful in atypical (posterior cortical atrophy) or early onset Alzheimers disease
bullmedial temporal lobe atrophy score (MTA score)
bullglobal cortical atrophy scale (GCA scale)
A number of measurements ratios are also useful
midbrain to pons area ratio (for PSP)
magnetic resonance parkinsonism index (MRPI) (for PSP)
ALZHEIMER DISEASE
Alzheimer disease (AD) is a common neurodegenerative disease responsible for the majority of all dementias and imposing a significant burden on developed nations
Most common cause of dementia and accounts for two thirds of cases of dementia in patients aged 60-70 years
Epidemiological risk factor advanced age female gender
apolipoprotein E (APOE) ε4 allele carrier status
current smoking
family history of dementia
Classicaltypical Alzheimer disease
with antegrade episodic memory deficits
Neuropsychiatric symptoms are also common and eventually affect almost all patients These include apathy depression anxiety aggressionagitation and psychosis
Atypicalvariant Alzheimer disease
These entities often recognised clinically well before they were identified to be pathologically identical to Alzheimer disease
slowly progressive focal cortical atrophy with symptoms and signs matched to the affected area
Examples include
posterior cortical atrophy
frontal variant of Alzheimer disease
a minority of cases of semantic dementia
Pathology
Alzheimer disease is characterised by the accumulation of senile (neuritic) plaques neuritic (neurofibrillary) tangles and progressive loss of neurons
The progression of pathology initially involves the transentorhinalregion and then spreads to the hippocampal complex and mesial temporal lobe structures and eventually the temporal lobes and basal forebrain
RADIOGRAPHIC FEATURES
The primary role of MRI (and CT) in the diagnosis of Alzheimer disease is the assessment of volume change in characteristic locations which can yield a diagnostic accuracy of up to 87
The diagnosis should be made on the basis of two features
mesial temporal lobe atrophy
temporoparietal cortical atrophy
MESIAL TEMPORAL LOBE ATROPHY
hippocampal and parahippocampal decrease in volume
Indirectly by examining enlargement of the parahippocampalfissures
The former is more sensitive and specific but ideally requires actual volumetric calculations rather than eye-balling the scan
These measures have been combined in the medial temporal atrophy score which has been shown to be predictive of progression from mild cognitive impairment (MCI) to dementiA
MEDIAL TEMPORAL LOBE ATROPHY SCORE
visual score performed on MRI of the brain using coronal T1 weighted images through the hippocampus at the level of the anterior pons and assesses three features
width of the choroid fissure
width of the temporal horn of the lateral ventricle
height of the hippocampus
These result in a score of 0 to 4
0 = no CSF is visible around the hippocampus
1 = choroid fissure is slightly widened
2 = moderate widening of the choroid fissure mild enlargement of the temporal horn and mild loss of hippocampal height
3 = marked widening of the choroid fissure moderate enlargement of the temporal horn and moderate loss of hippocampal height
4 = marked widening of the choroid fissure marked enlargement of the temporal horn and the hippocampus is markedly atrophied and internal structure is lost
In a patient younger than 75 years of age a score of 2 or more is abnormal
In a patient 75 years or older a score of 3 or more is abnormal
Atrophy has been shown to correlate with likelihood of progression from mild cognitive impairment (MCI) to dementia 4
MRI SPECTROSCOPY
increases in myoinositol (MI) (356 ppm) thought to reflect inhibition of enzyme(s) mediating conversion of MI to phosphatidyl inositol
decreased N-acetyl aspartate (NAA) (202 ppm) indicating decreased neuronal activity
TEMPOROPARIETAL CORTICAL ATROPHY Parietal atrophy particularly relevant to posterior cortical atrophy or early onset Alzheimer disease
the inter-hemispheric surface of the parietal lobe
TREATMENT AND PROGNOSIS
There is no cure for this disease some drugs have been developed trying to improve symptoms or at least temporarily slow down their progression
cholinsterase inhibitors
partial NMDA receptor antagonists
medications for behavioural symptoms
antidepressants
anxiolytics
antiparkinsonian (movement symptoms)
anticonvulsantssedatives (behavioural)
VASCULAR DEMENTIAalso known as vascular cognitive impairment
It is primarily seen in patients with atherosclerosis and chronic hypertension
Results from the accumulation of multiple white matter or cortical infarcts although cerebral haemorrhages can be variably included
strongly correlated with age seen in only 1 of patients over the age of 55 years of age but in over 4 of patients over 71 years of age
It is also possible to divide vascular dementia into subtypes
small vessel dementia (aka Binswanger disease)
cortical vascular dementia roughly equivalent to multi-infarct dementia
strategic infarct dementia
thalamic dementia
RADIOGRAPHIC FEATURES
Both CT and MRI are able to provide evidence of ischaemic damage
MRI is more sensitive especially to white matter small vessel ischaemic change as well as to microhaemorrhages seen in cerebral amyloid angiopathy and chronic hypertensive encephalopathy
bullsmall vessel dementia (aka Binswanger disease)
bullcerebral infarction
bulllacunar infarction
bullintracerebral haemorrhage
CEREBRAL AMYLOID ANGIOPATHY
SMALL VESSEL DEMENTIA
also known as Binswanger disease
Subcortical arteriosclerotic encephalopathy
refers to slowly progressive exclusively white-matter multi-infarct dementia
A genetically transmitted form of the disease is known as familial arteriopathic leukoencephalopathy
or
CADASIL (cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy)
CLINICAL CRITERIA FOR DIAGNOSIS
marked subcortical microangiopathic lesions at MR imaging
a negative family history for strokes early cognitive impairment or psychiatric disorders in first- and second-degree relatives
documented arterial hypertension systolic values higher than 160 mm Hg diastolic values higher than 95 mm Hg or both measured at several occasions 5
MRI
subcortical and periventricular lesions visible on T2 FLAIR T2-weighted and proton-density sequences
commonly grouped around the frontal and occipital horns and in the centrum semi ovale
Moderate generalised cerebral atrophy is invariably present and lacunar infarctsin the basal ganglia and
thalami are common
CT
Diffuse incompletely symmetrical hypodensities are present in deep white matter especially they are prominent in the frontal lobes and the centrum semiovale
CEREBRAL AUTOSOMAL DOMINANT ARTERIOPATHY WITH SUBCORTICAL INFARCTS AND LEUKOENCEPHALOPATHY (CADASIL)
occurs in the absence of hypertension and arteriosclerosis and presents in 71 of cases before the age of 60 years
Imaging features demonstrate severe microvascular changes with multiple subcortical infarcts
Not distinguishable from hypertensive type microvascular disease
DEMENTIA WITH LEWY BODIESPD
Neurodegenerative disease (a synucleinopathy to be specific) related to Parkinsons disease (PD)
Epidemiology
Dementia with Lewy bodies presents in older patients (onset typically in 50-70 years of age) and is sporadic
It is the second most common neurodegenerative cause of dementia in older patients after Alzheimers disease accounting for 15-20 of case
RADIOGRAPHIC FEATURES
MRI
Atrophy in various parts of the brain without a clearly identified unique pattern
Most helpful in distinguishing DLB from other entities resulting in dementia is the absence of features of other diseases
generalised decrease in cerebral volume most marked in
frontal lobes parietotemporal regions
enlargement of the lateral ventricles
relatively focal atrophy
midbrain
hypothalamus
SWALLOW TAIL SIGN
The swallow tail sign describes the normal axial imaging appearance of nigrosome-1 within the substantianigra on high resolution T2SWI weighted MRI
Absence of the sign (absent swallow tail sign) is reported to have a diagnostic accuracy of greater than 90 for Parkinson disease
Nuclear medicine
Occipital hypoperfusion on SPECT PET
May aid in differentiation from other types of dementia especially Alzheimers disease
TREATMENT AND PROGNOSIS
Unlike Parkinsons disease dementia with Lewy bodies respond less readily to L-dopa and also may have severe sensitivity reactions to neuroleptic drugs such as rigidity reduced consciousness pyrexia falling postural hypotension and collapse
Lewy body dementia also responds favourably to acetylcholinesteraseinhibitors
DIFFERENTIAL DIAGNOSISwith strong overlap between
bullAlzheimers diseasebull clinical may occasionally have similar clinical presentation with a frontal type dementia or posterior
cortical atrophy
bull imaging prominent involvement of hippocampi on imaging
bullFronto-temporal lobar degenerationbull clinical usually younger onset absent parkinsonian features absent visual hallucinations
bull imaging more pronounced frontal temporal atrophy L gt R asymmetry
FRONTO-TEMPORAL LOBAR DEGENERATION
Frontotemporal lobar degeneration (FTLD) is the pathological description of a group of neurodegenerative disorders characterised by focal atrophy of the frontal and temporal cortices
rontotemporal lobar degeneration can be divided as follows 3-4
bullbehavioural variant fronto-temporal lobar degeneration dementia (bvFTLD) (aka behavioural variant frontotemporal dementia)1
bulllanguage variant fronto-temporal lobar degeneration (lvFTLD) (aka primary progressive aphasia (PPA)6
bull agrammatic variant primary progressive aphasia (aka progressive non-fluent aphasia (PNFA)
bull semantic variant primary progressive aphasia (aka semantic dementia)
bull logopaenic variant primary progressive aphasia
RADIOGRAPHIC FEATURES
The frontal and temporal lobes are predominantly affected there is often striking asymmetry both of involvement of frontal vs temporal lobes and involvement of left and right hemispheres
In addition the degree of fronto-striatal dysfunction varies between the different FTLD subgroups with behavioural variant frontotemporal dementia (bvFTD) having the greatest involvement
As a result the caudate heads tend to be reduced in size in these patients to a much greater degree than in the language variants of frontotemporal dementia
BEHAVIOURAL VARIANT FRONTO-TEMPORAL LOBAR DEGENERATION (BVFTLD)also referred to as Pick disease
Patients with behavioural variant FTD typically present with a dysexecutive cognitive syndrome associated with changes in personality and social behaviour
As the disease progresses impairments in language and memory may develop and the cognitive phenotype may come to resemble one of the language variants of FTD
RADIOGRAPHIC FEATURES
MRI
typical radiographic finding is atrophy of the frontal lobes and to a lesser extent the temporal lobes
The degree of atrophy can be very asymmetric
Decrease in volume of the caudate heads This indicates loss of both efferent and afferent fibres
CREUTZFELDT-JAKOB DISEASEspongiform encephalopathy
Results in a rapidly progressive dementia
other non-specific neurological features
Three types of Creutzfeldt-Jakob disease have been described
bullsporadic (sCJD) accounts for 85-90 of cases
bullvariant (vCJD)
bullfamilial (fCJD) 10 of cases (these individuals carry a PRPc mutation)
Creutzfeldt-Jakob disease is characterized by rapidly progressive dementia cerebral atrophy myoclonus and death
Patients with vCJD present mostly with sensory and psychiatric symptoms
Patients with sCJD usually present with progressive cognitive impairment and cerebellar symptoms
PATHOLOGY
mediated via (infectious) prions
a type of protein which manifest in sheep as the disease scrapie and in cows as bovine spongiform encephalopathy
Prions are considered infectious in sense that they can alter the structure of neighbouring proteins
CJD leads to spongiform degeneration of the brain
the conversion of normal prion protein to proteinaceous infectious particles that accumulate in and around neurons and lead to cell death
RADIOGRAPHIC FEATURES
MRI
MRI findings may be bilateral or unilateral and symmetric or asymmetric and include
T2 hyperintensity
obasal ganglia (putamen and caudate)
othalamus ( hockey stick sign and pulvinar sign)
ocortex most common early manifestation
owhite matter
persistent restricted diffusion on DWI (considered the most sensitive sign)
Review of sequential studies also typically demonstrates rapidly progressive cerebral atrophy
hypometabolism on 18FDG-PET studies
TREATMENT AND PROGNOSIS
here is currently no curative treatment and the disease is invariably fatal with a mean survival of only 7 months for most cases
PROGRESSIVE SUPRANUCLEARPALSYlso known as the Steele-Richardson-Olszewski syndrome
Progressive supranuclear palsy typically becomes clinically apparent in the 6th decade of life
Progresses to death usually within a decade (2-17 years from diagnosis)
Progressive supranuclear palsy is characterised
decreased cognition
abnormal eye movements (supranuclear vertical gaze palsy)
postural instability and falls
as well as parkinsonian features and speech disturbances
RADIOGRAPHIC FEATURESMRI
midbrain atrophy
reduction of anteroposterior midline midbrain diameter at the level of the superior colliculi on axial imaging (from interpeduncular fossa to the intercolicular groove lt12mm 8) which can give a mickey mouse appearance
reduced area of the midbrain on midline sagittal and reduced midbrain to pons area ratio approx 012 (normal approx 024) on midline sagittal
Loss of the lateral convex margin of the tegmentum of midbrain has been described as the morning glory sign
hummingbird sign also known as the penguin sign The key is a flattening or concave outline to the superior aspect of the midbrain which should be upwardly convex
bullT2 diffuse high-signal lesions in
bull pontine tegmentum
bull tectum of the midbrain
bull inferior olivary nucleus
MICKEY MOUSE APPEARANCE
THE PENGUIN SIGN
MULTIPLE SYSTEM ATROPHY
sporadic neurodegenerative disease
Typically symptoms begin between 40 and 60 years of age
Clinical presentation is variable but typically presents in one of three patterns (initially described as separate entities)
Shy-Drager syndrome is used when autonomic symptoms predominate
striatonigral degeneration shows predominant parkinsonian features
olivopontocerebellar atrophy demonstrates primarily cerebellar dysfunction
MSA has been divided clinically into 2 forms according to the dominant non-autonomic symptoms
MSA-C predominance of cerebellar symptoms (olivopontocerebellar atrophy)
MSA-P predominance of parkinsonian signs and symptoms (striatonigraldegeneration)
RADIOGRAPHIC FEATURES
bullT2 hyperintensities typically present in the pontocerebellar tractsbull pons hot cross bun sign (MSA-C)
bull middle cerebellar peduncles
bull Cerebellum
putaminal findings in MSA-P reduced volume
reduced GRE and T2 signal relative to globus pallidus
reduced GRE and T2 signal relative to red nucleus
abnormal disruption of the normal high T2 linear rim
bullMSA-Cbull disproportionate atrophy of the cerebellum and brainstem (especially olivary nuclei and middle
cerebellar peduncle)
NUCLEAR MEDICINE
SPECT and PET studies tend to demonstrate hypometabolism in the superior parietal and superior frontal areas in the basal ganglia
HUNTINGTON DISEASE
autosomal dominant neurodegenerative disease
a loss of GABAergic neurons of the basal ganglia
especially atrophy of the caudate nucleus and putamen
Huntington disease has a prevalence of 5-10 per 100000 and is typically diagnosed between 30 and 50 years of age
In approximately 1-6 symptoms occur before the age of 20 so-called juvenile form
Presentation is typically with progressive rigidity choreoathetosis dementia psychosis and emotional lability
The juvenile form has a different presentation with cerebellar symptoms rigidity and hypokinesia being prominent
it is a autosomal dominant with complete penetrance and genetic anticipation particularly if inherited mutated allele is paternal
The mutation responsible is on chromosome 4p163 and consists of a CAG trineucleotide repeat
The usual 10-30 copies are amplified to greater than 36 and the greater the number of repeats the earlier the age of onset
RADIOGRAPHIC FEATURES
MRI
The most striking and best known feature is that of caudate head atrophy resulting in enlargement of the frontal horns often giving them a box like configuration
This can be quantified by an number of measurements
bullfrontal horn width to intercaudate distance ratio (FHCC)
bullintercaudate distance to inner table width ratio (CCIT)
Juvenile form
putamen are also atrophied and demonstrate increased T2 signal
basal ganglia may show decrease T2 signal and blooming on SWI in keeping with iron deposition
Generalised age inappropriate cortical volume loss is also recognised
FHCC ratio normal mean 22 to 26 (this ratio decreases with ageing as a result of enlargement of the frontal horns of the lateral ventricles)
CCIT ratio normal mean 009 to 012
AMYOTROPHIC LATERAL SCLEROSISalso known as Lou Gehrig disease or Charcot disease
Primary degeneration of the motor neurons within the brain brain stem and spinal cord
Patients typically present with progressive muscle weakness and limb and truncal atrophy combined with signs of spasticity
Mean age at the time of diagnosis is 55 years
RADIOGRAPHIC FEATURES
MRI
The earliest MR manifestation is hyperintensity on T2WI in the corticospinal tracts seen earliest in the internal capsule
Iron deposition in the cortex is demonstrated as loss of signal most evident on T2 weighted sequences
IS IT ATROPHY OR HYDROCEPHALUS
Abnormal accumulation of CSF in Ventricular system
Results from Structural or functional block to normal flow Of CSF
In effect all are obhstructive
Difficult to differentiate Atrophy from Hydrocephalus gt60yrs
Initially show increased ICT
Later stages may reach Equillibrium and Becomes NP hYdrocephalus
Types
Obstructive
Communicating
NPH ndash seen typically in old patients Diagnosis is more based on clinical feature
Dementia urinary incontinence and gait apraxias + Hydrocephalus = NPH
Radiologically w
1 degeree of ventricular dilatation is more with Thinning and bowing of CC
2 Sulcal effacement is invariable seen Hydrocephalus
3 dilatation or rounding of the Temporal Horns
4 Rounding and enlargement of the frontal horns
5 Enlargement and ballooning of 3rd
ventricle
6 Enlargement of fourth ventricle
SPOTTERS
THANK YOU
SCORING SYSTEMS AND MEASUREMENTS
bullFazekas scale for white matter lesions the deep white matter component is used in assessing the amount of chronic small vessel ischaemic change
bullposterior atrophy score of parietal atrophy (PA or PCA or Koedam score) useful in atypical (posterior cortical atrophy) or early onset Alzheimers disease
bullmedial temporal lobe atrophy score (MTA score)
bullglobal cortical atrophy scale (GCA scale)
A number of measurements ratios are also useful
midbrain to pons area ratio (for PSP)
magnetic resonance parkinsonism index (MRPI) (for PSP)
ALZHEIMER DISEASE
Alzheimer disease (AD) is a common neurodegenerative disease responsible for the majority of all dementias and imposing a significant burden on developed nations
Most common cause of dementia and accounts for two thirds of cases of dementia in patients aged 60-70 years
Epidemiological risk factor advanced age female gender
apolipoprotein E (APOE) ε4 allele carrier status
current smoking
family history of dementia
Classicaltypical Alzheimer disease
with antegrade episodic memory deficits
Neuropsychiatric symptoms are also common and eventually affect almost all patients These include apathy depression anxiety aggressionagitation and psychosis
Atypicalvariant Alzheimer disease
These entities often recognised clinically well before they were identified to be pathologically identical to Alzheimer disease
slowly progressive focal cortical atrophy with symptoms and signs matched to the affected area
Examples include
posterior cortical atrophy
frontal variant of Alzheimer disease
a minority of cases of semantic dementia
Pathology
Alzheimer disease is characterised by the accumulation of senile (neuritic) plaques neuritic (neurofibrillary) tangles and progressive loss of neurons
The progression of pathology initially involves the transentorhinalregion and then spreads to the hippocampal complex and mesial temporal lobe structures and eventually the temporal lobes and basal forebrain
RADIOGRAPHIC FEATURES
The primary role of MRI (and CT) in the diagnosis of Alzheimer disease is the assessment of volume change in characteristic locations which can yield a diagnostic accuracy of up to 87
The diagnosis should be made on the basis of two features
mesial temporal lobe atrophy
temporoparietal cortical atrophy
MESIAL TEMPORAL LOBE ATROPHY
hippocampal and parahippocampal decrease in volume
Indirectly by examining enlargement of the parahippocampalfissures
The former is more sensitive and specific but ideally requires actual volumetric calculations rather than eye-balling the scan
These measures have been combined in the medial temporal atrophy score which has been shown to be predictive of progression from mild cognitive impairment (MCI) to dementiA
MEDIAL TEMPORAL LOBE ATROPHY SCORE
visual score performed on MRI of the brain using coronal T1 weighted images through the hippocampus at the level of the anterior pons and assesses three features
width of the choroid fissure
width of the temporal horn of the lateral ventricle
height of the hippocampus
These result in a score of 0 to 4
0 = no CSF is visible around the hippocampus
1 = choroid fissure is slightly widened
2 = moderate widening of the choroid fissure mild enlargement of the temporal horn and mild loss of hippocampal height
3 = marked widening of the choroid fissure moderate enlargement of the temporal horn and moderate loss of hippocampal height
4 = marked widening of the choroid fissure marked enlargement of the temporal horn and the hippocampus is markedly atrophied and internal structure is lost
In a patient younger than 75 years of age a score of 2 or more is abnormal
In a patient 75 years or older a score of 3 or more is abnormal
Atrophy has been shown to correlate with likelihood of progression from mild cognitive impairment (MCI) to dementia 4
MRI SPECTROSCOPY
increases in myoinositol (MI) (356 ppm) thought to reflect inhibition of enzyme(s) mediating conversion of MI to phosphatidyl inositol
decreased N-acetyl aspartate (NAA) (202 ppm) indicating decreased neuronal activity
TEMPOROPARIETAL CORTICAL ATROPHY Parietal atrophy particularly relevant to posterior cortical atrophy or early onset Alzheimer disease
the inter-hemispheric surface of the parietal lobe
TREATMENT AND PROGNOSIS
There is no cure for this disease some drugs have been developed trying to improve symptoms or at least temporarily slow down their progression
cholinsterase inhibitors
partial NMDA receptor antagonists
medications for behavioural symptoms
antidepressants
anxiolytics
antiparkinsonian (movement symptoms)
anticonvulsantssedatives (behavioural)
VASCULAR DEMENTIAalso known as vascular cognitive impairment
It is primarily seen in patients with atherosclerosis and chronic hypertension
Results from the accumulation of multiple white matter or cortical infarcts although cerebral haemorrhages can be variably included
strongly correlated with age seen in only 1 of patients over the age of 55 years of age but in over 4 of patients over 71 years of age
It is also possible to divide vascular dementia into subtypes
small vessel dementia (aka Binswanger disease)
cortical vascular dementia roughly equivalent to multi-infarct dementia
strategic infarct dementia
thalamic dementia
RADIOGRAPHIC FEATURES
Both CT and MRI are able to provide evidence of ischaemic damage
MRI is more sensitive especially to white matter small vessel ischaemic change as well as to microhaemorrhages seen in cerebral amyloid angiopathy and chronic hypertensive encephalopathy
bullsmall vessel dementia (aka Binswanger disease)
bullcerebral infarction
bulllacunar infarction
bullintracerebral haemorrhage
CEREBRAL AMYLOID ANGIOPATHY
SMALL VESSEL DEMENTIA
also known as Binswanger disease
Subcortical arteriosclerotic encephalopathy
refers to slowly progressive exclusively white-matter multi-infarct dementia
A genetically transmitted form of the disease is known as familial arteriopathic leukoencephalopathy
or
CADASIL (cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy)
CLINICAL CRITERIA FOR DIAGNOSIS
marked subcortical microangiopathic lesions at MR imaging
a negative family history for strokes early cognitive impairment or psychiatric disorders in first- and second-degree relatives
documented arterial hypertension systolic values higher than 160 mm Hg diastolic values higher than 95 mm Hg or both measured at several occasions 5
MRI
subcortical and periventricular lesions visible on T2 FLAIR T2-weighted and proton-density sequences
commonly grouped around the frontal and occipital horns and in the centrum semi ovale
Moderate generalised cerebral atrophy is invariably present and lacunar infarctsin the basal ganglia and
thalami are common
CT
Diffuse incompletely symmetrical hypodensities are present in deep white matter especially they are prominent in the frontal lobes and the centrum semiovale
CEREBRAL AUTOSOMAL DOMINANT ARTERIOPATHY WITH SUBCORTICAL INFARCTS AND LEUKOENCEPHALOPATHY (CADASIL)
occurs in the absence of hypertension and arteriosclerosis and presents in 71 of cases before the age of 60 years
Imaging features demonstrate severe microvascular changes with multiple subcortical infarcts
Not distinguishable from hypertensive type microvascular disease
DEMENTIA WITH LEWY BODIESPD
Neurodegenerative disease (a synucleinopathy to be specific) related to Parkinsons disease (PD)
Epidemiology
Dementia with Lewy bodies presents in older patients (onset typically in 50-70 years of age) and is sporadic
It is the second most common neurodegenerative cause of dementia in older patients after Alzheimers disease accounting for 15-20 of case
RADIOGRAPHIC FEATURES
MRI
Atrophy in various parts of the brain without a clearly identified unique pattern
Most helpful in distinguishing DLB from other entities resulting in dementia is the absence of features of other diseases
generalised decrease in cerebral volume most marked in
frontal lobes parietotemporal regions
enlargement of the lateral ventricles
relatively focal atrophy
midbrain
hypothalamus
SWALLOW TAIL SIGN
The swallow tail sign describes the normal axial imaging appearance of nigrosome-1 within the substantianigra on high resolution T2SWI weighted MRI
Absence of the sign (absent swallow tail sign) is reported to have a diagnostic accuracy of greater than 90 for Parkinson disease
Nuclear medicine
Occipital hypoperfusion on SPECT PET
May aid in differentiation from other types of dementia especially Alzheimers disease
TREATMENT AND PROGNOSIS
Unlike Parkinsons disease dementia with Lewy bodies respond less readily to L-dopa and also may have severe sensitivity reactions to neuroleptic drugs such as rigidity reduced consciousness pyrexia falling postural hypotension and collapse
Lewy body dementia also responds favourably to acetylcholinesteraseinhibitors
DIFFERENTIAL DIAGNOSISwith strong overlap between
bullAlzheimers diseasebull clinical may occasionally have similar clinical presentation with a frontal type dementia or posterior
cortical atrophy
bull imaging prominent involvement of hippocampi on imaging
bullFronto-temporal lobar degenerationbull clinical usually younger onset absent parkinsonian features absent visual hallucinations
bull imaging more pronounced frontal temporal atrophy L gt R asymmetry
FRONTO-TEMPORAL LOBAR DEGENERATION
Frontotemporal lobar degeneration (FTLD) is the pathological description of a group of neurodegenerative disorders characterised by focal atrophy of the frontal and temporal cortices
rontotemporal lobar degeneration can be divided as follows 3-4
bullbehavioural variant fronto-temporal lobar degeneration dementia (bvFTLD) (aka behavioural variant frontotemporal dementia)1
bulllanguage variant fronto-temporal lobar degeneration (lvFTLD) (aka primary progressive aphasia (PPA)6
bull agrammatic variant primary progressive aphasia (aka progressive non-fluent aphasia (PNFA)
bull semantic variant primary progressive aphasia (aka semantic dementia)
bull logopaenic variant primary progressive aphasia
RADIOGRAPHIC FEATURES
The frontal and temporal lobes are predominantly affected there is often striking asymmetry both of involvement of frontal vs temporal lobes and involvement of left and right hemispheres
In addition the degree of fronto-striatal dysfunction varies between the different FTLD subgroups with behavioural variant frontotemporal dementia (bvFTD) having the greatest involvement
As a result the caudate heads tend to be reduced in size in these patients to a much greater degree than in the language variants of frontotemporal dementia
BEHAVIOURAL VARIANT FRONTO-TEMPORAL LOBAR DEGENERATION (BVFTLD)also referred to as Pick disease
Patients with behavioural variant FTD typically present with a dysexecutive cognitive syndrome associated with changes in personality and social behaviour
As the disease progresses impairments in language and memory may develop and the cognitive phenotype may come to resemble one of the language variants of FTD
RADIOGRAPHIC FEATURES
MRI
typical radiographic finding is atrophy of the frontal lobes and to a lesser extent the temporal lobes
The degree of atrophy can be very asymmetric
Decrease in volume of the caudate heads This indicates loss of both efferent and afferent fibres
CREUTZFELDT-JAKOB DISEASEspongiform encephalopathy
Results in a rapidly progressive dementia
other non-specific neurological features
Three types of Creutzfeldt-Jakob disease have been described
bullsporadic (sCJD) accounts for 85-90 of cases
bullvariant (vCJD)
bullfamilial (fCJD) 10 of cases (these individuals carry a PRPc mutation)
Creutzfeldt-Jakob disease is characterized by rapidly progressive dementia cerebral atrophy myoclonus and death
Patients with vCJD present mostly with sensory and psychiatric symptoms
Patients with sCJD usually present with progressive cognitive impairment and cerebellar symptoms
PATHOLOGY
mediated via (infectious) prions
a type of protein which manifest in sheep as the disease scrapie and in cows as bovine spongiform encephalopathy
Prions are considered infectious in sense that they can alter the structure of neighbouring proteins
CJD leads to spongiform degeneration of the brain
the conversion of normal prion protein to proteinaceous infectious particles that accumulate in and around neurons and lead to cell death
RADIOGRAPHIC FEATURES
MRI
MRI findings may be bilateral or unilateral and symmetric or asymmetric and include
T2 hyperintensity
obasal ganglia (putamen and caudate)
othalamus ( hockey stick sign and pulvinar sign)
ocortex most common early manifestation
owhite matter
persistent restricted diffusion on DWI (considered the most sensitive sign)
Review of sequential studies also typically demonstrates rapidly progressive cerebral atrophy
hypometabolism on 18FDG-PET studies
TREATMENT AND PROGNOSIS
here is currently no curative treatment and the disease is invariably fatal with a mean survival of only 7 months for most cases
PROGRESSIVE SUPRANUCLEARPALSYlso known as the Steele-Richardson-Olszewski syndrome
Progressive supranuclear palsy typically becomes clinically apparent in the 6th decade of life
Progresses to death usually within a decade (2-17 years from diagnosis)
Progressive supranuclear palsy is characterised
decreased cognition
abnormal eye movements (supranuclear vertical gaze palsy)
postural instability and falls
as well as parkinsonian features and speech disturbances
RADIOGRAPHIC FEATURESMRI
midbrain atrophy
reduction of anteroposterior midline midbrain diameter at the level of the superior colliculi on axial imaging (from interpeduncular fossa to the intercolicular groove lt12mm 8) which can give a mickey mouse appearance
reduced area of the midbrain on midline sagittal and reduced midbrain to pons area ratio approx 012 (normal approx 024) on midline sagittal
Loss of the lateral convex margin of the tegmentum of midbrain has been described as the morning glory sign
hummingbird sign also known as the penguin sign The key is a flattening or concave outline to the superior aspect of the midbrain which should be upwardly convex
bullT2 diffuse high-signal lesions in
bull pontine tegmentum
bull tectum of the midbrain
bull inferior olivary nucleus
MICKEY MOUSE APPEARANCE
THE PENGUIN SIGN
MULTIPLE SYSTEM ATROPHY
sporadic neurodegenerative disease
Typically symptoms begin between 40 and 60 years of age
Clinical presentation is variable but typically presents in one of three patterns (initially described as separate entities)
Shy-Drager syndrome is used when autonomic symptoms predominate
striatonigral degeneration shows predominant parkinsonian features
olivopontocerebellar atrophy demonstrates primarily cerebellar dysfunction
MSA has been divided clinically into 2 forms according to the dominant non-autonomic symptoms
MSA-C predominance of cerebellar symptoms (olivopontocerebellar atrophy)
MSA-P predominance of parkinsonian signs and symptoms (striatonigraldegeneration)
RADIOGRAPHIC FEATURES
bullT2 hyperintensities typically present in the pontocerebellar tractsbull pons hot cross bun sign (MSA-C)
bull middle cerebellar peduncles
bull Cerebellum
putaminal findings in MSA-P reduced volume
reduced GRE and T2 signal relative to globus pallidus
reduced GRE and T2 signal relative to red nucleus
abnormal disruption of the normal high T2 linear rim
bullMSA-Cbull disproportionate atrophy of the cerebellum and brainstem (especially olivary nuclei and middle
cerebellar peduncle)
NUCLEAR MEDICINE
SPECT and PET studies tend to demonstrate hypometabolism in the superior parietal and superior frontal areas in the basal ganglia
HUNTINGTON DISEASE
autosomal dominant neurodegenerative disease
a loss of GABAergic neurons of the basal ganglia
especially atrophy of the caudate nucleus and putamen
Huntington disease has a prevalence of 5-10 per 100000 and is typically diagnosed between 30 and 50 years of age
In approximately 1-6 symptoms occur before the age of 20 so-called juvenile form
Presentation is typically with progressive rigidity choreoathetosis dementia psychosis and emotional lability
The juvenile form has a different presentation with cerebellar symptoms rigidity and hypokinesia being prominent
it is a autosomal dominant with complete penetrance and genetic anticipation particularly if inherited mutated allele is paternal
The mutation responsible is on chromosome 4p163 and consists of a CAG trineucleotide repeat
The usual 10-30 copies are amplified to greater than 36 and the greater the number of repeats the earlier the age of onset
RADIOGRAPHIC FEATURES
MRI
The most striking and best known feature is that of caudate head atrophy resulting in enlargement of the frontal horns often giving them a box like configuration
This can be quantified by an number of measurements
bullfrontal horn width to intercaudate distance ratio (FHCC)
bullintercaudate distance to inner table width ratio (CCIT)
Juvenile form
putamen are also atrophied and demonstrate increased T2 signal
basal ganglia may show decrease T2 signal and blooming on SWI in keeping with iron deposition
Generalised age inappropriate cortical volume loss is also recognised
FHCC ratio normal mean 22 to 26 (this ratio decreases with ageing as a result of enlargement of the frontal horns of the lateral ventricles)
CCIT ratio normal mean 009 to 012
AMYOTROPHIC LATERAL SCLEROSISalso known as Lou Gehrig disease or Charcot disease
Primary degeneration of the motor neurons within the brain brain stem and spinal cord
Patients typically present with progressive muscle weakness and limb and truncal atrophy combined with signs of spasticity
Mean age at the time of diagnosis is 55 years
RADIOGRAPHIC FEATURES
MRI
The earliest MR manifestation is hyperintensity on T2WI in the corticospinal tracts seen earliest in the internal capsule
Iron deposition in the cortex is demonstrated as loss of signal most evident on T2 weighted sequences
IS IT ATROPHY OR HYDROCEPHALUS
Abnormal accumulation of CSF in Ventricular system
Results from Structural or functional block to normal flow Of CSF
In effect all are obhstructive
Difficult to differentiate Atrophy from Hydrocephalus gt60yrs
Initially show increased ICT
Later stages may reach Equillibrium and Becomes NP hYdrocephalus
Types
Obstructive
Communicating
NPH ndash seen typically in old patients Diagnosis is more based on clinical feature
Dementia urinary incontinence and gait apraxias + Hydrocephalus = NPH
Radiologically w
1 degeree of ventricular dilatation is more with Thinning and bowing of CC
2 Sulcal effacement is invariable seen Hydrocephalus
3 dilatation or rounding of the Temporal Horns
4 Rounding and enlargement of the frontal horns
5 Enlargement and ballooning of 3rd
ventricle
6 Enlargement of fourth ventricle
SPOTTERS
THANK YOU
ALZHEIMER DISEASE
Alzheimer disease (AD) is a common neurodegenerative disease responsible for the majority of all dementias and imposing a significant burden on developed nations
Most common cause of dementia and accounts for two thirds of cases of dementia in patients aged 60-70 years
Epidemiological risk factor advanced age female gender
apolipoprotein E (APOE) ε4 allele carrier status
current smoking
family history of dementia
Classicaltypical Alzheimer disease
with antegrade episodic memory deficits
Neuropsychiatric symptoms are also common and eventually affect almost all patients These include apathy depression anxiety aggressionagitation and psychosis
Atypicalvariant Alzheimer disease
These entities often recognised clinically well before they were identified to be pathologically identical to Alzheimer disease
slowly progressive focal cortical atrophy with symptoms and signs matched to the affected area
Examples include
posterior cortical atrophy
frontal variant of Alzheimer disease
a minority of cases of semantic dementia
Pathology
Alzheimer disease is characterised by the accumulation of senile (neuritic) plaques neuritic (neurofibrillary) tangles and progressive loss of neurons
The progression of pathology initially involves the transentorhinalregion and then spreads to the hippocampal complex and mesial temporal lobe structures and eventually the temporal lobes and basal forebrain
RADIOGRAPHIC FEATURES
The primary role of MRI (and CT) in the diagnosis of Alzheimer disease is the assessment of volume change in characteristic locations which can yield a diagnostic accuracy of up to 87
The diagnosis should be made on the basis of two features
mesial temporal lobe atrophy
temporoparietal cortical atrophy
MESIAL TEMPORAL LOBE ATROPHY
hippocampal and parahippocampal decrease in volume
Indirectly by examining enlargement of the parahippocampalfissures
The former is more sensitive and specific but ideally requires actual volumetric calculations rather than eye-balling the scan
These measures have been combined in the medial temporal atrophy score which has been shown to be predictive of progression from mild cognitive impairment (MCI) to dementiA
MEDIAL TEMPORAL LOBE ATROPHY SCORE
visual score performed on MRI of the brain using coronal T1 weighted images through the hippocampus at the level of the anterior pons and assesses three features
width of the choroid fissure
width of the temporal horn of the lateral ventricle
height of the hippocampus
These result in a score of 0 to 4
0 = no CSF is visible around the hippocampus
1 = choroid fissure is slightly widened
2 = moderate widening of the choroid fissure mild enlargement of the temporal horn and mild loss of hippocampal height
3 = marked widening of the choroid fissure moderate enlargement of the temporal horn and moderate loss of hippocampal height
4 = marked widening of the choroid fissure marked enlargement of the temporal horn and the hippocampus is markedly atrophied and internal structure is lost
In a patient younger than 75 years of age a score of 2 or more is abnormal
In a patient 75 years or older a score of 3 or more is abnormal
Atrophy has been shown to correlate with likelihood of progression from mild cognitive impairment (MCI) to dementia 4
MRI SPECTROSCOPY
increases in myoinositol (MI) (356 ppm) thought to reflect inhibition of enzyme(s) mediating conversion of MI to phosphatidyl inositol
decreased N-acetyl aspartate (NAA) (202 ppm) indicating decreased neuronal activity
TEMPOROPARIETAL CORTICAL ATROPHY Parietal atrophy particularly relevant to posterior cortical atrophy or early onset Alzheimer disease
the inter-hemispheric surface of the parietal lobe
TREATMENT AND PROGNOSIS
There is no cure for this disease some drugs have been developed trying to improve symptoms or at least temporarily slow down their progression
cholinsterase inhibitors
partial NMDA receptor antagonists
medications for behavioural symptoms
antidepressants
anxiolytics
antiparkinsonian (movement symptoms)
anticonvulsantssedatives (behavioural)
VASCULAR DEMENTIAalso known as vascular cognitive impairment
It is primarily seen in patients with atherosclerosis and chronic hypertension
Results from the accumulation of multiple white matter or cortical infarcts although cerebral haemorrhages can be variably included
strongly correlated with age seen in only 1 of patients over the age of 55 years of age but in over 4 of patients over 71 years of age
It is also possible to divide vascular dementia into subtypes
small vessel dementia (aka Binswanger disease)
cortical vascular dementia roughly equivalent to multi-infarct dementia
strategic infarct dementia
thalamic dementia
RADIOGRAPHIC FEATURES
Both CT and MRI are able to provide evidence of ischaemic damage
MRI is more sensitive especially to white matter small vessel ischaemic change as well as to microhaemorrhages seen in cerebral amyloid angiopathy and chronic hypertensive encephalopathy
bullsmall vessel dementia (aka Binswanger disease)
bullcerebral infarction
bulllacunar infarction
bullintracerebral haemorrhage
CEREBRAL AMYLOID ANGIOPATHY
SMALL VESSEL DEMENTIA
also known as Binswanger disease
Subcortical arteriosclerotic encephalopathy
refers to slowly progressive exclusively white-matter multi-infarct dementia
A genetically transmitted form of the disease is known as familial arteriopathic leukoencephalopathy
or
CADASIL (cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy)
CLINICAL CRITERIA FOR DIAGNOSIS
marked subcortical microangiopathic lesions at MR imaging
a negative family history for strokes early cognitive impairment or psychiatric disorders in first- and second-degree relatives
documented arterial hypertension systolic values higher than 160 mm Hg diastolic values higher than 95 mm Hg or both measured at several occasions 5
MRI
subcortical and periventricular lesions visible on T2 FLAIR T2-weighted and proton-density sequences
commonly grouped around the frontal and occipital horns and in the centrum semi ovale
Moderate generalised cerebral atrophy is invariably present and lacunar infarctsin the basal ganglia and
thalami are common
CT
Diffuse incompletely symmetrical hypodensities are present in deep white matter especially they are prominent in the frontal lobes and the centrum semiovale
CEREBRAL AUTOSOMAL DOMINANT ARTERIOPATHY WITH SUBCORTICAL INFARCTS AND LEUKOENCEPHALOPATHY (CADASIL)
occurs in the absence of hypertension and arteriosclerosis and presents in 71 of cases before the age of 60 years
Imaging features demonstrate severe microvascular changes with multiple subcortical infarcts
Not distinguishable from hypertensive type microvascular disease
DEMENTIA WITH LEWY BODIESPD
Neurodegenerative disease (a synucleinopathy to be specific) related to Parkinsons disease (PD)
Epidemiology
Dementia with Lewy bodies presents in older patients (onset typically in 50-70 years of age) and is sporadic
It is the second most common neurodegenerative cause of dementia in older patients after Alzheimers disease accounting for 15-20 of case
RADIOGRAPHIC FEATURES
MRI
Atrophy in various parts of the brain without a clearly identified unique pattern
Most helpful in distinguishing DLB from other entities resulting in dementia is the absence of features of other diseases
generalised decrease in cerebral volume most marked in
frontal lobes parietotemporal regions
enlargement of the lateral ventricles
relatively focal atrophy
midbrain
hypothalamus
SWALLOW TAIL SIGN
The swallow tail sign describes the normal axial imaging appearance of nigrosome-1 within the substantianigra on high resolution T2SWI weighted MRI
Absence of the sign (absent swallow tail sign) is reported to have a diagnostic accuracy of greater than 90 for Parkinson disease
Nuclear medicine
Occipital hypoperfusion on SPECT PET
May aid in differentiation from other types of dementia especially Alzheimers disease
TREATMENT AND PROGNOSIS
Unlike Parkinsons disease dementia with Lewy bodies respond less readily to L-dopa and also may have severe sensitivity reactions to neuroleptic drugs such as rigidity reduced consciousness pyrexia falling postural hypotension and collapse
Lewy body dementia also responds favourably to acetylcholinesteraseinhibitors
DIFFERENTIAL DIAGNOSISwith strong overlap between
bullAlzheimers diseasebull clinical may occasionally have similar clinical presentation with a frontal type dementia or posterior
cortical atrophy
bull imaging prominent involvement of hippocampi on imaging
bullFronto-temporal lobar degenerationbull clinical usually younger onset absent parkinsonian features absent visual hallucinations
bull imaging more pronounced frontal temporal atrophy L gt R asymmetry
FRONTO-TEMPORAL LOBAR DEGENERATION
Frontotemporal lobar degeneration (FTLD) is the pathological description of a group of neurodegenerative disorders characterised by focal atrophy of the frontal and temporal cortices
rontotemporal lobar degeneration can be divided as follows 3-4
bullbehavioural variant fronto-temporal lobar degeneration dementia (bvFTLD) (aka behavioural variant frontotemporal dementia)1
bulllanguage variant fronto-temporal lobar degeneration (lvFTLD) (aka primary progressive aphasia (PPA)6
bull agrammatic variant primary progressive aphasia (aka progressive non-fluent aphasia (PNFA)
bull semantic variant primary progressive aphasia (aka semantic dementia)
bull logopaenic variant primary progressive aphasia
RADIOGRAPHIC FEATURES
The frontal and temporal lobes are predominantly affected there is often striking asymmetry both of involvement of frontal vs temporal lobes and involvement of left and right hemispheres
In addition the degree of fronto-striatal dysfunction varies between the different FTLD subgroups with behavioural variant frontotemporal dementia (bvFTD) having the greatest involvement
As a result the caudate heads tend to be reduced in size in these patients to a much greater degree than in the language variants of frontotemporal dementia
BEHAVIOURAL VARIANT FRONTO-TEMPORAL LOBAR DEGENERATION (BVFTLD)also referred to as Pick disease
Patients with behavioural variant FTD typically present with a dysexecutive cognitive syndrome associated with changes in personality and social behaviour
As the disease progresses impairments in language and memory may develop and the cognitive phenotype may come to resemble one of the language variants of FTD
RADIOGRAPHIC FEATURES
MRI
typical radiographic finding is atrophy of the frontal lobes and to a lesser extent the temporal lobes
The degree of atrophy can be very asymmetric
Decrease in volume of the caudate heads This indicates loss of both efferent and afferent fibres
CREUTZFELDT-JAKOB DISEASEspongiform encephalopathy
Results in a rapidly progressive dementia
other non-specific neurological features
Three types of Creutzfeldt-Jakob disease have been described
bullsporadic (sCJD) accounts for 85-90 of cases
bullvariant (vCJD)
bullfamilial (fCJD) 10 of cases (these individuals carry a PRPc mutation)
Creutzfeldt-Jakob disease is characterized by rapidly progressive dementia cerebral atrophy myoclonus and death
Patients with vCJD present mostly with sensory and psychiatric symptoms
Patients with sCJD usually present with progressive cognitive impairment and cerebellar symptoms
PATHOLOGY
mediated via (infectious) prions
a type of protein which manifest in sheep as the disease scrapie and in cows as bovine spongiform encephalopathy
Prions are considered infectious in sense that they can alter the structure of neighbouring proteins
CJD leads to spongiform degeneration of the brain
the conversion of normal prion protein to proteinaceous infectious particles that accumulate in and around neurons and lead to cell death
RADIOGRAPHIC FEATURES
MRI
MRI findings may be bilateral or unilateral and symmetric or asymmetric and include
T2 hyperintensity
obasal ganglia (putamen and caudate)
othalamus ( hockey stick sign and pulvinar sign)
ocortex most common early manifestation
owhite matter
persistent restricted diffusion on DWI (considered the most sensitive sign)
Review of sequential studies also typically demonstrates rapidly progressive cerebral atrophy
hypometabolism on 18FDG-PET studies
TREATMENT AND PROGNOSIS
here is currently no curative treatment and the disease is invariably fatal with a mean survival of only 7 months for most cases
PROGRESSIVE SUPRANUCLEARPALSYlso known as the Steele-Richardson-Olszewski syndrome
Progressive supranuclear palsy typically becomes clinically apparent in the 6th decade of life
Progresses to death usually within a decade (2-17 years from diagnosis)
Progressive supranuclear palsy is characterised
decreased cognition
abnormal eye movements (supranuclear vertical gaze palsy)
postural instability and falls
as well as parkinsonian features and speech disturbances
RADIOGRAPHIC FEATURESMRI
midbrain atrophy
reduction of anteroposterior midline midbrain diameter at the level of the superior colliculi on axial imaging (from interpeduncular fossa to the intercolicular groove lt12mm 8) which can give a mickey mouse appearance
reduced area of the midbrain on midline sagittal and reduced midbrain to pons area ratio approx 012 (normal approx 024) on midline sagittal
Loss of the lateral convex margin of the tegmentum of midbrain has been described as the morning glory sign
hummingbird sign also known as the penguin sign The key is a flattening or concave outline to the superior aspect of the midbrain which should be upwardly convex
bullT2 diffuse high-signal lesions in
bull pontine tegmentum
bull tectum of the midbrain
bull inferior olivary nucleus
MICKEY MOUSE APPEARANCE
THE PENGUIN SIGN
MULTIPLE SYSTEM ATROPHY
sporadic neurodegenerative disease
Typically symptoms begin between 40 and 60 years of age
Clinical presentation is variable but typically presents in one of three patterns (initially described as separate entities)
Shy-Drager syndrome is used when autonomic symptoms predominate
striatonigral degeneration shows predominant parkinsonian features
olivopontocerebellar atrophy demonstrates primarily cerebellar dysfunction
MSA has been divided clinically into 2 forms according to the dominant non-autonomic symptoms
MSA-C predominance of cerebellar symptoms (olivopontocerebellar atrophy)
MSA-P predominance of parkinsonian signs and symptoms (striatonigraldegeneration)
RADIOGRAPHIC FEATURES
bullT2 hyperintensities typically present in the pontocerebellar tractsbull pons hot cross bun sign (MSA-C)
bull middle cerebellar peduncles
bull Cerebellum
putaminal findings in MSA-P reduced volume
reduced GRE and T2 signal relative to globus pallidus
reduced GRE and T2 signal relative to red nucleus
abnormal disruption of the normal high T2 linear rim
bullMSA-Cbull disproportionate atrophy of the cerebellum and brainstem (especially olivary nuclei and middle
cerebellar peduncle)
NUCLEAR MEDICINE
SPECT and PET studies tend to demonstrate hypometabolism in the superior parietal and superior frontal areas in the basal ganglia
HUNTINGTON DISEASE
autosomal dominant neurodegenerative disease
a loss of GABAergic neurons of the basal ganglia
especially atrophy of the caudate nucleus and putamen
Huntington disease has a prevalence of 5-10 per 100000 and is typically diagnosed between 30 and 50 years of age
In approximately 1-6 symptoms occur before the age of 20 so-called juvenile form
Presentation is typically with progressive rigidity choreoathetosis dementia psychosis and emotional lability
The juvenile form has a different presentation with cerebellar symptoms rigidity and hypokinesia being prominent
it is a autosomal dominant with complete penetrance and genetic anticipation particularly if inherited mutated allele is paternal
The mutation responsible is on chromosome 4p163 and consists of a CAG trineucleotide repeat
The usual 10-30 copies are amplified to greater than 36 and the greater the number of repeats the earlier the age of onset
RADIOGRAPHIC FEATURES
MRI
The most striking and best known feature is that of caudate head atrophy resulting in enlargement of the frontal horns often giving them a box like configuration
This can be quantified by an number of measurements
bullfrontal horn width to intercaudate distance ratio (FHCC)
bullintercaudate distance to inner table width ratio (CCIT)
Juvenile form
putamen are also atrophied and demonstrate increased T2 signal
basal ganglia may show decrease T2 signal and blooming on SWI in keeping with iron deposition
Generalised age inappropriate cortical volume loss is also recognised
FHCC ratio normal mean 22 to 26 (this ratio decreases with ageing as a result of enlargement of the frontal horns of the lateral ventricles)
CCIT ratio normal mean 009 to 012
AMYOTROPHIC LATERAL SCLEROSISalso known as Lou Gehrig disease or Charcot disease
Primary degeneration of the motor neurons within the brain brain stem and spinal cord
Patients typically present with progressive muscle weakness and limb and truncal atrophy combined with signs of spasticity
Mean age at the time of diagnosis is 55 years
RADIOGRAPHIC FEATURES
MRI
The earliest MR manifestation is hyperintensity on T2WI in the corticospinal tracts seen earliest in the internal capsule
Iron deposition in the cortex is demonstrated as loss of signal most evident on T2 weighted sequences
IS IT ATROPHY OR HYDROCEPHALUS
Abnormal accumulation of CSF in Ventricular system
Results from Structural or functional block to normal flow Of CSF
In effect all are obhstructive
Difficult to differentiate Atrophy from Hydrocephalus gt60yrs
Initially show increased ICT
Later stages may reach Equillibrium and Becomes NP hYdrocephalus
Types
Obstructive
Communicating
NPH ndash seen typically in old patients Diagnosis is more based on clinical feature
Dementia urinary incontinence and gait apraxias + Hydrocephalus = NPH
Radiologically w
1 degeree of ventricular dilatation is more with Thinning and bowing of CC
2 Sulcal effacement is invariable seen Hydrocephalus
3 dilatation or rounding of the Temporal Horns
4 Rounding and enlargement of the frontal horns
5 Enlargement and ballooning of 3rd
ventricle
6 Enlargement of fourth ventricle
SPOTTERS
THANK YOU
Classicaltypical Alzheimer disease
with antegrade episodic memory deficits
Neuropsychiatric symptoms are also common and eventually affect almost all patients These include apathy depression anxiety aggressionagitation and psychosis
Atypicalvariant Alzheimer disease
These entities often recognised clinically well before they were identified to be pathologically identical to Alzheimer disease
slowly progressive focal cortical atrophy with symptoms and signs matched to the affected area
Examples include
posterior cortical atrophy
frontal variant of Alzheimer disease
a minority of cases of semantic dementia
Pathology
Alzheimer disease is characterised by the accumulation of senile (neuritic) plaques neuritic (neurofibrillary) tangles and progressive loss of neurons
The progression of pathology initially involves the transentorhinalregion and then spreads to the hippocampal complex and mesial temporal lobe structures and eventually the temporal lobes and basal forebrain
RADIOGRAPHIC FEATURES
The primary role of MRI (and CT) in the diagnosis of Alzheimer disease is the assessment of volume change in characteristic locations which can yield a diagnostic accuracy of up to 87
The diagnosis should be made on the basis of two features
mesial temporal lobe atrophy
temporoparietal cortical atrophy
MESIAL TEMPORAL LOBE ATROPHY
hippocampal and parahippocampal decrease in volume
Indirectly by examining enlargement of the parahippocampalfissures
The former is more sensitive and specific but ideally requires actual volumetric calculations rather than eye-balling the scan
These measures have been combined in the medial temporal atrophy score which has been shown to be predictive of progression from mild cognitive impairment (MCI) to dementiA
MEDIAL TEMPORAL LOBE ATROPHY SCORE
visual score performed on MRI of the brain using coronal T1 weighted images through the hippocampus at the level of the anterior pons and assesses three features
width of the choroid fissure
width of the temporal horn of the lateral ventricle
height of the hippocampus
These result in a score of 0 to 4
0 = no CSF is visible around the hippocampus
1 = choroid fissure is slightly widened
2 = moderate widening of the choroid fissure mild enlargement of the temporal horn and mild loss of hippocampal height
3 = marked widening of the choroid fissure moderate enlargement of the temporal horn and moderate loss of hippocampal height
4 = marked widening of the choroid fissure marked enlargement of the temporal horn and the hippocampus is markedly atrophied and internal structure is lost
In a patient younger than 75 years of age a score of 2 or more is abnormal
In a patient 75 years or older a score of 3 or more is abnormal
Atrophy has been shown to correlate with likelihood of progression from mild cognitive impairment (MCI) to dementia 4
MRI SPECTROSCOPY
increases in myoinositol (MI) (356 ppm) thought to reflect inhibition of enzyme(s) mediating conversion of MI to phosphatidyl inositol
decreased N-acetyl aspartate (NAA) (202 ppm) indicating decreased neuronal activity
TEMPOROPARIETAL CORTICAL ATROPHY Parietal atrophy particularly relevant to posterior cortical atrophy or early onset Alzheimer disease
the inter-hemispheric surface of the parietal lobe
TREATMENT AND PROGNOSIS
There is no cure for this disease some drugs have been developed trying to improve symptoms or at least temporarily slow down their progression
cholinsterase inhibitors
partial NMDA receptor antagonists
medications for behavioural symptoms
antidepressants
anxiolytics
antiparkinsonian (movement symptoms)
anticonvulsantssedatives (behavioural)
VASCULAR DEMENTIAalso known as vascular cognitive impairment
It is primarily seen in patients with atherosclerosis and chronic hypertension
Results from the accumulation of multiple white matter or cortical infarcts although cerebral haemorrhages can be variably included
strongly correlated with age seen in only 1 of patients over the age of 55 years of age but in over 4 of patients over 71 years of age
It is also possible to divide vascular dementia into subtypes
small vessel dementia (aka Binswanger disease)
cortical vascular dementia roughly equivalent to multi-infarct dementia
strategic infarct dementia
thalamic dementia
RADIOGRAPHIC FEATURES
Both CT and MRI are able to provide evidence of ischaemic damage
MRI is more sensitive especially to white matter small vessel ischaemic change as well as to microhaemorrhages seen in cerebral amyloid angiopathy and chronic hypertensive encephalopathy
bullsmall vessel dementia (aka Binswanger disease)
bullcerebral infarction
bulllacunar infarction
bullintracerebral haemorrhage
CEREBRAL AMYLOID ANGIOPATHY
SMALL VESSEL DEMENTIA
also known as Binswanger disease
Subcortical arteriosclerotic encephalopathy
refers to slowly progressive exclusively white-matter multi-infarct dementia
A genetically transmitted form of the disease is known as familial arteriopathic leukoencephalopathy
or
CADASIL (cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy)
CLINICAL CRITERIA FOR DIAGNOSIS
marked subcortical microangiopathic lesions at MR imaging
a negative family history for strokes early cognitive impairment or psychiatric disorders in first- and second-degree relatives
documented arterial hypertension systolic values higher than 160 mm Hg diastolic values higher than 95 mm Hg or both measured at several occasions 5
MRI
subcortical and periventricular lesions visible on T2 FLAIR T2-weighted and proton-density sequences
commonly grouped around the frontal and occipital horns and in the centrum semi ovale
Moderate generalised cerebral atrophy is invariably present and lacunar infarctsin the basal ganglia and
thalami are common
CT
Diffuse incompletely symmetrical hypodensities are present in deep white matter especially they are prominent in the frontal lobes and the centrum semiovale
CEREBRAL AUTOSOMAL DOMINANT ARTERIOPATHY WITH SUBCORTICAL INFARCTS AND LEUKOENCEPHALOPATHY (CADASIL)
occurs in the absence of hypertension and arteriosclerosis and presents in 71 of cases before the age of 60 years
Imaging features demonstrate severe microvascular changes with multiple subcortical infarcts
Not distinguishable from hypertensive type microvascular disease
DEMENTIA WITH LEWY BODIESPD
Neurodegenerative disease (a synucleinopathy to be specific) related to Parkinsons disease (PD)
Epidemiology
Dementia with Lewy bodies presents in older patients (onset typically in 50-70 years of age) and is sporadic
It is the second most common neurodegenerative cause of dementia in older patients after Alzheimers disease accounting for 15-20 of case
RADIOGRAPHIC FEATURES
MRI
Atrophy in various parts of the brain without a clearly identified unique pattern
Most helpful in distinguishing DLB from other entities resulting in dementia is the absence of features of other diseases
generalised decrease in cerebral volume most marked in
frontal lobes parietotemporal regions
enlargement of the lateral ventricles
relatively focal atrophy
midbrain
hypothalamus
SWALLOW TAIL SIGN
The swallow tail sign describes the normal axial imaging appearance of nigrosome-1 within the substantianigra on high resolution T2SWI weighted MRI
Absence of the sign (absent swallow tail sign) is reported to have a diagnostic accuracy of greater than 90 for Parkinson disease
Nuclear medicine
Occipital hypoperfusion on SPECT PET
May aid in differentiation from other types of dementia especially Alzheimers disease
TREATMENT AND PROGNOSIS
Unlike Parkinsons disease dementia with Lewy bodies respond less readily to L-dopa and also may have severe sensitivity reactions to neuroleptic drugs such as rigidity reduced consciousness pyrexia falling postural hypotension and collapse
Lewy body dementia also responds favourably to acetylcholinesteraseinhibitors
DIFFERENTIAL DIAGNOSISwith strong overlap between
bullAlzheimers diseasebull clinical may occasionally have similar clinical presentation with a frontal type dementia or posterior
cortical atrophy
bull imaging prominent involvement of hippocampi on imaging
bullFronto-temporal lobar degenerationbull clinical usually younger onset absent parkinsonian features absent visual hallucinations
bull imaging more pronounced frontal temporal atrophy L gt R asymmetry
FRONTO-TEMPORAL LOBAR DEGENERATION
Frontotemporal lobar degeneration (FTLD) is the pathological description of a group of neurodegenerative disorders characterised by focal atrophy of the frontal and temporal cortices
rontotemporal lobar degeneration can be divided as follows 3-4
bullbehavioural variant fronto-temporal lobar degeneration dementia (bvFTLD) (aka behavioural variant frontotemporal dementia)1
bulllanguage variant fronto-temporal lobar degeneration (lvFTLD) (aka primary progressive aphasia (PPA)6
bull agrammatic variant primary progressive aphasia (aka progressive non-fluent aphasia (PNFA)
bull semantic variant primary progressive aphasia (aka semantic dementia)
bull logopaenic variant primary progressive aphasia
RADIOGRAPHIC FEATURES
The frontal and temporal lobes are predominantly affected there is often striking asymmetry both of involvement of frontal vs temporal lobes and involvement of left and right hemispheres
In addition the degree of fronto-striatal dysfunction varies between the different FTLD subgroups with behavioural variant frontotemporal dementia (bvFTD) having the greatest involvement
As a result the caudate heads tend to be reduced in size in these patients to a much greater degree than in the language variants of frontotemporal dementia
BEHAVIOURAL VARIANT FRONTO-TEMPORAL LOBAR DEGENERATION (BVFTLD)also referred to as Pick disease
Patients with behavioural variant FTD typically present with a dysexecutive cognitive syndrome associated with changes in personality and social behaviour
As the disease progresses impairments in language and memory may develop and the cognitive phenotype may come to resemble one of the language variants of FTD
RADIOGRAPHIC FEATURES
MRI
typical radiographic finding is atrophy of the frontal lobes and to a lesser extent the temporal lobes
The degree of atrophy can be very asymmetric
Decrease in volume of the caudate heads This indicates loss of both efferent and afferent fibres
CREUTZFELDT-JAKOB DISEASEspongiform encephalopathy
Results in a rapidly progressive dementia
other non-specific neurological features
Three types of Creutzfeldt-Jakob disease have been described
bullsporadic (sCJD) accounts for 85-90 of cases
bullvariant (vCJD)
bullfamilial (fCJD) 10 of cases (these individuals carry a PRPc mutation)
Creutzfeldt-Jakob disease is characterized by rapidly progressive dementia cerebral atrophy myoclonus and death
Patients with vCJD present mostly with sensory and psychiatric symptoms
Patients with sCJD usually present with progressive cognitive impairment and cerebellar symptoms
PATHOLOGY
mediated via (infectious) prions
a type of protein which manifest in sheep as the disease scrapie and in cows as bovine spongiform encephalopathy
Prions are considered infectious in sense that they can alter the structure of neighbouring proteins
CJD leads to spongiform degeneration of the brain
the conversion of normal prion protein to proteinaceous infectious particles that accumulate in and around neurons and lead to cell death
RADIOGRAPHIC FEATURES
MRI
MRI findings may be bilateral or unilateral and symmetric or asymmetric and include
T2 hyperintensity
obasal ganglia (putamen and caudate)
othalamus ( hockey stick sign and pulvinar sign)
ocortex most common early manifestation
owhite matter
persistent restricted diffusion on DWI (considered the most sensitive sign)
Review of sequential studies also typically demonstrates rapidly progressive cerebral atrophy
hypometabolism on 18FDG-PET studies
TREATMENT AND PROGNOSIS
here is currently no curative treatment and the disease is invariably fatal with a mean survival of only 7 months for most cases
PROGRESSIVE SUPRANUCLEARPALSYlso known as the Steele-Richardson-Olszewski syndrome
Progressive supranuclear palsy typically becomes clinically apparent in the 6th decade of life
Progresses to death usually within a decade (2-17 years from diagnosis)
Progressive supranuclear palsy is characterised
decreased cognition
abnormal eye movements (supranuclear vertical gaze palsy)
postural instability and falls
as well as parkinsonian features and speech disturbances
RADIOGRAPHIC FEATURESMRI
midbrain atrophy
reduction of anteroposterior midline midbrain diameter at the level of the superior colliculi on axial imaging (from interpeduncular fossa to the intercolicular groove lt12mm 8) which can give a mickey mouse appearance
reduced area of the midbrain on midline sagittal and reduced midbrain to pons area ratio approx 012 (normal approx 024) on midline sagittal
Loss of the lateral convex margin of the tegmentum of midbrain has been described as the morning glory sign
hummingbird sign also known as the penguin sign The key is a flattening or concave outline to the superior aspect of the midbrain which should be upwardly convex
bullT2 diffuse high-signal lesions in
bull pontine tegmentum
bull tectum of the midbrain
bull inferior olivary nucleus
MICKEY MOUSE APPEARANCE
THE PENGUIN SIGN
MULTIPLE SYSTEM ATROPHY
sporadic neurodegenerative disease
Typically symptoms begin between 40 and 60 years of age
Clinical presentation is variable but typically presents in one of three patterns (initially described as separate entities)
Shy-Drager syndrome is used when autonomic symptoms predominate
striatonigral degeneration shows predominant parkinsonian features
olivopontocerebellar atrophy demonstrates primarily cerebellar dysfunction
MSA has been divided clinically into 2 forms according to the dominant non-autonomic symptoms
MSA-C predominance of cerebellar symptoms (olivopontocerebellar atrophy)
MSA-P predominance of parkinsonian signs and symptoms (striatonigraldegeneration)
RADIOGRAPHIC FEATURES
bullT2 hyperintensities typically present in the pontocerebellar tractsbull pons hot cross bun sign (MSA-C)
bull middle cerebellar peduncles
bull Cerebellum
putaminal findings in MSA-P reduced volume
reduced GRE and T2 signal relative to globus pallidus
reduced GRE and T2 signal relative to red nucleus
abnormal disruption of the normal high T2 linear rim
bullMSA-Cbull disproportionate atrophy of the cerebellum and brainstem (especially olivary nuclei and middle
cerebellar peduncle)
NUCLEAR MEDICINE
SPECT and PET studies tend to demonstrate hypometabolism in the superior parietal and superior frontal areas in the basal ganglia
HUNTINGTON DISEASE
autosomal dominant neurodegenerative disease
a loss of GABAergic neurons of the basal ganglia
especially atrophy of the caudate nucleus and putamen
Huntington disease has a prevalence of 5-10 per 100000 and is typically diagnosed between 30 and 50 years of age
In approximately 1-6 symptoms occur before the age of 20 so-called juvenile form
Presentation is typically with progressive rigidity choreoathetosis dementia psychosis and emotional lability
The juvenile form has a different presentation with cerebellar symptoms rigidity and hypokinesia being prominent
it is a autosomal dominant with complete penetrance and genetic anticipation particularly if inherited mutated allele is paternal
The mutation responsible is on chromosome 4p163 and consists of a CAG trineucleotide repeat
The usual 10-30 copies are amplified to greater than 36 and the greater the number of repeats the earlier the age of onset
RADIOGRAPHIC FEATURES
MRI
The most striking and best known feature is that of caudate head atrophy resulting in enlargement of the frontal horns often giving them a box like configuration
This can be quantified by an number of measurements
bullfrontal horn width to intercaudate distance ratio (FHCC)
bullintercaudate distance to inner table width ratio (CCIT)
Juvenile form
putamen are also atrophied and demonstrate increased T2 signal
basal ganglia may show decrease T2 signal and blooming on SWI in keeping with iron deposition
Generalised age inappropriate cortical volume loss is also recognised
FHCC ratio normal mean 22 to 26 (this ratio decreases with ageing as a result of enlargement of the frontal horns of the lateral ventricles)
CCIT ratio normal mean 009 to 012
AMYOTROPHIC LATERAL SCLEROSISalso known as Lou Gehrig disease or Charcot disease
Primary degeneration of the motor neurons within the brain brain stem and spinal cord
Patients typically present with progressive muscle weakness and limb and truncal atrophy combined with signs of spasticity
Mean age at the time of diagnosis is 55 years
RADIOGRAPHIC FEATURES
MRI
The earliest MR manifestation is hyperintensity on T2WI in the corticospinal tracts seen earliest in the internal capsule
Iron deposition in the cortex is demonstrated as loss of signal most evident on T2 weighted sequences
IS IT ATROPHY OR HYDROCEPHALUS
Abnormal accumulation of CSF in Ventricular system
Results from Structural or functional block to normal flow Of CSF
In effect all are obhstructive
Difficult to differentiate Atrophy from Hydrocephalus gt60yrs
Initially show increased ICT
Later stages may reach Equillibrium and Becomes NP hYdrocephalus
Types
Obstructive
Communicating
NPH ndash seen typically in old patients Diagnosis is more based on clinical feature
Dementia urinary incontinence and gait apraxias + Hydrocephalus = NPH
Radiologically w
1 degeree of ventricular dilatation is more with Thinning and bowing of CC
2 Sulcal effacement is invariable seen Hydrocephalus
3 dilatation or rounding of the Temporal Horns
4 Rounding and enlargement of the frontal horns
5 Enlargement and ballooning of 3rd
ventricle
6 Enlargement of fourth ventricle
SPOTTERS
THANK YOU
Pathology
Alzheimer disease is characterised by the accumulation of senile (neuritic) plaques neuritic (neurofibrillary) tangles and progressive loss of neurons
The progression of pathology initially involves the transentorhinalregion and then spreads to the hippocampal complex and mesial temporal lobe structures and eventually the temporal lobes and basal forebrain
RADIOGRAPHIC FEATURES
The primary role of MRI (and CT) in the diagnosis of Alzheimer disease is the assessment of volume change in characteristic locations which can yield a diagnostic accuracy of up to 87
The diagnosis should be made on the basis of two features
mesial temporal lobe atrophy
temporoparietal cortical atrophy
MESIAL TEMPORAL LOBE ATROPHY
hippocampal and parahippocampal decrease in volume
Indirectly by examining enlargement of the parahippocampalfissures
The former is more sensitive and specific but ideally requires actual volumetric calculations rather than eye-balling the scan
These measures have been combined in the medial temporal atrophy score which has been shown to be predictive of progression from mild cognitive impairment (MCI) to dementiA
MEDIAL TEMPORAL LOBE ATROPHY SCORE
visual score performed on MRI of the brain using coronal T1 weighted images through the hippocampus at the level of the anterior pons and assesses three features
width of the choroid fissure
width of the temporal horn of the lateral ventricle
height of the hippocampus
These result in a score of 0 to 4
0 = no CSF is visible around the hippocampus
1 = choroid fissure is slightly widened
2 = moderate widening of the choroid fissure mild enlargement of the temporal horn and mild loss of hippocampal height
3 = marked widening of the choroid fissure moderate enlargement of the temporal horn and moderate loss of hippocampal height
4 = marked widening of the choroid fissure marked enlargement of the temporal horn and the hippocampus is markedly atrophied and internal structure is lost
In a patient younger than 75 years of age a score of 2 or more is abnormal
In a patient 75 years or older a score of 3 or more is abnormal
Atrophy has been shown to correlate with likelihood of progression from mild cognitive impairment (MCI) to dementia 4
MRI SPECTROSCOPY
increases in myoinositol (MI) (356 ppm) thought to reflect inhibition of enzyme(s) mediating conversion of MI to phosphatidyl inositol
decreased N-acetyl aspartate (NAA) (202 ppm) indicating decreased neuronal activity
TEMPOROPARIETAL CORTICAL ATROPHY Parietal atrophy particularly relevant to posterior cortical atrophy or early onset Alzheimer disease
the inter-hemispheric surface of the parietal lobe
TREATMENT AND PROGNOSIS
There is no cure for this disease some drugs have been developed trying to improve symptoms or at least temporarily slow down their progression
cholinsterase inhibitors
partial NMDA receptor antagonists
medications for behavioural symptoms
antidepressants
anxiolytics
antiparkinsonian (movement symptoms)
anticonvulsantssedatives (behavioural)
VASCULAR DEMENTIAalso known as vascular cognitive impairment
It is primarily seen in patients with atherosclerosis and chronic hypertension
Results from the accumulation of multiple white matter or cortical infarcts although cerebral haemorrhages can be variably included
strongly correlated with age seen in only 1 of patients over the age of 55 years of age but in over 4 of patients over 71 years of age
It is also possible to divide vascular dementia into subtypes
small vessel dementia (aka Binswanger disease)
cortical vascular dementia roughly equivalent to multi-infarct dementia
strategic infarct dementia
thalamic dementia
RADIOGRAPHIC FEATURES
Both CT and MRI are able to provide evidence of ischaemic damage
MRI is more sensitive especially to white matter small vessel ischaemic change as well as to microhaemorrhages seen in cerebral amyloid angiopathy and chronic hypertensive encephalopathy
bullsmall vessel dementia (aka Binswanger disease)
bullcerebral infarction
bulllacunar infarction
bullintracerebral haemorrhage
CEREBRAL AMYLOID ANGIOPATHY
SMALL VESSEL DEMENTIA
also known as Binswanger disease
Subcortical arteriosclerotic encephalopathy
refers to slowly progressive exclusively white-matter multi-infarct dementia
A genetically transmitted form of the disease is known as familial arteriopathic leukoencephalopathy
or
CADASIL (cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy)
CLINICAL CRITERIA FOR DIAGNOSIS
marked subcortical microangiopathic lesions at MR imaging
a negative family history for strokes early cognitive impairment or psychiatric disorders in first- and second-degree relatives
documented arterial hypertension systolic values higher than 160 mm Hg diastolic values higher than 95 mm Hg or both measured at several occasions 5
MRI
subcortical and periventricular lesions visible on T2 FLAIR T2-weighted and proton-density sequences
commonly grouped around the frontal and occipital horns and in the centrum semi ovale
Moderate generalised cerebral atrophy is invariably present and lacunar infarctsin the basal ganglia and
thalami are common
CT
Diffuse incompletely symmetrical hypodensities are present in deep white matter especially they are prominent in the frontal lobes and the centrum semiovale
CEREBRAL AUTOSOMAL DOMINANT ARTERIOPATHY WITH SUBCORTICAL INFARCTS AND LEUKOENCEPHALOPATHY (CADASIL)
occurs in the absence of hypertension and arteriosclerosis and presents in 71 of cases before the age of 60 years
Imaging features demonstrate severe microvascular changes with multiple subcortical infarcts
Not distinguishable from hypertensive type microvascular disease
DEMENTIA WITH LEWY BODIESPD
Neurodegenerative disease (a synucleinopathy to be specific) related to Parkinsons disease (PD)
Epidemiology
Dementia with Lewy bodies presents in older patients (onset typically in 50-70 years of age) and is sporadic
It is the second most common neurodegenerative cause of dementia in older patients after Alzheimers disease accounting for 15-20 of case
RADIOGRAPHIC FEATURES
MRI
Atrophy in various parts of the brain without a clearly identified unique pattern
Most helpful in distinguishing DLB from other entities resulting in dementia is the absence of features of other diseases
generalised decrease in cerebral volume most marked in
frontal lobes parietotemporal regions
enlargement of the lateral ventricles
relatively focal atrophy
midbrain
hypothalamus
SWALLOW TAIL SIGN
The swallow tail sign describes the normal axial imaging appearance of nigrosome-1 within the substantianigra on high resolution T2SWI weighted MRI
Absence of the sign (absent swallow tail sign) is reported to have a diagnostic accuracy of greater than 90 for Parkinson disease
Nuclear medicine
Occipital hypoperfusion on SPECT PET
May aid in differentiation from other types of dementia especially Alzheimers disease
TREATMENT AND PROGNOSIS
Unlike Parkinsons disease dementia with Lewy bodies respond less readily to L-dopa and also may have severe sensitivity reactions to neuroleptic drugs such as rigidity reduced consciousness pyrexia falling postural hypotension and collapse
Lewy body dementia also responds favourably to acetylcholinesteraseinhibitors
DIFFERENTIAL DIAGNOSISwith strong overlap between
bullAlzheimers diseasebull clinical may occasionally have similar clinical presentation with a frontal type dementia or posterior
cortical atrophy
bull imaging prominent involvement of hippocampi on imaging
bullFronto-temporal lobar degenerationbull clinical usually younger onset absent parkinsonian features absent visual hallucinations
bull imaging more pronounced frontal temporal atrophy L gt R asymmetry
FRONTO-TEMPORAL LOBAR DEGENERATION
Frontotemporal lobar degeneration (FTLD) is the pathological description of a group of neurodegenerative disorders characterised by focal atrophy of the frontal and temporal cortices
rontotemporal lobar degeneration can be divided as follows 3-4
bullbehavioural variant fronto-temporal lobar degeneration dementia (bvFTLD) (aka behavioural variant frontotemporal dementia)1
bulllanguage variant fronto-temporal lobar degeneration (lvFTLD) (aka primary progressive aphasia (PPA)6
bull agrammatic variant primary progressive aphasia (aka progressive non-fluent aphasia (PNFA)
bull semantic variant primary progressive aphasia (aka semantic dementia)
bull logopaenic variant primary progressive aphasia
RADIOGRAPHIC FEATURES
The frontal and temporal lobes are predominantly affected there is often striking asymmetry both of involvement of frontal vs temporal lobes and involvement of left and right hemispheres
In addition the degree of fronto-striatal dysfunction varies between the different FTLD subgroups with behavioural variant frontotemporal dementia (bvFTD) having the greatest involvement
As a result the caudate heads tend to be reduced in size in these patients to a much greater degree than in the language variants of frontotemporal dementia
BEHAVIOURAL VARIANT FRONTO-TEMPORAL LOBAR DEGENERATION (BVFTLD)also referred to as Pick disease
Patients with behavioural variant FTD typically present with a dysexecutive cognitive syndrome associated with changes in personality and social behaviour
As the disease progresses impairments in language and memory may develop and the cognitive phenotype may come to resemble one of the language variants of FTD
RADIOGRAPHIC FEATURES
MRI
typical radiographic finding is atrophy of the frontal lobes and to a lesser extent the temporal lobes
The degree of atrophy can be very asymmetric
Decrease in volume of the caudate heads This indicates loss of both efferent and afferent fibres
CREUTZFELDT-JAKOB DISEASEspongiform encephalopathy
Results in a rapidly progressive dementia
other non-specific neurological features
Three types of Creutzfeldt-Jakob disease have been described
bullsporadic (sCJD) accounts for 85-90 of cases
bullvariant (vCJD)
bullfamilial (fCJD) 10 of cases (these individuals carry a PRPc mutation)
Creutzfeldt-Jakob disease is characterized by rapidly progressive dementia cerebral atrophy myoclonus and death
Patients with vCJD present mostly with sensory and psychiatric symptoms
Patients with sCJD usually present with progressive cognitive impairment and cerebellar symptoms
PATHOLOGY
mediated via (infectious) prions
a type of protein which manifest in sheep as the disease scrapie and in cows as bovine spongiform encephalopathy
Prions are considered infectious in sense that they can alter the structure of neighbouring proteins
CJD leads to spongiform degeneration of the brain
the conversion of normal prion protein to proteinaceous infectious particles that accumulate in and around neurons and lead to cell death
RADIOGRAPHIC FEATURES
MRI
MRI findings may be bilateral or unilateral and symmetric or asymmetric and include
T2 hyperintensity
obasal ganglia (putamen and caudate)
othalamus ( hockey stick sign and pulvinar sign)
ocortex most common early manifestation
owhite matter
persistent restricted diffusion on DWI (considered the most sensitive sign)
Review of sequential studies also typically demonstrates rapidly progressive cerebral atrophy
hypometabolism on 18FDG-PET studies
TREATMENT AND PROGNOSIS
here is currently no curative treatment and the disease is invariably fatal with a mean survival of only 7 months for most cases
PROGRESSIVE SUPRANUCLEARPALSYlso known as the Steele-Richardson-Olszewski syndrome
Progressive supranuclear palsy typically becomes clinically apparent in the 6th decade of life
Progresses to death usually within a decade (2-17 years from diagnosis)
Progressive supranuclear palsy is characterised
decreased cognition
abnormal eye movements (supranuclear vertical gaze palsy)
postural instability and falls
as well as parkinsonian features and speech disturbances
RADIOGRAPHIC FEATURESMRI
midbrain atrophy
reduction of anteroposterior midline midbrain diameter at the level of the superior colliculi on axial imaging (from interpeduncular fossa to the intercolicular groove lt12mm 8) which can give a mickey mouse appearance
reduced area of the midbrain on midline sagittal and reduced midbrain to pons area ratio approx 012 (normal approx 024) on midline sagittal
Loss of the lateral convex margin of the tegmentum of midbrain has been described as the morning glory sign
hummingbird sign also known as the penguin sign The key is a flattening or concave outline to the superior aspect of the midbrain which should be upwardly convex
bullT2 diffuse high-signal lesions in
bull pontine tegmentum
bull tectum of the midbrain
bull inferior olivary nucleus
MICKEY MOUSE APPEARANCE
THE PENGUIN SIGN
MULTIPLE SYSTEM ATROPHY
sporadic neurodegenerative disease
Typically symptoms begin between 40 and 60 years of age
Clinical presentation is variable but typically presents in one of three patterns (initially described as separate entities)
Shy-Drager syndrome is used when autonomic symptoms predominate
striatonigral degeneration shows predominant parkinsonian features
olivopontocerebellar atrophy demonstrates primarily cerebellar dysfunction
MSA has been divided clinically into 2 forms according to the dominant non-autonomic symptoms
MSA-C predominance of cerebellar symptoms (olivopontocerebellar atrophy)
MSA-P predominance of parkinsonian signs and symptoms (striatonigraldegeneration)
RADIOGRAPHIC FEATURES
bullT2 hyperintensities typically present in the pontocerebellar tractsbull pons hot cross bun sign (MSA-C)
bull middle cerebellar peduncles
bull Cerebellum
putaminal findings in MSA-P reduced volume
reduced GRE and T2 signal relative to globus pallidus
reduced GRE and T2 signal relative to red nucleus
abnormal disruption of the normal high T2 linear rim
bullMSA-Cbull disproportionate atrophy of the cerebellum and brainstem (especially olivary nuclei and middle
cerebellar peduncle)
NUCLEAR MEDICINE
SPECT and PET studies tend to demonstrate hypometabolism in the superior parietal and superior frontal areas in the basal ganglia
HUNTINGTON DISEASE
autosomal dominant neurodegenerative disease
a loss of GABAergic neurons of the basal ganglia
especially atrophy of the caudate nucleus and putamen
Huntington disease has a prevalence of 5-10 per 100000 and is typically diagnosed between 30 and 50 years of age
In approximately 1-6 symptoms occur before the age of 20 so-called juvenile form
Presentation is typically with progressive rigidity choreoathetosis dementia psychosis and emotional lability
The juvenile form has a different presentation with cerebellar symptoms rigidity and hypokinesia being prominent
it is a autosomal dominant with complete penetrance and genetic anticipation particularly if inherited mutated allele is paternal
The mutation responsible is on chromosome 4p163 and consists of a CAG trineucleotide repeat
The usual 10-30 copies are amplified to greater than 36 and the greater the number of repeats the earlier the age of onset
RADIOGRAPHIC FEATURES
MRI
The most striking and best known feature is that of caudate head atrophy resulting in enlargement of the frontal horns often giving them a box like configuration
This can be quantified by an number of measurements
bullfrontal horn width to intercaudate distance ratio (FHCC)
bullintercaudate distance to inner table width ratio (CCIT)
Juvenile form
putamen are also atrophied and demonstrate increased T2 signal
basal ganglia may show decrease T2 signal and blooming on SWI in keeping with iron deposition
Generalised age inappropriate cortical volume loss is also recognised
FHCC ratio normal mean 22 to 26 (this ratio decreases with ageing as a result of enlargement of the frontal horns of the lateral ventricles)
CCIT ratio normal mean 009 to 012
AMYOTROPHIC LATERAL SCLEROSISalso known as Lou Gehrig disease or Charcot disease
Primary degeneration of the motor neurons within the brain brain stem and spinal cord
Patients typically present with progressive muscle weakness and limb and truncal atrophy combined with signs of spasticity
Mean age at the time of diagnosis is 55 years
RADIOGRAPHIC FEATURES
MRI
The earliest MR manifestation is hyperintensity on T2WI in the corticospinal tracts seen earliest in the internal capsule
Iron deposition in the cortex is demonstrated as loss of signal most evident on T2 weighted sequences
IS IT ATROPHY OR HYDROCEPHALUS
Abnormal accumulation of CSF in Ventricular system
Results from Structural or functional block to normal flow Of CSF
In effect all are obhstructive
Difficult to differentiate Atrophy from Hydrocephalus gt60yrs
Initially show increased ICT
Later stages may reach Equillibrium and Becomes NP hYdrocephalus
Types
Obstructive
Communicating
NPH ndash seen typically in old patients Diagnosis is more based on clinical feature
Dementia urinary incontinence and gait apraxias + Hydrocephalus = NPH
Radiologically w
1 degeree of ventricular dilatation is more with Thinning and bowing of CC
2 Sulcal effacement is invariable seen Hydrocephalus
3 dilatation or rounding of the Temporal Horns
4 Rounding and enlargement of the frontal horns
5 Enlargement and ballooning of 3rd
ventricle
6 Enlargement of fourth ventricle
SPOTTERS
THANK YOU
RADIOGRAPHIC FEATURES
The primary role of MRI (and CT) in the diagnosis of Alzheimer disease is the assessment of volume change in characteristic locations which can yield a diagnostic accuracy of up to 87
The diagnosis should be made on the basis of two features
mesial temporal lobe atrophy
temporoparietal cortical atrophy
MESIAL TEMPORAL LOBE ATROPHY
hippocampal and parahippocampal decrease in volume
Indirectly by examining enlargement of the parahippocampalfissures
The former is more sensitive and specific but ideally requires actual volumetric calculations rather than eye-balling the scan
These measures have been combined in the medial temporal atrophy score which has been shown to be predictive of progression from mild cognitive impairment (MCI) to dementiA
MEDIAL TEMPORAL LOBE ATROPHY SCORE
visual score performed on MRI of the brain using coronal T1 weighted images through the hippocampus at the level of the anterior pons and assesses three features
width of the choroid fissure
width of the temporal horn of the lateral ventricle
height of the hippocampus
These result in a score of 0 to 4
0 = no CSF is visible around the hippocampus
1 = choroid fissure is slightly widened
2 = moderate widening of the choroid fissure mild enlargement of the temporal horn and mild loss of hippocampal height
3 = marked widening of the choroid fissure moderate enlargement of the temporal horn and moderate loss of hippocampal height
4 = marked widening of the choroid fissure marked enlargement of the temporal horn and the hippocampus is markedly atrophied and internal structure is lost
In a patient younger than 75 years of age a score of 2 or more is abnormal
In a patient 75 years or older a score of 3 or more is abnormal
Atrophy has been shown to correlate with likelihood of progression from mild cognitive impairment (MCI) to dementia 4
MRI SPECTROSCOPY
increases in myoinositol (MI) (356 ppm) thought to reflect inhibition of enzyme(s) mediating conversion of MI to phosphatidyl inositol
decreased N-acetyl aspartate (NAA) (202 ppm) indicating decreased neuronal activity
TEMPOROPARIETAL CORTICAL ATROPHY Parietal atrophy particularly relevant to posterior cortical atrophy or early onset Alzheimer disease
the inter-hemispheric surface of the parietal lobe
TREATMENT AND PROGNOSIS
There is no cure for this disease some drugs have been developed trying to improve symptoms or at least temporarily slow down their progression
cholinsterase inhibitors
partial NMDA receptor antagonists
medications for behavioural symptoms
antidepressants
anxiolytics
antiparkinsonian (movement symptoms)
anticonvulsantssedatives (behavioural)
VASCULAR DEMENTIAalso known as vascular cognitive impairment
It is primarily seen in patients with atherosclerosis and chronic hypertension
Results from the accumulation of multiple white matter or cortical infarcts although cerebral haemorrhages can be variably included
strongly correlated with age seen in only 1 of patients over the age of 55 years of age but in over 4 of patients over 71 years of age
It is also possible to divide vascular dementia into subtypes
small vessel dementia (aka Binswanger disease)
cortical vascular dementia roughly equivalent to multi-infarct dementia
strategic infarct dementia
thalamic dementia
RADIOGRAPHIC FEATURES
Both CT and MRI are able to provide evidence of ischaemic damage
MRI is more sensitive especially to white matter small vessel ischaemic change as well as to microhaemorrhages seen in cerebral amyloid angiopathy and chronic hypertensive encephalopathy
bullsmall vessel dementia (aka Binswanger disease)
bullcerebral infarction
bulllacunar infarction
bullintracerebral haemorrhage
CEREBRAL AMYLOID ANGIOPATHY
SMALL VESSEL DEMENTIA
also known as Binswanger disease
Subcortical arteriosclerotic encephalopathy
refers to slowly progressive exclusively white-matter multi-infarct dementia
A genetically transmitted form of the disease is known as familial arteriopathic leukoencephalopathy
or
CADASIL (cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy)
CLINICAL CRITERIA FOR DIAGNOSIS
marked subcortical microangiopathic lesions at MR imaging
a negative family history for strokes early cognitive impairment or psychiatric disorders in first- and second-degree relatives
documented arterial hypertension systolic values higher than 160 mm Hg diastolic values higher than 95 mm Hg or both measured at several occasions 5
MRI
subcortical and periventricular lesions visible on T2 FLAIR T2-weighted and proton-density sequences
commonly grouped around the frontal and occipital horns and in the centrum semi ovale
Moderate generalised cerebral atrophy is invariably present and lacunar infarctsin the basal ganglia and
thalami are common
CT
Diffuse incompletely symmetrical hypodensities are present in deep white matter especially they are prominent in the frontal lobes and the centrum semiovale
CEREBRAL AUTOSOMAL DOMINANT ARTERIOPATHY WITH SUBCORTICAL INFARCTS AND LEUKOENCEPHALOPATHY (CADASIL)
occurs in the absence of hypertension and arteriosclerosis and presents in 71 of cases before the age of 60 years
Imaging features demonstrate severe microvascular changes with multiple subcortical infarcts
Not distinguishable from hypertensive type microvascular disease
DEMENTIA WITH LEWY BODIESPD
Neurodegenerative disease (a synucleinopathy to be specific) related to Parkinsons disease (PD)
Epidemiology
Dementia with Lewy bodies presents in older patients (onset typically in 50-70 years of age) and is sporadic
It is the second most common neurodegenerative cause of dementia in older patients after Alzheimers disease accounting for 15-20 of case
RADIOGRAPHIC FEATURES
MRI
Atrophy in various parts of the brain without a clearly identified unique pattern
Most helpful in distinguishing DLB from other entities resulting in dementia is the absence of features of other diseases
generalised decrease in cerebral volume most marked in
frontal lobes parietotemporal regions
enlargement of the lateral ventricles
relatively focal atrophy
midbrain
hypothalamus
SWALLOW TAIL SIGN
The swallow tail sign describes the normal axial imaging appearance of nigrosome-1 within the substantianigra on high resolution T2SWI weighted MRI
Absence of the sign (absent swallow tail sign) is reported to have a diagnostic accuracy of greater than 90 for Parkinson disease
Nuclear medicine
Occipital hypoperfusion on SPECT PET
May aid in differentiation from other types of dementia especially Alzheimers disease
TREATMENT AND PROGNOSIS
Unlike Parkinsons disease dementia with Lewy bodies respond less readily to L-dopa and also may have severe sensitivity reactions to neuroleptic drugs such as rigidity reduced consciousness pyrexia falling postural hypotension and collapse
Lewy body dementia also responds favourably to acetylcholinesteraseinhibitors
DIFFERENTIAL DIAGNOSISwith strong overlap between
bullAlzheimers diseasebull clinical may occasionally have similar clinical presentation with a frontal type dementia or posterior
cortical atrophy
bull imaging prominent involvement of hippocampi on imaging
bullFronto-temporal lobar degenerationbull clinical usually younger onset absent parkinsonian features absent visual hallucinations
bull imaging more pronounced frontal temporal atrophy L gt R asymmetry
FRONTO-TEMPORAL LOBAR DEGENERATION
Frontotemporal lobar degeneration (FTLD) is the pathological description of a group of neurodegenerative disorders characterised by focal atrophy of the frontal and temporal cortices
rontotemporal lobar degeneration can be divided as follows 3-4
bullbehavioural variant fronto-temporal lobar degeneration dementia (bvFTLD) (aka behavioural variant frontotemporal dementia)1
bulllanguage variant fronto-temporal lobar degeneration (lvFTLD) (aka primary progressive aphasia (PPA)6
bull agrammatic variant primary progressive aphasia (aka progressive non-fluent aphasia (PNFA)
bull semantic variant primary progressive aphasia (aka semantic dementia)
bull logopaenic variant primary progressive aphasia
RADIOGRAPHIC FEATURES
The frontal and temporal lobes are predominantly affected there is often striking asymmetry both of involvement of frontal vs temporal lobes and involvement of left and right hemispheres
In addition the degree of fronto-striatal dysfunction varies between the different FTLD subgroups with behavioural variant frontotemporal dementia (bvFTD) having the greatest involvement
As a result the caudate heads tend to be reduced in size in these patients to a much greater degree than in the language variants of frontotemporal dementia
BEHAVIOURAL VARIANT FRONTO-TEMPORAL LOBAR DEGENERATION (BVFTLD)also referred to as Pick disease
Patients with behavioural variant FTD typically present with a dysexecutive cognitive syndrome associated with changes in personality and social behaviour
As the disease progresses impairments in language and memory may develop and the cognitive phenotype may come to resemble one of the language variants of FTD
RADIOGRAPHIC FEATURES
MRI
typical radiographic finding is atrophy of the frontal lobes and to a lesser extent the temporal lobes
The degree of atrophy can be very asymmetric
Decrease in volume of the caudate heads This indicates loss of both efferent and afferent fibres
CREUTZFELDT-JAKOB DISEASEspongiform encephalopathy
Results in a rapidly progressive dementia
other non-specific neurological features
Three types of Creutzfeldt-Jakob disease have been described
bullsporadic (sCJD) accounts for 85-90 of cases
bullvariant (vCJD)
bullfamilial (fCJD) 10 of cases (these individuals carry a PRPc mutation)
Creutzfeldt-Jakob disease is characterized by rapidly progressive dementia cerebral atrophy myoclonus and death
Patients with vCJD present mostly with sensory and psychiatric symptoms
Patients with sCJD usually present with progressive cognitive impairment and cerebellar symptoms
PATHOLOGY
mediated via (infectious) prions
a type of protein which manifest in sheep as the disease scrapie and in cows as bovine spongiform encephalopathy
Prions are considered infectious in sense that they can alter the structure of neighbouring proteins
CJD leads to spongiform degeneration of the brain
the conversion of normal prion protein to proteinaceous infectious particles that accumulate in and around neurons and lead to cell death
RADIOGRAPHIC FEATURES
MRI
MRI findings may be bilateral or unilateral and symmetric or asymmetric and include
T2 hyperintensity
obasal ganglia (putamen and caudate)
othalamus ( hockey stick sign and pulvinar sign)
ocortex most common early manifestation
owhite matter
persistent restricted diffusion on DWI (considered the most sensitive sign)
Review of sequential studies also typically demonstrates rapidly progressive cerebral atrophy
hypometabolism on 18FDG-PET studies
TREATMENT AND PROGNOSIS
here is currently no curative treatment and the disease is invariably fatal with a mean survival of only 7 months for most cases
PROGRESSIVE SUPRANUCLEARPALSYlso known as the Steele-Richardson-Olszewski syndrome
Progressive supranuclear palsy typically becomes clinically apparent in the 6th decade of life
Progresses to death usually within a decade (2-17 years from diagnosis)
Progressive supranuclear palsy is characterised
decreased cognition
abnormal eye movements (supranuclear vertical gaze palsy)
postural instability and falls
as well as parkinsonian features and speech disturbances
RADIOGRAPHIC FEATURESMRI
midbrain atrophy
reduction of anteroposterior midline midbrain diameter at the level of the superior colliculi on axial imaging (from interpeduncular fossa to the intercolicular groove lt12mm 8) which can give a mickey mouse appearance
reduced area of the midbrain on midline sagittal and reduced midbrain to pons area ratio approx 012 (normal approx 024) on midline sagittal
Loss of the lateral convex margin of the tegmentum of midbrain has been described as the morning glory sign
hummingbird sign also known as the penguin sign The key is a flattening or concave outline to the superior aspect of the midbrain which should be upwardly convex
bullT2 diffuse high-signal lesions in
bull pontine tegmentum
bull tectum of the midbrain
bull inferior olivary nucleus
MICKEY MOUSE APPEARANCE
THE PENGUIN SIGN
MULTIPLE SYSTEM ATROPHY
sporadic neurodegenerative disease
Typically symptoms begin between 40 and 60 years of age
Clinical presentation is variable but typically presents in one of three patterns (initially described as separate entities)
Shy-Drager syndrome is used when autonomic symptoms predominate
striatonigral degeneration shows predominant parkinsonian features
olivopontocerebellar atrophy demonstrates primarily cerebellar dysfunction
MSA has been divided clinically into 2 forms according to the dominant non-autonomic symptoms
MSA-C predominance of cerebellar symptoms (olivopontocerebellar atrophy)
MSA-P predominance of parkinsonian signs and symptoms (striatonigraldegeneration)
RADIOGRAPHIC FEATURES
bullT2 hyperintensities typically present in the pontocerebellar tractsbull pons hot cross bun sign (MSA-C)
bull middle cerebellar peduncles
bull Cerebellum
putaminal findings in MSA-P reduced volume
reduced GRE and T2 signal relative to globus pallidus
reduced GRE and T2 signal relative to red nucleus
abnormal disruption of the normal high T2 linear rim
bullMSA-Cbull disproportionate atrophy of the cerebellum and brainstem (especially olivary nuclei and middle
cerebellar peduncle)
NUCLEAR MEDICINE
SPECT and PET studies tend to demonstrate hypometabolism in the superior parietal and superior frontal areas in the basal ganglia
HUNTINGTON DISEASE
autosomal dominant neurodegenerative disease
a loss of GABAergic neurons of the basal ganglia
especially atrophy of the caudate nucleus and putamen
Huntington disease has a prevalence of 5-10 per 100000 and is typically diagnosed between 30 and 50 years of age
In approximately 1-6 symptoms occur before the age of 20 so-called juvenile form
Presentation is typically with progressive rigidity choreoathetosis dementia psychosis and emotional lability
The juvenile form has a different presentation with cerebellar symptoms rigidity and hypokinesia being prominent
it is a autosomal dominant with complete penetrance and genetic anticipation particularly if inherited mutated allele is paternal
The mutation responsible is on chromosome 4p163 and consists of a CAG trineucleotide repeat
The usual 10-30 copies are amplified to greater than 36 and the greater the number of repeats the earlier the age of onset
RADIOGRAPHIC FEATURES
MRI
The most striking and best known feature is that of caudate head atrophy resulting in enlargement of the frontal horns often giving them a box like configuration
This can be quantified by an number of measurements
bullfrontal horn width to intercaudate distance ratio (FHCC)
bullintercaudate distance to inner table width ratio (CCIT)
Juvenile form
putamen are also atrophied and demonstrate increased T2 signal
basal ganglia may show decrease T2 signal and blooming on SWI in keeping with iron deposition
Generalised age inappropriate cortical volume loss is also recognised
FHCC ratio normal mean 22 to 26 (this ratio decreases with ageing as a result of enlargement of the frontal horns of the lateral ventricles)
CCIT ratio normal mean 009 to 012
AMYOTROPHIC LATERAL SCLEROSISalso known as Lou Gehrig disease or Charcot disease
Primary degeneration of the motor neurons within the brain brain stem and spinal cord
Patients typically present with progressive muscle weakness and limb and truncal atrophy combined with signs of spasticity
Mean age at the time of diagnosis is 55 years
RADIOGRAPHIC FEATURES
MRI
The earliest MR manifestation is hyperintensity on T2WI in the corticospinal tracts seen earliest in the internal capsule
Iron deposition in the cortex is demonstrated as loss of signal most evident on T2 weighted sequences
IS IT ATROPHY OR HYDROCEPHALUS
Abnormal accumulation of CSF in Ventricular system
Results from Structural or functional block to normal flow Of CSF
In effect all are obhstructive
Difficult to differentiate Atrophy from Hydrocephalus gt60yrs
Initially show increased ICT
Later stages may reach Equillibrium and Becomes NP hYdrocephalus
Types
Obstructive
Communicating
NPH ndash seen typically in old patients Diagnosis is more based on clinical feature
Dementia urinary incontinence and gait apraxias + Hydrocephalus = NPH
Radiologically w
1 degeree of ventricular dilatation is more with Thinning and bowing of CC
2 Sulcal effacement is invariable seen Hydrocephalus
3 dilatation or rounding of the Temporal Horns
4 Rounding and enlargement of the frontal horns
5 Enlargement and ballooning of 3rd
ventricle
6 Enlargement of fourth ventricle
SPOTTERS
THANK YOU
MESIAL TEMPORAL LOBE ATROPHY
hippocampal and parahippocampal decrease in volume
Indirectly by examining enlargement of the parahippocampalfissures
The former is more sensitive and specific but ideally requires actual volumetric calculations rather than eye-balling the scan
These measures have been combined in the medial temporal atrophy score which has been shown to be predictive of progression from mild cognitive impairment (MCI) to dementiA
MEDIAL TEMPORAL LOBE ATROPHY SCORE
visual score performed on MRI of the brain using coronal T1 weighted images through the hippocampus at the level of the anterior pons and assesses three features
width of the choroid fissure
width of the temporal horn of the lateral ventricle
height of the hippocampus
These result in a score of 0 to 4
0 = no CSF is visible around the hippocampus
1 = choroid fissure is slightly widened
2 = moderate widening of the choroid fissure mild enlargement of the temporal horn and mild loss of hippocampal height
3 = marked widening of the choroid fissure moderate enlargement of the temporal horn and moderate loss of hippocampal height
4 = marked widening of the choroid fissure marked enlargement of the temporal horn and the hippocampus is markedly atrophied and internal structure is lost
In a patient younger than 75 years of age a score of 2 or more is abnormal
In a patient 75 years or older a score of 3 or more is abnormal
Atrophy has been shown to correlate with likelihood of progression from mild cognitive impairment (MCI) to dementia 4
MRI SPECTROSCOPY
increases in myoinositol (MI) (356 ppm) thought to reflect inhibition of enzyme(s) mediating conversion of MI to phosphatidyl inositol
decreased N-acetyl aspartate (NAA) (202 ppm) indicating decreased neuronal activity
TEMPOROPARIETAL CORTICAL ATROPHY Parietal atrophy particularly relevant to posterior cortical atrophy or early onset Alzheimer disease
the inter-hemispheric surface of the parietal lobe
TREATMENT AND PROGNOSIS
There is no cure for this disease some drugs have been developed trying to improve symptoms or at least temporarily slow down their progression
cholinsterase inhibitors
partial NMDA receptor antagonists
medications for behavioural symptoms
antidepressants
anxiolytics
antiparkinsonian (movement symptoms)
anticonvulsantssedatives (behavioural)
VASCULAR DEMENTIAalso known as vascular cognitive impairment
It is primarily seen in patients with atherosclerosis and chronic hypertension
Results from the accumulation of multiple white matter or cortical infarcts although cerebral haemorrhages can be variably included
strongly correlated with age seen in only 1 of patients over the age of 55 years of age but in over 4 of patients over 71 years of age
It is also possible to divide vascular dementia into subtypes
small vessel dementia (aka Binswanger disease)
cortical vascular dementia roughly equivalent to multi-infarct dementia
strategic infarct dementia
thalamic dementia
RADIOGRAPHIC FEATURES
Both CT and MRI are able to provide evidence of ischaemic damage
MRI is more sensitive especially to white matter small vessel ischaemic change as well as to microhaemorrhages seen in cerebral amyloid angiopathy and chronic hypertensive encephalopathy
bullsmall vessel dementia (aka Binswanger disease)
bullcerebral infarction
bulllacunar infarction
bullintracerebral haemorrhage
CEREBRAL AMYLOID ANGIOPATHY
SMALL VESSEL DEMENTIA
also known as Binswanger disease
Subcortical arteriosclerotic encephalopathy
refers to slowly progressive exclusively white-matter multi-infarct dementia
A genetically transmitted form of the disease is known as familial arteriopathic leukoencephalopathy
or
CADASIL (cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy)
CLINICAL CRITERIA FOR DIAGNOSIS
marked subcortical microangiopathic lesions at MR imaging
a negative family history for strokes early cognitive impairment or psychiatric disorders in first- and second-degree relatives
documented arterial hypertension systolic values higher than 160 mm Hg diastolic values higher than 95 mm Hg or both measured at several occasions 5
MRI
subcortical and periventricular lesions visible on T2 FLAIR T2-weighted and proton-density sequences
commonly grouped around the frontal and occipital horns and in the centrum semi ovale
Moderate generalised cerebral atrophy is invariably present and lacunar infarctsin the basal ganglia and
thalami are common
CT
Diffuse incompletely symmetrical hypodensities are present in deep white matter especially they are prominent in the frontal lobes and the centrum semiovale
CEREBRAL AUTOSOMAL DOMINANT ARTERIOPATHY WITH SUBCORTICAL INFARCTS AND LEUKOENCEPHALOPATHY (CADASIL)
occurs in the absence of hypertension and arteriosclerosis and presents in 71 of cases before the age of 60 years
Imaging features demonstrate severe microvascular changes with multiple subcortical infarcts
Not distinguishable from hypertensive type microvascular disease
DEMENTIA WITH LEWY BODIESPD
Neurodegenerative disease (a synucleinopathy to be specific) related to Parkinsons disease (PD)
Epidemiology
Dementia with Lewy bodies presents in older patients (onset typically in 50-70 years of age) and is sporadic
It is the second most common neurodegenerative cause of dementia in older patients after Alzheimers disease accounting for 15-20 of case
RADIOGRAPHIC FEATURES
MRI
Atrophy in various parts of the brain without a clearly identified unique pattern
Most helpful in distinguishing DLB from other entities resulting in dementia is the absence of features of other diseases
generalised decrease in cerebral volume most marked in
frontal lobes parietotemporal regions
enlargement of the lateral ventricles
relatively focal atrophy
midbrain
hypothalamus
SWALLOW TAIL SIGN
The swallow tail sign describes the normal axial imaging appearance of nigrosome-1 within the substantianigra on high resolution T2SWI weighted MRI
Absence of the sign (absent swallow tail sign) is reported to have a diagnostic accuracy of greater than 90 for Parkinson disease
Nuclear medicine
Occipital hypoperfusion on SPECT PET
May aid in differentiation from other types of dementia especially Alzheimers disease
TREATMENT AND PROGNOSIS
Unlike Parkinsons disease dementia with Lewy bodies respond less readily to L-dopa and also may have severe sensitivity reactions to neuroleptic drugs such as rigidity reduced consciousness pyrexia falling postural hypotension and collapse
Lewy body dementia also responds favourably to acetylcholinesteraseinhibitors
DIFFERENTIAL DIAGNOSISwith strong overlap between
bullAlzheimers diseasebull clinical may occasionally have similar clinical presentation with a frontal type dementia or posterior
cortical atrophy
bull imaging prominent involvement of hippocampi on imaging
bullFronto-temporal lobar degenerationbull clinical usually younger onset absent parkinsonian features absent visual hallucinations
bull imaging more pronounced frontal temporal atrophy L gt R asymmetry
FRONTO-TEMPORAL LOBAR DEGENERATION
Frontotemporal lobar degeneration (FTLD) is the pathological description of a group of neurodegenerative disorders characterised by focal atrophy of the frontal and temporal cortices
rontotemporal lobar degeneration can be divided as follows 3-4
bullbehavioural variant fronto-temporal lobar degeneration dementia (bvFTLD) (aka behavioural variant frontotemporal dementia)1
bulllanguage variant fronto-temporal lobar degeneration (lvFTLD) (aka primary progressive aphasia (PPA)6
bull agrammatic variant primary progressive aphasia (aka progressive non-fluent aphasia (PNFA)
bull semantic variant primary progressive aphasia (aka semantic dementia)
bull logopaenic variant primary progressive aphasia
RADIOGRAPHIC FEATURES
The frontal and temporal lobes are predominantly affected there is often striking asymmetry both of involvement of frontal vs temporal lobes and involvement of left and right hemispheres
In addition the degree of fronto-striatal dysfunction varies between the different FTLD subgroups with behavioural variant frontotemporal dementia (bvFTD) having the greatest involvement
As a result the caudate heads tend to be reduced in size in these patients to a much greater degree than in the language variants of frontotemporal dementia
BEHAVIOURAL VARIANT FRONTO-TEMPORAL LOBAR DEGENERATION (BVFTLD)also referred to as Pick disease
Patients with behavioural variant FTD typically present with a dysexecutive cognitive syndrome associated with changes in personality and social behaviour
As the disease progresses impairments in language and memory may develop and the cognitive phenotype may come to resemble one of the language variants of FTD
RADIOGRAPHIC FEATURES
MRI
typical radiographic finding is atrophy of the frontal lobes and to a lesser extent the temporal lobes
The degree of atrophy can be very asymmetric
Decrease in volume of the caudate heads This indicates loss of both efferent and afferent fibres
CREUTZFELDT-JAKOB DISEASEspongiform encephalopathy
Results in a rapidly progressive dementia
other non-specific neurological features
Three types of Creutzfeldt-Jakob disease have been described
bullsporadic (sCJD) accounts for 85-90 of cases
bullvariant (vCJD)
bullfamilial (fCJD) 10 of cases (these individuals carry a PRPc mutation)
Creutzfeldt-Jakob disease is characterized by rapidly progressive dementia cerebral atrophy myoclonus and death
Patients with vCJD present mostly with sensory and psychiatric symptoms
Patients with sCJD usually present with progressive cognitive impairment and cerebellar symptoms
PATHOLOGY
mediated via (infectious) prions
a type of protein which manifest in sheep as the disease scrapie and in cows as bovine spongiform encephalopathy
Prions are considered infectious in sense that they can alter the structure of neighbouring proteins
CJD leads to spongiform degeneration of the brain
the conversion of normal prion protein to proteinaceous infectious particles that accumulate in and around neurons and lead to cell death
RADIOGRAPHIC FEATURES
MRI
MRI findings may be bilateral or unilateral and symmetric or asymmetric and include
T2 hyperintensity
obasal ganglia (putamen and caudate)
othalamus ( hockey stick sign and pulvinar sign)
ocortex most common early manifestation
owhite matter
persistent restricted diffusion on DWI (considered the most sensitive sign)
Review of sequential studies also typically demonstrates rapidly progressive cerebral atrophy
hypometabolism on 18FDG-PET studies
TREATMENT AND PROGNOSIS
here is currently no curative treatment and the disease is invariably fatal with a mean survival of only 7 months for most cases
PROGRESSIVE SUPRANUCLEARPALSYlso known as the Steele-Richardson-Olszewski syndrome
Progressive supranuclear palsy typically becomes clinically apparent in the 6th decade of life
Progresses to death usually within a decade (2-17 years from diagnosis)
Progressive supranuclear palsy is characterised
decreased cognition
abnormal eye movements (supranuclear vertical gaze palsy)
postural instability and falls
as well as parkinsonian features and speech disturbances
RADIOGRAPHIC FEATURESMRI
midbrain atrophy
reduction of anteroposterior midline midbrain diameter at the level of the superior colliculi on axial imaging (from interpeduncular fossa to the intercolicular groove lt12mm 8) which can give a mickey mouse appearance
reduced area of the midbrain on midline sagittal and reduced midbrain to pons area ratio approx 012 (normal approx 024) on midline sagittal
Loss of the lateral convex margin of the tegmentum of midbrain has been described as the morning glory sign
hummingbird sign also known as the penguin sign The key is a flattening or concave outline to the superior aspect of the midbrain which should be upwardly convex
bullT2 diffuse high-signal lesions in
bull pontine tegmentum
bull tectum of the midbrain
bull inferior olivary nucleus
MICKEY MOUSE APPEARANCE
THE PENGUIN SIGN
MULTIPLE SYSTEM ATROPHY
sporadic neurodegenerative disease
Typically symptoms begin between 40 and 60 years of age
Clinical presentation is variable but typically presents in one of three patterns (initially described as separate entities)
Shy-Drager syndrome is used when autonomic symptoms predominate
striatonigral degeneration shows predominant parkinsonian features
olivopontocerebellar atrophy demonstrates primarily cerebellar dysfunction
MSA has been divided clinically into 2 forms according to the dominant non-autonomic symptoms
MSA-C predominance of cerebellar symptoms (olivopontocerebellar atrophy)
MSA-P predominance of parkinsonian signs and symptoms (striatonigraldegeneration)
RADIOGRAPHIC FEATURES
bullT2 hyperintensities typically present in the pontocerebellar tractsbull pons hot cross bun sign (MSA-C)
bull middle cerebellar peduncles
bull Cerebellum
putaminal findings in MSA-P reduced volume
reduced GRE and T2 signal relative to globus pallidus
reduced GRE and T2 signal relative to red nucleus
abnormal disruption of the normal high T2 linear rim
bullMSA-Cbull disproportionate atrophy of the cerebellum and brainstem (especially olivary nuclei and middle
cerebellar peduncle)
NUCLEAR MEDICINE
SPECT and PET studies tend to demonstrate hypometabolism in the superior parietal and superior frontal areas in the basal ganglia
HUNTINGTON DISEASE
autosomal dominant neurodegenerative disease
a loss of GABAergic neurons of the basal ganglia
especially atrophy of the caudate nucleus and putamen
Huntington disease has a prevalence of 5-10 per 100000 and is typically diagnosed between 30 and 50 years of age
In approximately 1-6 symptoms occur before the age of 20 so-called juvenile form
Presentation is typically with progressive rigidity choreoathetosis dementia psychosis and emotional lability
The juvenile form has a different presentation with cerebellar symptoms rigidity and hypokinesia being prominent
it is a autosomal dominant with complete penetrance and genetic anticipation particularly if inherited mutated allele is paternal
The mutation responsible is on chromosome 4p163 and consists of a CAG trineucleotide repeat
The usual 10-30 copies are amplified to greater than 36 and the greater the number of repeats the earlier the age of onset
RADIOGRAPHIC FEATURES
MRI
The most striking and best known feature is that of caudate head atrophy resulting in enlargement of the frontal horns often giving them a box like configuration
This can be quantified by an number of measurements
bullfrontal horn width to intercaudate distance ratio (FHCC)
bullintercaudate distance to inner table width ratio (CCIT)
Juvenile form
putamen are also atrophied and demonstrate increased T2 signal
basal ganglia may show decrease T2 signal and blooming on SWI in keeping with iron deposition
Generalised age inappropriate cortical volume loss is also recognised
FHCC ratio normal mean 22 to 26 (this ratio decreases with ageing as a result of enlargement of the frontal horns of the lateral ventricles)
CCIT ratio normal mean 009 to 012
AMYOTROPHIC LATERAL SCLEROSISalso known as Lou Gehrig disease or Charcot disease
Primary degeneration of the motor neurons within the brain brain stem and spinal cord
Patients typically present with progressive muscle weakness and limb and truncal atrophy combined with signs of spasticity
Mean age at the time of diagnosis is 55 years
RADIOGRAPHIC FEATURES
MRI
The earliest MR manifestation is hyperintensity on T2WI in the corticospinal tracts seen earliest in the internal capsule
Iron deposition in the cortex is demonstrated as loss of signal most evident on T2 weighted sequences
IS IT ATROPHY OR HYDROCEPHALUS
Abnormal accumulation of CSF in Ventricular system
Results from Structural or functional block to normal flow Of CSF
In effect all are obhstructive
Difficult to differentiate Atrophy from Hydrocephalus gt60yrs
Initially show increased ICT
Later stages may reach Equillibrium and Becomes NP hYdrocephalus
Types
Obstructive
Communicating
NPH ndash seen typically in old patients Diagnosis is more based on clinical feature
Dementia urinary incontinence and gait apraxias + Hydrocephalus = NPH
Radiologically w
1 degeree of ventricular dilatation is more with Thinning and bowing of CC
2 Sulcal effacement is invariable seen Hydrocephalus
3 dilatation or rounding of the Temporal Horns
4 Rounding and enlargement of the frontal horns
5 Enlargement and ballooning of 3rd
ventricle
6 Enlargement of fourth ventricle
SPOTTERS
THANK YOU
MEDIAL TEMPORAL LOBE ATROPHY SCORE
visual score performed on MRI of the brain using coronal T1 weighted images through the hippocampus at the level of the anterior pons and assesses three features
width of the choroid fissure
width of the temporal horn of the lateral ventricle
height of the hippocampus
These result in a score of 0 to 4
0 = no CSF is visible around the hippocampus
1 = choroid fissure is slightly widened
2 = moderate widening of the choroid fissure mild enlargement of the temporal horn and mild loss of hippocampal height
3 = marked widening of the choroid fissure moderate enlargement of the temporal horn and moderate loss of hippocampal height
4 = marked widening of the choroid fissure marked enlargement of the temporal horn and the hippocampus is markedly atrophied and internal structure is lost
In a patient younger than 75 years of age a score of 2 or more is abnormal
In a patient 75 years or older a score of 3 or more is abnormal
Atrophy has been shown to correlate with likelihood of progression from mild cognitive impairment (MCI) to dementia 4
MRI SPECTROSCOPY
increases in myoinositol (MI) (356 ppm) thought to reflect inhibition of enzyme(s) mediating conversion of MI to phosphatidyl inositol
decreased N-acetyl aspartate (NAA) (202 ppm) indicating decreased neuronal activity
TEMPOROPARIETAL CORTICAL ATROPHY Parietal atrophy particularly relevant to posterior cortical atrophy or early onset Alzheimer disease
the inter-hemispheric surface of the parietal lobe
TREATMENT AND PROGNOSIS
There is no cure for this disease some drugs have been developed trying to improve symptoms or at least temporarily slow down their progression
cholinsterase inhibitors
partial NMDA receptor antagonists
medications for behavioural symptoms
antidepressants
anxiolytics
antiparkinsonian (movement symptoms)
anticonvulsantssedatives (behavioural)
VASCULAR DEMENTIAalso known as vascular cognitive impairment
It is primarily seen in patients with atherosclerosis and chronic hypertension
Results from the accumulation of multiple white matter or cortical infarcts although cerebral haemorrhages can be variably included
strongly correlated with age seen in only 1 of patients over the age of 55 years of age but in over 4 of patients over 71 years of age
It is also possible to divide vascular dementia into subtypes
small vessel dementia (aka Binswanger disease)
cortical vascular dementia roughly equivalent to multi-infarct dementia
strategic infarct dementia
thalamic dementia
RADIOGRAPHIC FEATURES
Both CT and MRI are able to provide evidence of ischaemic damage
MRI is more sensitive especially to white matter small vessel ischaemic change as well as to microhaemorrhages seen in cerebral amyloid angiopathy and chronic hypertensive encephalopathy
bullsmall vessel dementia (aka Binswanger disease)
bullcerebral infarction
bulllacunar infarction
bullintracerebral haemorrhage
CEREBRAL AMYLOID ANGIOPATHY
SMALL VESSEL DEMENTIA
also known as Binswanger disease
Subcortical arteriosclerotic encephalopathy
refers to slowly progressive exclusively white-matter multi-infarct dementia
A genetically transmitted form of the disease is known as familial arteriopathic leukoencephalopathy
or
CADASIL (cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy)
CLINICAL CRITERIA FOR DIAGNOSIS
marked subcortical microangiopathic lesions at MR imaging
a negative family history for strokes early cognitive impairment or psychiatric disorders in first- and second-degree relatives
documented arterial hypertension systolic values higher than 160 mm Hg diastolic values higher than 95 mm Hg or both measured at several occasions 5
MRI
subcortical and periventricular lesions visible on T2 FLAIR T2-weighted and proton-density sequences
commonly grouped around the frontal and occipital horns and in the centrum semi ovale
Moderate generalised cerebral atrophy is invariably present and lacunar infarctsin the basal ganglia and
thalami are common
CT
Diffuse incompletely symmetrical hypodensities are present in deep white matter especially they are prominent in the frontal lobes and the centrum semiovale
CEREBRAL AUTOSOMAL DOMINANT ARTERIOPATHY WITH SUBCORTICAL INFARCTS AND LEUKOENCEPHALOPATHY (CADASIL)
occurs in the absence of hypertension and arteriosclerosis and presents in 71 of cases before the age of 60 years
Imaging features demonstrate severe microvascular changes with multiple subcortical infarcts
Not distinguishable from hypertensive type microvascular disease
DEMENTIA WITH LEWY BODIESPD
Neurodegenerative disease (a synucleinopathy to be specific) related to Parkinsons disease (PD)
Epidemiology
Dementia with Lewy bodies presents in older patients (onset typically in 50-70 years of age) and is sporadic
It is the second most common neurodegenerative cause of dementia in older patients after Alzheimers disease accounting for 15-20 of case
RADIOGRAPHIC FEATURES
MRI
Atrophy in various parts of the brain without a clearly identified unique pattern
Most helpful in distinguishing DLB from other entities resulting in dementia is the absence of features of other diseases
generalised decrease in cerebral volume most marked in
frontal lobes parietotemporal regions
enlargement of the lateral ventricles
relatively focal atrophy
midbrain
hypothalamus
SWALLOW TAIL SIGN
The swallow tail sign describes the normal axial imaging appearance of nigrosome-1 within the substantianigra on high resolution T2SWI weighted MRI
Absence of the sign (absent swallow tail sign) is reported to have a diagnostic accuracy of greater than 90 for Parkinson disease
Nuclear medicine
Occipital hypoperfusion on SPECT PET
May aid in differentiation from other types of dementia especially Alzheimers disease
TREATMENT AND PROGNOSIS
Unlike Parkinsons disease dementia with Lewy bodies respond less readily to L-dopa and also may have severe sensitivity reactions to neuroleptic drugs such as rigidity reduced consciousness pyrexia falling postural hypotension and collapse
Lewy body dementia also responds favourably to acetylcholinesteraseinhibitors
DIFFERENTIAL DIAGNOSISwith strong overlap between
bullAlzheimers diseasebull clinical may occasionally have similar clinical presentation with a frontal type dementia or posterior
cortical atrophy
bull imaging prominent involvement of hippocampi on imaging
bullFronto-temporal lobar degenerationbull clinical usually younger onset absent parkinsonian features absent visual hallucinations
bull imaging more pronounced frontal temporal atrophy L gt R asymmetry
FRONTO-TEMPORAL LOBAR DEGENERATION
Frontotemporal lobar degeneration (FTLD) is the pathological description of a group of neurodegenerative disorders characterised by focal atrophy of the frontal and temporal cortices
rontotemporal lobar degeneration can be divided as follows 3-4
bullbehavioural variant fronto-temporal lobar degeneration dementia (bvFTLD) (aka behavioural variant frontotemporal dementia)1
bulllanguage variant fronto-temporal lobar degeneration (lvFTLD) (aka primary progressive aphasia (PPA)6
bull agrammatic variant primary progressive aphasia (aka progressive non-fluent aphasia (PNFA)
bull semantic variant primary progressive aphasia (aka semantic dementia)
bull logopaenic variant primary progressive aphasia
RADIOGRAPHIC FEATURES
The frontal and temporal lobes are predominantly affected there is often striking asymmetry both of involvement of frontal vs temporal lobes and involvement of left and right hemispheres
In addition the degree of fronto-striatal dysfunction varies between the different FTLD subgroups with behavioural variant frontotemporal dementia (bvFTD) having the greatest involvement
As a result the caudate heads tend to be reduced in size in these patients to a much greater degree than in the language variants of frontotemporal dementia
BEHAVIOURAL VARIANT FRONTO-TEMPORAL LOBAR DEGENERATION (BVFTLD)also referred to as Pick disease
Patients with behavioural variant FTD typically present with a dysexecutive cognitive syndrome associated with changes in personality and social behaviour
As the disease progresses impairments in language and memory may develop and the cognitive phenotype may come to resemble one of the language variants of FTD
RADIOGRAPHIC FEATURES
MRI
typical radiographic finding is atrophy of the frontal lobes and to a lesser extent the temporal lobes
The degree of atrophy can be very asymmetric
Decrease in volume of the caudate heads This indicates loss of both efferent and afferent fibres
CREUTZFELDT-JAKOB DISEASEspongiform encephalopathy
Results in a rapidly progressive dementia
other non-specific neurological features
Three types of Creutzfeldt-Jakob disease have been described
bullsporadic (sCJD) accounts for 85-90 of cases
bullvariant (vCJD)
bullfamilial (fCJD) 10 of cases (these individuals carry a PRPc mutation)
Creutzfeldt-Jakob disease is characterized by rapidly progressive dementia cerebral atrophy myoclonus and death
Patients with vCJD present mostly with sensory and psychiatric symptoms
Patients with sCJD usually present with progressive cognitive impairment and cerebellar symptoms
PATHOLOGY
mediated via (infectious) prions
a type of protein which manifest in sheep as the disease scrapie and in cows as bovine spongiform encephalopathy
Prions are considered infectious in sense that they can alter the structure of neighbouring proteins
CJD leads to spongiform degeneration of the brain
the conversion of normal prion protein to proteinaceous infectious particles that accumulate in and around neurons and lead to cell death
RADIOGRAPHIC FEATURES
MRI
MRI findings may be bilateral or unilateral and symmetric or asymmetric and include
T2 hyperintensity
obasal ganglia (putamen and caudate)
othalamus ( hockey stick sign and pulvinar sign)
ocortex most common early manifestation
owhite matter
persistent restricted diffusion on DWI (considered the most sensitive sign)
Review of sequential studies also typically demonstrates rapidly progressive cerebral atrophy
hypometabolism on 18FDG-PET studies
TREATMENT AND PROGNOSIS
here is currently no curative treatment and the disease is invariably fatal with a mean survival of only 7 months for most cases
PROGRESSIVE SUPRANUCLEARPALSYlso known as the Steele-Richardson-Olszewski syndrome
Progressive supranuclear palsy typically becomes clinically apparent in the 6th decade of life
Progresses to death usually within a decade (2-17 years from diagnosis)
Progressive supranuclear palsy is characterised
decreased cognition
abnormal eye movements (supranuclear vertical gaze palsy)
postural instability and falls
as well as parkinsonian features and speech disturbances
RADIOGRAPHIC FEATURESMRI
midbrain atrophy
reduction of anteroposterior midline midbrain diameter at the level of the superior colliculi on axial imaging (from interpeduncular fossa to the intercolicular groove lt12mm 8) which can give a mickey mouse appearance
reduced area of the midbrain on midline sagittal and reduced midbrain to pons area ratio approx 012 (normal approx 024) on midline sagittal
Loss of the lateral convex margin of the tegmentum of midbrain has been described as the morning glory sign
hummingbird sign also known as the penguin sign The key is a flattening or concave outline to the superior aspect of the midbrain which should be upwardly convex
bullT2 diffuse high-signal lesions in
bull pontine tegmentum
bull tectum of the midbrain
bull inferior olivary nucleus
MICKEY MOUSE APPEARANCE
THE PENGUIN SIGN
MULTIPLE SYSTEM ATROPHY
sporadic neurodegenerative disease
Typically symptoms begin between 40 and 60 years of age
Clinical presentation is variable but typically presents in one of three patterns (initially described as separate entities)
Shy-Drager syndrome is used when autonomic symptoms predominate
striatonigral degeneration shows predominant parkinsonian features
olivopontocerebellar atrophy demonstrates primarily cerebellar dysfunction
MSA has been divided clinically into 2 forms according to the dominant non-autonomic symptoms
MSA-C predominance of cerebellar symptoms (olivopontocerebellar atrophy)
MSA-P predominance of parkinsonian signs and symptoms (striatonigraldegeneration)
RADIOGRAPHIC FEATURES
bullT2 hyperintensities typically present in the pontocerebellar tractsbull pons hot cross bun sign (MSA-C)
bull middle cerebellar peduncles
bull Cerebellum
putaminal findings in MSA-P reduced volume
reduced GRE and T2 signal relative to globus pallidus
reduced GRE and T2 signal relative to red nucleus
abnormal disruption of the normal high T2 linear rim
bullMSA-Cbull disproportionate atrophy of the cerebellum and brainstem (especially olivary nuclei and middle
cerebellar peduncle)
NUCLEAR MEDICINE
SPECT and PET studies tend to demonstrate hypometabolism in the superior parietal and superior frontal areas in the basal ganglia
HUNTINGTON DISEASE
autosomal dominant neurodegenerative disease
a loss of GABAergic neurons of the basal ganglia
especially atrophy of the caudate nucleus and putamen
Huntington disease has a prevalence of 5-10 per 100000 and is typically diagnosed between 30 and 50 years of age
In approximately 1-6 symptoms occur before the age of 20 so-called juvenile form
Presentation is typically with progressive rigidity choreoathetosis dementia psychosis and emotional lability
The juvenile form has a different presentation with cerebellar symptoms rigidity and hypokinesia being prominent
it is a autosomal dominant with complete penetrance and genetic anticipation particularly if inherited mutated allele is paternal
The mutation responsible is on chromosome 4p163 and consists of a CAG trineucleotide repeat
The usual 10-30 copies are amplified to greater than 36 and the greater the number of repeats the earlier the age of onset
RADIOGRAPHIC FEATURES
MRI
The most striking and best known feature is that of caudate head atrophy resulting in enlargement of the frontal horns often giving them a box like configuration
This can be quantified by an number of measurements
bullfrontal horn width to intercaudate distance ratio (FHCC)
bullintercaudate distance to inner table width ratio (CCIT)
Juvenile form
putamen are also atrophied and demonstrate increased T2 signal
basal ganglia may show decrease T2 signal and blooming on SWI in keeping with iron deposition
Generalised age inappropriate cortical volume loss is also recognised
FHCC ratio normal mean 22 to 26 (this ratio decreases with ageing as a result of enlargement of the frontal horns of the lateral ventricles)
CCIT ratio normal mean 009 to 012
AMYOTROPHIC LATERAL SCLEROSISalso known as Lou Gehrig disease or Charcot disease
Primary degeneration of the motor neurons within the brain brain stem and spinal cord
Patients typically present with progressive muscle weakness and limb and truncal atrophy combined with signs of spasticity
Mean age at the time of diagnosis is 55 years
RADIOGRAPHIC FEATURES
MRI
The earliest MR manifestation is hyperintensity on T2WI in the corticospinal tracts seen earliest in the internal capsule
Iron deposition in the cortex is demonstrated as loss of signal most evident on T2 weighted sequences
IS IT ATROPHY OR HYDROCEPHALUS
Abnormal accumulation of CSF in Ventricular system
Results from Structural or functional block to normal flow Of CSF
In effect all are obhstructive
Difficult to differentiate Atrophy from Hydrocephalus gt60yrs
Initially show increased ICT
Later stages may reach Equillibrium and Becomes NP hYdrocephalus
Types
Obstructive
Communicating
NPH ndash seen typically in old patients Diagnosis is more based on clinical feature
Dementia urinary incontinence and gait apraxias + Hydrocephalus = NPH
Radiologically w
1 degeree of ventricular dilatation is more with Thinning and bowing of CC
2 Sulcal effacement is invariable seen Hydrocephalus
3 dilatation or rounding of the Temporal Horns
4 Rounding and enlargement of the frontal horns
5 Enlargement and ballooning of 3rd
ventricle
6 Enlargement of fourth ventricle
SPOTTERS
THANK YOU
In a patient younger than 75 years of age a score of 2 or more is abnormal
In a patient 75 years or older a score of 3 or more is abnormal
Atrophy has been shown to correlate with likelihood of progression from mild cognitive impairment (MCI) to dementia 4
MRI SPECTROSCOPY
increases in myoinositol (MI) (356 ppm) thought to reflect inhibition of enzyme(s) mediating conversion of MI to phosphatidyl inositol
decreased N-acetyl aspartate (NAA) (202 ppm) indicating decreased neuronal activity
TEMPOROPARIETAL CORTICAL ATROPHY Parietal atrophy particularly relevant to posterior cortical atrophy or early onset Alzheimer disease
the inter-hemispheric surface of the parietal lobe
TREATMENT AND PROGNOSIS
There is no cure for this disease some drugs have been developed trying to improve symptoms or at least temporarily slow down their progression
cholinsterase inhibitors
partial NMDA receptor antagonists
medications for behavioural symptoms
antidepressants
anxiolytics
antiparkinsonian (movement symptoms)
anticonvulsantssedatives (behavioural)
VASCULAR DEMENTIAalso known as vascular cognitive impairment
It is primarily seen in patients with atherosclerosis and chronic hypertension
Results from the accumulation of multiple white matter or cortical infarcts although cerebral haemorrhages can be variably included
strongly correlated with age seen in only 1 of patients over the age of 55 years of age but in over 4 of patients over 71 years of age
It is also possible to divide vascular dementia into subtypes
small vessel dementia (aka Binswanger disease)
cortical vascular dementia roughly equivalent to multi-infarct dementia
strategic infarct dementia
thalamic dementia
RADIOGRAPHIC FEATURES
Both CT and MRI are able to provide evidence of ischaemic damage
MRI is more sensitive especially to white matter small vessel ischaemic change as well as to microhaemorrhages seen in cerebral amyloid angiopathy and chronic hypertensive encephalopathy
bullsmall vessel dementia (aka Binswanger disease)
bullcerebral infarction
bulllacunar infarction
bullintracerebral haemorrhage
CEREBRAL AMYLOID ANGIOPATHY
SMALL VESSEL DEMENTIA
also known as Binswanger disease
Subcortical arteriosclerotic encephalopathy
refers to slowly progressive exclusively white-matter multi-infarct dementia
A genetically transmitted form of the disease is known as familial arteriopathic leukoencephalopathy
or
CADASIL (cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy)
CLINICAL CRITERIA FOR DIAGNOSIS
marked subcortical microangiopathic lesions at MR imaging
a negative family history for strokes early cognitive impairment or psychiatric disorders in first- and second-degree relatives
documented arterial hypertension systolic values higher than 160 mm Hg diastolic values higher than 95 mm Hg or both measured at several occasions 5
MRI
subcortical and periventricular lesions visible on T2 FLAIR T2-weighted and proton-density sequences
commonly grouped around the frontal and occipital horns and in the centrum semi ovale
Moderate generalised cerebral atrophy is invariably present and lacunar infarctsin the basal ganglia and
thalami are common
CT
Diffuse incompletely symmetrical hypodensities are present in deep white matter especially they are prominent in the frontal lobes and the centrum semiovale
CEREBRAL AUTOSOMAL DOMINANT ARTERIOPATHY WITH SUBCORTICAL INFARCTS AND LEUKOENCEPHALOPATHY (CADASIL)
occurs in the absence of hypertension and arteriosclerosis and presents in 71 of cases before the age of 60 years
Imaging features demonstrate severe microvascular changes with multiple subcortical infarcts
Not distinguishable from hypertensive type microvascular disease
DEMENTIA WITH LEWY BODIESPD
Neurodegenerative disease (a synucleinopathy to be specific) related to Parkinsons disease (PD)
Epidemiology
Dementia with Lewy bodies presents in older patients (onset typically in 50-70 years of age) and is sporadic
It is the second most common neurodegenerative cause of dementia in older patients after Alzheimers disease accounting for 15-20 of case
RADIOGRAPHIC FEATURES
MRI
Atrophy in various parts of the brain without a clearly identified unique pattern
Most helpful in distinguishing DLB from other entities resulting in dementia is the absence of features of other diseases
generalised decrease in cerebral volume most marked in
frontal lobes parietotemporal regions
enlargement of the lateral ventricles
relatively focal atrophy
midbrain
hypothalamus
SWALLOW TAIL SIGN
The swallow tail sign describes the normal axial imaging appearance of nigrosome-1 within the substantianigra on high resolution T2SWI weighted MRI
Absence of the sign (absent swallow tail sign) is reported to have a diagnostic accuracy of greater than 90 for Parkinson disease
Nuclear medicine
Occipital hypoperfusion on SPECT PET
May aid in differentiation from other types of dementia especially Alzheimers disease
TREATMENT AND PROGNOSIS
Unlike Parkinsons disease dementia with Lewy bodies respond less readily to L-dopa and also may have severe sensitivity reactions to neuroleptic drugs such as rigidity reduced consciousness pyrexia falling postural hypotension and collapse
Lewy body dementia also responds favourably to acetylcholinesteraseinhibitors
DIFFERENTIAL DIAGNOSISwith strong overlap between
bullAlzheimers diseasebull clinical may occasionally have similar clinical presentation with a frontal type dementia or posterior
cortical atrophy
bull imaging prominent involvement of hippocampi on imaging
bullFronto-temporal lobar degenerationbull clinical usually younger onset absent parkinsonian features absent visual hallucinations
bull imaging more pronounced frontal temporal atrophy L gt R asymmetry
FRONTO-TEMPORAL LOBAR DEGENERATION
Frontotemporal lobar degeneration (FTLD) is the pathological description of a group of neurodegenerative disorders characterised by focal atrophy of the frontal and temporal cortices
rontotemporal lobar degeneration can be divided as follows 3-4
bullbehavioural variant fronto-temporal lobar degeneration dementia (bvFTLD) (aka behavioural variant frontotemporal dementia)1
bulllanguage variant fronto-temporal lobar degeneration (lvFTLD) (aka primary progressive aphasia (PPA)6
bull agrammatic variant primary progressive aphasia (aka progressive non-fluent aphasia (PNFA)
bull semantic variant primary progressive aphasia (aka semantic dementia)
bull logopaenic variant primary progressive aphasia
RADIOGRAPHIC FEATURES
The frontal and temporal lobes are predominantly affected there is often striking asymmetry both of involvement of frontal vs temporal lobes and involvement of left and right hemispheres
In addition the degree of fronto-striatal dysfunction varies between the different FTLD subgroups with behavioural variant frontotemporal dementia (bvFTD) having the greatest involvement
As a result the caudate heads tend to be reduced in size in these patients to a much greater degree than in the language variants of frontotemporal dementia
BEHAVIOURAL VARIANT FRONTO-TEMPORAL LOBAR DEGENERATION (BVFTLD)also referred to as Pick disease
Patients with behavioural variant FTD typically present with a dysexecutive cognitive syndrome associated with changes in personality and social behaviour
As the disease progresses impairments in language and memory may develop and the cognitive phenotype may come to resemble one of the language variants of FTD
RADIOGRAPHIC FEATURES
MRI
typical radiographic finding is atrophy of the frontal lobes and to a lesser extent the temporal lobes
The degree of atrophy can be very asymmetric
Decrease in volume of the caudate heads This indicates loss of both efferent and afferent fibres
CREUTZFELDT-JAKOB DISEASEspongiform encephalopathy
Results in a rapidly progressive dementia
other non-specific neurological features
Three types of Creutzfeldt-Jakob disease have been described
bullsporadic (sCJD) accounts for 85-90 of cases
bullvariant (vCJD)
bullfamilial (fCJD) 10 of cases (these individuals carry a PRPc mutation)
Creutzfeldt-Jakob disease is characterized by rapidly progressive dementia cerebral atrophy myoclonus and death
Patients with vCJD present mostly with sensory and psychiatric symptoms
Patients with sCJD usually present with progressive cognitive impairment and cerebellar symptoms
PATHOLOGY
mediated via (infectious) prions
a type of protein which manifest in sheep as the disease scrapie and in cows as bovine spongiform encephalopathy
Prions are considered infectious in sense that they can alter the structure of neighbouring proteins
CJD leads to spongiform degeneration of the brain
the conversion of normal prion protein to proteinaceous infectious particles that accumulate in and around neurons and lead to cell death
RADIOGRAPHIC FEATURES
MRI
MRI findings may be bilateral or unilateral and symmetric or asymmetric and include
T2 hyperintensity
obasal ganglia (putamen and caudate)
othalamus ( hockey stick sign and pulvinar sign)
ocortex most common early manifestation
owhite matter
persistent restricted diffusion on DWI (considered the most sensitive sign)
Review of sequential studies also typically demonstrates rapidly progressive cerebral atrophy
hypometabolism on 18FDG-PET studies
TREATMENT AND PROGNOSIS
here is currently no curative treatment and the disease is invariably fatal with a mean survival of only 7 months for most cases
PROGRESSIVE SUPRANUCLEARPALSYlso known as the Steele-Richardson-Olszewski syndrome
Progressive supranuclear palsy typically becomes clinically apparent in the 6th decade of life
Progresses to death usually within a decade (2-17 years from diagnosis)
Progressive supranuclear palsy is characterised
decreased cognition
abnormal eye movements (supranuclear vertical gaze palsy)
postural instability and falls
as well as parkinsonian features and speech disturbances
RADIOGRAPHIC FEATURESMRI
midbrain atrophy
reduction of anteroposterior midline midbrain diameter at the level of the superior colliculi on axial imaging (from interpeduncular fossa to the intercolicular groove lt12mm 8) which can give a mickey mouse appearance
reduced area of the midbrain on midline sagittal and reduced midbrain to pons area ratio approx 012 (normal approx 024) on midline sagittal
Loss of the lateral convex margin of the tegmentum of midbrain has been described as the morning glory sign
hummingbird sign also known as the penguin sign The key is a flattening or concave outline to the superior aspect of the midbrain which should be upwardly convex
bullT2 diffuse high-signal lesions in
bull pontine tegmentum
bull tectum of the midbrain
bull inferior olivary nucleus
MICKEY MOUSE APPEARANCE
THE PENGUIN SIGN
MULTIPLE SYSTEM ATROPHY
sporadic neurodegenerative disease
Typically symptoms begin between 40 and 60 years of age
Clinical presentation is variable but typically presents in one of three patterns (initially described as separate entities)
Shy-Drager syndrome is used when autonomic symptoms predominate
striatonigral degeneration shows predominant parkinsonian features
olivopontocerebellar atrophy demonstrates primarily cerebellar dysfunction
MSA has been divided clinically into 2 forms according to the dominant non-autonomic symptoms
MSA-C predominance of cerebellar symptoms (olivopontocerebellar atrophy)
MSA-P predominance of parkinsonian signs and symptoms (striatonigraldegeneration)
RADIOGRAPHIC FEATURES
bullT2 hyperintensities typically present in the pontocerebellar tractsbull pons hot cross bun sign (MSA-C)
bull middle cerebellar peduncles
bull Cerebellum
putaminal findings in MSA-P reduced volume
reduced GRE and T2 signal relative to globus pallidus
reduced GRE and T2 signal relative to red nucleus
abnormal disruption of the normal high T2 linear rim
bullMSA-Cbull disproportionate atrophy of the cerebellum and brainstem (especially olivary nuclei and middle
cerebellar peduncle)
NUCLEAR MEDICINE
SPECT and PET studies tend to demonstrate hypometabolism in the superior parietal and superior frontal areas in the basal ganglia
HUNTINGTON DISEASE
autosomal dominant neurodegenerative disease
a loss of GABAergic neurons of the basal ganglia
especially atrophy of the caudate nucleus and putamen
Huntington disease has a prevalence of 5-10 per 100000 and is typically diagnosed between 30 and 50 years of age
In approximately 1-6 symptoms occur before the age of 20 so-called juvenile form
Presentation is typically with progressive rigidity choreoathetosis dementia psychosis and emotional lability
The juvenile form has a different presentation with cerebellar symptoms rigidity and hypokinesia being prominent
it is a autosomal dominant with complete penetrance and genetic anticipation particularly if inherited mutated allele is paternal
The mutation responsible is on chromosome 4p163 and consists of a CAG trineucleotide repeat
The usual 10-30 copies are amplified to greater than 36 and the greater the number of repeats the earlier the age of onset
RADIOGRAPHIC FEATURES
MRI
The most striking and best known feature is that of caudate head atrophy resulting in enlargement of the frontal horns often giving them a box like configuration
This can be quantified by an number of measurements
bullfrontal horn width to intercaudate distance ratio (FHCC)
bullintercaudate distance to inner table width ratio (CCIT)
Juvenile form
putamen are also atrophied and demonstrate increased T2 signal
basal ganglia may show decrease T2 signal and blooming on SWI in keeping with iron deposition
Generalised age inappropriate cortical volume loss is also recognised
FHCC ratio normal mean 22 to 26 (this ratio decreases with ageing as a result of enlargement of the frontal horns of the lateral ventricles)
CCIT ratio normal mean 009 to 012
AMYOTROPHIC LATERAL SCLEROSISalso known as Lou Gehrig disease or Charcot disease
Primary degeneration of the motor neurons within the brain brain stem and spinal cord
Patients typically present with progressive muscle weakness and limb and truncal atrophy combined with signs of spasticity
Mean age at the time of diagnosis is 55 years
RADIOGRAPHIC FEATURES
MRI
The earliest MR manifestation is hyperintensity on T2WI in the corticospinal tracts seen earliest in the internal capsule
Iron deposition in the cortex is demonstrated as loss of signal most evident on T2 weighted sequences
IS IT ATROPHY OR HYDROCEPHALUS
Abnormal accumulation of CSF in Ventricular system
Results from Structural or functional block to normal flow Of CSF
In effect all are obhstructive
Difficult to differentiate Atrophy from Hydrocephalus gt60yrs
Initially show increased ICT
Later stages may reach Equillibrium and Becomes NP hYdrocephalus
Types
Obstructive
Communicating
NPH ndash seen typically in old patients Diagnosis is more based on clinical feature
Dementia urinary incontinence and gait apraxias + Hydrocephalus = NPH
Radiologically w
1 degeree of ventricular dilatation is more with Thinning and bowing of CC
2 Sulcal effacement is invariable seen Hydrocephalus
3 dilatation or rounding of the Temporal Horns
4 Rounding and enlargement of the frontal horns
5 Enlargement and ballooning of 3rd
ventricle
6 Enlargement of fourth ventricle
SPOTTERS
THANK YOU
MRI SPECTROSCOPY
increases in myoinositol (MI) (356 ppm) thought to reflect inhibition of enzyme(s) mediating conversion of MI to phosphatidyl inositol
decreased N-acetyl aspartate (NAA) (202 ppm) indicating decreased neuronal activity
TEMPOROPARIETAL CORTICAL ATROPHY Parietal atrophy particularly relevant to posterior cortical atrophy or early onset Alzheimer disease
the inter-hemispheric surface of the parietal lobe
TREATMENT AND PROGNOSIS
There is no cure for this disease some drugs have been developed trying to improve symptoms or at least temporarily slow down their progression
cholinsterase inhibitors
partial NMDA receptor antagonists
medications for behavioural symptoms
antidepressants
anxiolytics
antiparkinsonian (movement symptoms)
anticonvulsantssedatives (behavioural)
VASCULAR DEMENTIAalso known as vascular cognitive impairment
It is primarily seen in patients with atherosclerosis and chronic hypertension
Results from the accumulation of multiple white matter or cortical infarcts although cerebral haemorrhages can be variably included
strongly correlated with age seen in only 1 of patients over the age of 55 years of age but in over 4 of patients over 71 years of age
It is also possible to divide vascular dementia into subtypes
small vessel dementia (aka Binswanger disease)
cortical vascular dementia roughly equivalent to multi-infarct dementia
strategic infarct dementia
thalamic dementia
RADIOGRAPHIC FEATURES
Both CT and MRI are able to provide evidence of ischaemic damage
MRI is more sensitive especially to white matter small vessel ischaemic change as well as to microhaemorrhages seen in cerebral amyloid angiopathy and chronic hypertensive encephalopathy
bullsmall vessel dementia (aka Binswanger disease)
bullcerebral infarction
bulllacunar infarction
bullintracerebral haemorrhage
CEREBRAL AMYLOID ANGIOPATHY
SMALL VESSEL DEMENTIA
also known as Binswanger disease
Subcortical arteriosclerotic encephalopathy
refers to slowly progressive exclusively white-matter multi-infarct dementia
A genetically transmitted form of the disease is known as familial arteriopathic leukoencephalopathy
or
CADASIL (cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy)
CLINICAL CRITERIA FOR DIAGNOSIS
marked subcortical microangiopathic lesions at MR imaging
a negative family history for strokes early cognitive impairment or psychiatric disorders in first- and second-degree relatives
documented arterial hypertension systolic values higher than 160 mm Hg diastolic values higher than 95 mm Hg or both measured at several occasions 5
MRI
subcortical and periventricular lesions visible on T2 FLAIR T2-weighted and proton-density sequences
commonly grouped around the frontal and occipital horns and in the centrum semi ovale
Moderate generalised cerebral atrophy is invariably present and lacunar infarctsin the basal ganglia and
thalami are common
CT
Diffuse incompletely symmetrical hypodensities are present in deep white matter especially they are prominent in the frontal lobes and the centrum semiovale
CEREBRAL AUTOSOMAL DOMINANT ARTERIOPATHY WITH SUBCORTICAL INFARCTS AND LEUKOENCEPHALOPATHY (CADASIL)
occurs in the absence of hypertension and arteriosclerosis and presents in 71 of cases before the age of 60 years
Imaging features demonstrate severe microvascular changes with multiple subcortical infarcts
Not distinguishable from hypertensive type microvascular disease
DEMENTIA WITH LEWY BODIESPD
Neurodegenerative disease (a synucleinopathy to be specific) related to Parkinsons disease (PD)
Epidemiology
Dementia with Lewy bodies presents in older patients (onset typically in 50-70 years of age) and is sporadic
It is the second most common neurodegenerative cause of dementia in older patients after Alzheimers disease accounting for 15-20 of case
RADIOGRAPHIC FEATURES
MRI
Atrophy in various parts of the brain without a clearly identified unique pattern
Most helpful in distinguishing DLB from other entities resulting in dementia is the absence of features of other diseases
generalised decrease in cerebral volume most marked in
frontal lobes parietotemporal regions
enlargement of the lateral ventricles
relatively focal atrophy
midbrain
hypothalamus
SWALLOW TAIL SIGN
The swallow tail sign describes the normal axial imaging appearance of nigrosome-1 within the substantianigra on high resolution T2SWI weighted MRI
Absence of the sign (absent swallow tail sign) is reported to have a diagnostic accuracy of greater than 90 for Parkinson disease
Nuclear medicine
Occipital hypoperfusion on SPECT PET
May aid in differentiation from other types of dementia especially Alzheimers disease
TREATMENT AND PROGNOSIS
Unlike Parkinsons disease dementia with Lewy bodies respond less readily to L-dopa and also may have severe sensitivity reactions to neuroleptic drugs such as rigidity reduced consciousness pyrexia falling postural hypotension and collapse
Lewy body dementia also responds favourably to acetylcholinesteraseinhibitors
DIFFERENTIAL DIAGNOSISwith strong overlap between
bullAlzheimers diseasebull clinical may occasionally have similar clinical presentation with a frontal type dementia or posterior
cortical atrophy
bull imaging prominent involvement of hippocampi on imaging
bullFronto-temporal lobar degenerationbull clinical usually younger onset absent parkinsonian features absent visual hallucinations
bull imaging more pronounced frontal temporal atrophy L gt R asymmetry
FRONTO-TEMPORAL LOBAR DEGENERATION
Frontotemporal lobar degeneration (FTLD) is the pathological description of a group of neurodegenerative disorders characterised by focal atrophy of the frontal and temporal cortices
rontotemporal lobar degeneration can be divided as follows 3-4
bullbehavioural variant fronto-temporal lobar degeneration dementia (bvFTLD) (aka behavioural variant frontotemporal dementia)1
bulllanguage variant fronto-temporal lobar degeneration (lvFTLD) (aka primary progressive aphasia (PPA)6
bull agrammatic variant primary progressive aphasia (aka progressive non-fluent aphasia (PNFA)
bull semantic variant primary progressive aphasia (aka semantic dementia)
bull logopaenic variant primary progressive aphasia
RADIOGRAPHIC FEATURES
The frontal and temporal lobes are predominantly affected there is often striking asymmetry both of involvement of frontal vs temporal lobes and involvement of left and right hemispheres
In addition the degree of fronto-striatal dysfunction varies between the different FTLD subgroups with behavioural variant frontotemporal dementia (bvFTD) having the greatest involvement
As a result the caudate heads tend to be reduced in size in these patients to a much greater degree than in the language variants of frontotemporal dementia
BEHAVIOURAL VARIANT FRONTO-TEMPORAL LOBAR DEGENERATION (BVFTLD)also referred to as Pick disease
Patients with behavioural variant FTD typically present with a dysexecutive cognitive syndrome associated with changes in personality and social behaviour
As the disease progresses impairments in language and memory may develop and the cognitive phenotype may come to resemble one of the language variants of FTD
RADIOGRAPHIC FEATURES
MRI
typical radiographic finding is atrophy of the frontal lobes and to a lesser extent the temporal lobes
The degree of atrophy can be very asymmetric
Decrease in volume of the caudate heads This indicates loss of both efferent and afferent fibres
CREUTZFELDT-JAKOB DISEASEspongiform encephalopathy
Results in a rapidly progressive dementia
other non-specific neurological features
Three types of Creutzfeldt-Jakob disease have been described
bullsporadic (sCJD) accounts for 85-90 of cases
bullvariant (vCJD)
bullfamilial (fCJD) 10 of cases (these individuals carry a PRPc mutation)
Creutzfeldt-Jakob disease is characterized by rapidly progressive dementia cerebral atrophy myoclonus and death
Patients with vCJD present mostly with sensory and psychiatric symptoms
Patients with sCJD usually present with progressive cognitive impairment and cerebellar symptoms
PATHOLOGY
mediated via (infectious) prions
a type of protein which manifest in sheep as the disease scrapie and in cows as bovine spongiform encephalopathy
Prions are considered infectious in sense that they can alter the structure of neighbouring proteins
CJD leads to spongiform degeneration of the brain
the conversion of normal prion protein to proteinaceous infectious particles that accumulate in and around neurons and lead to cell death
RADIOGRAPHIC FEATURES
MRI
MRI findings may be bilateral or unilateral and symmetric or asymmetric and include
T2 hyperintensity
obasal ganglia (putamen and caudate)
othalamus ( hockey stick sign and pulvinar sign)
ocortex most common early manifestation
owhite matter
persistent restricted diffusion on DWI (considered the most sensitive sign)
Review of sequential studies also typically demonstrates rapidly progressive cerebral atrophy
hypometabolism on 18FDG-PET studies
TREATMENT AND PROGNOSIS
here is currently no curative treatment and the disease is invariably fatal with a mean survival of only 7 months for most cases
PROGRESSIVE SUPRANUCLEARPALSYlso known as the Steele-Richardson-Olszewski syndrome
Progressive supranuclear palsy typically becomes clinically apparent in the 6th decade of life
Progresses to death usually within a decade (2-17 years from diagnosis)
Progressive supranuclear palsy is characterised
decreased cognition
abnormal eye movements (supranuclear vertical gaze palsy)
postural instability and falls
as well as parkinsonian features and speech disturbances
RADIOGRAPHIC FEATURESMRI
midbrain atrophy
reduction of anteroposterior midline midbrain diameter at the level of the superior colliculi on axial imaging (from interpeduncular fossa to the intercolicular groove lt12mm 8) which can give a mickey mouse appearance
reduced area of the midbrain on midline sagittal and reduced midbrain to pons area ratio approx 012 (normal approx 024) on midline sagittal
Loss of the lateral convex margin of the tegmentum of midbrain has been described as the morning glory sign
hummingbird sign also known as the penguin sign The key is a flattening or concave outline to the superior aspect of the midbrain which should be upwardly convex
bullT2 diffuse high-signal lesions in
bull pontine tegmentum
bull tectum of the midbrain
bull inferior olivary nucleus
MICKEY MOUSE APPEARANCE
THE PENGUIN SIGN
MULTIPLE SYSTEM ATROPHY
sporadic neurodegenerative disease
Typically symptoms begin between 40 and 60 years of age
Clinical presentation is variable but typically presents in one of three patterns (initially described as separate entities)
Shy-Drager syndrome is used when autonomic symptoms predominate
striatonigral degeneration shows predominant parkinsonian features
olivopontocerebellar atrophy demonstrates primarily cerebellar dysfunction
MSA has been divided clinically into 2 forms according to the dominant non-autonomic symptoms
MSA-C predominance of cerebellar symptoms (olivopontocerebellar atrophy)
MSA-P predominance of parkinsonian signs and symptoms (striatonigraldegeneration)
RADIOGRAPHIC FEATURES
bullT2 hyperintensities typically present in the pontocerebellar tractsbull pons hot cross bun sign (MSA-C)
bull middle cerebellar peduncles
bull Cerebellum
putaminal findings in MSA-P reduced volume
reduced GRE and T2 signal relative to globus pallidus
reduced GRE and T2 signal relative to red nucleus
abnormal disruption of the normal high T2 linear rim
bullMSA-Cbull disproportionate atrophy of the cerebellum and brainstem (especially olivary nuclei and middle
cerebellar peduncle)
NUCLEAR MEDICINE
SPECT and PET studies tend to demonstrate hypometabolism in the superior parietal and superior frontal areas in the basal ganglia
HUNTINGTON DISEASE
autosomal dominant neurodegenerative disease
a loss of GABAergic neurons of the basal ganglia
especially atrophy of the caudate nucleus and putamen
Huntington disease has a prevalence of 5-10 per 100000 and is typically diagnosed between 30 and 50 years of age
In approximately 1-6 symptoms occur before the age of 20 so-called juvenile form
Presentation is typically with progressive rigidity choreoathetosis dementia psychosis and emotional lability
The juvenile form has a different presentation with cerebellar symptoms rigidity and hypokinesia being prominent
it is a autosomal dominant with complete penetrance and genetic anticipation particularly if inherited mutated allele is paternal
The mutation responsible is on chromosome 4p163 and consists of a CAG trineucleotide repeat
The usual 10-30 copies are amplified to greater than 36 and the greater the number of repeats the earlier the age of onset
RADIOGRAPHIC FEATURES
MRI
The most striking and best known feature is that of caudate head atrophy resulting in enlargement of the frontal horns often giving them a box like configuration
This can be quantified by an number of measurements
bullfrontal horn width to intercaudate distance ratio (FHCC)
bullintercaudate distance to inner table width ratio (CCIT)
Juvenile form
putamen are also atrophied and demonstrate increased T2 signal
basal ganglia may show decrease T2 signal and blooming on SWI in keeping with iron deposition
Generalised age inappropriate cortical volume loss is also recognised
FHCC ratio normal mean 22 to 26 (this ratio decreases with ageing as a result of enlargement of the frontal horns of the lateral ventricles)
CCIT ratio normal mean 009 to 012
AMYOTROPHIC LATERAL SCLEROSISalso known as Lou Gehrig disease or Charcot disease
Primary degeneration of the motor neurons within the brain brain stem and spinal cord
Patients typically present with progressive muscle weakness and limb and truncal atrophy combined with signs of spasticity
Mean age at the time of diagnosis is 55 years
RADIOGRAPHIC FEATURES
MRI
The earliest MR manifestation is hyperintensity on T2WI in the corticospinal tracts seen earliest in the internal capsule
Iron deposition in the cortex is demonstrated as loss of signal most evident on T2 weighted sequences
IS IT ATROPHY OR HYDROCEPHALUS
Abnormal accumulation of CSF in Ventricular system
Results from Structural or functional block to normal flow Of CSF
In effect all are obhstructive
Difficult to differentiate Atrophy from Hydrocephalus gt60yrs
Initially show increased ICT
Later stages may reach Equillibrium and Becomes NP hYdrocephalus
Types
Obstructive
Communicating
NPH ndash seen typically in old patients Diagnosis is more based on clinical feature
Dementia urinary incontinence and gait apraxias + Hydrocephalus = NPH
Radiologically w
1 degeree of ventricular dilatation is more with Thinning and bowing of CC
2 Sulcal effacement is invariable seen Hydrocephalus
3 dilatation or rounding of the Temporal Horns
4 Rounding and enlargement of the frontal horns
5 Enlargement and ballooning of 3rd
ventricle
6 Enlargement of fourth ventricle
SPOTTERS
THANK YOU
TEMPOROPARIETAL CORTICAL ATROPHY Parietal atrophy particularly relevant to posterior cortical atrophy or early onset Alzheimer disease
the inter-hemispheric surface of the parietal lobe
TREATMENT AND PROGNOSIS
There is no cure for this disease some drugs have been developed trying to improve symptoms or at least temporarily slow down their progression
cholinsterase inhibitors
partial NMDA receptor antagonists
medications for behavioural symptoms
antidepressants
anxiolytics
antiparkinsonian (movement symptoms)
anticonvulsantssedatives (behavioural)
VASCULAR DEMENTIAalso known as vascular cognitive impairment
It is primarily seen in patients with atherosclerosis and chronic hypertension
Results from the accumulation of multiple white matter or cortical infarcts although cerebral haemorrhages can be variably included
strongly correlated with age seen in only 1 of patients over the age of 55 years of age but in over 4 of patients over 71 years of age
It is also possible to divide vascular dementia into subtypes
small vessel dementia (aka Binswanger disease)
cortical vascular dementia roughly equivalent to multi-infarct dementia
strategic infarct dementia
thalamic dementia
RADIOGRAPHIC FEATURES
Both CT and MRI are able to provide evidence of ischaemic damage
MRI is more sensitive especially to white matter small vessel ischaemic change as well as to microhaemorrhages seen in cerebral amyloid angiopathy and chronic hypertensive encephalopathy
bullsmall vessel dementia (aka Binswanger disease)
bullcerebral infarction
bulllacunar infarction
bullintracerebral haemorrhage
CEREBRAL AMYLOID ANGIOPATHY
SMALL VESSEL DEMENTIA
also known as Binswanger disease
Subcortical arteriosclerotic encephalopathy
refers to slowly progressive exclusively white-matter multi-infarct dementia
A genetically transmitted form of the disease is known as familial arteriopathic leukoencephalopathy
or
CADASIL (cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy)
CLINICAL CRITERIA FOR DIAGNOSIS
marked subcortical microangiopathic lesions at MR imaging
a negative family history for strokes early cognitive impairment or psychiatric disorders in first- and second-degree relatives
documented arterial hypertension systolic values higher than 160 mm Hg diastolic values higher than 95 mm Hg or both measured at several occasions 5
MRI
subcortical and periventricular lesions visible on T2 FLAIR T2-weighted and proton-density sequences
commonly grouped around the frontal and occipital horns and in the centrum semi ovale
Moderate generalised cerebral atrophy is invariably present and lacunar infarctsin the basal ganglia and
thalami are common
CT
Diffuse incompletely symmetrical hypodensities are present in deep white matter especially they are prominent in the frontal lobes and the centrum semiovale
CEREBRAL AUTOSOMAL DOMINANT ARTERIOPATHY WITH SUBCORTICAL INFARCTS AND LEUKOENCEPHALOPATHY (CADASIL)
occurs in the absence of hypertension and arteriosclerosis and presents in 71 of cases before the age of 60 years
Imaging features demonstrate severe microvascular changes with multiple subcortical infarcts
Not distinguishable from hypertensive type microvascular disease
DEMENTIA WITH LEWY BODIESPD
Neurodegenerative disease (a synucleinopathy to be specific) related to Parkinsons disease (PD)
Epidemiology
Dementia with Lewy bodies presents in older patients (onset typically in 50-70 years of age) and is sporadic
It is the second most common neurodegenerative cause of dementia in older patients after Alzheimers disease accounting for 15-20 of case
RADIOGRAPHIC FEATURES
MRI
Atrophy in various parts of the brain without a clearly identified unique pattern
Most helpful in distinguishing DLB from other entities resulting in dementia is the absence of features of other diseases
generalised decrease in cerebral volume most marked in
frontal lobes parietotemporal regions
enlargement of the lateral ventricles
relatively focal atrophy
midbrain
hypothalamus
SWALLOW TAIL SIGN
The swallow tail sign describes the normal axial imaging appearance of nigrosome-1 within the substantianigra on high resolution T2SWI weighted MRI
Absence of the sign (absent swallow tail sign) is reported to have a diagnostic accuracy of greater than 90 for Parkinson disease
Nuclear medicine
Occipital hypoperfusion on SPECT PET
May aid in differentiation from other types of dementia especially Alzheimers disease
TREATMENT AND PROGNOSIS
Unlike Parkinsons disease dementia with Lewy bodies respond less readily to L-dopa and also may have severe sensitivity reactions to neuroleptic drugs such as rigidity reduced consciousness pyrexia falling postural hypotension and collapse
Lewy body dementia also responds favourably to acetylcholinesteraseinhibitors
DIFFERENTIAL DIAGNOSISwith strong overlap between
bullAlzheimers diseasebull clinical may occasionally have similar clinical presentation with a frontal type dementia or posterior
cortical atrophy
bull imaging prominent involvement of hippocampi on imaging
bullFronto-temporal lobar degenerationbull clinical usually younger onset absent parkinsonian features absent visual hallucinations
bull imaging more pronounced frontal temporal atrophy L gt R asymmetry
FRONTO-TEMPORAL LOBAR DEGENERATION
Frontotemporal lobar degeneration (FTLD) is the pathological description of a group of neurodegenerative disorders characterised by focal atrophy of the frontal and temporal cortices
rontotemporal lobar degeneration can be divided as follows 3-4
bullbehavioural variant fronto-temporal lobar degeneration dementia (bvFTLD) (aka behavioural variant frontotemporal dementia)1
bulllanguage variant fronto-temporal lobar degeneration (lvFTLD) (aka primary progressive aphasia (PPA)6
bull agrammatic variant primary progressive aphasia (aka progressive non-fluent aphasia (PNFA)
bull semantic variant primary progressive aphasia (aka semantic dementia)
bull logopaenic variant primary progressive aphasia
RADIOGRAPHIC FEATURES
The frontal and temporal lobes are predominantly affected there is often striking asymmetry both of involvement of frontal vs temporal lobes and involvement of left and right hemispheres
In addition the degree of fronto-striatal dysfunction varies between the different FTLD subgroups with behavioural variant frontotemporal dementia (bvFTD) having the greatest involvement
As a result the caudate heads tend to be reduced in size in these patients to a much greater degree than in the language variants of frontotemporal dementia
BEHAVIOURAL VARIANT FRONTO-TEMPORAL LOBAR DEGENERATION (BVFTLD)also referred to as Pick disease
Patients with behavioural variant FTD typically present with a dysexecutive cognitive syndrome associated with changes in personality and social behaviour
As the disease progresses impairments in language and memory may develop and the cognitive phenotype may come to resemble one of the language variants of FTD
RADIOGRAPHIC FEATURES
MRI
typical radiographic finding is atrophy of the frontal lobes and to a lesser extent the temporal lobes
The degree of atrophy can be very asymmetric
Decrease in volume of the caudate heads This indicates loss of both efferent and afferent fibres
CREUTZFELDT-JAKOB DISEASEspongiform encephalopathy
Results in a rapidly progressive dementia
other non-specific neurological features
Three types of Creutzfeldt-Jakob disease have been described
bullsporadic (sCJD) accounts for 85-90 of cases
bullvariant (vCJD)
bullfamilial (fCJD) 10 of cases (these individuals carry a PRPc mutation)
Creutzfeldt-Jakob disease is characterized by rapidly progressive dementia cerebral atrophy myoclonus and death
Patients with vCJD present mostly with sensory and psychiatric symptoms
Patients with sCJD usually present with progressive cognitive impairment and cerebellar symptoms
PATHOLOGY
mediated via (infectious) prions
a type of protein which manifest in sheep as the disease scrapie and in cows as bovine spongiform encephalopathy
Prions are considered infectious in sense that they can alter the structure of neighbouring proteins
CJD leads to spongiform degeneration of the brain
the conversion of normal prion protein to proteinaceous infectious particles that accumulate in and around neurons and lead to cell death
RADIOGRAPHIC FEATURES
MRI
MRI findings may be bilateral or unilateral and symmetric or asymmetric and include
T2 hyperintensity
obasal ganglia (putamen and caudate)
othalamus ( hockey stick sign and pulvinar sign)
ocortex most common early manifestation
owhite matter
persistent restricted diffusion on DWI (considered the most sensitive sign)
Review of sequential studies also typically demonstrates rapidly progressive cerebral atrophy
hypometabolism on 18FDG-PET studies
TREATMENT AND PROGNOSIS
here is currently no curative treatment and the disease is invariably fatal with a mean survival of only 7 months for most cases
PROGRESSIVE SUPRANUCLEARPALSYlso known as the Steele-Richardson-Olszewski syndrome
Progressive supranuclear palsy typically becomes clinically apparent in the 6th decade of life
Progresses to death usually within a decade (2-17 years from diagnosis)
Progressive supranuclear palsy is characterised
decreased cognition
abnormal eye movements (supranuclear vertical gaze palsy)
postural instability and falls
as well as parkinsonian features and speech disturbances
RADIOGRAPHIC FEATURESMRI
midbrain atrophy
reduction of anteroposterior midline midbrain diameter at the level of the superior colliculi on axial imaging (from interpeduncular fossa to the intercolicular groove lt12mm 8) which can give a mickey mouse appearance
reduced area of the midbrain on midline sagittal and reduced midbrain to pons area ratio approx 012 (normal approx 024) on midline sagittal
Loss of the lateral convex margin of the tegmentum of midbrain has been described as the morning glory sign
hummingbird sign also known as the penguin sign The key is a flattening or concave outline to the superior aspect of the midbrain which should be upwardly convex
bullT2 diffuse high-signal lesions in
bull pontine tegmentum
bull tectum of the midbrain
bull inferior olivary nucleus
MICKEY MOUSE APPEARANCE
THE PENGUIN SIGN
MULTIPLE SYSTEM ATROPHY
sporadic neurodegenerative disease
Typically symptoms begin between 40 and 60 years of age
Clinical presentation is variable but typically presents in one of three patterns (initially described as separate entities)
Shy-Drager syndrome is used when autonomic symptoms predominate
striatonigral degeneration shows predominant parkinsonian features
olivopontocerebellar atrophy demonstrates primarily cerebellar dysfunction
MSA has been divided clinically into 2 forms according to the dominant non-autonomic symptoms
MSA-C predominance of cerebellar symptoms (olivopontocerebellar atrophy)
MSA-P predominance of parkinsonian signs and symptoms (striatonigraldegeneration)
RADIOGRAPHIC FEATURES
bullT2 hyperintensities typically present in the pontocerebellar tractsbull pons hot cross bun sign (MSA-C)
bull middle cerebellar peduncles
bull Cerebellum
putaminal findings in MSA-P reduced volume
reduced GRE and T2 signal relative to globus pallidus
reduced GRE and T2 signal relative to red nucleus
abnormal disruption of the normal high T2 linear rim
bullMSA-Cbull disproportionate atrophy of the cerebellum and brainstem (especially olivary nuclei and middle
cerebellar peduncle)
NUCLEAR MEDICINE
SPECT and PET studies tend to demonstrate hypometabolism in the superior parietal and superior frontal areas in the basal ganglia
HUNTINGTON DISEASE
autosomal dominant neurodegenerative disease
a loss of GABAergic neurons of the basal ganglia
especially atrophy of the caudate nucleus and putamen
Huntington disease has a prevalence of 5-10 per 100000 and is typically diagnosed between 30 and 50 years of age
In approximately 1-6 symptoms occur before the age of 20 so-called juvenile form
Presentation is typically with progressive rigidity choreoathetosis dementia psychosis and emotional lability
The juvenile form has a different presentation with cerebellar symptoms rigidity and hypokinesia being prominent
it is a autosomal dominant with complete penetrance and genetic anticipation particularly if inherited mutated allele is paternal
The mutation responsible is on chromosome 4p163 and consists of a CAG trineucleotide repeat
The usual 10-30 copies are amplified to greater than 36 and the greater the number of repeats the earlier the age of onset
RADIOGRAPHIC FEATURES
MRI
The most striking and best known feature is that of caudate head atrophy resulting in enlargement of the frontal horns often giving them a box like configuration
This can be quantified by an number of measurements
bullfrontal horn width to intercaudate distance ratio (FHCC)
bullintercaudate distance to inner table width ratio (CCIT)
Juvenile form
putamen are also atrophied and demonstrate increased T2 signal
basal ganglia may show decrease T2 signal and blooming on SWI in keeping with iron deposition
Generalised age inappropriate cortical volume loss is also recognised
FHCC ratio normal mean 22 to 26 (this ratio decreases with ageing as a result of enlargement of the frontal horns of the lateral ventricles)
CCIT ratio normal mean 009 to 012
AMYOTROPHIC LATERAL SCLEROSISalso known as Lou Gehrig disease or Charcot disease
Primary degeneration of the motor neurons within the brain brain stem and spinal cord
Patients typically present with progressive muscle weakness and limb and truncal atrophy combined with signs of spasticity
Mean age at the time of diagnosis is 55 years
RADIOGRAPHIC FEATURES
MRI
The earliest MR manifestation is hyperintensity on T2WI in the corticospinal tracts seen earliest in the internal capsule
Iron deposition in the cortex is demonstrated as loss of signal most evident on T2 weighted sequences
IS IT ATROPHY OR HYDROCEPHALUS
Abnormal accumulation of CSF in Ventricular system
Results from Structural or functional block to normal flow Of CSF
In effect all are obhstructive
Difficult to differentiate Atrophy from Hydrocephalus gt60yrs
Initially show increased ICT
Later stages may reach Equillibrium and Becomes NP hYdrocephalus
Types
Obstructive
Communicating
NPH ndash seen typically in old patients Diagnosis is more based on clinical feature
Dementia urinary incontinence and gait apraxias + Hydrocephalus = NPH
Radiologically w
1 degeree of ventricular dilatation is more with Thinning and bowing of CC
2 Sulcal effacement is invariable seen Hydrocephalus
3 dilatation or rounding of the Temporal Horns
4 Rounding and enlargement of the frontal horns
5 Enlargement and ballooning of 3rd
ventricle
6 Enlargement of fourth ventricle
SPOTTERS
THANK YOU
TREATMENT AND PROGNOSIS
There is no cure for this disease some drugs have been developed trying to improve symptoms or at least temporarily slow down their progression
cholinsterase inhibitors
partial NMDA receptor antagonists
medications for behavioural symptoms
antidepressants
anxiolytics
antiparkinsonian (movement symptoms)
anticonvulsantssedatives (behavioural)
VASCULAR DEMENTIAalso known as vascular cognitive impairment
It is primarily seen in patients with atherosclerosis and chronic hypertension
Results from the accumulation of multiple white matter or cortical infarcts although cerebral haemorrhages can be variably included
strongly correlated with age seen in only 1 of patients over the age of 55 years of age but in over 4 of patients over 71 years of age
It is also possible to divide vascular dementia into subtypes
small vessel dementia (aka Binswanger disease)
cortical vascular dementia roughly equivalent to multi-infarct dementia
strategic infarct dementia
thalamic dementia
RADIOGRAPHIC FEATURES
Both CT and MRI are able to provide evidence of ischaemic damage
MRI is more sensitive especially to white matter small vessel ischaemic change as well as to microhaemorrhages seen in cerebral amyloid angiopathy and chronic hypertensive encephalopathy
bullsmall vessel dementia (aka Binswanger disease)
bullcerebral infarction
bulllacunar infarction
bullintracerebral haemorrhage
CEREBRAL AMYLOID ANGIOPATHY
SMALL VESSEL DEMENTIA
also known as Binswanger disease
Subcortical arteriosclerotic encephalopathy
refers to slowly progressive exclusively white-matter multi-infarct dementia
A genetically transmitted form of the disease is known as familial arteriopathic leukoencephalopathy
or
CADASIL (cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy)
CLINICAL CRITERIA FOR DIAGNOSIS
marked subcortical microangiopathic lesions at MR imaging
a negative family history for strokes early cognitive impairment or psychiatric disorders in first- and second-degree relatives
documented arterial hypertension systolic values higher than 160 mm Hg diastolic values higher than 95 mm Hg or both measured at several occasions 5
MRI
subcortical and periventricular lesions visible on T2 FLAIR T2-weighted and proton-density sequences
commonly grouped around the frontal and occipital horns and in the centrum semi ovale
Moderate generalised cerebral atrophy is invariably present and lacunar infarctsin the basal ganglia and
thalami are common
CT
Diffuse incompletely symmetrical hypodensities are present in deep white matter especially they are prominent in the frontal lobes and the centrum semiovale
CEREBRAL AUTOSOMAL DOMINANT ARTERIOPATHY WITH SUBCORTICAL INFARCTS AND LEUKOENCEPHALOPATHY (CADASIL)
occurs in the absence of hypertension and arteriosclerosis and presents in 71 of cases before the age of 60 years
Imaging features demonstrate severe microvascular changes with multiple subcortical infarcts
Not distinguishable from hypertensive type microvascular disease
DEMENTIA WITH LEWY BODIESPD
Neurodegenerative disease (a synucleinopathy to be specific) related to Parkinsons disease (PD)
Epidemiology
Dementia with Lewy bodies presents in older patients (onset typically in 50-70 years of age) and is sporadic
It is the second most common neurodegenerative cause of dementia in older patients after Alzheimers disease accounting for 15-20 of case
RADIOGRAPHIC FEATURES
MRI
Atrophy in various parts of the brain without a clearly identified unique pattern
Most helpful in distinguishing DLB from other entities resulting in dementia is the absence of features of other diseases
generalised decrease in cerebral volume most marked in
frontal lobes parietotemporal regions
enlargement of the lateral ventricles
relatively focal atrophy
midbrain
hypothalamus
SWALLOW TAIL SIGN
The swallow tail sign describes the normal axial imaging appearance of nigrosome-1 within the substantianigra on high resolution T2SWI weighted MRI
Absence of the sign (absent swallow tail sign) is reported to have a diagnostic accuracy of greater than 90 for Parkinson disease
Nuclear medicine
Occipital hypoperfusion on SPECT PET
May aid in differentiation from other types of dementia especially Alzheimers disease
TREATMENT AND PROGNOSIS
Unlike Parkinsons disease dementia with Lewy bodies respond less readily to L-dopa and also may have severe sensitivity reactions to neuroleptic drugs such as rigidity reduced consciousness pyrexia falling postural hypotension and collapse
Lewy body dementia also responds favourably to acetylcholinesteraseinhibitors
DIFFERENTIAL DIAGNOSISwith strong overlap between
bullAlzheimers diseasebull clinical may occasionally have similar clinical presentation with a frontal type dementia or posterior
cortical atrophy
bull imaging prominent involvement of hippocampi on imaging
bullFronto-temporal lobar degenerationbull clinical usually younger onset absent parkinsonian features absent visual hallucinations
bull imaging more pronounced frontal temporal atrophy L gt R asymmetry
FRONTO-TEMPORAL LOBAR DEGENERATION
Frontotemporal lobar degeneration (FTLD) is the pathological description of a group of neurodegenerative disorders characterised by focal atrophy of the frontal and temporal cortices
rontotemporal lobar degeneration can be divided as follows 3-4
bullbehavioural variant fronto-temporal lobar degeneration dementia (bvFTLD) (aka behavioural variant frontotemporal dementia)1
bulllanguage variant fronto-temporal lobar degeneration (lvFTLD) (aka primary progressive aphasia (PPA)6
bull agrammatic variant primary progressive aphasia (aka progressive non-fluent aphasia (PNFA)
bull semantic variant primary progressive aphasia (aka semantic dementia)
bull logopaenic variant primary progressive aphasia
RADIOGRAPHIC FEATURES
The frontal and temporal lobes are predominantly affected there is often striking asymmetry both of involvement of frontal vs temporal lobes and involvement of left and right hemispheres
In addition the degree of fronto-striatal dysfunction varies between the different FTLD subgroups with behavioural variant frontotemporal dementia (bvFTD) having the greatest involvement
As a result the caudate heads tend to be reduced in size in these patients to a much greater degree than in the language variants of frontotemporal dementia
BEHAVIOURAL VARIANT FRONTO-TEMPORAL LOBAR DEGENERATION (BVFTLD)also referred to as Pick disease
Patients with behavioural variant FTD typically present with a dysexecutive cognitive syndrome associated with changes in personality and social behaviour
As the disease progresses impairments in language and memory may develop and the cognitive phenotype may come to resemble one of the language variants of FTD
RADIOGRAPHIC FEATURES
MRI
typical radiographic finding is atrophy of the frontal lobes and to a lesser extent the temporal lobes
The degree of atrophy can be very asymmetric
Decrease in volume of the caudate heads This indicates loss of both efferent and afferent fibres
CREUTZFELDT-JAKOB DISEASEspongiform encephalopathy
Results in a rapidly progressive dementia
other non-specific neurological features
Three types of Creutzfeldt-Jakob disease have been described
bullsporadic (sCJD) accounts for 85-90 of cases
bullvariant (vCJD)
bullfamilial (fCJD) 10 of cases (these individuals carry a PRPc mutation)
Creutzfeldt-Jakob disease is characterized by rapidly progressive dementia cerebral atrophy myoclonus and death
Patients with vCJD present mostly with sensory and psychiatric symptoms
Patients with sCJD usually present with progressive cognitive impairment and cerebellar symptoms
PATHOLOGY
mediated via (infectious) prions
a type of protein which manifest in sheep as the disease scrapie and in cows as bovine spongiform encephalopathy
Prions are considered infectious in sense that they can alter the structure of neighbouring proteins
CJD leads to spongiform degeneration of the brain
the conversion of normal prion protein to proteinaceous infectious particles that accumulate in and around neurons and lead to cell death
RADIOGRAPHIC FEATURES
MRI
MRI findings may be bilateral or unilateral and symmetric or asymmetric and include
T2 hyperintensity
obasal ganglia (putamen and caudate)
othalamus ( hockey stick sign and pulvinar sign)
ocortex most common early manifestation
owhite matter
persistent restricted diffusion on DWI (considered the most sensitive sign)
Review of sequential studies also typically demonstrates rapidly progressive cerebral atrophy
hypometabolism on 18FDG-PET studies
TREATMENT AND PROGNOSIS
here is currently no curative treatment and the disease is invariably fatal with a mean survival of only 7 months for most cases
PROGRESSIVE SUPRANUCLEARPALSYlso known as the Steele-Richardson-Olszewski syndrome
Progressive supranuclear palsy typically becomes clinically apparent in the 6th decade of life
Progresses to death usually within a decade (2-17 years from diagnosis)
Progressive supranuclear palsy is characterised
decreased cognition
abnormal eye movements (supranuclear vertical gaze palsy)
postural instability and falls
as well as parkinsonian features and speech disturbances
RADIOGRAPHIC FEATURESMRI
midbrain atrophy
reduction of anteroposterior midline midbrain diameter at the level of the superior colliculi on axial imaging (from interpeduncular fossa to the intercolicular groove lt12mm 8) which can give a mickey mouse appearance
reduced area of the midbrain on midline sagittal and reduced midbrain to pons area ratio approx 012 (normal approx 024) on midline sagittal
Loss of the lateral convex margin of the tegmentum of midbrain has been described as the morning glory sign
hummingbird sign also known as the penguin sign The key is a flattening or concave outline to the superior aspect of the midbrain which should be upwardly convex
bullT2 diffuse high-signal lesions in
bull pontine tegmentum
bull tectum of the midbrain
bull inferior olivary nucleus
MICKEY MOUSE APPEARANCE
THE PENGUIN SIGN
MULTIPLE SYSTEM ATROPHY
sporadic neurodegenerative disease
Typically symptoms begin between 40 and 60 years of age
Clinical presentation is variable but typically presents in one of three patterns (initially described as separate entities)
Shy-Drager syndrome is used when autonomic symptoms predominate
striatonigral degeneration shows predominant parkinsonian features
olivopontocerebellar atrophy demonstrates primarily cerebellar dysfunction
MSA has been divided clinically into 2 forms according to the dominant non-autonomic symptoms
MSA-C predominance of cerebellar symptoms (olivopontocerebellar atrophy)
MSA-P predominance of parkinsonian signs and symptoms (striatonigraldegeneration)
RADIOGRAPHIC FEATURES
bullT2 hyperintensities typically present in the pontocerebellar tractsbull pons hot cross bun sign (MSA-C)
bull middle cerebellar peduncles
bull Cerebellum
putaminal findings in MSA-P reduced volume
reduced GRE and T2 signal relative to globus pallidus
reduced GRE and T2 signal relative to red nucleus
abnormal disruption of the normal high T2 linear rim
bullMSA-Cbull disproportionate atrophy of the cerebellum and brainstem (especially olivary nuclei and middle
cerebellar peduncle)
NUCLEAR MEDICINE
SPECT and PET studies tend to demonstrate hypometabolism in the superior parietal and superior frontal areas in the basal ganglia
HUNTINGTON DISEASE
autosomal dominant neurodegenerative disease
a loss of GABAergic neurons of the basal ganglia
especially atrophy of the caudate nucleus and putamen
Huntington disease has a prevalence of 5-10 per 100000 and is typically diagnosed between 30 and 50 years of age
In approximately 1-6 symptoms occur before the age of 20 so-called juvenile form
Presentation is typically with progressive rigidity choreoathetosis dementia psychosis and emotional lability
The juvenile form has a different presentation with cerebellar symptoms rigidity and hypokinesia being prominent
it is a autosomal dominant with complete penetrance and genetic anticipation particularly if inherited mutated allele is paternal
The mutation responsible is on chromosome 4p163 and consists of a CAG trineucleotide repeat
The usual 10-30 copies are amplified to greater than 36 and the greater the number of repeats the earlier the age of onset
RADIOGRAPHIC FEATURES
MRI
The most striking and best known feature is that of caudate head atrophy resulting in enlargement of the frontal horns often giving them a box like configuration
This can be quantified by an number of measurements
bullfrontal horn width to intercaudate distance ratio (FHCC)
bullintercaudate distance to inner table width ratio (CCIT)
Juvenile form
putamen are also atrophied and demonstrate increased T2 signal
basal ganglia may show decrease T2 signal and blooming on SWI in keeping with iron deposition
Generalised age inappropriate cortical volume loss is also recognised
FHCC ratio normal mean 22 to 26 (this ratio decreases with ageing as a result of enlargement of the frontal horns of the lateral ventricles)
CCIT ratio normal mean 009 to 012
AMYOTROPHIC LATERAL SCLEROSISalso known as Lou Gehrig disease or Charcot disease
Primary degeneration of the motor neurons within the brain brain stem and spinal cord
Patients typically present with progressive muscle weakness and limb and truncal atrophy combined with signs of spasticity
Mean age at the time of diagnosis is 55 years
RADIOGRAPHIC FEATURES
MRI
The earliest MR manifestation is hyperintensity on T2WI in the corticospinal tracts seen earliest in the internal capsule
Iron deposition in the cortex is demonstrated as loss of signal most evident on T2 weighted sequences
IS IT ATROPHY OR HYDROCEPHALUS
Abnormal accumulation of CSF in Ventricular system
Results from Structural or functional block to normal flow Of CSF
In effect all are obhstructive
Difficult to differentiate Atrophy from Hydrocephalus gt60yrs
Initially show increased ICT
Later stages may reach Equillibrium and Becomes NP hYdrocephalus
Types
Obstructive
Communicating
NPH ndash seen typically in old patients Diagnosis is more based on clinical feature
Dementia urinary incontinence and gait apraxias + Hydrocephalus = NPH
Radiologically w
1 degeree of ventricular dilatation is more with Thinning and bowing of CC
2 Sulcal effacement is invariable seen Hydrocephalus
3 dilatation or rounding of the Temporal Horns
4 Rounding and enlargement of the frontal horns
5 Enlargement and ballooning of 3rd
ventricle
6 Enlargement of fourth ventricle
SPOTTERS
THANK YOU
VASCULAR DEMENTIAalso known as vascular cognitive impairment
It is primarily seen in patients with atherosclerosis and chronic hypertension
Results from the accumulation of multiple white matter or cortical infarcts although cerebral haemorrhages can be variably included
strongly correlated with age seen in only 1 of patients over the age of 55 years of age but in over 4 of patients over 71 years of age
It is also possible to divide vascular dementia into subtypes
small vessel dementia (aka Binswanger disease)
cortical vascular dementia roughly equivalent to multi-infarct dementia
strategic infarct dementia
thalamic dementia
RADIOGRAPHIC FEATURES
Both CT and MRI are able to provide evidence of ischaemic damage
MRI is more sensitive especially to white matter small vessel ischaemic change as well as to microhaemorrhages seen in cerebral amyloid angiopathy and chronic hypertensive encephalopathy
bullsmall vessel dementia (aka Binswanger disease)
bullcerebral infarction
bulllacunar infarction
bullintracerebral haemorrhage
CEREBRAL AMYLOID ANGIOPATHY
SMALL VESSEL DEMENTIA
also known as Binswanger disease
Subcortical arteriosclerotic encephalopathy
refers to slowly progressive exclusively white-matter multi-infarct dementia
A genetically transmitted form of the disease is known as familial arteriopathic leukoencephalopathy
or
CADASIL (cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy)
CLINICAL CRITERIA FOR DIAGNOSIS
marked subcortical microangiopathic lesions at MR imaging
a negative family history for strokes early cognitive impairment or psychiatric disorders in first- and second-degree relatives
documented arterial hypertension systolic values higher than 160 mm Hg diastolic values higher than 95 mm Hg or both measured at several occasions 5
MRI
subcortical and periventricular lesions visible on T2 FLAIR T2-weighted and proton-density sequences
commonly grouped around the frontal and occipital horns and in the centrum semi ovale
Moderate generalised cerebral atrophy is invariably present and lacunar infarctsin the basal ganglia and
thalami are common
CT
Diffuse incompletely symmetrical hypodensities are present in deep white matter especially they are prominent in the frontal lobes and the centrum semiovale
CEREBRAL AUTOSOMAL DOMINANT ARTERIOPATHY WITH SUBCORTICAL INFARCTS AND LEUKOENCEPHALOPATHY (CADASIL)
occurs in the absence of hypertension and arteriosclerosis and presents in 71 of cases before the age of 60 years
Imaging features demonstrate severe microvascular changes with multiple subcortical infarcts
Not distinguishable from hypertensive type microvascular disease
DEMENTIA WITH LEWY BODIESPD
Neurodegenerative disease (a synucleinopathy to be specific) related to Parkinsons disease (PD)
Epidemiology
Dementia with Lewy bodies presents in older patients (onset typically in 50-70 years of age) and is sporadic
It is the second most common neurodegenerative cause of dementia in older patients after Alzheimers disease accounting for 15-20 of case
RADIOGRAPHIC FEATURES
MRI
Atrophy in various parts of the brain without a clearly identified unique pattern
Most helpful in distinguishing DLB from other entities resulting in dementia is the absence of features of other diseases
generalised decrease in cerebral volume most marked in
frontal lobes parietotemporal regions
enlargement of the lateral ventricles
relatively focal atrophy
midbrain
hypothalamus
SWALLOW TAIL SIGN
The swallow tail sign describes the normal axial imaging appearance of nigrosome-1 within the substantianigra on high resolution T2SWI weighted MRI
Absence of the sign (absent swallow tail sign) is reported to have a diagnostic accuracy of greater than 90 for Parkinson disease
Nuclear medicine
Occipital hypoperfusion on SPECT PET
May aid in differentiation from other types of dementia especially Alzheimers disease
TREATMENT AND PROGNOSIS
Unlike Parkinsons disease dementia with Lewy bodies respond less readily to L-dopa and also may have severe sensitivity reactions to neuroleptic drugs such as rigidity reduced consciousness pyrexia falling postural hypotension and collapse
Lewy body dementia also responds favourably to acetylcholinesteraseinhibitors
DIFFERENTIAL DIAGNOSISwith strong overlap between
bullAlzheimers diseasebull clinical may occasionally have similar clinical presentation with a frontal type dementia or posterior
cortical atrophy
bull imaging prominent involvement of hippocampi on imaging
bullFronto-temporal lobar degenerationbull clinical usually younger onset absent parkinsonian features absent visual hallucinations
bull imaging more pronounced frontal temporal atrophy L gt R asymmetry
FRONTO-TEMPORAL LOBAR DEGENERATION
Frontotemporal lobar degeneration (FTLD) is the pathological description of a group of neurodegenerative disorders characterised by focal atrophy of the frontal and temporal cortices
rontotemporal lobar degeneration can be divided as follows 3-4
bullbehavioural variant fronto-temporal lobar degeneration dementia (bvFTLD) (aka behavioural variant frontotemporal dementia)1
bulllanguage variant fronto-temporal lobar degeneration (lvFTLD) (aka primary progressive aphasia (PPA)6
bull agrammatic variant primary progressive aphasia (aka progressive non-fluent aphasia (PNFA)
bull semantic variant primary progressive aphasia (aka semantic dementia)
bull logopaenic variant primary progressive aphasia
RADIOGRAPHIC FEATURES
The frontal and temporal lobes are predominantly affected there is often striking asymmetry both of involvement of frontal vs temporal lobes and involvement of left and right hemispheres
In addition the degree of fronto-striatal dysfunction varies between the different FTLD subgroups with behavioural variant frontotemporal dementia (bvFTD) having the greatest involvement
As a result the caudate heads tend to be reduced in size in these patients to a much greater degree than in the language variants of frontotemporal dementia
BEHAVIOURAL VARIANT FRONTO-TEMPORAL LOBAR DEGENERATION (BVFTLD)also referred to as Pick disease
Patients with behavioural variant FTD typically present with a dysexecutive cognitive syndrome associated with changes in personality and social behaviour
As the disease progresses impairments in language and memory may develop and the cognitive phenotype may come to resemble one of the language variants of FTD
RADIOGRAPHIC FEATURES
MRI
typical radiographic finding is atrophy of the frontal lobes and to a lesser extent the temporal lobes
The degree of atrophy can be very asymmetric
Decrease in volume of the caudate heads This indicates loss of both efferent and afferent fibres
CREUTZFELDT-JAKOB DISEASEspongiform encephalopathy
Results in a rapidly progressive dementia
other non-specific neurological features
Three types of Creutzfeldt-Jakob disease have been described
bullsporadic (sCJD) accounts for 85-90 of cases
bullvariant (vCJD)
bullfamilial (fCJD) 10 of cases (these individuals carry a PRPc mutation)
Creutzfeldt-Jakob disease is characterized by rapidly progressive dementia cerebral atrophy myoclonus and death
Patients with vCJD present mostly with sensory and psychiatric symptoms
Patients with sCJD usually present with progressive cognitive impairment and cerebellar symptoms
PATHOLOGY
mediated via (infectious) prions
a type of protein which manifest in sheep as the disease scrapie and in cows as bovine spongiform encephalopathy
Prions are considered infectious in sense that they can alter the structure of neighbouring proteins
CJD leads to spongiform degeneration of the brain
the conversion of normal prion protein to proteinaceous infectious particles that accumulate in and around neurons and lead to cell death
RADIOGRAPHIC FEATURES
MRI
MRI findings may be bilateral or unilateral and symmetric or asymmetric and include
T2 hyperintensity
obasal ganglia (putamen and caudate)
othalamus ( hockey stick sign and pulvinar sign)
ocortex most common early manifestation
owhite matter
persistent restricted diffusion on DWI (considered the most sensitive sign)
Review of sequential studies also typically demonstrates rapidly progressive cerebral atrophy
hypometabolism on 18FDG-PET studies
TREATMENT AND PROGNOSIS
here is currently no curative treatment and the disease is invariably fatal with a mean survival of only 7 months for most cases
PROGRESSIVE SUPRANUCLEARPALSYlso known as the Steele-Richardson-Olszewski syndrome
Progressive supranuclear palsy typically becomes clinically apparent in the 6th decade of life
Progresses to death usually within a decade (2-17 years from diagnosis)
Progressive supranuclear palsy is characterised
decreased cognition
abnormal eye movements (supranuclear vertical gaze palsy)
postural instability and falls
as well as parkinsonian features and speech disturbances
RADIOGRAPHIC FEATURESMRI
midbrain atrophy
reduction of anteroposterior midline midbrain diameter at the level of the superior colliculi on axial imaging (from interpeduncular fossa to the intercolicular groove lt12mm 8) which can give a mickey mouse appearance
reduced area of the midbrain on midline sagittal and reduced midbrain to pons area ratio approx 012 (normal approx 024) on midline sagittal
Loss of the lateral convex margin of the tegmentum of midbrain has been described as the morning glory sign
hummingbird sign also known as the penguin sign The key is a flattening or concave outline to the superior aspect of the midbrain which should be upwardly convex
bullT2 diffuse high-signal lesions in
bull pontine tegmentum
bull tectum of the midbrain
bull inferior olivary nucleus
MICKEY MOUSE APPEARANCE
THE PENGUIN SIGN
MULTIPLE SYSTEM ATROPHY
sporadic neurodegenerative disease
Typically symptoms begin between 40 and 60 years of age
Clinical presentation is variable but typically presents in one of three patterns (initially described as separate entities)
Shy-Drager syndrome is used when autonomic symptoms predominate
striatonigral degeneration shows predominant parkinsonian features
olivopontocerebellar atrophy demonstrates primarily cerebellar dysfunction
MSA has been divided clinically into 2 forms according to the dominant non-autonomic symptoms
MSA-C predominance of cerebellar symptoms (olivopontocerebellar atrophy)
MSA-P predominance of parkinsonian signs and symptoms (striatonigraldegeneration)
RADIOGRAPHIC FEATURES
bullT2 hyperintensities typically present in the pontocerebellar tractsbull pons hot cross bun sign (MSA-C)
bull middle cerebellar peduncles
bull Cerebellum
putaminal findings in MSA-P reduced volume
reduced GRE and T2 signal relative to globus pallidus
reduced GRE and T2 signal relative to red nucleus
abnormal disruption of the normal high T2 linear rim
bullMSA-Cbull disproportionate atrophy of the cerebellum and brainstem (especially olivary nuclei and middle
cerebellar peduncle)
NUCLEAR MEDICINE
SPECT and PET studies tend to demonstrate hypometabolism in the superior parietal and superior frontal areas in the basal ganglia
HUNTINGTON DISEASE
autosomal dominant neurodegenerative disease
a loss of GABAergic neurons of the basal ganglia
especially atrophy of the caudate nucleus and putamen
Huntington disease has a prevalence of 5-10 per 100000 and is typically diagnosed between 30 and 50 years of age
In approximately 1-6 symptoms occur before the age of 20 so-called juvenile form
Presentation is typically with progressive rigidity choreoathetosis dementia psychosis and emotional lability
The juvenile form has a different presentation with cerebellar symptoms rigidity and hypokinesia being prominent
it is a autosomal dominant with complete penetrance and genetic anticipation particularly if inherited mutated allele is paternal
The mutation responsible is on chromosome 4p163 and consists of a CAG trineucleotide repeat
The usual 10-30 copies are amplified to greater than 36 and the greater the number of repeats the earlier the age of onset
RADIOGRAPHIC FEATURES
MRI
The most striking and best known feature is that of caudate head atrophy resulting in enlargement of the frontal horns often giving them a box like configuration
This can be quantified by an number of measurements
bullfrontal horn width to intercaudate distance ratio (FHCC)
bullintercaudate distance to inner table width ratio (CCIT)
Juvenile form
putamen are also atrophied and demonstrate increased T2 signal
basal ganglia may show decrease T2 signal and blooming on SWI in keeping with iron deposition
Generalised age inappropriate cortical volume loss is also recognised
FHCC ratio normal mean 22 to 26 (this ratio decreases with ageing as a result of enlargement of the frontal horns of the lateral ventricles)
CCIT ratio normal mean 009 to 012
AMYOTROPHIC LATERAL SCLEROSISalso known as Lou Gehrig disease or Charcot disease
Primary degeneration of the motor neurons within the brain brain stem and spinal cord
Patients typically present with progressive muscle weakness and limb and truncal atrophy combined with signs of spasticity
Mean age at the time of diagnosis is 55 years
RADIOGRAPHIC FEATURES
MRI
The earliest MR manifestation is hyperintensity on T2WI in the corticospinal tracts seen earliest in the internal capsule
Iron deposition in the cortex is demonstrated as loss of signal most evident on T2 weighted sequences
IS IT ATROPHY OR HYDROCEPHALUS
Abnormal accumulation of CSF in Ventricular system
Results from Structural or functional block to normal flow Of CSF
In effect all are obhstructive
Difficult to differentiate Atrophy from Hydrocephalus gt60yrs
Initially show increased ICT
Later stages may reach Equillibrium and Becomes NP hYdrocephalus
Types
Obstructive
Communicating
NPH ndash seen typically in old patients Diagnosis is more based on clinical feature
Dementia urinary incontinence and gait apraxias + Hydrocephalus = NPH
Radiologically w
1 degeree of ventricular dilatation is more with Thinning and bowing of CC
2 Sulcal effacement is invariable seen Hydrocephalus
3 dilatation or rounding of the Temporal Horns
4 Rounding and enlargement of the frontal horns
5 Enlargement and ballooning of 3rd
ventricle
6 Enlargement of fourth ventricle
SPOTTERS
THANK YOU
RADIOGRAPHIC FEATURES
Both CT and MRI are able to provide evidence of ischaemic damage
MRI is more sensitive especially to white matter small vessel ischaemic change as well as to microhaemorrhages seen in cerebral amyloid angiopathy and chronic hypertensive encephalopathy
bullsmall vessel dementia (aka Binswanger disease)
bullcerebral infarction
bulllacunar infarction
bullintracerebral haemorrhage
CEREBRAL AMYLOID ANGIOPATHY
SMALL VESSEL DEMENTIA
also known as Binswanger disease
Subcortical arteriosclerotic encephalopathy
refers to slowly progressive exclusively white-matter multi-infarct dementia
A genetically transmitted form of the disease is known as familial arteriopathic leukoencephalopathy
or
CADASIL (cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy)
CLINICAL CRITERIA FOR DIAGNOSIS
marked subcortical microangiopathic lesions at MR imaging
a negative family history for strokes early cognitive impairment or psychiatric disorders in first- and second-degree relatives
documented arterial hypertension systolic values higher than 160 mm Hg diastolic values higher than 95 mm Hg or both measured at several occasions 5
MRI
subcortical and periventricular lesions visible on T2 FLAIR T2-weighted and proton-density sequences
commonly grouped around the frontal and occipital horns and in the centrum semi ovale
Moderate generalised cerebral atrophy is invariably present and lacunar infarctsin the basal ganglia and
thalami are common
CT
Diffuse incompletely symmetrical hypodensities are present in deep white matter especially they are prominent in the frontal lobes and the centrum semiovale
CEREBRAL AUTOSOMAL DOMINANT ARTERIOPATHY WITH SUBCORTICAL INFARCTS AND LEUKOENCEPHALOPATHY (CADASIL)
occurs in the absence of hypertension and arteriosclerosis and presents in 71 of cases before the age of 60 years
Imaging features demonstrate severe microvascular changes with multiple subcortical infarcts
Not distinguishable from hypertensive type microvascular disease
DEMENTIA WITH LEWY BODIESPD
Neurodegenerative disease (a synucleinopathy to be specific) related to Parkinsons disease (PD)
Epidemiology
Dementia with Lewy bodies presents in older patients (onset typically in 50-70 years of age) and is sporadic
It is the second most common neurodegenerative cause of dementia in older patients after Alzheimers disease accounting for 15-20 of case
RADIOGRAPHIC FEATURES
MRI
Atrophy in various parts of the brain without a clearly identified unique pattern
Most helpful in distinguishing DLB from other entities resulting in dementia is the absence of features of other diseases
generalised decrease in cerebral volume most marked in
frontal lobes parietotemporal regions
enlargement of the lateral ventricles
relatively focal atrophy
midbrain
hypothalamus
SWALLOW TAIL SIGN
The swallow tail sign describes the normal axial imaging appearance of nigrosome-1 within the substantianigra on high resolution T2SWI weighted MRI
Absence of the sign (absent swallow tail sign) is reported to have a diagnostic accuracy of greater than 90 for Parkinson disease
Nuclear medicine
Occipital hypoperfusion on SPECT PET
May aid in differentiation from other types of dementia especially Alzheimers disease
TREATMENT AND PROGNOSIS
Unlike Parkinsons disease dementia with Lewy bodies respond less readily to L-dopa and also may have severe sensitivity reactions to neuroleptic drugs such as rigidity reduced consciousness pyrexia falling postural hypotension and collapse
Lewy body dementia also responds favourably to acetylcholinesteraseinhibitors
DIFFERENTIAL DIAGNOSISwith strong overlap between
bullAlzheimers diseasebull clinical may occasionally have similar clinical presentation with a frontal type dementia or posterior
cortical atrophy
bull imaging prominent involvement of hippocampi on imaging
bullFronto-temporal lobar degenerationbull clinical usually younger onset absent parkinsonian features absent visual hallucinations
bull imaging more pronounced frontal temporal atrophy L gt R asymmetry
FRONTO-TEMPORAL LOBAR DEGENERATION
Frontotemporal lobar degeneration (FTLD) is the pathological description of a group of neurodegenerative disorders characterised by focal atrophy of the frontal and temporal cortices
rontotemporal lobar degeneration can be divided as follows 3-4
bullbehavioural variant fronto-temporal lobar degeneration dementia (bvFTLD) (aka behavioural variant frontotemporal dementia)1
bulllanguage variant fronto-temporal lobar degeneration (lvFTLD) (aka primary progressive aphasia (PPA)6
bull agrammatic variant primary progressive aphasia (aka progressive non-fluent aphasia (PNFA)
bull semantic variant primary progressive aphasia (aka semantic dementia)
bull logopaenic variant primary progressive aphasia
RADIOGRAPHIC FEATURES
The frontal and temporal lobes are predominantly affected there is often striking asymmetry both of involvement of frontal vs temporal lobes and involvement of left and right hemispheres
In addition the degree of fronto-striatal dysfunction varies between the different FTLD subgroups with behavioural variant frontotemporal dementia (bvFTD) having the greatest involvement
As a result the caudate heads tend to be reduced in size in these patients to a much greater degree than in the language variants of frontotemporal dementia
BEHAVIOURAL VARIANT FRONTO-TEMPORAL LOBAR DEGENERATION (BVFTLD)also referred to as Pick disease
Patients with behavioural variant FTD typically present with a dysexecutive cognitive syndrome associated with changes in personality and social behaviour
As the disease progresses impairments in language and memory may develop and the cognitive phenotype may come to resemble one of the language variants of FTD
RADIOGRAPHIC FEATURES
MRI
typical radiographic finding is atrophy of the frontal lobes and to a lesser extent the temporal lobes
The degree of atrophy can be very asymmetric
Decrease in volume of the caudate heads This indicates loss of both efferent and afferent fibres
CREUTZFELDT-JAKOB DISEASEspongiform encephalopathy
Results in a rapidly progressive dementia
other non-specific neurological features
Three types of Creutzfeldt-Jakob disease have been described
bullsporadic (sCJD) accounts for 85-90 of cases
bullvariant (vCJD)
bullfamilial (fCJD) 10 of cases (these individuals carry a PRPc mutation)
Creutzfeldt-Jakob disease is characterized by rapidly progressive dementia cerebral atrophy myoclonus and death
Patients with vCJD present mostly with sensory and psychiatric symptoms
Patients with sCJD usually present with progressive cognitive impairment and cerebellar symptoms
PATHOLOGY
mediated via (infectious) prions
a type of protein which manifest in sheep as the disease scrapie and in cows as bovine spongiform encephalopathy
Prions are considered infectious in sense that they can alter the structure of neighbouring proteins
CJD leads to spongiform degeneration of the brain
the conversion of normal prion protein to proteinaceous infectious particles that accumulate in and around neurons and lead to cell death
RADIOGRAPHIC FEATURES
MRI
MRI findings may be bilateral or unilateral and symmetric or asymmetric and include
T2 hyperintensity
obasal ganglia (putamen and caudate)
othalamus ( hockey stick sign and pulvinar sign)
ocortex most common early manifestation
owhite matter
persistent restricted diffusion on DWI (considered the most sensitive sign)
Review of sequential studies also typically demonstrates rapidly progressive cerebral atrophy
hypometabolism on 18FDG-PET studies
TREATMENT AND PROGNOSIS
here is currently no curative treatment and the disease is invariably fatal with a mean survival of only 7 months for most cases
PROGRESSIVE SUPRANUCLEARPALSYlso known as the Steele-Richardson-Olszewski syndrome
Progressive supranuclear palsy typically becomes clinically apparent in the 6th decade of life
Progresses to death usually within a decade (2-17 years from diagnosis)
Progressive supranuclear palsy is characterised
decreased cognition
abnormal eye movements (supranuclear vertical gaze palsy)
postural instability and falls
as well as parkinsonian features and speech disturbances
RADIOGRAPHIC FEATURESMRI
midbrain atrophy
reduction of anteroposterior midline midbrain diameter at the level of the superior colliculi on axial imaging (from interpeduncular fossa to the intercolicular groove lt12mm 8) which can give a mickey mouse appearance
reduced area of the midbrain on midline sagittal and reduced midbrain to pons area ratio approx 012 (normal approx 024) on midline sagittal
Loss of the lateral convex margin of the tegmentum of midbrain has been described as the morning glory sign
hummingbird sign also known as the penguin sign The key is a flattening or concave outline to the superior aspect of the midbrain which should be upwardly convex
bullT2 diffuse high-signal lesions in
bull pontine tegmentum
bull tectum of the midbrain
bull inferior olivary nucleus
MICKEY MOUSE APPEARANCE
THE PENGUIN SIGN
MULTIPLE SYSTEM ATROPHY
sporadic neurodegenerative disease
Typically symptoms begin between 40 and 60 years of age
Clinical presentation is variable but typically presents in one of three patterns (initially described as separate entities)
Shy-Drager syndrome is used when autonomic symptoms predominate
striatonigral degeneration shows predominant parkinsonian features
olivopontocerebellar atrophy demonstrates primarily cerebellar dysfunction
MSA has been divided clinically into 2 forms according to the dominant non-autonomic symptoms
MSA-C predominance of cerebellar symptoms (olivopontocerebellar atrophy)
MSA-P predominance of parkinsonian signs and symptoms (striatonigraldegeneration)
RADIOGRAPHIC FEATURES
bullT2 hyperintensities typically present in the pontocerebellar tractsbull pons hot cross bun sign (MSA-C)
bull middle cerebellar peduncles
bull Cerebellum
putaminal findings in MSA-P reduced volume
reduced GRE and T2 signal relative to globus pallidus
reduced GRE and T2 signal relative to red nucleus
abnormal disruption of the normal high T2 linear rim
bullMSA-Cbull disproportionate atrophy of the cerebellum and brainstem (especially olivary nuclei and middle
cerebellar peduncle)
NUCLEAR MEDICINE
SPECT and PET studies tend to demonstrate hypometabolism in the superior parietal and superior frontal areas in the basal ganglia
HUNTINGTON DISEASE
autosomal dominant neurodegenerative disease
a loss of GABAergic neurons of the basal ganglia
especially atrophy of the caudate nucleus and putamen
Huntington disease has a prevalence of 5-10 per 100000 and is typically diagnosed between 30 and 50 years of age
In approximately 1-6 symptoms occur before the age of 20 so-called juvenile form
Presentation is typically with progressive rigidity choreoathetosis dementia psychosis and emotional lability
The juvenile form has a different presentation with cerebellar symptoms rigidity and hypokinesia being prominent
it is a autosomal dominant with complete penetrance and genetic anticipation particularly if inherited mutated allele is paternal
The mutation responsible is on chromosome 4p163 and consists of a CAG trineucleotide repeat
The usual 10-30 copies are amplified to greater than 36 and the greater the number of repeats the earlier the age of onset
RADIOGRAPHIC FEATURES
MRI
The most striking and best known feature is that of caudate head atrophy resulting in enlargement of the frontal horns often giving them a box like configuration
This can be quantified by an number of measurements
bullfrontal horn width to intercaudate distance ratio (FHCC)
bullintercaudate distance to inner table width ratio (CCIT)
Juvenile form
putamen are also atrophied and demonstrate increased T2 signal
basal ganglia may show decrease T2 signal and blooming on SWI in keeping with iron deposition
Generalised age inappropriate cortical volume loss is also recognised
FHCC ratio normal mean 22 to 26 (this ratio decreases with ageing as a result of enlargement of the frontal horns of the lateral ventricles)
CCIT ratio normal mean 009 to 012
AMYOTROPHIC LATERAL SCLEROSISalso known as Lou Gehrig disease or Charcot disease
Primary degeneration of the motor neurons within the brain brain stem and spinal cord
Patients typically present with progressive muscle weakness and limb and truncal atrophy combined with signs of spasticity
Mean age at the time of diagnosis is 55 years
RADIOGRAPHIC FEATURES
MRI
The earliest MR manifestation is hyperintensity on T2WI in the corticospinal tracts seen earliest in the internal capsule
Iron deposition in the cortex is demonstrated as loss of signal most evident on T2 weighted sequences
IS IT ATROPHY OR HYDROCEPHALUS
Abnormal accumulation of CSF in Ventricular system
Results from Structural or functional block to normal flow Of CSF
In effect all are obhstructive
Difficult to differentiate Atrophy from Hydrocephalus gt60yrs
Initially show increased ICT
Later stages may reach Equillibrium and Becomes NP hYdrocephalus
Types
Obstructive
Communicating
NPH ndash seen typically in old patients Diagnosis is more based on clinical feature
Dementia urinary incontinence and gait apraxias + Hydrocephalus = NPH
Radiologically w
1 degeree of ventricular dilatation is more with Thinning and bowing of CC
2 Sulcal effacement is invariable seen Hydrocephalus
3 dilatation or rounding of the Temporal Horns
4 Rounding and enlargement of the frontal horns
5 Enlargement and ballooning of 3rd
ventricle
6 Enlargement of fourth ventricle
SPOTTERS
THANK YOU
CEREBRAL AMYLOID ANGIOPATHY
SMALL VESSEL DEMENTIA
also known as Binswanger disease
Subcortical arteriosclerotic encephalopathy
refers to slowly progressive exclusively white-matter multi-infarct dementia
A genetically transmitted form of the disease is known as familial arteriopathic leukoencephalopathy
or
CADASIL (cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy)
CLINICAL CRITERIA FOR DIAGNOSIS
marked subcortical microangiopathic lesions at MR imaging
a negative family history for strokes early cognitive impairment or psychiatric disorders in first- and second-degree relatives
documented arterial hypertension systolic values higher than 160 mm Hg diastolic values higher than 95 mm Hg or both measured at several occasions 5
MRI
subcortical and periventricular lesions visible on T2 FLAIR T2-weighted and proton-density sequences
commonly grouped around the frontal and occipital horns and in the centrum semi ovale
Moderate generalised cerebral atrophy is invariably present and lacunar infarctsin the basal ganglia and
thalami are common
CT
Diffuse incompletely symmetrical hypodensities are present in deep white matter especially they are prominent in the frontal lobes and the centrum semiovale
CEREBRAL AUTOSOMAL DOMINANT ARTERIOPATHY WITH SUBCORTICAL INFARCTS AND LEUKOENCEPHALOPATHY (CADASIL)
occurs in the absence of hypertension and arteriosclerosis and presents in 71 of cases before the age of 60 years
Imaging features demonstrate severe microvascular changes with multiple subcortical infarcts
Not distinguishable from hypertensive type microvascular disease
DEMENTIA WITH LEWY BODIESPD
Neurodegenerative disease (a synucleinopathy to be specific) related to Parkinsons disease (PD)
Epidemiology
Dementia with Lewy bodies presents in older patients (onset typically in 50-70 years of age) and is sporadic
It is the second most common neurodegenerative cause of dementia in older patients after Alzheimers disease accounting for 15-20 of case
RADIOGRAPHIC FEATURES
MRI
Atrophy in various parts of the brain without a clearly identified unique pattern
Most helpful in distinguishing DLB from other entities resulting in dementia is the absence of features of other diseases
generalised decrease in cerebral volume most marked in
frontal lobes parietotemporal regions
enlargement of the lateral ventricles
relatively focal atrophy
midbrain
hypothalamus
SWALLOW TAIL SIGN
The swallow tail sign describes the normal axial imaging appearance of nigrosome-1 within the substantianigra on high resolution T2SWI weighted MRI
Absence of the sign (absent swallow tail sign) is reported to have a diagnostic accuracy of greater than 90 for Parkinson disease
Nuclear medicine
Occipital hypoperfusion on SPECT PET
May aid in differentiation from other types of dementia especially Alzheimers disease
TREATMENT AND PROGNOSIS
Unlike Parkinsons disease dementia with Lewy bodies respond less readily to L-dopa and also may have severe sensitivity reactions to neuroleptic drugs such as rigidity reduced consciousness pyrexia falling postural hypotension and collapse
Lewy body dementia also responds favourably to acetylcholinesteraseinhibitors
DIFFERENTIAL DIAGNOSISwith strong overlap between
bullAlzheimers diseasebull clinical may occasionally have similar clinical presentation with a frontal type dementia or posterior
cortical atrophy
bull imaging prominent involvement of hippocampi on imaging
bullFronto-temporal lobar degenerationbull clinical usually younger onset absent parkinsonian features absent visual hallucinations
bull imaging more pronounced frontal temporal atrophy L gt R asymmetry
FRONTO-TEMPORAL LOBAR DEGENERATION
Frontotemporal lobar degeneration (FTLD) is the pathological description of a group of neurodegenerative disorders characterised by focal atrophy of the frontal and temporal cortices
rontotemporal lobar degeneration can be divided as follows 3-4
bullbehavioural variant fronto-temporal lobar degeneration dementia (bvFTLD) (aka behavioural variant frontotemporal dementia)1
bulllanguage variant fronto-temporal lobar degeneration (lvFTLD) (aka primary progressive aphasia (PPA)6
bull agrammatic variant primary progressive aphasia (aka progressive non-fluent aphasia (PNFA)
bull semantic variant primary progressive aphasia (aka semantic dementia)
bull logopaenic variant primary progressive aphasia
RADIOGRAPHIC FEATURES
The frontal and temporal lobes are predominantly affected there is often striking asymmetry both of involvement of frontal vs temporal lobes and involvement of left and right hemispheres
In addition the degree of fronto-striatal dysfunction varies between the different FTLD subgroups with behavioural variant frontotemporal dementia (bvFTD) having the greatest involvement
As a result the caudate heads tend to be reduced in size in these patients to a much greater degree than in the language variants of frontotemporal dementia
BEHAVIOURAL VARIANT FRONTO-TEMPORAL LOBAR DEGENERATION (BVFTLD)also referred to as Pick disease
Patients with behavioural variant FTD typically present with a dysexecutive cognitive syndrome associated with changes in personality and social behaviour
As the disease progresses impairments in language and memory may develop and the cognitive phenotype may come to resemble one of the language variants of FTD
RADIOGRAPHIC FEATURES
MRI
typical radiographic finding is atrophy of the frontal lobes and to a lesser extent the temporal lobes
The degree of atrophy can be very asymmetric
Decrease in volume of the caudate heads This indicates loss of both efferent and afferent fibres
CREUTZFELDT-JAKOB DISEASEspongiform encephalopathy
Results in a rapidly progressive dementia
other non-specific neurological features
Three types of Creutzfeldt-Jakob disease have been described
bullsporadic (sCJD) accounts for 85-90 of cases
bullvariant (vCJD)
bullfamilial (fCJD) 10 of cases (these individuals carry a PRPc mutation)
Creutzfeldt-Jakob disease is characterized by rapidly progressive dementia cerebral atrophy myoclonus and death
Patients with vCJD present mostly with sensory and psychiatric symptoms
Patients with sCJD usually present with progressive cognitive impairment and cerebellar symptoms
PATHOLOGY
mediated via (infectious) prions
a type of protein which manifest in sheep as the disease scrapie and in cows as bovine spongiform encephalopathy
Prions are considered infectious in sense that they can alter the structure of neighbouring proteins
CJD leads to spongiform degeneration of the brain
the conversion of normal prion protein to proteinaceous infectious particles that accumulate in and around neurons and lead to cell death
RADIOGRAPHIC FEATURES
MRI
MRI findings may be bilateral or unilateral and symmetric or asymmetric and include
T2 hyperintensity
obasal ganglia (putamen and caudate)
othalamus ( hockey stick sign and pulvinar sign)
ocortex most common early manifestation
owhite matter
persistent restricted diffusion on DWI (considered the most sensitive sign)
Review of sequential studies also typically demonstrates rapidly progressive cerebral atrophy
hypometabolism on 18FDG-PET studies
TREATMENT AND PROGNOSIS
here is currently no curative treatment and the disease is invariably fatal with a mean survival of only 7 months for most cases
PROGRESSIVE SUPRANUCLEARPALSYlso known as the Steele-Richardson-Olszewski syndrome
Progressive supranuclear palsy typically becomes clinically apparent in the 6th decade of life
Progresses to death usually within a decade (2-17 years from diagnosis)
Progressive supranuclear palsy is characterised
decreased cognition
abnormal eye movements (supranuclear vertical gaze palsy)
postural instability and falls
as well as parkinsonian features and speech disturbances
RADIOGRAPHIC FEATURESMRI
midbrain atrophy
reduction of anteroposterior midline midbrain diameter at the level of the superior colliculi on axial imaging (from interpeduncular fossa to the intercolicular groove lt12mm 8) which can give a mickey mouse appearance
reduced area of the midbrain on midline sagittal and reduced midbrain to pons area ratio approx 012 (normal approx 024) on midline sagittal
Loss of the lateral convex margin of the tegmentum of midbrain has been described as the morning glory sign
hummingbird sign also known as the penguin sign The key is a flattening or concave outline to the superior aspect of the midbrain which should be upwardly convex
bullT2 diffuse high-signal lesions in
bull pontine tegmentum
bull tectum of the midbrain
bull inferior olivary nucleus
MICKEY MOUSE APPEARANCE
THE PENGUIN SIGN
MULTIPLE SYSTEM ATROPHY
sporadic neurodegenerative disease
Typically symptoms begin between 40 and 60 years of age
Clinical presentation is variable but typically presents in one of three patterns (initially described as separate entities)
Shy-Drager syndrome is used when autonomic symptoms predominate
striatonigral degeneration shows predominant parkinsonian features
olivopontocerebellar atrophy demonstrates primarily cerebellar dysfunction
MSA has been divided clinically into 2 forms according to the dominant non-autonomic symptoms
MSA-C predominance of cerebellar symptoms (olivopontocerebellar atrophy)
MSA-P predominance of parkinsonian signs and symptoms (striatonigraldegeneration)
RADIOGRAPHIC FEATURES
bullT2 hyperintensities typically present in the pontocerebellar tractsbull pons hot cross bun sign (MSA-C)
bull middle cerebellar peduncles
bull Cerebellum
putaminal findings in MSA-P reduced volume
reduced GRE and T2 signal relative to globus pallidus
reduced GRE and T2 signal relative to red nucleus
abnormal disruption of the normal high T2 linear rim
bullMSA-Cbull disproportionate atrophy of the cerebellum and brainstem (especially olivary nuclei and middle
cerebellar peduncle)
NUCLEAR MEDICINE
SPECT and PET studies tend to demonstrate hypometabolism in the superior parietal and superior frontal areas in the basal ganglia
HUNTINGTON DISEASE
autosomal dominant neurodegenerative disease
a loss of GABAergic neurons of the basal ganglia
especially atrophy of the caudate nucleus and putamen
Huntington disease has a prevalence of 5-10 per 100000 and is typically diagnosed between 30 and 50 years of age
In approximately 1-6 symptoms occur before the age of 20 so-called juvenile form
Presentation is typically with progressive rigidity choreoathetosis dementia psychosis and emotional lability
The juvenile form has a different presentation with cerebellar symptoms rigidity and hypokinesia being prominent
it is a autosomal dominant with complete penetrance and genetic anticipation particularly if inherited mutated allele is paternal
The mutation responsible is on chromosome 4p163 and consists of a CAG trineucleotide repeat
The usual 10-30 copies are amplified to greater than 36 and the greater the number of repeats the earlier the age of onset
RADIOGRAPHIC FEATURES
MRI
The most striking and best known feature is that of caudate head atrophy resulting in enlargement of the frontal horns often giving them a box like configuration
This can be quantified by an number of measurements
bullfrontal horn width to intercaudate distance ratio (FHCC)
bullintercaudate distance to inner table width ratio (CCIT)
Juvenile form
putamen are also atrophied and demonstrate increased T2 signal
basal ganglia may show decrease T2 signal and blooming on SWI in keeping with iron deposition
Generalised age inappropriate cortical volume loss is also recognised
FHCC ratio normal mean 22 to 26 (this ratio decreases with ageing as a result of enlargement of the frontal horns of the lateral ventricles)
CCIT ratio normal mean 009 to 012
AMYOTROPHIC LATERAL SCLEROSISalso known as Lou Gehrig disease or Charcot disease
Primary degeneration of the motor neurons within the brain brain stem and spinal cord
Patients typically present with progressive muscle weakness and limb and truncal atrophy combined with signs of spasticity
Mean age at the time of diagnosis is 55 years
RADIOGRAPHIC FEATURES
MRI
The earliest MR manifestation is hyperintensity on T2WI in the corticospinal tracts seen earliest in the internal capsule
Iron deposition in the cortex is demonstrated as loss of signal most evident on T2 weighted sequences
IS IT ATROPHY OR HYDROCEPHALUS
Abnormal accumulation of CSF in Ventricular system
Results from Structural or functional block to normal flow Of CSF
In effect all are obhstructive
Difficult to differentiate Atrophy from Hydrocephalus gt60yrs
Initially show increased ICT
Later stages may reach Equillibrium and Becomes NP hYdrocephalus
Types
Obstructive
Communicating
NPH ndash seen typically in old patients Diagnosis is more based on clinical feature
Dementia urinary incontinence and gait apraxias + Hydrocephalus = NPH
Radiologically w
1 degeree of ventricular dilatation is more with Thinning and bowing of CC
2 Sulcal effacement is invariable seen Hydrocephalus
3 dilatation or rounding of the Temporal Horns
4 Rounding and enlargement of the frontal horns
5 Enlargement and ballooning of 3rd
ventricle
6 Enlargement of fourth ventricle
SPOTTERS
THANK YOU
SMALL VESSEL DEMENTIA
also known as Binswanger disease
Subcortical arteriosclerotic encephalopathy
refers to slowly progressive exclusively white-matter multi-infarct dementia
A genetically transmitted form of the disease is known as familial arteriopathic leukoencephalopathy
or
CADASIL (cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy)
CLINICAL CRITERIA FOR DIAGNOSIS
marked subcortical microangiopathic lesions at MR imaging
a negative family history for strokes early cognitive impairment or psychiatric disorders in first- and second-degree relatives
documented arterial hypertension systolic values higher than 160 mm Hg diastolic values higher than 95 mm Hg or both measured at several occasions 5
MRI
subcortical and periventricular lesions visible on T2 FLAIR T2-weighted and proton-density sequences
commonly grouped around the frontal and occipital horns and in the centrum semi ovale
Moderate generalised cerebral atrophy is invariably present and lacunar infarctsin the basal ganglia and
thalami are common
CT
Diffuse incompletely symmetrical hypodensities are present in deep white matter especially they are prominent in the frontal lobes and the centrum semiovale
CEREBRAL AUTOSOMAL DOMINANT ARTERIOPATHY WITH SUBCORTICAL INFARCTS AND LEUKOENCEPHALOPATHY (CADASIL)
occurs in the absence of hypertension and arteriosclerosis and presents in 71 of cases before the age of 60 years
Imaging features demonstrate severe microvascular changes with multiple subcortical infarcts
Not distinguishable from hypertensive type microvascular disease
DEMENTIA WITH LEWY BODIESPD
Neurodegenerative disease (a synucleinopathy to be specific) related to Parkinsons disease (PD)
Epidemiology
Dementia with Lewy bodies presents in older patients (onset typically in 50-70 years of age) and is sporadic
It is the second most common neurodegenerative cause of dementia in older patients after Alzheimers disease accounting for 15-20 of case
RADIOGRAPHIC FEATURES
MRI
Atrophy in various parts of the brain without a clearly identified unique pattern
Most helpful in distinguishing DLB from other entities resulting in dementia is the absence of features of other diseases
generalised decrease in cerebral volume most marked in
frontal lobes parietotemporal regions
enlargement of the lateral ventricles
relatively focal atrophy
midbrain
hypothalamus
SWALLOW TAIL SIGN
The swallow tail sign describes the normal axial imaging appearance of nigrosome-1 within the substantianigra on high resolution T2SWI weighted MRI
Absence of the sign (absent swallow tail sign) is reported to have a diagnostic accuracy of greater than 90 for Parkinson disease
Nuclear medicine
Occipital hypoperfusion on SPECT PET
May aid in differentiation from other types of dementia especially Alzheimers disease
TREATMENT AND PROGNOSIS
Unlike Parkinsons disease dementia with Lewy bodies respond less readily to L-dopa and also may have severe sensitivity reactions to neuroleptic drugs such as rigidity reduced consciousness pyrexia falling postural hypotension and collapse
Lewy body dementia also responds favourably to acetylcholinesteraseinhibitors
DIFFERENTIAL DIAGNOSISwith strong overlap between
bullAlzheimers diseasebull clinical may occasionally have similar clinical presentation with a frontal type dementia or posterior
cortical atrophy
bull imaging prominent involvement of hippocampi on imaging
bullFronto-temporal lobar degenerationbull clinical usually younger onset absent parkinsonian features absent visual hallucinations
bull imaging more pronounced frontal temporal atrophy L gt R asymmetry
FRONTO-TEMPORAL LOBAR DEGENERATION
Frontotemporal lobar degeneration (FTLD) is the pathological description of a group of neurodegenerative disorders characterised by focal atrophy of the frontal and temporal cortices
rontotemporal lobar degeneration can be divided as follows 3-4
bullbehavioural variant fronto-temporal lobar degeneration dementia (bvFTLD) (aka behavioural variant frontotemporal dementia)1
bulllanguage variant fronto-temporal lobar degeneration (lvFTLD) (aka primary progressive aphasia (PPA)6
bull agrammatic variant primary progressive aphasia (aka progressive non-fluent aphasia (PNFA)
bull semantic variant primary progressive aphasia (aka semantic dementia)
bull logopaenic variant primary progressive aphasia
RADIOGRAPHIC FEATURES
The frontal and temporal lobes are predominantly affected there is often striking asymmetry both of involvement of frontal vs temporal lobes and involvement of left and right hemispheres
In addition the degree of fronto-striatal dysfunction varies between the different FTLD subgroups with behavioural variant frontotemporal dementia (bvFTD) having the greatest involvement
As a result the caudate heads tend to be reduced in size in these patients to a much greater degree than in the language variants of frontotemporal dementia
BEHAVIOURAL VARIANT FRONTO-TEMPORAL LOBAR DEGENERATION (BVFTLD)also referred to as Pick disease
Patients with behavioural variant FTD typically present with a dysexecutive cognitive syndrome associated with changes in personality and social behaviour
As the disease progresses impairments in language and memory may develop and the cognitive phenotype may come to resemble one of the language variants of FTD
RADIOGRAPHIC FEATURES
MRI
typical radiographic finding is atrophy of the frontal lobes and to a lesser extent the temporal lobes
The degree of atrophy can be very asymmetric
Decrease in volume of the caudate heads This indicates loss of both efferent and afferent fibres
CREUTZFELDT-JAKOB DISEASEspongiform encephalopathy
Results in a rapidly progressive dementia
other non-specific neurological features
Three types of Creutzfeldt-Jakob disease have been described
bullsporadic (sCJD) accounts for 85-90 of cases
bullvariant (vCJD)
bullfamilial (fCJD) 10 of cases (these individuals carry a PRPc mutation)
Creutzfeldt-Jakob disease is characterized by rapidly progressive dementia cerebral atrophy myoclonus and death
Patients with vCJD present mostly with sensory and psychiatric symptoms
Patients with sCJD usually present with progressive cognitive impairment and cerebellar symptoms
PATHOLOGY
mediated via (infectious) prions
a type of protein which manifest in sheep as the disease scrapie and in cows as bovine spongiform encephalopathy
Prions are considered infectious in sense that they can alter the structure of neighbouring proteins
CJD leads to spongiform degeneration of the brain
the conversion of normal prion protein to proteinaceous infectious particles that accumulate in and around neurons and lead to cell death
RADIOGRAPHIC FEATURES
MRI
MRI findings may be bilateral or unilateral and symmetric or asymmetric and include
T2 hyperintensity
obasal ganglia (putamen and caudate)
othalamus ( hockey stick sign and pulvinar sign)
ocortex most common early manifestation
owhite matter
persistent restricted diffusion on DWI (considered the most sensitive sign)
Review of sequential studies also typically demonstrates rapidly progressive cerebral atrophy
hypometabolism on 18FDG-PET studies
TREATMENT AND PROGNOSIS
here is currently no curative treatment and the disease is invariably fatal with a mean survival of only 7 months for most cases
PROGRESSIVE SUPRANUCLEARPALSYlso known as the Steele-Richardson-Olszewski syndrome
Progressive supranuclear palsy typically becomes clinically apparent in the 6th decade of life
Progresses to death usually within a decade (2-17 years from diagnosis)
Progressive supranuclear palsy is characterised
decreased cognition
abnormal eye movements (supranuclear vertical gaze palsy)
postural instability and falls
as well as parkinsonian features and speech disturbances
RADIOGRAPHIC FEATURESMRI
midbrain atrophy
reduction of anteroposterior midline midbrain diameter at the level of the superior colliculi on axial imaging (from interpeduncular fossa to the intercolicular groove lt12mm 8) which can give a mickey mouse appearance
reduced area of the midbrain on midline sagittal and reduced midbrain to pons area ratio approx 012 (normal approx 024) on midline sagittal
Loss of the lateral convex margin of the tegmentum of midbrain has been described as the morning glory sign
hummingbird sign also known as the penguin sign The key is a flattening or concave outline to the superior aspect of the midbrain which should be upwardly convex
bullT2 diffuse high-signal lesions in
bull pontine tegmentum
bull tectum of the midbrain
bull inferior olivary nucleus
MICKEY MOUSE APPEARANCE
THE PENGUIN SIGN
MULTIPLE SYSTEM ATROPHY
sporadic neurodegenerative disease
Typically symptoms begin between 40 and 60 years of age
Clinical presentation is variable but typically presents in one of three patterns (initially described as separate entities)
Shy-Drager syndrome is used when autonomic symptoms predominate
striatonigral degeneration shows predominant parkinsonian features
olivopontocerebellar atrophy demonstrates primarily cerebellar dysfunction
MSA has been divided clinically into 2 forms according to the dominant non-autonomic symptoms
MSA-C predominance of cerebellar symptoms (olivopontocerebellar atrophy)
MSA-P predominance of parkinsonian signs and symptoms (striatonigraldegeneration)
RADIOGRAPHIC FEATURES
bullT2 hyperintensities typically present in the pontocerebellar tractsbull pons hot cross bun sign (MSA-C)
bull middle cerebellar peduncles
bull Cerebellum
putaminal findings in MSA-P reduced volume
reduced GRE and T2 signal relative to globus pallidus
reduced GRE and T2 signal relative to red nucleus
abnormal disruption of the normal high T2 linear rim
bullMSA-Cbull disproportionate atrophy of the cerebellum and brainstem (especially olivary nuclei and middle
cerebellar peduncle)
NUCLEAR MEDICINE
SPECT and PET studies tend to demonstrate hypometabolism in the superior parietal and superior frontal areas in the basal ganglia
HUNTINGTON DISEASE
autosomal dominant neurodegenerative disease
a loss of GABAergic neurons of the basal ganglia
especially atrophy of the caudate nucleus and putamen
Huntington disease has a prevalence of 5-10 per 100000 and is typically diagnosed between 30 and 50 years of age
In approximately 1-6 symptoms occur before the age of 20 so-called juvenile form
Presentation is typically with progressive rigidity choreoathetosis dementia psychosis and emotional lability
The juvenile form has a different presentation with cerebellar symptoms rigidity and hypokinesia being prominent
it is a autosomal dominant with complete penetrance and genetic anticipation particularly if inherited mutated allele is paternal
The mutation responsible is on chromosome 4p163 and consists of a CAG trineucleotide repeat
The usual 10-30 copies are amplified to greater than 36 and the greater the number of repeats the earlier the age of onset
RADIOGRAPHIC FEATURES
MRI
The most striking and best known feature is that of caudate head atrophy resulting in enlargement of the frontal horns often giving them a box like configuration
This can be quantified by an number of measurements
bullfrontal horn width to intercaudate distance ratio (FHCC)
bullintercaudate distance to inner table width ratio (CCIT)
Juvenile form
putamen are also atrophied and demonstrate increased T2 signal
basal ganglia may show decrease T2 signal and blooming on SWI in keeping with iron deposition
Generalised age inappropriate cortical volume loss is also recognised
FHCC ratio normal mean 22 to 26 (this ratio decreases with ageing as a result of enlargement of the frontal horns of the lateral ventricles)
CCIT ratio normal mean 009 to 012
AMYOTROPHIC LATERAL SCLEROSISalso known as Lou Gehrig disease or Charcot disease
Primary degeneration of the motor neurons within the brain brain stem and spinal cord
Patients typically present with progressive muscle weakness and limb and truncal atrophy combined with signs of spasticity
Mean age at the time of diagnosis is 55 years
RADIOGRAPHIC FEATURES
MRI
The earliest MR manifestation is hyperintensity on T2WI in the corticospinal tracts seen earliest in the internal capsule
Iron deposition in the cortex is demonstrated as loss of signal most evident on T2 weighted sequences
IS IT ATROPHY OR HYDROCEPHALUS
Abnormal accumulation of CSF in Ventricular system
Results from Structural or functional block to normal flow Of CSF
In effect all are obhstructive
Difficult to differentiate Atrophy from Hydrocephalus gt60yrs
Initially show increased ICT
Later stages may reach Equillibrium and Becomes NP hYdrocephalus
Types
Obstructive
Communicating
NPH ndash seen typically in old patients Diagnosis is more based on clinical feature
Dementia urinary incontinence and gait apraxias + Hydrocephalus = NPH
Radiologically w
1 degeree of ventricular dilatation is more with Thinning and bowing of CC
2 Sulcal effacement is invariable seen Hydrocephalus
3 dilatation or rounding of the Temporal Horns
4 Rounding and enlargement of the frontal horns
5 Enlargement and ballooning of 3rd
ventricle
6 Enlargement of fourth ventricle
SPOTTERS
THANK YOU
CLINICAL CRITERIA FOR DIAGNOSIS
marked subcortical microangiopathic lesions at MR imaging
a negative family history for strokes early cognitive impairment or psychiatric disorders in first- and second-degree relatives
documented arterial hypertension systolic values higher than 160 mm Hg diastolic values higher than 95 mm Hg or both measured at several occasions 5
MRI
subcortical and periventricular lesions visible on T2 FLAIR T2-weighted and proton-density sequences
commonly grouped around the frontal and occipital horns and in the centrum semi ovale
Moderate generalised cerebral atrophy is invariably present and lacunar infarctsin the basal ganglia and
thalami are common
CT
Diffuse incompletely symmetrical hypodensities are present in deep white matter especially they are prominent in the frontal lobes and the centrum semiovale
CEREBRAL AUTOSOMAL DOMINANT ARTERIOPATHY WITH SUBCORTICAL INFARCTS AND LEUKOENCEPHALOPATHY (CADASIL)
occurs in the absence of hypertension and arteriosclerosis and presents in 71 of cases before the age of 60 years
Imaging features demonstrate severe microvascular changes with multiple subcortical infarcts
Not distinguishable from hypertensive type microvascular disease
DEMENTIA WITH LEWY BODIESPD
Neurodegenerative disease (a synucleinopathy to be specific) related to Parkinsons disease (PD)
Epidemiology
Dementia with Lewy bodies presents in older patients (onset typically in 50-70 years of age) and is sporadic
It is the second most common neurodegenerative cause of dementia in older patients after Alzheimers disease accounting for 15-20 of case
RADIOGRAPHIC FEATURES
MRI
Atrophy in various parts of the brain without a clearly identified unique pattern
Most helpful in distinguishing DLB from other entities resulting in dementia is the absence of features of other diseases
generalised decrease in cerebral volume most marked in
frontal lobes parietotemporal regions
enlargement of the lateral ventricles
relatively focal atrophy
midbrain
hypothalamus
SWALLOW TAIL SIGN
The swallow tail sign describes the normal axial imaging appearance of nigrosome-1 within the substantianigra on high resolution T2SWI weighted MRI
Absence of the sign (absent swallow tail sign) is reported to have a diagnostic accuracy of greater than 90 for Parkinson disease
Nuclear medicine
Occipital hypoperfusion on SPECT PET
May aid in differentiation from other types of dementia especially Alzheimers disease
TREATMENT AND PROGNOSIS
Unlike Parkinsons disease dementia with Lewy bodies respond less readily to L-dopa and also may have severe sensitivity reactions to neuroleptic drugs such as rigidity reduced consciousness pyrexia falling postural hypotension and collapse
Lewy body dementia also responds favourably to acetylcholinesteraseinhibitors
DIFFERENTIAL DIAGNOSISwith strong overlap between
bullAlzheimers diseasebull clinical may occasionally have similar clinical presentation with a frontal type dementia or posterior
cortical atrophy
bull imaging prominent involvement of hippocampi on imaging
bullFronto-temporal lobar degenerationbull clinical usually younger onset absent parkinsonian features absent visual hallucinations
bull imaging more pronounced frontal temporal atrophy L gt R asymmetry
FRONTO-TEMPORAL LOBAR DEGENERATION
Frontotemporal lobar degeneration (FTLD) is the pathological description of a group of neurodegenerative disorders characterised by focal atrophy of the frontal and temporal cortices
rontotemporal lobar degeneration can be divided as follows 3-4
bullbehavioural variant fronto-temporal lobar degeneration dementia (bvFTLD) (aka behavioural variant frontotemporal dementia)1
bulllanguage variant fronto-temporal lobar degeneration (lvFTLD) (aka primary progressive aphasia (PPA)6
bull agrammatic variant primary progressive aphasia (aka progressive non-fluent aphasia (PNFA)
bull semantic variant primary progressive aphasia (aka semantic dementia)
bull logopaenic variant primary progressive aphasia
RADIOGRAPHIC FEATURES
The frontal and temporal lobes are predominantly affected there is often striking asymmetry both of involvement of frontal vs temporal lobes and involvement of left and right hemispheres
In addition the degree of fronto-striatal dysfunction varies between the different FTLD subgroups with behavioural variant frontotemporal dementia (bvFTD) having the greatest involvement
As a result the caudate heads tend to be reduced in size in these patients to a much greater degree than in the language variants of frontotemporal dementia
BEHAVIOURAL VARIANT FRONTO-TEMPORAL LOBAR DEGENERATION (BVFTLD)also referred to as Pick disease
Patients with behavioural variant FTD typically present with a dysexecutive cognitive syndrome associated with changes in personality and social behaviour
As the disease progresses impairments in language and memory may develop and the cognitive phenotype may come to resemble one of the language variants of FTD
RADIOGRAPHIC FEATURES
MRI
typical radiographic finding is atrophy of the frontal lobes and to a lesser extent the temporal lobes
The degree of atrophy can be very asymmetric
Decrease in volume of the caudate heads This indicates loss of both efferent and afferent fibres
CREUTZFELDT-JAKOB DISEASEspongiform encephalopathy
Results in a rapidly progressive dementia
other non-specific neurological features
Three types of Creutzfeldt-Jakob disease have been described
bullsporadic (sCJD) accounts for 85-90 of cases
bullvariant (vCJD)
bullfamilial (fCJD) 10 of cases (these individuals carry a PRPc mutation)
Creutzfeldt-Jakob disease is characterized by rapidly progressive dementia cerebral atrophy myoclonus and death
Patients with vCJD present mostly with sensory and psychiatric symptoms
Patients with sCJD usually present with progressive cognitive impairment and cerebellar symptoms
PATHOLOGY
mediated via (infectious) prions
a type of protein which manifest in sheep as the disease scrapie and in cows as bovine spongiform encephalopathy
Prions are considered infectious in sense that they can alter the structure of neighbouring proteins
CJD leads to spongiform degeneration of the brain
the conversion of normal prion protein to proteinaceous infectious particles that accumulate in and around neurons and lead to cell death
RADIOGRAPHIC FEATURES
MRI
MRI findings may be bilateral or unilateral and symmetric or asymmetric and include
T2 hyperintensity
obasal ganglia (putamen and caudate)
othalamus ( hockey stick sign and pulvinar sign)
ocortex most common early manifestation
owhite matter
persistent restricted diffusion on DWI (considered the most sensitive sign)
Review of sequential studies also typically demonstrates rapidly progressive cerebral atrophy
hypometabolism on 18FDG-PET studies
TREATMENT AND PROGNOSIS
here is currently no curative treatment and the disease is invariably fatal with a mean survival of only 7 months for most cases
PROGRESSIVE SUPRANUCLEARPALSYlso known as the Steele-Richardson-Olszewski syndrome
Progressive supranuclear palsy typically becomes clinically apparent in the 6th decade of life
Progresses to death usually within a decade (2-17 years from diagnosis)
Progressive supranuclear palsy is characterised
decreased cognition
abnormal eye movements (supranuclear vertical gaze palsy)
postural instability and falls
as well as parkinsonian features and speech disturbances
RADIOGRAPHIC FEATURESMRI
midbrain atrophy
reduction of anteroposterior midline midbrain diameter at the level of the superior colliculi on axial imaging (from interpeduncular fossa to the intercolicular groove lt12mm 8) which can give a mickey mouse appearance
reduced area of the midbrain on midline sagittal and reduced midbrain to pons area ratio approx 012 (normal approx 024) on midline sagittal
Loss of the lateral convex margin of the tegmentum of midbrain has been described as the morning glory sign
hummingbird sign also known as the penguin sign The key is a flattening or concave outline to the superior aspect of the midbrain which should be upwardly convex
bullT2 diffuse high-signal lesions in
bull pontine tegmentum
bull tectum of the midbrain
bull inferior olivary nucleus
MICKEY MOUSE APPEARANCE
THE PENGUIN SIGN
MULTIPLE SYSTEM ATROPHY
sporadic neurodegenerative disease
Typically symptoms begin between 40 and 60 years of age
Clinical presentation is variable but typically presents in one of three patterns (initially described as separate entities)
Shy-Drager syndrome is used when autonomic symptoms predominate
striatonigral degeneration shows predominant parkinsonian features
olivopontocerebellar atrophy demonstrates primarily cerebellar dysfunction
MSA has been divided clinically into 2 forms according to the dominant non-autonomic symptoms
MSA-C predominance of cerebellar symptoms (olivopontocerebellar atrophy)
MSA-P predominance of parkinsonian signs and symptoms (striatonigraldegeneration)
RADIOGRAPHIC FEATURES
bullT2 hyperintensities typically present in the pontocerebellar tractsbull pons hot cross bun sign (MSA-C)
bull middle cerebellar peduncles
bull Cerebellum
putaminal findings in MSA-P reduced volume
reduced GRE and T2 signal relative to globus pallidus
reduced GRE and T2 signal relative to red nucleus
abnormal disruption of the normal high T2 linear rim
bullMSA-Cbull disproportionate atrophy of the cerebellum and brainstem (especially olivary nuclei and middle
cerebellar peduncle)
NUCLEAR MEDICINE
SPECT and PET studies tend to demonstrate hypometabolism in the superior parietal and superior frontal areas in the basal ganglia
HUNTINGTON DISEASE
autosomal dominant neurodegenerative disease
a loss of GABAergic neurons of the basal ganglia
especially atrophy of the caudate nucleus and putamen
Huntington disease has a prevalence of 5-10 per 100000 and is typically diagnosed between 30 and 50 years of age
In approximately 1-6 symptoms occur before the age of 20 so-called juvenile form
Presentation is typically with progressive rigidity choreoathetosis dementia psychosis and emotional lability
The juvenile form has a different presentation with cerebellar symptoms rigidity and hypokinesia being prominent
it is a autosomal dominant with complete penetrance and genetic anticipation particularly if inherited mutated allele is paternal
The mutation responsible is on chromosome 4p163 and consists of a CAG trineucleotide repeat
The usual 10-30 copies are amplified to greater than 36 and the greater the number of repeats the earlier the age of onset
RADIOGRAPHIC FEATURES
MRI
The most striking and best known feature is that of caudate head atrophy resulting in enlargement of the frontal horns often giving them a box like configuration
This can be quantified by an number of measurements
bullfrontal horn width to intercaudate distance ratio (FHCC)
bullintercaudate distance to inner table width ratio (CCIT)
Juvenile form
putamen are also atrophied and demonstrate increased T2 signal
basal ganglia may show decrease T2 signal and blooming on SWI in keeping with iron deposition
Generalised age inappropriate cortical volume loss is also recognised
FHCC ratio normal mean 22 to 26 (this ratio decreases with ageing as a result of enlargement of the frontal horns of the lateral ventricles)
CCIT ratio normal mean 009 to 012
AMYOTROPHIC LATERAL SCLEROSISalso known as Lou Gehrig disease or Charcot disease
Primary degeneration of the motor neurons within the brain brain stem and spinal cord
Patients typically present with progressive muscle weakness and limb and truncal atrophy combined with signs of spasticity
Mean age at the time of diagnosis is 55 years
RADIOGRAPHIC FEATURES
MRI
The earliest MR manifestation is hyperintensity on T2WI in the corticospinal tracts seen earliest in the internal capsule
Iron deposition in the cortex is demonstrated as loss of signal most evident on T2 weighted sequences
IS IT ATROPHY OR HYDROCEPHALUS
Abnormal accumulation of CSF in Ventricular system
Results from Structural or functional block to normal flow Of CSF
In effect all are obhstructive
Difficult to differentiate Atrophy from Hydrocephalus gt60yrs
Initially show increased ICT
Later stages may reach Equillibrium and Becomes NP hYdrocephalus
Types
Obstructive
Communicating
NPH ndash seen typically in old patients Diagnosis is more based on clinical feature
Dementia urinary incontinence and gait apraxias + Hydrocephalus = NPH
Radiologically w
1 degeree of ventricular dilatation is more with Thinning and bowing of CC
2 Sulcal effacement is invariable seen Hydrocephalus
3 dilatation or rounding of the Temporal Horns
4 Rounding and enlargement of the frontal horns
5 Enlargement and ballooning of 3rd
ventricle
6 Enlargement of fourth ventricle
SPOTTERS
THANK YOU
MRI
subcortical and periventricular lesions visible on T2 FLAIR T2-weighted and proton-density sequences
commonly grouped around the frontal and occipital horns and in the centrum semi ovale
Moderate generalised cerebral atrophy is invariably present and lacunar infarctsin the basal ganglia and
thalami are common
CT
Diffuse incompletely symmetrical hypodensities are present in deep white matter especially they are prominent in the frontal lobes and the centrum semiovale
CEREBRAL AUTOSOMAL DOMINANT ARTERIOPATHY WITH SUBCORTICAL INFARCTS AND LEUKOENCEPHALOPATHY (CADASIL)
occurs in the absence of hypertension and arteriosclerosis and presents in 71 of cases before the age of 60 years
Imaging features demonstrate severe microvascular changes with multiple subcortical infarcts
Not distinguishable from hypertensive type microvascular disease
DEMENTIA WITH LEWY BODIESPD
Neurodegenerative disease (a synucleinopathy to be specific) related to Parkinsons disease (PD)
Epidemiology
Dementia with Lewy bodies presents in older patients (onset typically in 50-70 years of age) and is sporadic
It is the second most common neurodegenerative cause of dementia in older patients after Alzheimers disease accounting for 15-20 of case
RADIOGRAPHIC FEATURES
MRI
Atrophy in various parts of the brain without a clearly identified unique pattern
Most helpful in distinguishing DLB from other entities resulting in dementia is the absence of features of other diseases
generalised decrease in cerebral volume most marked in
frontal lobes parietotemporal regions
enlargement of the lateral ventricles
relatively focal atrophy
midbrain
hypothalamus
SWALLOW TAIL SIGN
The swallow tail sign describes the normal axial imaging appearance of nigrosome-1 within the substantianigra on high resolution T2SWI weighted MRI
Absence of the sign (absent swallow tail sign) is reported to have a diagnostic accuracy of greater than 90 for Parkinson disease
Nuclear medicine
Occipital hypoperfusion on SPECT PET
May aid in differentiation from other types of dementia especially Alzheimers disease
TREATMENT AND PROGNOSIS
Unlike Parkinsons disease dementia with Lewy bodies respond less readily to L-dopa and also may have severe sensitivity reactions to neuroleptic drugs such as rigidity reduced consciousness pyrexia falling postural hypotension and collapse
Lewy body dementia also responds favourably to acetylcholinesteraseinhibitors
DIFFERENTIAL DIAGNOSISwith strong overlap between
bullAlzheimers diseasebull clinical may occasionally have similar clinical presentation with a frontal type dementia or posterior
cortical atrophy
bull imaging prominent involvement of hippocampi on imaging
bullFronto-temporal lobar degenerationbull clinical usually younger onset absent parkinsonian features absent visual hallucinations
bull imaging more pronounced frontal temporal atrophy L gt R asymmetry
FRONTO-TEMPORAL LOBAR DEGENERATION
Frontotemporal lobar degeneration (FTLD) is the pathological description of a group of neurodegenerative disorders characterised by focal atrophy of the frontal and temporal cortices
rontotemporal lobar degeneration can be divided as follows 3-4
bullbehavioural variant fronto-temporal lobar degeneration dementia (bvFTLD) (aka behavioural variant frontotemporal dementia)1
bulllanguage variant fronto-temporal lobar degeneration (lvFTLD) (aka primary progressive aphasia (PPA)6
bull agrammatic variant primary progressive aphasia (aka progressive non-fluent aphasia (PNFA)
bull semantic variant primary progressive aphasia (aka semantic dementia)
bull logopaenic variant primary progressive aphasia
RADIOGRAPHIC FEATURES
The frontal and temporal lobes are predominantly affected there is often striking asymmetry both of involvement of frontal vs temporal lobes and involvement of left and right hemispheres
In addition the degree of fronto-striatal dysfunction varies between the different FTLD subgroups with behavioural variant frontotemporal dementia (bvFTD) having the greatest involvement
As a result the caudate heads tend to be reduced in size in these patients to a much greater degree than in the language variants of frontotemporal dementia
BEHAVIOURAL VARIANT FRONTO-TEMPORAL LOBAR DEGENERATION (BVFTLD)also referred to as Pick disease
Patients with behavioural variant FTD typically present with a dysexecutive cognitive syndrome associated with changes in personality and social behaviour
As the disease progresses impairments in language and memory may develop and the cognitive phenotype may come to resemble one of the language variants of FTD
RADIOGRAPHIC FEATURES
MRI
typical radiographic finding is atrophy of the frontal lobes and to a lesser extent the temporal lobes
The degree of atrophy can be very asymmetric
Decrease in volume of the caudate heads This indicates loss of both efferent and afferent fibres
CREUTZFELDT-JAKOB DISEASEspongiform encephalopathy
Results in a rapidly progressive dementia
other non-specific neurological features
Three types of Creutzfeldt-Jakob disease have been described
bullsporadic (sCJD) accounts for 85-90 of cases
bullvariant (vCJD)
bullfamilial (fCJD) 10 of cases (these individuals carry a PRPc mutation)
Creutzfeldt-Jakob disease is characterized by rapidly progressive dementia cerebral atrophy myoclonus and death
Patients with vCJD present mostly with sensory and psychiatric symptoms
Patients with sCJD usually present with progressive cognitive impairment and cerebellar symptoms
PATHOLOGY
mediated via (infectious) prions
a type of protein which manifest in sheep as the disease scrapie and in cows as bovine spongiform encephalopathy
Prions are considered infectious in sense that they can alter the structure of neighbouring proteins
CJD leads to spongiform degeneration of the brain
the conversion of normal prion protein to proteinaceous infectious particles that accumulate in and around neurons and lead to cell death
RADIOGRAPHIC FEATURES
MRI
MRI findings may be bilateral or unilateral and symmetric or asymmetric and include
T2 hyperintensity
obasal ganglia (putamen and caudate)
othalamus ( hockey stick sign and pulvinar sign)
ocortex most common early manifestation
owhite matter
persistent restricted diffusion on DWI (considered the most sensitive sign)
Review of sequential studies also typically demonstrates rapidly progressive cerebral atrophy
hypometabolism on 18FDG-PET studies
TREATMENT AND PROGNOSIS
here is currently no curative treatment and the disease is invariably fatal with a mean survival of only 7 months for most cases
PROGRESSIVE SUPRANUCLEARPALSYlso known as the Steele-Richardson-Olszewski syndrome
Progressive supranuclear palsy typically becomes clinically apparent in the 6th decade of life
Progresses to death usually within a decade (2-17 years from diagnosis)
Progressive supranuclear palsy is characterised
decreased cognition
abnormal eye movements (supranuclear vertical gaze palsy)
postural instability and falls
as well as parkinsonian features and speech disturbances
RADIOGRAPHIC FEATURESMRI
midbrain atrophy
reduction of anteroposterior midline midbrain diameter at the level of the superior colliculi on axial imaging (from interpeduncular fossa to the intercolicular groove lt12mm 8) which can give a mickey mouse appearance
reduced area of the midbrain on midline sagittal and reduced midbrain to pons area ratio approx 012 (normal approx 024) on midline sagittal
Loss of the lateral convex margin of the tegmentum of midbrain has been described as the morning glory sign
hummingbird sign also known as the penguin sign The key is a flattening or concave outline to the superior aspect of the midbrain which should be upwardly convex
bullT2 diffuse high-signal lesions in
bull pontine tegmentum
bull tectum of the midbrain
bull inferior olivary nucleus
MICKEY MOUSE APPEARANCE
THE PENGUIN SIGN
MULTIPLE SYSTEM ATROPHY
sporadic neurodegenerative disease
Typically symptoms begin between 40 and 60 years of age
Clinical presentation is variable but typically presents in one of three patterns (initially described as separate entities)
Shy-Drager syndrome is used when autonomic symptoms predominate
striatonigral degeneration shows predominant parkinsonian features
olivopontocerebellar atrophy demonstrates primarily cerebellar dysfunction
MSA has been divided clinically into 2 forms according to the dominant non-autonomic symptoms
MSA-C predominance of cerebellar symptoms (olivopontocerebellar atrophy)
MSA-P predominance of parkinsonian signs and symptoms (striatonigraldegeneration)
RADIOGRAPHIC FEATURES
bullT2 hyperintensities typically present in the pontocerebellar tractsbull pons hot cross bun sign (MSA-C)
bull middle cerebellar peduncles
bull Cerebellum
putaminal findings in MSA-P reduced volume
reduced GRE and T2 signal relative to globus pallidus
reduced GRE and T2 signal relative to red nucleus
abnormal disruption of the normal high T2 linear rim
bullMSA-Cbull disproportionate atrophy of the cerebellum and brainstem (especially olivary nuclei and middle
cerebellar peduncle)
NUCLEAR MEDICINE
SPECT and PET studies tend to demonstrate hypometabolism in the superior parietal and superior frontal areas in the basal ganglia
HUNTINGTON DISEASE
autosomal dominant neurodegenerative disease
a loss of GABAergic neurons of the basal ganglia
especially atrophy of the caudate nucleus and putamen
Huntington disease has a prevalence of 5-10 per 100000 and is typically diagnosed between 30 and 50 years of age
In approximately 1-6 symptoms occur before the age of 20 so-called juvenile form
Presentation is typically with progressive rigidity choreoathetosis dementia psychosis and emotional lability
The juvenile form has a different presentation with cerebellar symptoms rigidity and hypokinesia being prominent
it is a autosomal dominant with complete penetrance and genetic anticipation particularly if inherited mutated allele is paternal
The mutation responsible is on chromosome 4p163 and consists of a CAG trineucleotide repeat
The usual 10-30 copies are amplified to greater than 36 and the greater the number of repeats the earlier the age of onset
RADIOGRAPHIC FEATURES
MRI
The most striking and best known feature is that of caudate head atrophy resulting in enlargement of the frontal horns often giving them a box like configuration
This can be quantified by an number of measurements
bullfrontal horn width to intercaudate distance ratio (FHCC)
bullintercaudate distance to inner table width ratio (CCIT)
Juvenile form
putamen are also atrophied and demonstrate increased T2 signal
basal ganglia may show decrease T2 signal and blooming on SWI in keeping with iron deposition
Generalised age inappropriate cortical volume loss is also recognised
FHCC ratio normal mean 22 to 26 (this ratio decreases with ageing as a result of enlargement of the frontal horns of the lateral ventricles)
CCIT ratio normal mean 009 to 012
AMYOTROPHIC LATERAL SCLEROSISalso known as Lou Gehrig disease or Charcot disease
Primary degeneration of the motor neurons within the brain brain stem and spinal cord
Patients typically present with progressive muscle weakness and limb and truncal atrophy combined with signs of spasticity
Mean age at the time of diagnosis is 55 years
RADIOGRAPHIC FEATURES
MRI
The earliest MR manifestation is hyperintensity on T2WI in the corticospinal tracts seen earliest in the internal capsule
Iron deposition in the cortex is demonstrated as loss of signal most evident on T2 weighted sequences
IS IT ATROPHY OR HYDROCEPHALUS
Abnormal accumulation of CSF in Ventricular system
Results from Structural or functional block to normal flow Of CSF
In effect all are obhstructive
Difficult to differentiate Atrophy from Hydrocephalus gt60yrs
Initially show increased ICT
Later stages may reach Equillibrium and Becomes NP hYdrocephalus
Types
Obstructive
Communicating
NPH ndash seen typically in old patients Diagnosis is more based on clinical feature
Dementia urinary incontinence and gait apraxias + Hydrocephalus = NPH
Radiologically w
1 degeree of ventricular dilatation is more with Thinning and bowing of CC
2 Sulcal effacement is invariable seen Hydrocephalus
3 dilatation or rounding of the Temporal Horns
4 Rounding and enlargement of the frontal horns
5 Enlargement and ballooning of 3rd
ventricle
6 Enlargement of fourth ventricle
SPOTTERS
THANK YOU
CEREBRAL AUTOSOMAL DOMINANT ARTERIOPATHY WITH SUBCORTICAL INFARCTS AND LEUKOENCEPHALOPATHY (CADASIL)
occurs in the absence of hypertension and arteriosclerosis and presents in 71 of cases before the age of 60 years
Imaging features demonstrate severe microvascular changes with multiple subcortical infarcts
Not distinguishable from hypertensive type microvascular disease
DEMENTIA WITH LEWY BODIESPD
Neurodegenerative disease (a synucleinopathy to be specific) related to Parkinsons disease (PD)
Epidemiology
Dementia with Lewy bodies presents in older patients (onset typically in 50-70 years of age) and is sporadic
It is the second most common neurodegenerative cause of dementia in older patients after Alzheimers disease accounting for 15-20 of case
RADIOGRAPHIC FEATURES
MRI
Atrophy in various parts of the brain without a clearly identified unique pattern
Most helpful in distinguishing DLB from other entities resulting in dementia is the absence of features of other diseases
generalised decrease in cerebral volume most marked in
frontal lobes parietotemporal regions
enlargement of the lateral ventricles
relatively focal atrophy
midbrain
hypothalamus
SWALLOW TAIL SIGN
The swallow tail sign describes the normal axial imaging appearance of nigrosome-1 within the substantianigra on high resolution T2SWI weighted MRI
Absence of the sign (absent swallow tail sign) is reported to have a diagnostic accuracy of greater than 90 for Parkinson disease
Nuclear medicine
Occipital hypoperfusion on SPECT PET
May aid in differentiation from other types of dementia especially Alzheimers disease
TREATMENT AND PROGNOSIS
Unlike Parkinsons disease dementia with Lewy bodies respond less readily to L-dopa and also may have severe sensitivity reactions to neuroleptic drugs such as rigidity reduced consciousness pyrexia falling postural hypotension and collapse
Lewy body dementia also responds favourably to acetylcholinesteraseinhibitors
DIFFERENTIAL DIAGNOSISwith strong overlap between
bullAlzheimers diseasebull clinical may occasionally have similar clinical presentation with a frontal type dementia or posterior
cortical atrophy
bull imaging prominent involvement of hippocampi on imaging
bullFronto-temporal lobar degenerationbull clinical usually younger onset absent parkinsonian features absent visual hallucinations
bull imaging more pronounced frontal temporal atrophy L gt R asymmetry
FRONTO-TEMPORAL LOBAR DEGENERATION
Frontotemporal lobar degeneration (FTLD) is the pathological description of a group of neurodegenerative disorders characterised by focal atrophy of the frontal and temporal cortices
rontotemporal lobar degeneration can be divided as follows 3-4
bullbehavioural variant fronto-temporal lobar degeneration dementia (bvFTLD) (aka behavioural variant frontotemporal dementia)1
bulllanguage variant fronto-temporal lobar degeneration (lvFTLD) (aka primary progressive aphasia (PPA)6
bull agrammatic variant primary progressive aphasia (aka progressive non-fluent aphasia (PNFA)
bull semantic variant primary progressive aphasia (aka semantic dementia)
bull logopaenic variant primary progressive aphasia
RADIOGRAPHIC FEATURES
The frontal and temporal lobes are predominantly affected there is often striking asymmetry both of involvement of frontal vs temporal lobes and involvement of left and right hemispheres
In addition the degree of fronto-striatal dysfunction varies between the different FTLD subgroups with behavioural variant frontotemporal dementia (bvFTD) having the greatest involvement
As a result the caudate heads tend to be reduced in size in these patients to a much greater degree than in the language variants of frontotemporal dementia
BEHAVIOURAL VARIANT FRONTO-TEMPORAL LOBAR DEGENERATION (BVFTLD)also referred to as Pick disease
Patients with behavioural variant FTD typically present with a dysexecutive cognitive syndrome associated with changes in personality and social behaviour
As the disease progresses impairments in language and memory may develop and the cognitive phenotype may come to resemble one of the language variants of FTD
RADIOGRAPHIC FEATURES
MRI
typical radiographic finding is atrophy of the frontal lobes and to a lesser extent the temporal lobes
The degree of atrophy can be very asymmetric
Decrease in volume of the caudate heads This indicates loss of both efferent and afferent fibres
CREUTZFELDT-JAKOB DISEASEspongiform encephalopathy
Results in a rapidly progressive dementia
other non-specific neurological features
Three types of Creutzfeldt-Jakob disease have been described
bullsporadic (sCJD) accounts for 85-90 of cases
bullvariant (vCJD)
bullfamilial (fCJD) 10 of cases (these individuals carry a PRPc mutation)
Creutzfeldt-Jakob disease is characterized by rapidly progressive dementia cerebral atrophy myoclonus and death
Patients with vCJD present mostly with sensory and psychiatric symptoms
Patients with sCJD usually present with progressive cognitive impairment and cerebellar symptoms
PATHOLOGY
mediated via (infectious) prions
a type of protein which manifest in sheep as the disease scrapie and in cows as bovine spongiform encephalopathy
Prions are considered infectious in sense that they can alter the structure of neighbouring proteins
CJD leads to spongiform degeneration of the brain
the conversion of normal prion protein to proteinaceous infectious particles that accumulate in and around neurons and lead to cell death
RADIOGRAPHIC FEATURES
MRI
MRI findings may be bilateral or unilateral and symmetric or asymmetric and include
T2 hyperintensity
obasal ganglia (putamen and caudate)
othalamus ( hockey stick sign and pulvinar sign)
ocortex most common early manifestation
owhite matter
persistent restricted diffusion on DWI (considered the most sensitive sign)
Review of sequential studies also typically demonstrates rapidly progressive cerebral atrophy
hypometabolism on 18FDG-PET studies
TREATMENT AND PROGNOSIS
here is currently no curative treatment and the disease is invariably fatal with a mean survival of only 7 months for most cases
PROGRESSIVE SUPRANUCLEARPALSYlso known as the Steele-Richardson-Olszewski syndrome
Progressive supranuclear palsy typically becomes clinically apparent in the 6th decade of life
Progresses to death usually within a decade (2-17 years from diagnosis)
Progressive supranuclear palsy is characterised
decreased cognition
abnormal eye movements (supranuclear vertical gaze palsy)
postural instability and falls
as well as parkinsonian features and speech disturbances
RADIOGRAPHIC FEATURESMRI
midbrain atrophy
reduction of anteroposterior midline midbrain diameter at the level of the superior colliculi on axial imaging (from interpeduncular fossa to the intercolicular groove lt12mm 8) which can give a mickey mouse appearance
reduced area of the midbrain on midline sagittal and reduced midbrain to pons area ratio approx 012 (normal approx 024) on midline sagittal
Loss of the lateral convex margin of the tegmentum of midbrain has been described as the morning glory sign
hummingbird sign also known as the penguin sign The key is a flattening or concave outline to the superior aspect of the midbrain which should be upwardly convex
bullT2 diffuse high-signal lesions in
bull pontine tegmentum
bull tectum of the midbrain
bull inferior olivary nucleus
MICKEY MOUSE APPEARANCE
THE PENGUIN SIGN
MULTIPLE SYSTEM ATROPHY
sporadic neurodegenerative disease
Typically symptoms begin between 40 and 60 years of age
Clinical presentation is variable but typically presents in one of three patterns (initially described as separate entities)
Shy-Drager syndrome is used when autonomic symptoms predominate
striatonigral degeneration shows predominant parkinsonian features
olivopontocerebellar atrophy demonstrates primarily cerebellar dysfunction
MSA has been divided clinically into 2 forms according to the dominant non-autonomic symptoms
MSA-C predominance of cerebellar symptoms (olivopontocerebellar atrophy)
MSA-P predominance of parkinsonian signs and symptoms (striatonigraldegeneration)
RADIOGRAPHIC FEATURES
bullT2 hyperintensities typically present in the pontocerebellar tractsbull pons hot cross bun sign (MSA-C)
bull middle cerebellar peduncles
bull Cerebellum
putaminal findings in MSA-P reduced volume
reduced GRE and T2 signal relative to globus pallidus
reduced GRE and T2 signal relative to red nucleus
abnormal disruption of the normal high T2 linear rim
bullMSA-Cbull disproportionate atrophy of the cerebellum and brainstem (especially olivary nuclei and middle
cerebellar peduncle)
NUCLEAR MEDICINE
SPECT and PET studies tend to demonstrate hypometabolism in the superior parietal and superior frontal areas in the basal ganglia
HUNTINGTON DISEASE
autosomal dominant neurodegenerative disease
a loss of GABAergic neurons of the basal ganglia
especially atrophy of the caudate nucleus and putamen
Huntington disease has a prevalence of 5-10 per 100000 and is typically diagnosed between 30 and 50 years of age
In approximately 1-6 symptoms occur before the age of 20 so-called juvenile form
Presentation is typically with progressive rigidity choreoathetosis dementia psychosis and emotional lability
The juvenile form has a different presentation with cerebellar symptoms rigidity and hypokinesia being prominent
it is a autosomal dominant with complete penetrance and genetic anticipation particularly if inherited mutated allele is paternal
The mutation responsible is on chromosome 4p163 and consists of a CAG trineucleotide repeat
The usual 10-30 copies are amplified to greater than 36 and the greater the number of repeats the earlier the age of onset
RADIOGRAPHIC FEATURES
MRI
The most striking and best known feature is that of caudate head atrophy resulting in enlargement of the frontal horns often giving them a box like configuration
This can be quantified by an number of measurements
bullfrontal horn width to intercaudate distance ratio (FHCC)
bullintercaudate distance to inner table width ratio (CCIT)
Juvenile form
putamen are also atrophied and demonstrate increased T2 signal
basal ganglia may show decrease T2 signal and blooming on SWI in keeping with iron deposition
Generalised age inappropriate cortical volume loss is also recognised
FHCC ratio normal mean 22 to 26 (this ratio decreases with ageing as a result of enlargement of the frontal horns of the lateral ventricles)
CCIT ratio normal mean 009 to 012
AMYOTROPHIC LATERAL SCLEROSISalso known as Lou Gehrig disease or Charcot disease
Primary degeneration of the motor neurons within the brain brain stem and spinal cord
Patients typically present with progressive muscle weakness and limb and truncal atrophy combined with signs of spasticity
Mean age at the time of diagnosis is 55 years
RADIOGRAPHIC FEATURES
MRI
The earliest MR manifestation is hyperintensity on T2WI in the corticospinal tracts seen earliest in the internal capsule
Iron deposition in the cortex is demonstrated as loss of signal most evident on T2 weighted sequences
IS IT ATROPHY OR HYDROCEPHALUS
Abnormal accumulation of CSF in Ventricular system
Results from Structural or functional block to normal flow Of CSF
In effect all are obhstructive
Difficult to differentiate Atrophy from Hydrocephalus gt60yrs
Initially show increased ICT
Later stages may reach Equillibrium and Becomes NP hYdrocephalus
Types
Obstructive
Communicating
NPH ndash seen typically in old patients Diagnosis is more based on clinical feature
Dementia urinary incontinence and gait apraxias + Hydrocephalus = NPH
Radiologically w
1 degeree of ventricular dilatation is more with Thinning and bowing of CC
2 Sulcal effacement is invariable seen Hydrocephalus
3 dilatation or rounding of the Temporal Horns
4 Rounding and enlargement of the frontal horns
5 Enlargement and ballooning of 3rd
ventricle
6 Enlargement of fourth ventricle
SPOTTERS
THANK YOU
DEMENTIA WITH LEWY BODIESPD
Neurodegenerative disease (a synucleinopathy to be specific) related to Parkinsons disease (PD)
Epidemiology
Dementia with Lewy bodies presents in older patients (onset typically in 50-70 years of age) and is sporadic
It is the second most common neurodegenerative cause of dementia in older patients after Alzheimers disease accounting for 15-20 of case
RADIOGRAPHIC FEATURES
MRI
Atrophy in various parts of the brain without a clearly identified unique pattern
Most helpful in distinguishing DLB from other entities resulting in dementia is the absence of features of other diseases
generalised decrease in cerebral volume most marked in
frontal lobes parietotemporal regions
enlargement of the lateral ventricles
relatively focal atrophy
midbrain
hypothalamus
SWALLOW TAIL SIGN
The swallow tail sign describes the normal axial imaging appearance of nigrosome-1 within the substantianigra on high resolution T2SWI weighted MRI
Absence of the sign (absent swallow tail sign) is reported to have a diagnostic accuracy of greater than 90 for Parkinson disease
Nuclear medicine
Occipital hypoperfusion on SPECT PET
May aid in differentiation from other types of dementia especially Alzheimers disease
TREATMENT AND PROGNOSIS
Unlike Parkinsons disease dementia with Lewy bodies respond less readily to L-dopa and also may have severe sensitivity reactions to neuroleptic drugs such as rigidity reduced consciousness pyrexia falling postural hypotension and collapse
Lewy body dementia also responds favourably to acetylcholinesteraseinhibitors
DIFFERENTIAL DIAGNOSISwith strong overlap between
bullAlzheimers diseasebull clinical may occasionally have similar clinical presentation with a frontal type dementia or posterior
cortical atrophy
bull imaging prominent involvement of hippocampi on imaging
bullFronto-temporal lobar degenerationbull clinical usually younger onset absent parkinsonian features absent visual hallucinations
bull imaging more pronounced frontal temporal atrophy L gt R asymmetry
FRONTO-TEMPORAL LOBAR DEGENERATION
Frontotemporal lobar degeneration (FTLD) is the pathological description of a group of neurodegenerative disorders characterised by focal atrophy of the frontal and temporal cortices
rontotemporal lobar degeneration can be divided as follows 3-4
bullbehavioural variant fronto-temporal lobar degeneration dementia (bvFTLD) (aka behavioural variant frontotemporal dementia)1
bulllanguage variant fronto-temporal lobar degeneration (lvFTLD) (aka primary progressive aphasia (PPA)6
bull agrammatic variant primary progressive aphasia (aka progressive non-fluent aphasia (PNFA)
bull semantic variant primary progressive aphasia (aka semantic dementia)
bull logopaenic variant primary progressive aphasia
RADIOGRAPHIC FEATURES
The frontal and temporal lobes are predominantly affected there is often striking asymmetry both of involvement of frontal vs temporal lobes and involvement of left and right hemispheres
In addition the degree of fronto-striatal dysfunction varies between the different FTLD subgroups with behavioural variant frontotemporal dementia (bvFTD) having the greatest involvement
As a result the caudate heads tend to be reduced in size in these patients to a much greater degree than in the language variants of frontotemporal dementia
BEHAVIOURAL VARIANT FRONTO-TEMPORAL LOBAR DEGENERATION (BVFTLD)also referred to as Pick disease
Patients with behavioural variant FTD typically present with a dysexecutive cognitive syndrome associated with changes in personality and social behaviour
As the disease progresses impairments in language and memory may develop and the cognitive phenotype may come to resemble one of the language variants of FTD
RADIOGRAPHIC FEATURES
MRI
typical radiographic finding is atrophy of the frontal lobes and to a lesser extent the temporal lobes
The degree of atrophy can be very asymmetric
Decrease in volume of the caudate heads This indicates loss of both efferent and afferent fibres
CREUTZFELDT-JAKOB DISEASEspongiform encephalopathy
Results in a rapidly progressive dementia
other non-specific neurological features
Three types of Creutzfeldt-Jakob disease have been described
bullsporadic (sCJD) accounts for 85-90 of cases
bullvariant (vCJD)
bullfamilial (fCJD) 10 of cases (these individuals carry a PRPc mutation)
Creutzfeldt-Jakob disease is characterized by rapidly progressive dementia cerebral atrophy myoclonus and death
Patients with vCJD present mostly with sensory and psychiatric symptoms
Patients with sCJD usually present with progressive cognitive impairment and cerebellar symptoms
PATHOLOGY
mediated via (infectious) prions
a type of protein which manifest in sheep as the disease scrapie and in cows as bovine spongiform encephalopathy
Prions are considered infectious in sense that they can alter the structure of neighbouring proteins
CJD leads to spongiform degeneration of the brain
the conversion of normal prion protein to proteinaceous infectious particles that accumulate in and around neurons and lead to cell death
RADIOGRAPHIC FEATURES
MRI
MRI findings may be bilateral or unilateral and symmetric or asymmetric and include
T2 hyperintensity
obasal ganglia (putamen and caudate)
othalamus ( hockey stick sign and pulvinar sign)
ocortex most common early manifestation
owhite matter
persistent restricted diffusion on DWI (considered the most sensitive sign)
Review of sequential studies also typically demonstrates rapidly progressive cerebral atrophy
hypometabolism on 18FDG-PET studies
TREATMENT AND PROGNOSIS
here is currently no curative treatment and the disease is invariably fatal with a mean survival of only 7 months for most cases
PROGRESSIVE SUPRANUCLEARPALSYlso known as the Steele-Richardson-Olszewski syndrome
Progressive supranuclear palsy typically becomes clinically apparent in the 6th decade of life
Progresses to death usually within a decade (2-17 years from diagnosis)
Progressive supranuclear palsy is characterised
decreased cognition
abnormal eye movements (supranuclear vertical gaze palsy)
postural instability and falls
as well as parkinsonian features and speech disturbances
RADIOGRAPHIC FEATURESMRI
midbrain atrophy
reduction of anteroposterior midline midbrain diameter at the level of the superior colliculi on axial imaging (from interpeduncular fossa to the intercolicular groove lt12mm 8) which can give a mickey mouse appearance
reduced area of the midbrain on midline sagittal and reduced midbrain to pons area ratio approx 012 (normal approx 024) on midline sagittal
Loss of the lateral convex margin of the tegmentum of midbrain has been described as the morning glory sign
hummingbird sign also known as the penguin sign The key is a flattening or concave outline to the superior aspect of the midbrain which should be upwardly convex
bullT2 diffuse high-signal lesions in
bull pontine tegmentum
bull tectum of the midbrain
bull inferior olivary nucleus
MICKEY MOUSE APPEARANCE
THE PENGUIN SIGN
MULTIPLE SYSTEM ATROPHY
sporadic neurodegenerative disease
Typically symptoms begin between 40 and 60 years of age
Clinical presentation is variable but typically presents in one of three patterns (initially described as separate entities)
Shy-Drager syndrome is used when autonomic symptoms predominate
striatonigral degeneration shows predominant parkinsonian features
olivopontocerebellar atrophy demonstrates primarily cerebellar dysfunction
MSA has been divided clinically into 2 forms according to the dominant non-autonomic symptoms
MSA-C predominance of cerebellar symptoms (olivopontocerebellar atrophy)
MSA-P predominance of parkinsonian signs and symptoms (striatonigraldegeneration)
RADIOGRAPHIC FEATURES
bullT2 hyperintensities typically present in the pontocerebellar tractsbull pons hot cross bun sign (MSA-C)
bull middle cerebellar peduncles
bull Cerebellum
putaminal findings in MSA-P reduced volume
reduced GRE and T2 signal relative to globus pallidus
reduced GRE and T2 signal relative to red nucleus
abnormal disruption of the normal high T2 linear rim
bullMSA-Cbull disproportionate atrophy of the cerebellum and brainstem (especially olivary nuclei and middle
cerebellar peduncle)
NUCLEAR MEDICINE
SPECT and PET studies tend to demonstrate hypometabolism in the superior parietal and superior frontal areas in the basal ganglia
HUNTINGTON DISEASE
autosomal dominant neurodegenerative disease
a loss of GABAergic neurons of the basal ganglia
especially atrophy of the caudate nucleus and putamen
Huntington disease has a prevalence of 5-10 per 100000 and is typically diagnosed between 30 and 50 years of age
In approximately 1-6 symptoms occur before the age of 20 so-called juvenile form
Presentation is typically with progressive rigidity choreoathetosis dementia psychosis and emotional lability
The juvenile form has a different presentation with cerebellar symptoms rigidity and hypokinesia being prominent
it is a autosomal dominant with complete penetrance and genetic anticipation particularly if inherited mutated allele is paternal
The mutation responsible is on chromosome 4p163 and consists of a CAG trineucleotide repeat
The usual 10-30 copies are amplified to greater than 36 and the greater the number of repeats the earlier the age of onset
RADIOGRAPHIC FEATURES
MRI
The most striking and best known feature is that of caudate head atrophy resulting in enlargement of the frontal horns often giving them a box like configuration
This can be quantified by an number of measurements
bullfrontal horn width to intercaudate distance ratio (FHCC)
bullintercaudate distance to inner table width ratio (CCIT)
Juvenile form
putamen are also atrophied and demonstrate increased T2 signal
basal ganglia may show decrease T2 signal and blooming on SWI in keeping with iron deposition
Generalised age inappropriate cortical volume loss is also recognised
FHCC ratio normal mean 22 to 26 (this ratio decreases with ageing as a result of enlargement of the frontal horns of the lateral ventricles)
CCIT ratio normal mean 009 to 012
AMYOTROPHIC LATERAL SCLEROSISalso known as Lou Gehrig disease or Charcot disease
Primary degeneration of the motor neurons within the brain brain stem and spinal cord
Patients typically present with progressive muscle weakness and limb and truncal atrophy combined with signs of spasticity
Mean age at the time of diagnosis is 55 years
RADIOGRAPHIC FEATURES
MRI
The earliest MR manifestation is hyperintensity on T2WI in the corticospinal tracts seen earliest in the internal capsule
Iron deposition in the cortex is demonstrated as loss of signal most evident on T2 weighted sequences
IS IT ATROPHY OR HYDROCEPHALUS
Abnormal accumulation of CSF in Ventricular system
Results from Structural or functional block to normal flow Of CSF
In effect all are obhstructive
Difficult to differentiate Atrophy from Hydrocephalus gt60yrs
Initially show increased ICT
Later stages may reach Equillibrium and Becomes NP hYdrocephalus
Types
Obstructive
Communicating
NPH ndash seen typically in old patients Diagnosis is more based on clinical feature
Dementia urinary incontinence and gait apraxias + Hydrocephalus = NPH
Radiologically w
1 degeree of ventricular dilatation is more with Thinning and bowing of CC
2 Sulcal effacement is invariable seen Hydrocephalus
3 dilatation or rounding of the Temporal Horns
4 Rounding and enlargement of the frontal horns
5 Enlargement and ballooning of 3rd
ventricle
6 Enlargement of fourth ventricle
SPOTTERS
THANK YOU
RADIOGRAPHIC FEATURES
MRI
Atrophy in various parts of the brain without a clearly identified unique pattern
Most helpful in distinguishing DLB from other entities resulting in dementia is the absence of features of other diseases
generalised decrease in cerebral volume most marked in
frontal lobes parietotemporal regions
enlargement of the lateral ventricles
relatively focal atrophy
midbrain
hypothalamus
SWALLOW TAIL SIGN
The swallow tail sign describes the normal axial imaging appearance of nigrosome-1 within the substantianigra on high resolution T2SWI weighted MRI
Absence of the sign (absent swallow tail sign) is reported to have a diagnostic accuracy of greater than 90 for Parkinson disease
Nuclear medicine
Occipital hypoperfusion on SPECT PET
May aid in differentiation from other types of dementia especially Alzheimers disease
TREATMENT AND PROGNOSIS
Unlike Parkinsons disease dementia with Lewy bodies respond less readily to L-dopa and also may have severe sensitivity reactions to neuroleptic drugs such as rigidity reduced consciousness pyrexia falling postural hypotension and collapse
Lewy body dementia also responds favourably to acetylcholinesteraseinhibitors
DIFFERENTIAL DIAGNOSISwith strong overlap between
bullAlzheimers diseasebull clinical may occasionally have similar clinical presentation with a frontal type dementia or posterior
cortical atrophy
bull imaging prominent involvement of hippocampi on imaging
bullFronto-temporal lobar degenerationbull clinical usually younger onset absent parkinsonian features absent visual hallucinations
bull imaging more pronounced frontal temporal atrophy L gt R asymmetry
FRONTO-TEMPORAL LOBAR DEGENERATION
Frontotemporal lobar degeneration (FTLD) is the pathological description of a group of neurodegenerative disorders characterised by focal atrophy of the frontal and temporal cortices
rontotemporal lobar degeneration can be divided as follows 3-4
bullbehavioural variant fronto-temporal lobar degeneration dementia (bvFTLD) (aka behavioural variant frontotemporal dementia)1
bulllanguage variant fronto-temporal lobar degeneration (lvFTLD) (aka primary progressive aphasia (PPA)6
bull agrammatic variant primary progressive aphasia (aka progressive non-fluent aphasia (PNFA)
bull semantic variant primary progressive aphasia (aka semantic dementia)
bull logopaenic variant primary progressive aphasia
RADIOGRAPHIC FEATURES
The frontal and temporal lobes are predominantly affected there is often striking asymmetry both of involvement of frontal vs temporal lobes and involvement of left and right hemispheres
In addition the degree of fronto-striatal dysfunction varies between the different FTLD subgroups with behavioural variant frontotemporal dementia (bvFTD) having the greatest involvement
As a result the caudate heads tend to be reduced in size in these patients to a much greater degree than in the language variants of frontotemporal dementia
BEHAVIOURAL VARIANT FRONTO-TEMPORAL LOBAR DEGENERATION (BVFTLD)also referred to as Pick disease
Patients with behavioural variant FTD typically present with a dysexecutive cognitive syndrome associated with changes in personality and social behaviour
As the disease progresses impairments in language and memory may develop and the cognitive phenotype may come to resemble one of the language variants of FTD
RADIOGRAPHIC FEATURES
MRI
typical radiographic finding is atrophy of the frontal lobes and to a lesser extent the temporal lobes
The degree of atrophy can be very asymmetric
Decrease in volume of the caudate heads This indicates loss of both efferent and afferent fibres
CREUTZFELDT-JAKOB DISEASEspongiform encephalopathy
Results in a rapidly progressive dementia
other non-specific neurological features
Three types of Creutzfeldt-Jakob disease have been described
bullsporadic (sCJD) accounts for 85-90 of cases
bullvariant (vCJD)
bullfamilial (fCJD) 10 of cases (these individuals carry a PRPc mutation)
Creutzfeldt-Jakob disease is characterized by rapidly progressive dementia cerebral atrophy myoclonus and death
Patients with vCJD present mostly with sensory and psychiatric symptoms
Patients with sCJD usually present with progressive cognitive impairment and cerebellar symptoms
PATHOLOGY
mediated via (infectious) prions
a type of protein which manifest in sheep as the disease scrapie and in cows as bovine spongiform encephalopathy
Prions are considered infectious in sense that they can alter the structure of neighbouring proteins
CJD leads to spongiform degeneration of the brain
the conversion of normal prion protein to proteinaceous infectious particles that accumulate in and around neurons and lead to cell death
RADIOGRAPHIC FEATURES
MRI
MRI findings may be bilateral or unilateral and symmetric or asymmetric and include
T2 hyperintensity
obasal ganglia (putamen and caudate)
othalamus ( hockey stick sign and pulvinar sign)
ocortex most common early manifestation
owhite matter
persistent restricted diffusion on DWI (considered the most sensitive sign)
Review of sequential studies also typically demonstrates rapidly progressive cerebral atrophy
hypometabolism on 18FDG-PET studies
TREATMENT AND PROGNOSIS
here is currently no curative treatment and the disease is invariably fatal with a mean survival of only 7 months for most cases
PROGRESSIVE SUPRANUCLEARPALSYlso known as the Steele-Richardson-Olszewski syndrome
Progressive supranuclear palsy typically becomes clinically apparent in the 6th decade of life
Progresses to death usually within a decade (2-17 years from diagnosis)
Progressive supranuclear palsy is characterised
decreased cognition
abnormal eye movements (supranuclear vertical gaze palsy)
postural instability and falls
as well as parkinsonian features and speech disturbances
RADIOGRAPHIC FEATURESMRI
midbrain atrophy
reduction of anteroposterior midline midbrain diameter at the level of the superior colliculi on axial imaging (from interpeduncular fossa to the intercolicular groove lt12mm 8) which can give a mickey mouse appearance
reduced area of the midbrain on midline sagittal and reduced midbrain to pons area ratio approx 012 (normal approx 024) on midline sagittal
Loss of the lateral convex margin of the tegmentum of midbrain has been described as the morning glory sign
hummingbird sign also known as the penguin sign The key is a flattening or concave outline to the superior aspect of the midbrain which should be upwardly convex
bullT2 diffuse high-signal lesions in
bull pontine tegmentum
bull tectum of the midbrain
bull inferior olivary nucleus
MICKEY MOUSE APPEARANCE
THE PENGUIN SIGN
MULTIPLE SYSTEM ATROPHY
sporadic neurodegenerative disease
Typically symptoms begin between 40 and 60 years of age
Clinical presentation is variable but typically presents in one of three patterns (initially described as separate entities)
Shy-Drager syndrome is used when autonomic symptoms predominate
striatonigral degeneration shows predominant parkinsonian features
olivopontocerebellar atrophy demonstrates primarily cerebellar dysfunction
MSA has been divided clinically into 2 forms according to the dominant non-autonomic symptoms
MSA-C predominance of cerebellar symptoms (olivopontocerebellar atrophy)
MSA-P predominance of parkinsonian signs and symptoms (striatonigraldegeneration)
RADIOGRAPHIC FEATURES
bullT2 hyperintensities typically present in the pontocerebellar tractsbull pons hot cross bun sign (MSA-C)
bull middle cerebellar peduncles
bull Cerebellum
putaminal findings in MSA-P reduced volume
reduced GRE and T2 signal relative to globus pallidus
reduced GRE and T2 signal relative to red nucleus
abnormal disruption of the normal high T2 linear rim
bullMSA-Cbull disproportionate atrophy of the cerebellum and brainstem (especially olivary nuclei and middle
cerebellar peduncle)
NUCLEAR MEDICINE
SPECT and PET studies tend to demonstrate hypometabolism in the superior parietal and superior frontal areas in the basal ganglia
HUNTINGTON DISEASE
autosomal dominant neurodegenerative disease
a loss of GABAergic neurons of the basal ganglia
especially atrophy of the caudate nucleus and putamen
Huntington disease has a prevalence of 5-10 per 100000 and is typically diagnosed between 30 and 50 years of age
In approximately 1-6 symptoms occur before the age of 20 so-called juvenile form
Presentation is typically with progressive rigidity choreoathetosis dementia psychosis and emotional lability
The juvenile form has a different presentation with cerebellar symptoms rigidity and hypokinesia being prominent
it is a autosomal dominant with complete penetrance and genetic anticipation particularly if inherited mutated allele is paternal
The mutation responsible is on chromosome 4p163 and consists of a CAG trineucleotide repeat
The usual 10-30 copies are amplified to greater than 36 and the greater the number of repeats the earlier the age of onset
RADIOGRAPHIC FEATURES
MRI
The most striking and best known feature is that of caudate head atrophy resulting in enlargement of the frontal horns often giving them a box like configuration
This can be quantified by an number of measurements
bullfrontal horn width to intercaudate distance ratio (FHCC)
bullintercaudate distance to inner table width ratio (CCIT)
Juvenile form
putamen are also atrophied and demonstrate increased T2 signal
basal ganglia may show decrease T2 signal and blooming on SWI in keeping with iron deposition
Generalised age inappropriate cortical volume loss is also recognised
FHCC ratio normal mean 22 to 26 (this ratio decreases with ageing as a result of enlargement of the frontal horns of the lateral ventricles)
CCIT ratio normal mean 009 to 012
AMYOTROPHIC LATERAL SCLEROSISalso known as Lou Gehrig disease or Charcot disease
Primary degeneration of the motor neurons within the brain brain stem and spinal cord
Patients typically present with progressive muscle weakness and limb and truncal atrophy combined with signs of spasticity
Mean age at the time of diagnosis is 55 years
RADIOGRAPHIC FEATURES
MRI
The earliest MR manifestation is hyperintensity on T2WI in the corticospinal tracts seen earliest in the internal capsule
Iron deposition in the cortex is demonstrated as loss of signal most evident on T2 weighted sequences
IS IT ATROPHY OR HYDROCEPHALUS
Abnormal accumulation of CSF in Ventricular system
Results from Structural or functional block to normal flow Of CSF
In effect all are obhstructive
Difficult to differentiate Atrophy from Hydrocephalus gt60yrs
Initially show increased ICT
Later stages may reach Equillibrium and Becomes NP hYdrocephalus
Types
Obstructive
Communicating
NPH ndash seen typically in old patients Diagnosis is more based on clinical feature
Dementia urinary incontinence and gait apraxias + Hydrocephalus = NPH
Radiologically w
1 degeree of ventricular dilatation is more with Thinning and bowing of CC
2 Sulcal effacement is invariable seen Hydrocephalus
3 dilatation or rounding of the Temporal Horns
4 Rounding and enlargement of the frontal horns
5 Enlargement and ballooning of 3rd
ventricle
6 Enlargement of fourth ventricle
SPOTTERS
THANK YOU
SWALLOW TAIL SIGN
The swallow tail sign describes the normal axial imaging appearance of nigrosome-1 within the substantianigra on high resolution T2SWI weighted MRI
Absence of the sign (absent swallow tail sign) is reported to have a diagnostic accuracy of greater than 90 for Parkinson disease
Nuclear medicine
Occipital hypoperfusion on SPECT PET
May aid in differentiation from other types of dementia especially Alzheimers disease
TREATMENT AND PROGNOSIS
Unlike Parkinsons disease dementia with Lewy bodies respond less readily to L-dopa and also may have severe sensitivity reactions to neuroleptic drugs such as rigidity reduced consciousness pyrexia falling postural hypotension and collapse
Lewy body dementia also responds favourably to acetylcholinesteraseinhibitors
DIFFERENTIAL DIAGNOSISwith strong overlap between
bullAlzheimers diseasebull clinical may occasionally have similar clinical presentation with a frontal type dementia or posterior
cortical atrophy
bull imaging prominent involvement of hippocampi on imaging
bullFronto-temporal lobar degenerationbull clinical usually younger onset absent parkinsonian features absent visual hallucinations
bull imaging more pronounced frontal temporal atrophy L gt R asymmetry
FRONTO-TEMPORAL LOBAR DEGENERATION
Frontotemporal lobar degeneration (FTLD) is the pathological description of a group of neurodegenerative disorders characterised by focal atrophy of the frontal and temporal cortices
rontotemporal lobar degeneration can be divided as follows 3-4
bullbehavioural variant fronto-temporal lobar degeneration dementia (bvFTLD) (aka behavioural variant frontotemporal dementia)1
bulllanguage variant fronto-temporal lobar degeneration (lvFTLD) (aka primary progressive aphasia (PPA)6
bull agrammatic variant primary progressive aphasia (aka progressive non-fluent aphasia (PNFA)
bull semantic variant primary progressive aphasia (aka semantic dementia)
bull logopaenic variant primary progressive aphasia
RADIOGRAPHIC FEATURES
The frontal and temporal lobes are predominantly affected there is often striking asymmetry both of involvement of frontal vs temporal lobes and involvement of left and right hemispheres
In addition the degree of fronto-striatal dysfunction varies between the different FTLD subgroups with behavioural variant frontotemporal dementia (bvFTD) having the greatest involvement
As a result the caudate heads tend to be reduced in size in these patients to a much greater degree than in the language variants of frontotemporal dementia
BEHAVIOURAL VARIANT FRONTO-TEMPORAL LOBAR DEGENERATION (BVFTLD)also referred to as Pick disease
Patients with behavioural variant FTD typically present with a dysexecutive cognitive syndrome associated with changes in personality and social behaviour
As the disease progresses impairments in language and memory may develop and the cognitive phenotype may come to resemble one of the language variants of FTD
RADIOGRAPHIC FEATURES
MRI
typical radiographic finding is atrophy of the frontal lobes and to a lesser extent the temporal lobes
The degree of atrophy can be very asymmetric
Decrease in volume of the caudate heads This indicates loss of both efferent and afferent fibres
CREUTZFELDT-JAKOB DISEASEspongiform encephalopathy
Results in a rapidly progressive dementia
other non-specific neurological features
Three types of Creutzfeldt-Jakob disease have been described
bullsporadic (sCJD) accounts for 85-90 of cases
bullvariant (vCJD)
bullfamilial (fCJD) 10 of cases (these individuals carry a PRPc mutation)
Creutzfeldt-Jakob disease is characterized by rapidly progressive dementia cerebral atrophy myoclonus and death
Patients with vCJD present mostly with sensory and psychiatric symptoms
Patients with sCJD usually present with progressive cognitive impairment and cerebellar symptoms
PATHOLOGY
mediated via (infectious) prions
a type of protein which manifest in sheep as the disease scrapie and in cows as bovine spongiform encephalopathy
Prions are considered infectious in sense that they can alter the structure of neighbouring proteins
CJD leads to spongiform degeneration of the brain
the conversion of normal prion protein to proteinaceous infectious particles that accumulate in and around neurons and lead to cell death
RADIOGRAPHIC FEATURES
MRI
MRI findings may be bilateral or unilateral and symmetric or asymmetric and include
T2 hyperintensity
obasal ganglia (putamen and caudate)
othalamus ( hockey stick sign and pulvinar sign)
ocortex most common early manifestation
owhite matter
persistent restricted diffusion on DWI (considered the most sensitive sign)
Review of sequential studies also typically demonstrates rapidly progressive cerebral atrophy
hypometabolism on 18FDG-PET studies
TREATMENT AND PROGNOSIS
here is currently no curative treatment and the disease is invariably fatal with a mean survival of only 7 months for most cases
PROGRESSIVE SUPRANUCLEARPALSYlso known as the Steele-Richardson-Olszewski syndrome
Progressive supranuclear palsy typically becomes clinically apparent in the 6th decade of life
Progresses to death usually within a decade (2-17 years from diagnosis)
Progressive supranuclear palsy is characterised
decreased cognition
abnormal eye movements (supranuclear vertical gaze palsy)
postural instability and falls
as well as parkinsonian features and speech disturbances
RADIOGRAPHIC FEATURESMRI
midbrain atrophy
reduction of anteroposterior midline midbrain diameter at the level of the superior colliculi on axial imaging (from interpeduncular fossa to the intercolicular groove lt12mm 8) which can give a mickey mouse appearance
reduced area of the midbrain on midline sagittal and reduced midbrain to pons area ratio approx 012 (normal approx 024) on midline sagittal
Loss of the lateral convex margin of the tegmentum of midbrain has been described as the morning glory sign
hummingbird sign also known as the penguin sign The key is a flattening or concave outline to the superior aspect of the midbrain which should be upwardly convex
bullT2 diffuse high-signal lesions in
bull pontine tegmentum
bull tectum of the midbrain
bull inferior olivary nucleus
MICKEY MOUSE APPEARANCE
THE PENGUIN SIGN
MULTIPLE SYSTEM ATROPHY
sporadic neurodegenerative disease
Typically symptoms begin between 40 and 60 years of age
Clinical presentation is variable but typically presents in one of three patterns (initially described as separate entities)
Shy-Drager syndrome is used when autonomic symptoms predominate
striatonigral degeneration shows predominant parkinsonian features
olivopontocerebellar atrophy demonstrates primarily cerebellar dysfunction
MSA has been divided clinically into 2 forms according to the dominant non-autonomic symptoms
MSA-C predominance of cerebellar symptoms (olivopontocerebellar atrophy)
MSA-P predominance of parkinsonian signs and symptoms (striatonigraldegeneration)
RADIOGRAPHIC FEATURES
bullT2 hyperintensities typically present in the pontocerebellar tractsbull pons hot cross bun sign (MSA-C)
bull middle cerebellar peduncles
bull Cerebellum
putaminal findings in MSA-P reduced volume
reduced GRE and T2 signal relative to globus pallidus
reduced GRE and T2 signal relative to red nucleus
abnormal disruption of the normal high T2 linear rim
bullMSA-Cbull disproportionate atrophy of the cerebellum and brainstem (especially olivary nuclei and middle
cerebellar peduncle)
NUCLEAR MEDICINE
SPECT and PET studies tend to demonstrate hypometabolism in the superior parietal and superior frontal areas in the basal ganglia
HUNTINGTON DISEASE
autosomal dominant neurodegenerative disease
a loss of GABAergic neurons of the basal ganglia
especially atrophy of the caudate nucleus and putamen
Huntington disease has a prevalence of 5-10 per 100000 and is typically diagnosed between 30 and 50 years of age
In approximately 1-6 symptoms occur before the age of 20 so-called juvenile form
Presentation is typically with progressive rigidity choreoathetosis dementia psychosis and emotional lability
The juvenile form has a different presentation with cerebellar symptoms rigidity and hypokinesia being prominent
it is a autosomal dominant with complete penetrance and genetic anticipation particularly if inherited mutated allele is paternal
The mutation responsible is on chromosome 4p163 and consists of a CAG trineucleotide repeat
The usual 10-30 copies are amplified to greater than 36 and the greater the number of repeats the earlier the age of onset
RADIOGRAPHIC FEATURES
MRI
The most striking and best known feature is that of caudate head atrophy resulting in enlargement of the frontal horns often giving them a box like configuration
This can be quantified by an number of measurements
bullfrontal horn width to intercaudate distance ratio (FHCC)
bullintercaudate distance to inner table width ratio (CCIT)
Juvenile form
putamen are also atrophied and demonstrate increased T2 signal
basal ganglia may show decrease T2 signal and blooming on SWI in keeping with iron deposition
Generalised age inappropriate cortical volume loss is also recognised
FHCC ratio normal mean 22 to 26 (this ratio decreases with ageing as a result of enlargement of the frontal horns of the lateral ventricles)
CCIT ratio normal mean 009 to 012
AMYOTROPHIC LATERAL SCLEROSISalso known as Lou Gehrig disease or Charcot disease
Primary degeneration of the motor neurons within the brain brain stem and spinal cord
Patients typically present with progressive muscle weakness and limb and truncal atrophy combined with signs of spasticity
Mean age at the time of diagnosis is 55 years
RADIOGRAPHIC FEATURES
MRI
The earliest MR manifestation is hyperintensity on T2WI in the corticospinal tracts seen earliest in the internal capsule
Iron deposition in the cortex is demonstrated as loss of signal most evident on T2 weighted sequences
IS IT ATROPHY OR HYDROCEPHALUS
Abnormal accumulation of CSF in Ventricular system
Results from Structural or functional block to normal flow Of CSF
In effect all are obhstructive
Difficult to differentiate Atrophy from Hydrocephalus gt60yrs
Initially show increased ICT
Later stages may reach Equillibrium and Becomes NP hYdrocephalus
Types
Obstructive
Communicating
NPH ndash seen typically in old patients Diagnosis is more based on clinical feature
Dementia urinary incontinence and gait apraxias + Hydrocephalus = NPH
Radiologically w
1 degeree of ventricular dilatation is more with Thinning and bowing of CC
2 Sulcal effacement is invariable seen Hydrocephalus
3 dilatation or rounding of the Temporal Horns
4 Rounding and enlargement of the frontal horns
5 Enlargement and ballooning of 3rd
ventricle
6 Enlargement of fourth ventricle
SPOTTERS
THANK YOU
Nuclear medicine
Occipital hypoperfusion on SPECT PET
May aid in differentiation from other types of dementia especially Alzheimers disease
TREATMENT AND PROGNOSIS
Unlike Parkinsons disease dementia with Lewy bodies respond less readily to L-dopa and also may have severe sensitivity reactions to neuroleptic drugs such as rigidity reduced consciousness pyrexia falling postural hypotension and collapse
Lewy body dementia also responds favourably to acetylcholinesteraseinhibitors
DIFFERENTIAL DIAGNOSISwith strong overlap between
bullAlzheimers diseasebull clinical may occasionally have similar clinical presentation with a frontal type dementia or posterior
cortical atrophy
bull imaging prominent involvement of hippocampi on imaging
bullFronto-temporal lobar degenerationbull clinical usually younger onset absent parkinsonian features absent visual hallucinations
bull imaging more pronounced frontal temporal atrophy L gt R asymmetry
FRONTO-TEMPORAL LOBAR DEGENERATION
Frontotemporal lobar degeneration (FTLD) is the pathological description of a group of neurodegenerative disorders characterised by focal atrophy of the frontal and temporal cortices
rontotemporal lobar degeneration can be divided as follows 3-4
bullbehavioural variant fronto-temporal lobar degeneration dementia (bvFTLD) (aka behavioural variant frontotemporal dementia)1
bulllanguage variant fronto-temporal lobar degeneration (lvFTLD) (aka primary progressive aphasia (PPA)6
bull agrammatic variant primary progressive aphasia (aka progressive non-fluent aphasia (PNFA)
bull semantic variant primary progressive aphasia (aka semantic dementia)
bull logopaenic variant primary progressive aphasia
RADIOGRAPHIC FEATURES
The frontal and temporal lobes are predominantly affected there is often striking asymmetry both of involvement of frontal vs temporal lobes and involvement of left and right hemispheres
In addition the degree of fronto-striatal dysfunction varies between the different FTLD subgroups with behavioural variant frontotemporal dementia (bvFTD) having the greatest involvement
As a result the caudate heads tend to be reduced in size in these patients to a much greater degree than in the language variants of frontotemporal dementia
BEHAVIOURAL VARIANT FRONTO-TEMPORAL LOBAR DEGENERATION (BVFTLD)also referred to as Pick disease
Patients with behavioural variant FTD typically present with a dysexecutive cognitive syndrome associated with changes in personality and social behaviour
As the disease progresses impairments in language and memory may develop and the cognitive phenotype may come to resemble one of the language variants of FTD
RADIOGRAPHIC FEATURES
MRI
typical radiographic finding is atrophy of the frontal lobes and to a lesser extent the temporal lobes
The degree of atrophy can be very asymmetric
Decrease in volume of the caudate heads This indicates loss of both efferent and afferent fibres
CREUTZFELDT-JAKOB DISEASEspongiform encephalopathy
Results in a rapidly progressive dementia
other non-specific neurological features
Three types of Creutzfeldt-Jakob disease have been described
bullsporadic (sCJD) accounts for 85-90 of cases
bullvariant (vCJD)
bullfamilial (fCJD) 10 of cases (these individuals carry a PRPc mutation)
Creutzfeldt-Jakob disease is characterized by rapidly progressive dementia cerebral atrophy myoclonus and death
Patients with vCJD present mostly with sensory and psychiatric symptoms
Patients with sCJD usually present with progressive cognitive impairment and cerebellar symptoms
PATHOLOGY
mediated via (infectious) prions
a type of protein which manifest in sheep as the disease scrapie and in cows as bovine spongiform encephalopathy
Prions are considered infectious in sense that they can alter the structure of neighbouring proteins
CJD leads to spongiform degeneration of the brain
the conversion of normal prion protein to proteinaceous infectious particles that accumulate in and around neurons and lead to cell death
RADIOGRAPHIC FEATURES
MRI
MRI findings may be bilateral or unilateral and symmetric or asymmetric and include
T2 hyperintensity
obasal ganglia (putamen and caudate)
othalamus ( hockey stick sign and pulvinar sign)
ocortex most common early manifestation
owhite matter
persistent restricted diffusion on DWI (considered the most sensitive sign)
Review of sequential studies also typically demonstrates rapidly progressive cerebral atrophy
hypometabolism on 18FDG-PET studies
TREATMENT AND PROGNOSIS
here is currently no curative treatment and the disease is invariably fatal with a mean survival of only 7 months for most cases
PROGRESSIVE SUPRANUCLEARPALSYlso known as the Steele-Richardson-Olszewski syndrome
Progressive supranuclear palsy typically becomes clinically apparent in the 6th decade of life
Progresses to death usually within a decade (2-17 years from diagnosis)
Progressive supranuclear palsy is characterised
decreased cognition
abnormal eye movements (supranuclear vertical gaze palsy)
postural instability and falls
as well as parkinsonian features and speech disturbances
RADIOGRAPHIC FEATURESMRI
midbrain atrophy
reduction of anteroposterior midline midbrain diameter at the level of the superior colliculi on axial imaging (from interpeduncular fossa to the intercolicular groove lt12mm 8) which can give a mickey mouse appearance
reduced area of the midbrain on midline sagittal and reduced midbrain to pons area ratio approx 012 (normal approx 024) on midline sagittal
Loss of the lateral convex margin of the tegmentum of midbrain has been described as the morning glory sign
hummingbird sign also known as the penguin sign The key is a flattening or concave outline to the superior aspect of the midbrain which should be upwardly convex
bullT2 diffuse high-signal lesions in
bull pontine tegmentum
bull tectum of the midbrain
bull inferior olivary nucleus
MICKEY MOUSE APPEARANCE
THE PENGUIN SIGN
MULTIPLE SYSTEM ATROPHY
sporadic neurodegenerative disease
Typically symptoms begin between 40 and 60 years of age
Clinical presentation is variable but typically presents in one of three patterns (initially described as separate entities)
Shy-Drager syndrome is used when autonomic symptoms predominate
striatonigral degeneration shows predominant parkinsonian features
olivopontocerebellar atrophy demonstrates primarily cerebellar dysfunction
MSA has been divided clinically into 2 forms according to the dominant non-autonomic symptoms
MSA-C predominance of cerebellar symptoms (olivopontocerebellar atrophy)
MSA-P predominance of parkinsonian signs and symptoms (striatonigraldegeneration)
RADIOGRAPHIC FEATURES
bullT2 hyperintensities typically present in the pontocerebellar tractsbull pons hot cross bun sign (MSA-C)
bull middle cerebellar peduncles
bull Cerebellum
putaminal findings in MSA-P reduced volume
reduced GRE and T2 signal relative to globus pallidus
reduced GRE and T2 signal relative to red nucleus
abnormal disruption of the normal high T2 linear rim
bullMSA-Cbull disproportionate atrophy of the cerebellum and brainstem (especially olivary nuclei and middle
cerebellar peduncle)
NUCLEAR MEDICINE
SPECT and PET studies tend to demonstrate hypometabolism in the superior parietal and superior frontal areas in the basal ganglia
HUNTINGTON DISEASE
autosomal dominant neurodegenerative disease
a loss of GABAergic neurons of the basal ganglia
especially atrophy of the caudate nucleus and putamen
Huntington disease has a prevalence of 5-10 per 100000 and is typically diagnosed between 30 and 50 years of age
In approximately 1-6 symptoms occur before the age of 20 so-called juvenile form
Presentation is typically with progressive rigidity choreoathetosis dementia psychosis and emotional lability
The juvenile form has a different presentation with cerebellar symptoms rigidity and hypokinesia being prominent
it is a autosomal dominant with complete penetrance and genetic anticipation particularly if inherited mutated allele is paternal
The mutation responsible is on chromosome 4p163 and consists of a CAG trineucleotide repeat
The usual 10-30 copies are amplified to greater than 36 and the greater the number of repeats the earlier the age of onset
RADIOGRAPHIC FEATURES
MRI
The most striking and best known feature is that of caudate head atrophy resulting in enlargement of the frontal horns often giving them a box like configuration
This can be quantified by an number of measurements
bullfrontal horn width to intercaudate distance ratio (FHCC)
bullintercaudate distance to inner table width ratio (CCIT)
Juvenile form
putamen are also atrophied and demonstrate increased T2 signal
basal ganglia may show decrease T2 signal and blooming on SWI in keeping with iron deposition
Generalised age inappropriate cortical volume loss is also recognised
FHCC ratio normal mean 22 to 26 (this ratio decreases with ageing as a result of enlargement of the frontal horns of the lateral ventricles)
CCIT ratio normal mean 009 to 012
AMYOTROPHIC LATERAL SCLEROSISalso known as Lou Gehrig disease or Charcot disease
Primary degeneration of the motor neurons within the brain brain stem and spinal cord
Patients typically present with progressive muscle weakness and limb and truncal atrophy combined with signs of spasticity
Mean age at the time of diagnosis is 55 years
RADIOGRAPHIC FEATURES
MRI
The earliest MR manifestation is hyperintensity on T2WI in the corticospinal tracts seen earliest in the internal capsule
Iron deposition in the cortex is demonstrated as loss of signal most evident on T2 weighted sequences
IS IT ATROPHY OR HYDROCEPHALUS
Abnormal accumulation of CSF in Ventricular system
Results from Structural or functional block to normal flow Of CSF
In effect all are obhstructive
Difficult to differentiate Atrophy from Hydrocephalus gt60yrs
Initially show increased ICT
Later stages may reach Equillibrium and Becomes NP hYdrocephalus
Types
Obstructive
Communicating
NPH ndash seen typically in old patients Diagnosis is more based on clinical feature
Dementia urinary incontinence and gait apraxias + Hydrocephalus = NPH
Radiologically w
1 degeree of ventricular dilatation is more with Thinning and bowing of CC
2 Sulcal effacement is invariable seen Hydrocephalus
3 dilatation or rounding of the Temporal Horns
4 Rounding and enlargement of the frontal horns
5 Enlargement and ballooning of 3rd
ventricle
6 Enlargement of fourth ventricle
SPOTTERS
THANK YOU
TREATMENT AND PROGNOSIS
Unlike Parkinsons disease dementia with Lewy bodies respond less readily to L-dopa and also may have severe sensitivity reactions to neuroleptic drugs such as rigidity reduced consciousness pyrexia falling postural hypotension and collapse
Lewy body dementia also responds favourably to acetylcholinesteraseinhibitors
DIFFERENTIAL DIAGNOSISwith strong overlap between
bullAlzheimers diseasebull clinical may occasionally have similar clinical presentation with a frontal type dementia or posterior
cortical atrophy
bull imaging prominent involvement of hippocampi on imaging
bullFronto-temporal lobar degenerationbull clinical usually younger onset absent parkinsonian features absent visual hallucinations
bull imaging more pronounced frontal temporal atrophy L gt R asymmetry
FRONTO-TEMPORAL LOBAR DEGENERATION
Frontotemporal lobar degeneration (FTLD) is the pathological description of a group of neurodegenerative disorders characterised by focal atrophy of the frontal and temporal cortices
rontotemporal lobar degeneration can be divided as follows 3-4
bullbehavioural variant fronto-temporal lobar degeneration dementia (bvFTLD) (aka behavioural variant frontotemporal dementia)1
bulllanguage variant fronto-temporal lobar degeneration (lvFTLD) (aka primary progressive aphasia (PPA)6
bull agrammatic variant primary progressive aphasia (aka progressive non-fluent aphasia (PNFA)
bull semantic variant primary progressive aphasia (aka semantic dementia)
bull logopaenic variant primary progressive aphasia
RADIOGRAPHIC FEATURES
The frontal and temporal lobes are predominantly affected there is often striking asymmetry both of involvement of frontal vs temporal lobes and involvement of left and right hemispheres
In addition the degree of fronto-striatal dysfunction varies between the different FTLD subgroups with behavioural variant frontotemporal dementia (bvFTD) having the greatest involvement
As a result the caudate heads tend to be reduced in size in these patients to a much greater degree than in the language variants of frontotemporal dementia
BEHAVIOURAL VARIANT FRONTO-TEMPORAL LOBAR DEGENERATION (BVFTLD)also referred to as Pick disease
Patients with behavioural variant FTD typically present with a dysexecutive cognitive syndrome associated with changes in personality and social behaviour
As the disease progresses impairments in language and memory may develop and the cognitive phenotype may come to resemble one of the language variants of FTD
RADIOGRAPHIC FEATURES
MRI
typical radiographic finding is atrophy of the frontal lobes and to a lesser extent the temporal lobes
The degree of atrophy can be very asymmetric
Decrease in volume of the caudate heads This indicates loss of both efferent and afferent fibres
CREUTZFELDT-JAKOB DISEASEspongiform encephalopathy
Results in a rapidly progressive dementia
other non-specific neurological features
Three types of Creutzfeldt-Jakob disease have been described
bullsporadic (sCJD) accounts for 85-90 of cases
bullvariant (vCJD)
bullfamilial (fCJD) 10 of cases (these individuals carry a PRPc mutation)
Creutzfeldt-Jakob disease is characterized by rapidly progressive dementia cerebral atrophy myoclonus and death
Patients with vCJD present mostly with sensory and psychiatric symptoms
Patients with sCJD usually present with progressive cognitive impairment and cerebellar symptoms
PATHOLOGY
mediated via (infectious) prions
a type of protein which manifest in sheep as the disease scrapie and in cows as bovine spongiform encephalopathy
Prions are considered infectious in sense that they can alter the structure of neighbouring proteins
CJD leads to spongiform degeneration of the brain
the conversion of normal prion protein to proteinaceous infectious particles that accumulate in and around neurons and lead to cell death
RADIOGRAPHIC FEATURES
MRI
MRI findings may be bilateral or unilateral and symmetric or asymmetric and include
T2 hyperintensity
obasal ganglia (putamen and caudate)
othalamus ( hockey stick sign and pulvinar sign)
ocortex most common early manifestation
owhite matter
persistent restricted diffusion on DWI (considered the most sensitive sign)
Review of sequential studies also typically demonstrates rapidly progressive cerebral atrophy
hypometabolism on 18FDG-PET studies
TREATMENT AND PROGNOSIS
here is currently no curative treatment and the disease is invariably fatal with a mean survival of only 7 months for most cases
PROGRESSIVE SUPRANUCLEARPALSYlso known as the Steele-Richardson-Olszewski syndrome
Progressive supranuclear palsy typically becomes clinically apparent in the 6th decade of life
Progresses to death usually within a decade (2-17 years from diagnosis)
Progressive supranuclear palsy is characterised
decreased cognition
abnormal eye movements (supranuclear vertical gaze palsy)
postural instability and falls
as well as parkinsonian features and speech disturbances
RADIOGRAPHIC FEATURESMRI
midbrain atrophy
reduction of anteroposterior midline midbrain diameter at the level of the superior colliculi on axial imaging (from interpeduncular fossa to the intercolicular groove lt12mm 8) which can give a mickey mouse appearance
reduced area of the midbrain on midline sagittal and reduced midbrain to pons area ratio approx 012 (normal approx 024) on midline sagittal
Loss of the lateral convex margin of the tegmentum of midbrain has been described as the morning glory sign
hummingbird sign also known as the penguin sign The key is a flattening or concave outline to the superior aspect of the midbrain which should be upwardly convex
bullT2 diffuse high-signal lesions in
bull pontine tegmentum
bull tectum of the midbrain
bull inferior olivary nucleus
MICKEY MOUSE APPEARANCE
THE PENGUIN SIGN
MULTIPLE SYSTEM ATROPHY
sporadic neurodegenerative disease
Typically symptoms begin between 40 and 60 years of age
Clinical presentation is variable but typically presents in one of three patterns (initially described as separate entities)
Shy-Drager syndrome is used when autonomic symptoms predominate
striatonigral degeneration shows predominant parkinsonian features
olivopontocerebellar atrophy demonstrates primarily cerebellar dysfunction
MSA has been divided clinically into 2 forms according to the dominant non-autonomic symptoms
MSA-C predominance of cerebellar symptoms (olivopontocerebellar atrophy)
MSA-P predominance of parkinsonian signs and symptoms (striatonigraldegeneration)
RADIOGRAPHIC FEATURES
bullT2 hyperintensities typically present in the pontocerebellar tractsbull pons hot cross bun sign (MSA-C)
bull middle cerebellar peduncles
bull Cerebellum
putaminal findings in MSA-P reduced volume
reduced GRE and T2 signal relative to globus pallidus
reduced GRE and T2 signal relative to red nucleus
abnormal disruption of the normal high T2 linear rim
bullMSA-Cbull disproportionate atrophy of the cerebellum and brainstem (especially olivary nuclei and middle
cerebellar peduncle)
NUCLEAR MEDICINE
SPECT and PET studies tend to demonstrate hypometabolism in the superior parietal and superior frontal areas in the basal ganglia
HUNTINGTON DISEASE
autosomal dominant neurodegenerative disease
a loss of GABAergic neurons of the basal ganglia
especially atrophy of the caudate nucleus and putamen
Huntington disease has a prevalence of 5-10 per 100000 and is typically diagnosed between 30 and 50 years of age
In approximately 1-6 symptoms occur before the age of 20 so-called juvenile form
Presentation is typically with progressive rigidity choreoathetosis dementia psychosis and emotional lability
The juvenile form has a different presentation with cerebellar symptoms rigidity and hypokinesia being prominent
it is a autosomal dominant with complete penetrance and genetic anticipation particularly if inherited mutated allele is paternal
The mutation responsible is on chromosome 4p163 and consists of a CAG trineucleotide repeat
The usual 10-30 copies are amplified to greater than 36 and the greater the number of repeats the earlier the age of onset
RADIOGRAPHIC FEATURES
MRI
The most striking and best known feature is that of caudate head atrophy resulting in enlargement of the frontal horns often giving them a box like configuration
This can be quantified by an number of measurements
bullfrontal horn width to intercaudate distance ratio (FHCC)
bullintercaudate distance to inner table width ratio (CCIT)
Juvenile form
putamen are also atrophied and demonstrate increased T2 signal
basal ganglia may show decrease T2 signal and blooming on SWI in keeping with iron deposition
Generalised age inappropriate cortical volume loss is also recognised
FHCC ratio normal mean 22 to 26 (this ratio decreases with ageing as a result of enlargement of the frontal horns of the lateral ventricles)
CCIT ratio normal mean 009 to 012
AMYOTROPHIC LATERAL SCLEROSISalso known as Lou Gehrig disease or Charcot disease
Primary degeneration of the motor neurons within the brain brain stem and spinal cord
Patients typically present with progressive muscle weakness and limb and truncal atrophy combined with signs of spasticity
Mean age at the time of diagnosis is 55 years
RADIOGRAPHIC FEATURES
MRI
The earliest MR manifestation is hyperintensity on T2WI in the corticospinal tracts seen earliest in the internal capsule
Iron deposition in the cortex is demonstrated as loss of signal most evident on T2 weighted sequences
IS IT ATROPHY OR HYDROCEPHALUS
Abnormal accumulation of CSF in Ventricular system
Results from Structural or functional block to normal flow Of CSF
In effect all are obhstructive
Difficult to differentiate Atrophy from Hydrocephalus gt60yrs
Initially show increased ICT
Later stages may reach Equillibrium and Becomes NP hYdrocephalus
Types
Obstructive
Communicating
NPH ndash seen typically in old patients Diagnosis is more based on clinical feature
Dementia urinary incontinence and gait apraxias + Hydrocephalus = NPH
Radiologically w
1 degeree of ventricular dilatation is more with Thinning and bowing of CC
2 Sulcal effacement is invariable seen Hydrocephalus
3 dilatation or rounding of the Temporal Horns
4 Rounding and enlargement of the frontal horns
5 Enlargement and ballooning of 3rd
ventricle
6 Enlargement of fourth ventricle
SPOTTERS
THANK YOU
DIFFERENTIAL DIAGNOSISwith strong overlap between
bullAlzheimers diseasebull clinical may occasionally have similar clinical presentation with a frontal type dementia or posterior
cortical atrophy
bull imaging prominent involvement of hippocampi on imaging
bullFronto-temporal lobar degenerationbull clinical usually younger onset absent parkinsonian features absent visual hallucinations
bull imaging more pronounced frontal temporal atrophy L gt R asymmetry
FRONTO-TEMPORAL LOBAR DEGENERATION
Frontotemporal lobar degeneration (FTLD) is the pathological description of a group of neurodegenerative disorders characterised by focal atrophy of the frontal and temporal cortices
rontotemporal lobar degeneration can be divided as follows 3-4
bullbehavioural variant fronto-temporal lobar degeneration dementia (bvFTLD) (aka behavioural variant frontotemporal dementia)1
bulllanguage variant fronto-temporal lobar degeneration (lvFTLD) (aka primary progressive aphasia (PPA)6
bull agrammatic variant primary progressive aphasia (aka progressive non-fluent aphasia (PNFA)
bull semantic variant primary progressive aphasia (aka semantic dementia)
bull logopaenic variant primary progressive aphasia
RADIOGRAPHIC FEATURES
The frontal and temporal lobes are predominantly affected there is often striking asymmetry both of involvement of frontal vs temporal lobes and involvement of left and right hemispheres
In addition the degree of fronto-striatal dysfunction varies between the different FTLD subgroups with behavioural variant frontotemporal dementia (bvFTD) having the greatest involvement
As a result the caudate heads tend to be reduced in size in these patients to a much greater degree than in the language variants of frontotemporal dementia
BEHAVIOURAL VARIANT FRONTO-TEMPORAL LOBAR DEGENERATION (BVFTLD)also referred to as Pick disease
Patients with behavioural variant FTD typically present with a dysexecutive cognitive syndrome associated with changes in personality and social behaviour
As the disease progresses impairments in language and memory may develop and the cognitive phenotype may come to resemble one of the language variants of FTD
RADIOGRAPHIC FEATURES
MRI
typical radiographic finding is atrophy of the frontal lobes and to a lesser extent the temporal lobes
The degree of atrophy can be very asymmetric
Decrease in volume of the caudate heads This indicates loss of both efferent and afferent fibres
CREUTZFELDT-JAKOB DISEASEspongiform encephalopathy
Results in a rapidly progressive dementia
other non-specific neurological features
Three types of Creutzfeldt-Jakob disease have been described
bullsporadic (sCJD) accounts for 85-90 of cases
bullvariant (vCJD)
bullfamilial (fCJD) 10 of cases (these individuals carry a PRPc mutation)
Creutzfeldt-Jakob disease is characterized by rapidly progressive dementia cerebral atrophy myoclonus and death
Patients with vCJD present mostly with sensory and psychiatric symptoms
Patients with sCJD usually present with progressive cognitive impairment and cerebellar symptoms
PATHOLOGY
mediated via (infectious) prions
a type of protein which manifest in sheep as the disease scrapie and in cows as bovine spongiform encephalopathy
Prions are considered infectious in sense that they can alter the structure of neighbouring proteins
CJD leads to spongiform degeneration of the brain
the conversion of normal prion protein to proteinaceous infectious particles that accumulate in and around neurons and lead to cell death
RADIOGRAPHIC FEATURES
MRI
MRI findings may be bilateral or unilateral and symmetric or asymmetric and include
T2 hyperintensity
obasal ganglia (putamen and caudate)
othalamus ( hockey stick sign and pulvinar sign)
ocortex most common early manifestation
owhite matter
persistent restricted diffusion on DWI (considered the most sensitive sign)
Review of sequential studies also typically demonstrates rapidly progressive cerebral atrophy
hypometabolism on 18FDG-PET studies
TREATMENT AND PROGNOSIS
here is currently no curative treatment and the disease is invariably fatal with a mean survival of only 7 months for most cases
PROGRESSIVE SUPRANUCLEARPALSYlso known as the Steele-Richardson-Olszewski syndrome
Progressive supranuclear palsy typically becomes clinically apparent in the 6th decade of life
Progresses to death usually within a decade (2-17 years from diagnosis)
Progressive supranuclear palsy is characterised
decreased cognition
abnormal eye movements (supranuclear vertical gaze palsy)
postural instability and falls
as well as parkinsonian features and speech disturbances
RADIOGRAPHIC FEATURESMRI
midbrain atrophy
reduction of anteroposterior midline midbrain diameter at the level of the superior colliculi on axial imaging (from interpeduncular fossa to the intercolicular groove lt12mm 8) which can give a mickey mouse appearance
reduced area of the midbrain on midline sagittal and reduced midbrain to pons area ratio approx 012 (normal approx 024) on midline sagittal
Loss of the lateral convex margin of the tegmentum of midbrain has been described as the morning glory sign
hummingbird sign also known as the penguin sign The key is a flattening or concave outline to the superior aspect of the midbrain which should be upwardly convex
bullT2 diffuse high-signal lesions in
bull pontine tegmentum
bull tectum of the midbrain
bull inferior olivary nucleus
MICKEY MOUSE APPEARANCE
THE PENGUIN SIGN
MULTIPLE SYSTEM ATROPHY
sporadic neurodegenerative disease
Typically symptoms begin between 40 and 60 years of age
Clinical presentation is variable but typically presents in one of three patterns (initially described as separate entities)
Shy-Drager syndrome is used when autonomic symptoms predominate
striatonigral degeneration shows predominant parkinsonian features
olivopontocerebellar atrophy demonstrates primarily cerebellar dysfunction
MSA has been divided clinically into 2 forms according to the dominant non-autonomic symptoms
MSA-C predominance of cerebellar symptoms (olivopontocerebellar atrophy)
MSA-P predominance of parkinsonian signs and symptoms (striatonigraldegeneration)
RADIOGRAPHIC FEATURES
bullT2 hyperintensities typically present in the pontocerebellar tractsbull pons hot cross bun sign (MSA-C)
bull middle cerebellar peduncles
bull Cerebellum
putaminal findings in MSA-P reduced volume
reduced GRE and T2 signal relative to globus pallidus
reduced GRE and T2 signal relative to red nucleus
abnormal disruption of the normal high T2 linear rim
bullMSA-Cbull disproportionate atrophy of the cerebellum and brainstem (especially olivary nuclei and middle
cerebellar peduncle)
NUCLEAR MEDICINE
SPECT and PET studies tend to demonstrate hypometabolism in the superior parietal and superior frontal areas in the basal ganglia
HUNTINGTON DISEASE
autosomal dominant neurodegenerative disease
a loss of GABAergic neurons of the basal ganglia
especially atrophy of the caudate nucleus and putamen
Huntington disease has a prevalence of 5-10 per 100000 and is typically diagnosed between 30 and 50 years of age
In approximately 1-6 symptoms occur before the age of 20 so-called juvenile form
Presentation is typically with progressive rigidity choreoathetosis dementia psychosis and emotional lability
The juvenile form has a different presentation with cerebellar symptoms rigidity and hypokinesia being prominent
it is a autosomal dominant with complete penetrance and genetic anticipation particularly if inherited mutated allele is paternal
The mutation responsible is on chromosome 4p163 and consists of a CAG trineucleotide repeat
The usual 10-30 copies are amplified to greater than 36 and the greater the number of repeats the earlier the age of onset
RADIOGRAPHIC FEATURES
MRI
The most striking and best known feature is that of caudate head atrophy resulting in enlargement of the frontal horns often giving them a box like configuration
This can be quantified by an number of measurements
bullfrontal horn width to intercaudate distance ratio (FHCC)
bullintercaudate distance to inner table width ratio (CCIT)
Juvenile form
putamen are also atrophied and demonstrate increased T2 signal
basal ganglia may show decrease T2 signal and blooming on SWI in keeping with iron deposition
Generalised age inappropriate cortical volume loss is also recognised
FHCC ratio normal mean 22 to 26 (this ratio decreases with ageing as a result of enlargement of the frontal horns of the lateral ventricles)
CCIT ratio normal mean 009 to 012
AMYOTROPHIC LATERAL SCLEROSISalso known as Lou Gehrig disease or Charcot disease
Primary degeneration of the motor neurons within the brain brain stem and spinal cord
Patients typically present with progressive muscle weakness and limb and truncal atrophy combined with signs of spasticity
Mean age at the time of diagnosis is 55 years
RADIOGRAPHIC FEATURES
MRI
The earliest MR manifestation is hyperintensity on T2WI in the corticospinal tracts seen earliest in the internal capsule
Iron deposition in the cortex is demonstrated as loss of signal most evident on T2 weighted sequences
IS IT ATROPHY OR HYDROCEPHALUS
Abnormal accumulation of CSF in Ventricular system
Results from Structural or functional block to normal flow Of CSF
In effect all are obhstructive
Difficult to differentiate Atrophy from Hydrocephalus gt60yrs
Initially show increased ICT
Later stages may reach Equillibrium and Becomes NP hYdrocephalus
Types
Obstructive
Communicating
NPH ndash seen typically in old patients Diagnosis is more based on clinical feature
Dementia urinary incontinence and gait apraxias + Hydrocephalus = NPH
Radiologically w
1 degeree of ventricular dilatation is more with Thinning and bowing of CC
2 Sulcal effacement is invariable seen Hydrocephalus
3 dilatation or rounding of the Temporal Horns
4 Rounding and enlargement of the frontal horns
5 Enlargement and ballooning of 3rd
ventricle
6 Enlargement of fourth ventricle
SPOTTERS
THANK YOU
FRONTO-TEMPORAL LOBAR DEGENERATION
Frontotemporal lobar degeneration (FTLD) is the pathological description of a group of neurodegenerative disorders characterised by focal atrophy of the frontal and temporal cortices
rontotemporal lobar degeneration can be divided as follows 3-4
bullbehavioural variant fronto-temporal lobar degeneration dementia (bvFTLD) (aka behavioural variant frontotemporal dementia)1
bulllanguage variant fronto-temporal lobar degeneration (lvFTLD) (aka primary progressive aphasia (PPA)6
bull agrammatic variant primary progressive aphasia (aka progressive non-fluent aphasia (PNFA)
bull semantic variant primary progressive aphasia (aka semantic dementia)
bull logopaenic variant primary progressive aphasia
RADIOGRAPHIC FEATURES
The frontal and temporal lobes are predominantly affected there is often striking asymmetry both of involvement of frontal vs temporal lobes and involvement of left and right hemispheres
In addition the degree of fronto-striatal dysfunction varies between the different FTLD subgroups with behavioural variant frontotemporal dementia (bvFTD) having the greatest involvement
As a result the caudate heads tend to be reduced in size in these patients to a much greater degree than in the language variants of frontotemporal dementia
BEHAVIOURAL VARIANT FRONTO-TEMPORAL LOBAR DEGENERATION (BVFTLD)also referred to as Pick disease
Patients with behavioural variant FTD typically present with a dysexecutive cognitive syndrome associated with changes in personality and social behaviour
As the disease progresses impairments in language and memory may develop and the cognitive phenotype may come to resemble one of the language variants of FTD
RADIOGRAPHIC FEATURES
MRI
typical radiographic finding is atrophy of the frontal lobes and to a lesser extent the temporal lobes
The degree of atrophy can be very asymmetric
Decrease in volume of the caudate heads This indicates loss of both efferent and afferent fibres
CREUTZFELDT-JAKOB DISEASEspongiform encephalopathy
Results in a rapidly progressive dementia
other non-specific neurological features
Three types of Creutzfeldt-Jakob disease have been described
bullsporadic (sCJD) accounts for 85-90 of cases
bullvariant (vCJD)
bullfamilial (fCJD) 10 of cases (these individuals carry a PRPc mutation)
Creutzfeldt-Jakob disease is characterized by rapidly progressive dementia cerebral atrophy myoclonus and death
Patients with vCJD present mostly with sensory and psychiatric symptoms
Patients with sCJD usually present with progressive cognitive impairment and cerebellar symptoms
PATHOLOGY
mediated via (infectious) prions
a type of protein which manifest in sheep as the disease scrapie and in cows as bovine spongiform encephalopathy
Prions are considered infectious in sense that they can alter the structure of neighbouring proteins
CJD leads to spongiform degeneration of the brain
the conversion of normal prion protein to proteinaceous infectious particles that accumulate in and around neurons and lead to cell death
RADIOGRAPHIC FEATURES
MRI
MRI findings may be bilateral or unilateral and symmetric or asymmetric and include
T2 hyperintensity
obasal ganglia (putamen and caudate)
othalamus ( hockey stick sign and pulvinar sign)
ocortex most common early manifestation
owhite matter
persistent restricted diffusion on DWI (considered the most sensitive sign)
Review of sequential studies also typically demonstrates rapidly progressive cerebral atrophy
hypometabolism on 18FDG-PET studies
TREATMENT AND PROGNOSIS
here is currently no curative treatment and the disease is invariably fatal with a mean survival of only 7 months for most cases
PROGRESSIVE SUPRANUCLEARPALSYlso known as the Steele-Richardson-Olszewski syndrome
Progressive supranuclear palsy typically becomes clinically apparent in the 6th decade of life
Progresses to death usually within a decade (2-17 years from diagnosis)
Progressive supranuclear palsy is characterised
decreased cognition
abnormal eye movements (supranuclear vertical gaze palsy)
postural instability and falls
as well as parkinsonian features and speech disturbances
RADIOGRAPHIC FEATURESMRI
midbrain atrophy
reduction of anteroposterior midline midbrain diameter at the level of the superior colliculi on axial imaging (from interpeduncular fossa to the intercolicular groove lt12mm 8) which can give a mickey mouse appearance
reduced area of the midbrain on midline sagittal and reduced midbrain to pons area ratio approx 012 (normal approx 024) on midline sagittal
Loss of the lateral convex margin of the tegmentum of midbrain has been described as the morning glory sign
hummingbird sign also known as the penguin sign The key is a flattening or concave outline to the superior aspect of the midbrain which should be upwardly convex
bullT2 diffuse high-signal lesions in
bull pontine tegmentum
bull tectum of the midbrain
bull inferior olivary nucleus
MICKEY MOUSE APPEARANCE
THE PENGUIN SIGN
MULTIPLE SYSTEM ATROPHY
sporadic neurodegenerative disease
Typically symptoms begin between 40 and 60 years of age
Clinical presentation is variable but typically presents in one of three patterns (initially described as separate entities)
Shy-Drager syndrome is used when autonomic symptoms predominate
striatonigral degeneration shows predominant parkinsonian features
olivopontocerebellar atrophy demonstrates primarily cerebellar dysfunction
MSA has been divided clinically into 2 forms according to the dominant non-autonomic symptoms
MSA-C predominance of cerebellar symptoms (olivopontocerebellar atrophy)
MSA-P predominance of parkinsonian signs and symptoms (striatonigraldegeneration)
RADIOGRAPHIC FEATURES
bullT2 hyperintensities typically present in the pontocerebellar tractsbull pons hot cross bun sign (MSA-C)
bull middle cerebellar peduncles
bull Cerebellum
putaminal findings in MSA-P reduced volume
reduced GRE and T2 signal relative to globus pallidus
reduced GRE and T2 signal relative to red nucleus
abnormal disruption of the normal high T2 linear rim
bullMSA-Cbull disproportionate atrophy of the cerebellum and brainstem (especially olivary nuclei and middle
cerebellar peduncle)
NUCLEAR MEDICINE
SPECT and PET studies tend to demonstrate hypometabolism in the superior parietal and superior frontal areas in the basal ganglia
HUNTINGTON DISEASE
autosomal dominant neurodegenerative disease
a loss of GABAergic neurons of the basal ganglia
especially atrophy of the caudate nucleus and putamen
Huntington disease has a prevalence of 5-10 per 100000 and is typically diagnosed between 30 and 50 years of age
In approximately 1-6 symptoms occur before the age of 20 so-called juvenile form
Presentation is typically with progressive rigidity choreoathetosis dementia psychosis and emotional lability
The juvenile form has a different presentation with cerebellar symptoms rigidity and hypokinesia being prominent
it is a autosomal dominant with complete penetrance and genetic anticipation particularly if inherited mutated allele is paternal
The mutation responsible is on chromosome 4p163 and consists of a CAG trineucleotide repeat
The usual 10-30 copies are amplified to greater than 36 and the greater the number of repeats the earlier the age of onset
RADIOGRAPHIC FEATURES
MRI
The most striking and best known feature is that of caudate head atrophy resulting in enlargement of the frontal horns often giving them a box like configuration
This can be quantified by an number of measurements
bullfrontal horn width to intercaudate distance ratio (FHCC)
bullintercaudate distance to inner table width ratio (CCIT)
Juvenile form
putamen are also atrophied and demonstrate increased T2 signal
basal ganglia may show decrease T2 signal and blooming on SWI in keeping with iron deposition
Generalised age inappropriate cortical volume loss is also recognised
FHCC ratio normal mean 22 to 26 (this ratio decreases with ageing as a result of enlargement of the frontal horns of the lateral ventricles)
CCIT ratio normal mean 009 to 012
AMYOTROPHIC LATERAL SCLEROSISalso known as Lou Gehrig disease or Charcot disease
Primary degeneration of the motor neurons within the brain brain stem and spinal cord
Patients typically present with progressive muscle weakness and limb and truncal atrophy combined with signs of spasticity
Mean age at the time of diagnosis is 55 years
RADIOGRAPHIC FEATURES
MRI
The earliest MR manifestation is hyperintensity on T2WI in the corticospinal tracts seen earliest in the internal capsule
Iron deposition in the cortex is demonstrated as loss of signal most evident on T2 weighted sequences
IS IT ATROPHY OR HYDROCEPHALUS
Abnormal accumulation of CSF in Ventricular system
Results from Structural or functional block to normal flow Of CSF
In effect all are obhstructive
Difficult to differentiate Atrophy from Hydrocephalus gt60yrs
Initially show increased ICT
Later stages may reach Equillibrium and Becomes NP hYdrocephalus
Types
Obstructive
Communicating
NPH ndash seen typically in old patients Diagnosis is more based on clinical feature
Dementia urinary incontinence and gait apraxias + Hydrocephalus = NPH
Radiologically w
1 degeree of ventricular dilatation is more with Thinning and bowing of CC
2 Sulcal effacement is invariable seen Hydrocephalus
3 dilatation or rounding of the Temporal Horns
4 Rounding and enlargement of the frontal horns
5 Enlargement and ballooning of 3rd
ventricle
6 Enlargement of fourth ventricle
SPOTTERS
THANK YOU
RADIOGRAPHIC FEATURES
The frontal and temporal lobes are predominantly affected there is often striking asymmetry both of involvement of frontal vs temporal lobes and involvement of left and right hemispheres
In addition the degree of fronto-striatal dysfunction varies between the different FTLD subgroups with behavioural variant frontotemporal dementia (bvFTD) having the greatest involvement
As a result the caudate heads tend to be reduced in size in these patients to a much greater degree than in the language variants of frontotemporal dementia
BEHAVIOURAL VARIANT FRONTO-TEMPORAL LOBAR DEGENERATION (BVFTLD)also referred to as Pick disease
Patients with behavioural variant FTD typically present with a dysexecutive cognitive syndrome associated with changes in personality and social behaviour
As the disease progresses impairments in language and memory may develop and the cognitive phenotype may come to resemble one of the language variants of FTD
RADIOGRAPHIC FEATURES
MRI
typical radiographic finding is atrophy of the frontal lobes and to a lesser extent the temporal lobes
The degree of atrophy can be very asymmetric
Decrease in volume of the caudate heads This indicates loss of both efferent and afferent fibres
CREUTZFELDT-JAKOB DISEASEspongiform encephalopathy
Results in a rapidly progressive dementia
other non-specific neurological features
Three types of Creutzfeldt-Jakob disease have been described
bullsporadic (sCJD) accounts for 85-90 of cases
bullvariant (vCJD)
bullfamilial (fCJD) 10 of cases (these individuals carry a PRPc mutation)
Creutzfeldt-Jakob disease is characterized by rapidly progressive dementia cerebral atrophy myoclonus and death
Patients with vCJD present mostly with sensory and psychiatric symptoms
Patients with sCJD usually present with progressive cognitive impairment and cerebellar symptoms
PATHOLOGY
mediated via (infectious) prions
a type of protein which manifest in sheep as the disease scrapie and in cows as bovine spongiform encephalopathy
Prions are considered infectious in sense that they can alter the structure of neighbouring proteins
CJD leads to spongiform degeneration of the brain
the conversion of normal prion protein to proteinaceous infectious particles that accumulate in and around neurons and lead to cell death
RADIOGRAPHIC FEATURES
MRI
MRI findings may be bilateral or unilateral and symmetric or asymmetric and include
T2 hyperintensity
obasal ganglia (putamen and caudate)
othalamus ( hockey stick sign and pulvinar sign)
ocortex most common early manifestation
owhite matter
persistent restricted diffusion on DWI (considered the most sensitive sign)
Review of sequential studies also typically demonstrates rapidly progressive cerebral atrophy
hypometabolism on 18FDG-PET studies
TREATMENT AND PROGNOSIS
here is currently no curative treatment and the disease is invariably fatal with a mean survival of only 7 months for most cases
PROGRESSIVE SUPRANUCLEARPALSYlso known as the Steele-Richardson-Olszewski syndrome
Progressive supranuclear palsy typically becomes clinically apparent in the 6th decade of life
Progresses to death usually within a decade (2-17 years from diagnosis)
Progressive supranuclear palsy is characterised
decreased cognition
abnormal eye movements (supranuclear vertical gaze palsy)
postural instability and falls
as well as parkinsonian features and speech disturbances
RADIOGRAPHIC FEATURESMRI
midbrain atrophy
reduction of anteroposterior midline midbrain diameter at the level of the superior colliculi on axial imaging (from interpeduncular fossa to the intercolicular groove lt12mm 8) which can give a mickey mouse appearance
reduced area of the midbrain on midline sagittal and reduced midbrain to pons area ratio approx 012 (normal approx 024) on midline sagittal
Loss of the lateral convex margin of the tegmentum of midbrain has been described as the morning glory sign
hummingbird sign also known as the penguin sign The key is a flattening or concave outline to the superior aspect of the midbrain which should be upwardly convex
bullT2 diffuse high-signal lesions in
bull pontine tegmentum
bull tectum of the midbrain
bull inferior olivary nucleus
MICKEY MOUSE APPEARANCE
THE PENGUIN SIGN
MULTIPLE SYSTEM ATROPHY
sporadic neurodegenerative disease
Typically symptoms begin between 40 and 60 years of age
Clinical presentation is variable but typically presents in one of three patterns (initially described as separate entities)
Shy-Drager syndrome is used when autonomic symptoms predominate
striatonigral degeneration shows predominant parkinsonian features
olivopontocerebellar atrophy demonstrates primarily cerebellar dysfunction
MSA has been divided clinically into 2 forms according to the dominant non-autonomic symptoms
MSA-C predominance of cerebellar symptoms (olivopontocerebellar atrophy)
MSA-P predominance of parkinsonian signs and symptoms (striatonigraldegeneration)
RADIOGRAPHIC FEATURES
bullT2 hyperintensities typically present in the pontocerebellar tractsbull pons hot cross bun sign (MSA-C)
bull middle cerebellar peduncles
bull Cerebellum
putaminal findings in MSA-P reduced volume
reduced GRE and T2 signal relative to globus pallidus
reduced GRE and T2 signal relative to red nucleus
abnormal disruption of the normal high T2 linear rim
bullMSA-Cbull disproportionate atrophy of the cerebellum and brainstem (especially olivary nuclei and middle
cerebellar peduncle)
NUCLEAR MEDICINE
SPECT and PET studies tend to demonstrate hypometabolism in the superior parietal and superior frontal areas in the basal ganglia
HUNTINGTON DISEASE
autosomal dominant neurodegenerative disease
a loss of GABAergic neurons of the basal ganglia
especially atrophy of the caudate nucleus and putamen
Huntington disease has a prevalence of 5-10 per 100000 and is typically diagnosed between 30 and 50 years of age
In approximately 1-6 symptoms occur before the age of 20 so-called juvenile form
Presentation is typically with progressive rigidity choreoathetosis dementia psychosis and emotional lability
The juvenile form has a different presentation with cerebellar symptoms rigidity and hypokinesia being prominent
it is a autosomal dominant with complete penetrance and genetic anticipation particularly if inherited mutated allele is paternal
The mutation responsible is on chromosome 4p163 and consists of a CAG trineucleotide repeat
The usual 10-30 copies are amplified to greater than 36 and the greater the number of repeats the earlier the age of onset
RADIOGRAPHIC FEATURES
MRI
The most striking and best known feature is that of caudate head atrophy resulting in enlargement of the frontal horns often giving them a box like configuration
This can be quantified by an number of measurements
bullfrontal horn width to intercaudate distance ratio (FHCC)
bullintercaudate distance to inner table width ratio (CCIT)
Juvenile form
putamen are also atrophied and demonstrate increased T2 signal
basal ganglia may show decrease T2 signal and blooming on SWI in keeping with iron deposition
Generalised age inappropriate cortical volume loss is also recognised
FHCC ratio normal mean 22 to 26 (this ratio decreases with ageing as a result of enlargement of the frontal horns of the lateral ventricles)
CCIT ratio normal mean 009 to 012
AMYOTROPHIC LATERAL SCLEROSISalso known as Lou Gehrig disease or Charcot disease
Primary degeneration of the motor neurons within the brain brain stem and spinal cord
Patients typically present with progressive muscle weakness and limb and truncal atrophy combined with signs of spasticity
Mean age at the time of diagnosis is 55 years
RADIOGRAPHIC FEATURES
MRI
The earliest MR manifestation is hyperintensity on T2WI in the corticospinal tracts seen earliest in the internal capsule
Iron deposition in the cortex is demonstrated as loss of signal most evident on T2 weighted sequences
IS IT ATROPHY OR HYDROCEPHALUS
Abnormal accumulation of CSF in Ventricular system
Results from Structural or functional block to normal flow Of CSF
In effect all are obhstructive
Difficult to differentiate Atrophy from Hydrocephalus gt60yrs
Initially show increased ICT
Later stages may reach Equillibrium and Becomes NP hYdrocephalus
Types
Obstructive
Communicating
NPH ndash seen typically in old patients Diagnosis is more based on clinical feature
Dementia urinary incontinence and gait apraxias + Hydrocephalus = NPH
Radiologically w
1 degeree of ventricular dilatation is more with Thinning and bowing of CC
2 Sulcal effacement is invariable seen Hydrocephalus
3 dilatation or rounding of the Temporal Horns
4 Rounding and enlargement of the frontal horns
5 Enlargement and ballooning of 3rd
ventricle
6 Enlargement of fourth ventricle
SPOTTERS
THANK YOU
BEHAVIOURAL VARIANT FRONTO-TEMPORAL LOBAR DEGENERATION (BVFTLD)also referred to as Pick disease
Patients with behavioural variant FTD typically present with a dysexecutive cognitive syndrome associated with changes in personality and social behaviour
As the disease progresses impairments in language and memory may develop and the cognitive phenotype may come to resemble one of the language variants of FTD
RADIOGRAPHIC FEATURES
MRI
typical radiographic finding is atrophy of the frontal lobes and to a lesser extent the temporal lobes
The degree of atrophy can be very asymmetric
Decrease in volume of the caudate heads This indicates loss of both efferent and afferent fibres
CREUTZFELDT-JAKOB DISEASEspongiform encephalopathy
Results in a rapidly progressive dementia
other non-specific neurological features
Three types of Creutzfeldt-Jakob disease have been described
bullsporadic (sCJD) accounts for 85-90 of cases
bullvariant (vCJD)
bullfamilial (fCJD) 10 of cases (these individuals carry a PRPc mutation)
Creutzfeldt-Jakob disease is characterized by rapidly progressive dementia cerebral atrophy myoclonus and death
Patients with vCJD present mostly with sensory and psychiatric symptoms
Patients with sCJD usually present with progressive cognitive impairment and cerebellar symptoms
PATHOLOGY
mediated via (infectious) prions
a type of protein which manifest in sheep as the disease scrapie and in cows as bovine spongiform encephalopathy
Prions are considered infectious in sense that they can alter the structure of neighbouring proteins
CJD leads to spongiform degeneration of the brain
the conversion of normal prion protein to proteinaceous infectious particles that accumulate in and around neurons and lead to cell death
RADIOGRAPHIC FEATURES
MRI
MRI findings may be bilateral or unilateral and symmetric or asymmetric and include
T2 hyperintensity
obasal ganglia (putamen and caudate)
othalamus ( hockey stick sign and pulvinar sign)
ocortex most common early manifestation
owhite matter
persistent restricted diffusion on DWI (considered the most sensitive sign)
Review of sequential studies also typically demonstrates rapidly progressive cerebral atrophy
hypometabolism on 18FDG-PET studies
TREATMENT AND PROGNOSIS
here is currently no curative treatment and the disease is invariably fatal with a mean survival of only 7 months for most cases
PROGRESSIVE SUPRANUCLEARPALSYlso known as the Steele-Richardson-Olszewski syndrome
Progressive supranuclear palsy typically becomes clinically apparent in the 6th decade of life
Progresses to death usually within a decade (2-17 years from diagnosis)
Progressive supranuclear palsy is characterised
decreased cognition
abnormal eye movements (supranuclear vertical gaze palsy)
postural instability and falls
as well as parkinsonian features and speech disturbances
RADIOGRAPHIC FEATURESMRI
midbrain atrophy
reduction of anteroposterior midline midbrain diameter at the level of the superior colliculi on axial imaging (from interpeduncular fossa to the intercolicular groove lt12mm 8) which can give a mickey mouse appearance
reduced area of the midbrain on midline sagittal and reduced midbrain to pons area ratio approx 012 (normal approx 024) on midline sagittal
Loss of the lateral convex margin of the tegmentum of midbrain has been described as the morning glory sign
hummingbird sign also known as the penguin sign The key is a flattening or concave outline to the superior aspect of the midbrain which should be upwardly convex
bullT2 diffuse high-signal lesions in
bull pontine tegmentum
bull tectum of the midbrain
bull inferior olivary nucleus
MICKEY MOUSE APPEARANCE
THE PENGUIN SIGN
MULTIPLE SYSTEM ATROPHY
sporadic neurodegenerative disease
Typically symptoms begin between 40 and 60 years of age
Clinical presentation is variable but typically presents in one of three patterns (initially described as separate entities)
Shy-Drager syndrome is used when autonomic symptoms predominate
striatonigral degeneration shows predominant parkinsonian features
olivopontocerebellar atrophy demonstrates primarily cerebellar dysfunction
MSA has been divided clinically into 2 forms according to the dominant non-autonomic symptoms
MSA-C predominance of cerebellar symptoms (olivopontocerebellar atrophy)
MSA-P predominance of parkinsonian signs and symptoms (striatonigraldegeneration)
RADIOGRAPHIC FEATURES
bullT2 hyperintensities typically present in the pontocerebellar tractsbull pons hot cross bun sign (MSA-C)
bull middle cerebellar peduncles
bull Cerebellum
putaminal findings in MSA-P reduced volume
reduced GRE and T2 signal relative to globus pallidus
reduced GRE and T2 signal relative to red nucleus
abnormal disruption of the normal high T2 linear rim
bullMSA-Cbull disproportionate atrophy of the cerebellum and brainstem (especially olivary nuclei and middle
cerebellar peduncle)
NUCLEAR MEDICINE
SPECT and PET studies tend to demonstrate hypometabolism in the superior parietal and superior frontal areas in the basal ganglia
HUNTINGTON DISEASE
autosomal dominant neurodegenerative disease
a loss of GABAergic neurons of the basal ganglia
especially atrophy of the caudate nucleus and putamen
Huntington disease has a prevalence of 5-10 per 100000 and is typically diagnosed between 30 and 50 years of age
In approximately 1-6 symptoms occur before the age of 20 so-called juvenile form
Presentation is typically with progressive rigidity choreoathetosis dementia psychosis and emotional lability
The juvenile form has a different presentation with cerebellar symptoms rigidity and hypokinesia being prominent
it is a autosomal dominant with complete penetrance and genetic anticipation particularly if inherited mutated allele is paternal
The mutation responsible is on chromosome 4p163 and consists of a CAG trineucleotide repeat
The usual 10-30 copies are amplified to greater than 36 and the greater the number of repeats the earlier the age of onset
RADIOGRAPHIC FEATURES
MRI
The most striking and best known feature is that of caudate head atrophy resulting in enlargement of the frontal horns often giving them a box like configuration
This can be quantified by an number of measurements
bullfrontal horn width to intercaudate distance ratio (FHCC)
bullintercaudate distance to inner table width ratio (CCIT)
Juvenile form
putamen are also atrophied and demonstrate increased T2 signal
basal ganglia may show decrease T2 signal and blooming on SWI in keeping with iron deposition
Generalised age inappropriate cortical volume loss is also recognised
FHCC ratio normal mean 22 to 26 (this ratio decreases with ageing as a result of enlargement of the frontal horns of the lateral ventricles)
CCIT ratio normal mean 009 to 012
AMYOTROPHIC LATERAL SCLEROSISalso known as Lou Gehrig disease or Charcot disease
Primary degeneration of the motor neurons within the brain brain stem and spinal cord
Patients typically present with progressive muscle weakness and limb and truncal atrophy combined with signs of spasticity
Mean age at the time of diagnosis is 55 years
RADIOGRAPHIC FEATURES
MRI
The earliest MR manifestation is hyperintensity on T2WI in the corticospinal tracts seen earliest in the internal capsule
Iron deposition in the cortex is demonstrated as loss of signal most evident on T2 weighted sequences
IS IT ATROPHY OR HYDROCEPHALUS
Abnormal accumulation of CSF in Ventricular system
Results from Structural or functional block to normal flow Of CSF
In effect all are obhstructive
Difficult to differentiate Atrophy from Hydrocephalus gt60yrs
Initially show increased ICT
Later stages may reach Equillibrium and Becomes NP hYdrocephalus
Types
Obstructive
Communicating
NPH ndash seen typically in old patients Diagnosis is more based on clinical feature
Dementia urinary incontinence and gait apraxias + Hydrocephalus = NPH
Radiologically w
1 degeree of ventricular dilatation is more with Thinning and bowing of CC
2 Sulcal effacement is invariable seen Hydrocephalus
3 dilatation or rounding of the Temporal Horns
4 Rounding and enlargement of the frontal horns
5 Enlargement and ballooning of 3rd
ventricle
6 Enlargement of fourth ventricle
SPOTTERS
THANK YOU
RADIOGRAPHIC FEATURES
MRI
typical radiographic finding is atrophy of the frontal lobes and to a lesser extent the temporal lobes
The degree of atrophy can be very asymmetric
Decrease in volume of the caudate heads This indicates loss of both efferent and afferent fibres
CREUTZFELDT-JAKOB DISEASEspongiform encephalopathy
Results in a rapidly progressive dementia
other non-specific neurological features
Three types of Creutzfeldt-Jakob disease have been described
bullsporadic (sCJD) accounts for 85-90 of cases
bullvariant (vCJD)
bullfamilial (fCJD) 10 of cases (these individuals carry a PRPc mutation)
Creutzfeldt-Jakob disease is characterized by rapidly progressive dementia cerebral atrophy myoclonus and death
Patients with vCJD present mostly with sensory and psychiatric symptoms
Patients with sCJD usually present with progressive cognitive impairment and cerebellar symptoms
PATHOLOGY
mediated via (infectious) prions
a type of protein which manifest in sheep as the disease scrapie and in cows as bovine spongiform encephalopathy
Prions are considered infectious in sense that they can alter the structure of neighbouring proteins
CJD leads to spongiform degeneration of the brain
the conversion of normal prion protein to proteinaceous infectious particles that accumulate in and around neurons and lead to cell death
RADIOGRAPHIC FEATURES
MRI
MRI findings may be bilateral or unilateral and symmetric or asymmetric and include
T2 hyperintensity
obasal ganglia (putamen and caudate)
othalamus ( hockey stick sign and pulvinar sign)
ocortex most common early manifestation
owhite matter
persistent restricted diffusion on DWI (considered the most sensitive sign)
Review of sequential studies also typically demonstrates rapidly progressive cerebral atrophy
hypometabolism on 18FDG-PET studies
TREATMENT AND PROGNOSIS
here is currently no curative treatment and the disease is invariably fatal with a mean survival of only 7 months for most cases
PROGRESSIVE SUPRANUCLEARPALSYlso known as the Steele-Richardson-Olszewski syndrome
Progressive supranuclear palsy typically becomes clinically apparent in the 6th decade of life
Progresses to death usually within a decade (2-17 years from diagnosis)
Progressive supranuclear palsy is characterised
decreased cognition
abnormal eye movements (supranuclear vertical gaze palsy)
postural instability and falls
as well as parkinsonian features and speech disturbances
RADIOGRAPHIC FEATURESMRI
midbrain atrophy
reduction of anteroposterior midline midbrain diameter at the level of the superior colliculi on axial imaging (from interpeduncular fossa to the intercolicular groove lt12mm 8) which can give a mickey mouse appearance
reduced area of the midbrain on midline sagittal and reduced midbrain to pons area ratio approx 012 (normal approx 024) on midline sagittal
Loss of the lateral convex margin of the tegmentum of midbrain has been described as the morning glory sign
hummingbird sign also known as the penguin sign The key is a flattening or concave outline to the superior aspect of the midbrain which should be upwardly convex
bullT2 diffuse high-signal lesions in
bull pontine tegmentum
bull tectum of the midbrain
bull inferior olivary nucleus
MICKEY MOUSE APPEARANCE
THE PENGUIN SIGN
MULTIPLE SYSTEM ATROPHY
sporadic neurodegenerative disease
Typically symptoms begin between 40 and 60 years of age
Clinical presentation is variable but typically presents in one of three patterns (initially described as separate entities)
Shy-Drager syndrome is used when autonomic symptoms predominate
striatonigral degeneration shows predominant parkinsonian features
olivopontocerebellar atrophy demonstrates primarily cerebellar dysfunction
MSA has been divided clinically into 2 forms according to the dominant non-autonomic symptoms
MSA-C predominance of cerebellar symptoms (olivopontocerebellar atrophy)
MSA-P predominance of parkinsonian signs and symptoms (striatonigraldegeneration)
RADIOGRAPHIC FEATURES
bullT2 hyperintensities typically present in the pontocerebellar tractsbull pons hot cross bun sign (MSA-C)
bull middle cerebellar peduncles
bull Cerebellum
putaminal findings in MSA-P reduced volume
reduced GRE and T2 signal relative to globus pallidus
reduced GRE and T2 signal relative to red nucleus
abnormal disruption of the normal high T2 linear rim
bullMSA-Cbull disproportionate atrophy of the cerebellum and brainstem (especially olivary nuclei and middle
cerebellar peduncle)
NUCLEAR MEDICINE
SPECT and PET studies tend to demonstrate hypometabolism in the superior parietal and superior frontal areas in the basal ganglia
HUNTINGTON DISEASE
autosomal dominant neurodegenerative disease
a loss of GABAergic neurons of the basal ganglia
especially atrophy of the caudate nucleus and putamen
Huntington disease has a prevalence of 5-10 per 100000 and is typically diagnosed between 30 and 50 years of age
In approximately 1-6 symptoms occur before the age of 20 so-called juvenile form
Presentation is typically with progressive rigidity choreoathetosis dementia psychosis and emotional lability
The juvenile form has a different presentation with cerebellar symptoms rigidity and hypokinesia being prominent
it is a autosomal dominant with complete penetrance and genetic anticipation particularly if inherited mutated allele is paternal
The mutation responsible is on chromosome 4p163 and consists of a CAG trineucleotide repeat
The usual 10-30 copies are amplified to greater than 36 and the greater the number of repeats the earlier the age of onset
RADIOGRAPHIC FEATURES
MRI
The most striking and best known feature is that of caudate head atrophy resulting in enlargement of the frontal horns often giving them a box like configuration
This can be quantified by an number of measurements
bullfrontal horn width to intercaudate distance ratio (FHCC)
bullintercaudate distance to inner table width ratio (CCIT)
Juvenile form
putamen are also atrophied and demonstrate increased T2 signal
basal ganglia may show decrease T2 signal and blooming on SWI in keeping with iron deposition
Generalised age inappropriate cortical volume loss is also recognised
FHCC ratio normal mean 22 to 26 (this ratio decreases with ageing as a result of enlargement of the frontal horns of the lateral ventricles)
CCIT ratio normal mean 009 to 012
AMYOTROPHIC LATERAL SCLEROSISalso known as Lou Gehrig disease or Charcot disease
Primary degeneration of the motor neurons within the brain brain stem and spinal cord
Patients typically present with progressive muscle weakness and limb and truncal atrophy combined with signs of spasticity
Mean age at the time of diagnosis is 55 years
RADIOGRAPHIC FEATURES
MRI
The earliest MR manifestation is hyperintensity on T2WI in the corticospinal tracts seen earliest in the internal capsule
Iron deposition in the cortex is demonstrated as loss of signal most evident on T2 weighted sequences
IS IT ATROPHY OR HYDROCEPHALUS
Abnormal accumulation of CSF in Ventricular system
Results from Structural or functional block to normal flow Of CSF
In effect all are obhstructive
Difficult to differentiate Atrophy from Hydrocephalus gt60yrs
Initially show increased ICT
Later stages may reach Equillibrium and Becomes NP hYdrocephalus
Types
Obstructive
Communicating
NPH ndash seen typically in old patients Diagnosis is more based on clinical feature
Dementia urinary incontinence and gait apraxias + Hydrocephalus = NPH
Radiologically w
1 degeree of ventricular dilatation is more with Thinning and bowing of CC
2 Sulcal effacement is invariable seen Hydrocephalus
3 dilatation or rounding of the Temporal Horns
4 Rounding and enlargement of the frontal horns
5 Enlargement and ballooning of 3rd
ventricle
6 Enlargement of fourth ventricle
SPOTTERS
THANK YOU
CREUTZFELDT-JAKOB DISEASEspongiform encephalopathy
Results in a rapidly progressive dementia
other non-specific neurological features
Three types of Creutzfeldt-Jakob disease have been described
bullsporadic (sCJD) accounts for 85-90 of cases
bullvariant (vCJD)
bullfamilial (fCJD) 10 of cases (these individuals carry a PRPc mutation)
Creutzfeldt-Jakob disease is characterized by rapidly progressive dementia cerebral atrophy myoclonus and death
Patients with vCJD present mostly with sensory and psychiatric symptoms
Patients with sCJD usually present with progressive cognitive impairment and cerebellar symptoms
PATHOLOGY
mediated via (infectious) prions
a type of protein which manifest in sheep as the disease scrapie and in cows as bovine spongiform encephalopathy
Prions are considered infectious in sense that they can alter the structure of neighbouring proteins
CJD leads to spongiform degeneration of the brain
the conversion of normal prion protein to proteinaceous infectious particles that accumulate in and around neurons and lead to cell death
RADIOGRAPHIC FEATURES
MRI
MRI findings may be bilateral or unilateral and symmetric or asymmetric and include
T2 hyperintensity
obasal ganglia (putamen and caudate)
othalamus ( hockey stick sign and pulvinar sign)
ocortex most common early manifestation
owhite matter
persistent restricted diffusion on DWI (considered the most sensitive sign)
Review of sequential studies also typically demonstrates rapidly progressive cerebral atrophy
hypometabolism on 18FDG-PET studies
TREATMENT AND PROGNOSIS
here is currently no curative treatment and the disease is invariably fatal with a mean survival of only 7 months for most cases
PROGRESSIVE SUPRANUCLEARPALSYlso known as the Steele-Richardson-Olszewski syndrome
Progressive supranuclear palsy typically becomes clinically apparent in the 6th decade of life
Progresses to death usually within a decade (2-17 years from diagnosis)
Progressive supranuclear palsy is characterised
decreased cognition
abnormal eye movements (supranuclear vertical gaze palsy)
postural instability and falls
as well as parkinsonian features and speech disturbances
RADIOGRAPHIC FEATURESMRI
midbrain atrophy
reduction of anteroposterior midline midbrain diameter at the level of the superior colliculi on axial imaging (from interpeduncular fossa to the intercolicular groove lt12mm 8) which can give a mickey mouse appearance
reduced area of the midbrain on midline sagittal and reduced midbrain to pons area ratio approx 012 (normal approx 024) on midline sagittal
Loss of the lateral convex margin of the tegmentum of midbrain has been described as the morning glory sign
hummingbird sign also known as the penguin sign The key is a flattening or concave outline to the superior aspect of the midbrain which should be upwardly convex
bullT2 diffuse high-signal lesions in
bull pontine tegmentum
bull tectum of the midbrain
bull inferior olivary nucleus
MICKEY MOUSE APPEARANCE
THE PENGUIN SIGN
MULTIPLE SYSTEM ATROPHY
sporadic neurodegenerative disease
Typically symptoms begin between 40 and 60 years of age
Clinical presentation is variable but typically presents in one of three patterns (initially described as separate entities)
Shy-Drager syndrome is used when autonomic symptoms predominate
striatonigral degeneration shows predominant parkinsonian features
olivopontocerebellar atrophy demonstrates primarily cerebellar dysfunction
MSA has been divided clinically into 2 forms according to the dominant non-autonomic symptoms
MSA-C predominance of cerebellar symptoms (olivopontocerebellar atrophy)
MSA-P predominance of parkinsonian signs and symptoms (striatonigraldegeneration)
RADIOGRAPHIC FEATURES
bullT2 hyperintensities typically present in the pontocerebellar tractsbull pons hot cross bun sign (MSA-C)
bull middle cerebellar peduncles
bull Cerebellum
putaminal findings in MSA-P reduced volume
reduced GRE and T2 signal relative to globus pallidus
reduced GRE and T2 signal relative to red nucleus
abnormal disruption of the normal high T2 linear rim
bullMSA-Cbull disproportionate atrophy of the cerebellum and brainstem (especially olivary nuclei and middle
cerebellar peduncle)
NUCLEAR MEDICINE
SPECT and PET studies tend to demonstrate hypometabolism in the superior parietal and superior frontal areas in the basal ganglia
HUNTINGTON DISEASE
autosomal dominant neurodegenerative disease
a loss of GABAergic neurons of the basal ganglia
especially atrophy of the caudate nucleus and putamen
Huntington disease has a prevalence of 5-10 per 100000 and is typically diagnosed between 30 and 50 years of age
In approximately 1-6 symptoms occur before the age of 20 so-called juvenile form
Presentation is typically with progressive rigidity choreoathetosis dementia psychosis and emotional lability
The juvenile form has a different presentation with cerebellar symptoms rigidity and hypokinesia being prominent
it is a autosomal dominant with complete penetrance and genetic anticipation particularly if inherited mutated allele is paternal
The mutation responsible is on chromosome 4p163 and consists of a CAG trineucleotide repeat
The usual 10-30 copies are amplified to greater than 36 and the greater the number of repeats the earlier the age of onset
RADIOGRAPHIC FEATURES
MRI
The most striking and best known feature is that of caudate head atrophy resulting in enlargement of the frontal horns often giving them a box like configuration
This can be quantified by an number of measurements
bullfrontal horn width to intercaudate distance ratio (FHCC)
bullintercaudate distance to inner table width ratio (CCIT)
Juvenile form
putamen are also atrophied and demonstrate increased T2 signal
basal ganglia may show decrease T2 signal and blooming on SWI in keeping with iron deposition
Generalised age inappropriate cortical volume loss is also recognised
FHCC ratio normal mean 22 to 26 (this ratio decreases with ageing as a result of enlargement of the frontal horns of the lateral ventricles)
CCIT ratio normal mean 009 to 012
AMYOTROPHIC LATERAL SCLEROSISalso known as Lou Gehrig disease or Charcot disease
Primary degeneration of the motor neurons within the brain brain stem and spinal cord
Patients typically present with progressive muscle weakness and limb and truncal atrophy combined with signs of spasticity
Mean age at the time of diagnosis is 55 years
RADIOGRAPHIC FEATURES
MRI
The earliest MR manifestation is hyperintensity on T2WI in the corticospinal tracts seen earliest in the internal capsule
Iron deposition in the cortex is demonstrated as loss of signal most evident on T2 weighted sequences
IS IT ATROPHY OR HYDROCEPHALUS
Abnormal accumulation of CSF in Ventricular system
Results from Structural or functional block to normal flow Of CSF
In effect all are obhstructive
Difficult to differentiate Atrophy from Hydrocephalus gt60yrs
Initially show increased ICT
Later stages may reach Equillibrium and Becomes NP hYdrocephalus
Types
Obstructive
Communicating
NPH ndash seen typically in old patients Diagnosis is more based on clinical feature
Dementia urinary incontinence and gait apraxias + Hydrocephalus = NPH
Radiologically w
1 degeree of ventricular dilatation is more with Thinning and bowing of CC
2 Sulcal effacement is invariable seen Hydrocephalus
3 dilatation or rounding of the Temporal Horns
4 Rounding and enlargement of the frontal horns
5 Enlargement and ballooning of 3rd
ventricle
6 Enlargement of fourth ventricle
SPOTTERS
THANK YOU
Creutzfeldt-Jakob disease is characterized by rapidly progressive dementia cerebral atrophy myoclonus and death
Patients with vCJD present mostly with sensory and psychiatric symptoms
Patients with sCJD usually present with progressive cognitive impairment and cerebellar symptoms
PATHOLOGY
mediated via (infectious) prions
a type of protein which manifest in sheep as the disease scrapie and in cows as bovine spongiform encephalopathy
Prions are considered infectious in sense that they can alter the structure of neighbouring proteins
CJD leads to spongiform degeneration of the brain
the conversion of normal prion protein to proteinaceous infectious particles that accumulate in and around neurons and lead to cell death
RADIOGRAPHIC FEATURES
MRI
MRI findings may be bilateral or unilateral and symmetric or asymmetric and include
T2 hyperintensity
obasal ganglia (putamen and caudate)
othalamus ( hockey stick sign and pulvinar sign)
ocortex most common early manifestation
owhite matter
persistent restricted diffusion on DWI (considered the most sensitive sign)
Review of sequential studies also typically demonstrates rapidly progressive cerebral atrophy
hypometabolism on 18FDG-PET studies
TREATMENT AND PROGNOSIS
here is currently no curative treatment and the disease is invariably fatal with a mean survival of only 7 months for most cases
PROGRESSIVE SUPRANUCLEARPALSYlso known as the Steele-Richardson-Olszewski syndrome
Progressive supranuclear palsy typically becomes clinically apparent in the 6th decade of life
Progresses to death usually within a decade (2-17 years from diagnosis)
Progressive supranuclear palsy is characterised
decreased cognition
abnormal eye movements (supranuclear vertical gaze palsy)
postural instability and falls
as well as parkinsonian features and speech disturbances
RADIOGRAPHIC FEATURESMRI
midbrain atrophy
reduction of anteroposterior midline midbrain diameter at the level of the superior colliculi on axial imaging (from interpeduncular fossa to the intercolicular groove lt12mm 8) which can give a mickey mouse appearance
reduced area of the midbrain on midline sagittal and reduced midbrain to pons area ratio approx 012 (normal approx 024) on midline sagittal
Loss of the lateral convex margin of the tegmentum of midbrain has been described as the morning glory sign
hummingbird sign also known as the penguin sign The key is a flattening or concave outline to the superior aspect of the midbrain which should be upwardly convex
bullT2 diffuse high-signal lesions in
bull pontine tegmentum
bull tectum of the midbrain
bull inferior olivary nucleus
MICKEY MOUSE APPEARANCE
THE PENGUIN SIGN
MULTIPLE SYSTEM ATROPHY
sporadic neurodegenerative disease
Typically symptoms begin between 40 and 60 years of age
Clinical presentation is variable but typically presents in one of three patterns (initially described as separate entities)
Shy-Drager syndrome is used when autonomic symptoms predominate
striatonigral degeneration shows predominant parkinsonian features
olivopontocerebellar atrophy demonstrates primarily cerebellar dysfunction
MSA has been divided clinically into 2 forms according to the dominant non-autonomic symptoms
MSA-C predominance of cerebellar symptoms (olivopontocerebellar atrophy)
MSA-P predominance of parkinsonian signs and symptoms (striatonigraldegeneration)
RADIOGRAPHIC FEATURES
bullT2 hyperintensities typically present in the pontocerebellar tractsbull pons hot cross bun sign (MSA-C)
bull middle cerebellar peduncles
bull Cerebellum
putaminal findings in MSA-P reduced volume
reduced GRE and T2 signal relative to globus pallidus
reduced GRE and T2 signal relative to red nucleus
abnormal disruption of the normal high T2 linear rim
bullMSA-Cbull disproportionate atrophy of the cerebellum and brainstem (especially olivary nuclei and middle
cerebellar peduncle)
NUCLEAR MEDICINE
SPECT and PET studies tend to demonstrate hypometabolism in the superior parietal and superior frontal areas in the basal ganglia
HUNTINGTON DISEASE
autosomal dominant neurodegenerative disease
a loss of GABAergic neurons of the basal ganglia
especially atrophy of the caudate nucleus and putamen
Huntington disease has a prevalence of 5-10 per 100000 and is typically diagnosed between 30 and 50 years of age
In approximately 1-6 symptoms occur before the age of 20 so-called juvenile form
Presentation is typically with progressive rigidity choreoathetosis dementia psychosis and emotional lability
The juvenile form has a different presentation with cerebellar symptoms rigidity and hypokinesia being prominent
it is a autosomal dominant with complete penetrance and genetic anticipation particularly if inherited mutated allele is paternal
The mutation responsible is on chromosome 4p163 and consists of a CAG trineucleotide repeat
The usual 10-30 copies are amplified to greater than 36 and the greater the number of repeats the earlier the age of onset
RADIOGRAPHIC FEATURES
MRI
The most striking and best known feature is that of caudate head atrophy resulting in enlargement of the frontal horns often giving them a box like configuration
This can be quantified by an number of measurements
bullfrontal horn width to intercaudate distance ratio (FHCC)
bullintercaudate distance to inner table width ratio (CCIT)
Juvenile form
putamen are also atrophied and demonstrate increased T2 signal
basal ganglia may show decrease T2 signal and blooming on SWI in keeping with iron deposition
Generalised age inappropriate cortical volume loss is also recognised
FHCC ratio normal mean 22 to 26 (this ratio decreases with ageing as a result of enlargement of the frontal horns of the lateral ventricles)
CCIT ratio normal mean 009 to 012
AMYOTROPHIC LATERAL SCLEROSISalso known as Lou Gehrig disease or Charcot disease
Primary degeneration of the motor neurons within the brain brain stem and spinal cord
Patients typically present with progressive muscle weakness and limb and truncal atrophy combined with signs of spasticity
Mean age at the time of diagnosis is 55 years
RADIOGRAPHIC FEATURES
MRI
The earliest MR manifestation is hyperintensity on T2WI in the corticospinal tracts seen earliest in the internal capsule
Iron deposition in the cortex is demonstrated as loss of signal most evident on T2 weighted sequences
IS IT ATROPHY OR HYDROCEPHALUS
Abnormal accumulation of CSF in Ventricular system
Results from Structural or functional block to normal flow Of CSF
In effect all are obhstructive
Difficult to differentiate Atrophy from Hydrocephalus gt60yrs
Initially show increased ICT
Later stages may reach Equillibrium and Becomes NP hYdrocephalus
Types
Obstructive
Communicating
NPH ndash seen typically in old patients Diagnosis is more based on clinical feature
Dementia urinary incontinence and gait apraxias + Hydrocephalus = NPH
Radiologically w
1 degeree of ventricular dilatation is more with Thinning and bowing of CC
2 Sulcal effacement is invariable seen Hydrocephalus
3 dilatation or rounding of the Temporal Horns
4 Rounding and enlargement of the frontal horns
5 Enlargement and ballooning of 3rd
ventricle
6 Enlargement of fourth ventricle
SPOTTERS
THANK YOU
PATHOLOGY
mediated via (infectious) prions
a type of protein which manifest in sheep as the disease scrapie and in cows as bovine spongiform encephalopathy
Prions are considered infectious in sense that they can alter the structure of neighbouring proteins
CJD leads to spongiform degeneration of the brain
the conversion of normal prion protein to proteinaceous infectious particles that accumulate in and around neurons and lead to cell death
RADIOGRAPHIC FEATURES
MRI
MRI findings may be bilateral or unilateral and symmetric or asymmetric and include
T2 hyperintensity
obasal ganglia (putamen and caudate)
othalamus ( hockey stick sign and pulvinar sign)
ocortex most common early manifestation
owhite matter
persistent restricted diffusion on DWI (considered the most sensitive sign)
Review of sequential studies also typically demonstrates rapidly progressive cerebral atrophy
hypometabolism on 18FDG-PET studies
TREATMENT AND PROGNOSIS
here is currently no curative treatment and the disease is invariably fatal with a mean survival of only 7 months for most cases
PROGRESSIVE SUPRANUCLEARPALSYlso known as the Steele-Richardson-Olszewski syndrome
Progressive supranuclear palsy typically becomes clinically apparent in the 6th decade of life
Progresses to death usually within a decade (2-17 years from diagnosis)
Progressive supranuclear palsy is characterised
decreased cognition
abnormal eye movements (supranuclear vertical gaze palsy)
postural instability and falls
as well as parkinsonian features and speech disturbances
RADIOGRAPHIC FEATURESMRI
midbrain atrophy
reduction of anteroposterior midline midbrain diameter at the level of the superior colliculi on axial imaging (from interpeduncular fossa to the intercolicular groove lt12mm 8) which can give a mickey mouse appearance
reduced area of the midbrain on midline sagittal and reduced midbrain to pons area ratio approx 012 (normal approx 024) on midline sagittal
Loss of the lateral convex margin of the tegmentum of midbrain has been described as the morning glory sign
hummingbird sign also known as the penguin sign The key is a flattening or concave outline to the superior aspect of the midbrain which should be upwardly convex
bullT2 diffuse high-signal lesions in
bull pontine tegmentum
bull tectum of the midbrain
bull inferior olivary nucleus
MICKEY MOUSE APPEARANCE
THE PENGUIN SIGN
MULTIPLE SYSTEM ATROPHY
sporadic neurodegenerative disease
Typically symptoms begin between 40 and 60 years of age
Clinical presentation is variable but typically presents in one of three patterns (initially described as separate entities)
Shy-Drager syndrome is used when autonomic symptoms predominate
striatonigral degeneration shows predominant parkinsonian features
olivopontocerebellar atrophy demonstrates primarily cerebellar dysfunction
MSA has been divided clinically into 2 forms according to the dominant non-autonomic symptoms
MSA-C predominance of cerebellar symptoms (olivopontocerebellar atrophy)
MSA-P predominance of parkinsonian signs and symptoms (striatonigraldegeneration)
RADIOGRAPHIC FEATURES
bullT2 hyperintensities typically present in the pontocerebellar tractsbull pons hot cross bun sign (MSA-C)
bull middle cerebellar peduncles
bull Cerebellum
putaminal findings in MSA-P reduced volume
reduced GRE and T2 signal relative to globus pallidus
reduced GRE and T2 signal relative to red nucleus
abnormal disruption of the normal high T2 linear rim
bullMSA-Cbull disproportionate atrophy of the cerebellum and brainstem (especially olivary nuclei and middle
cerebellar peduncle)
NUCLEAR MEDICINE
SPECT and PET studies tend to demonstrate hypometabolism in the superior parietal and superior frontal areas in the basal ganglia
HUNTINGTON DISEASE
autosomal dominant neurodegenerative disease
a loss of GABAergic neurons of the basal ganglia
especially atrophy of the caudate nucleus and putamen
Huntington disease has a prevalence of 5-10 per 100000 and is typically diagnosed between 30 and 50 years of age
In approximately 1-6 symptoms occur before the age of 20 so-called juvenile form
Presentation is typically with progressive rigidity choreoathetosis dementia psychosis and emotional lability
The juvenile form has a different presentation with cerebellar symptoms rigidity and hypokinesia being prominent
it is a autosomal dominant with complete penetrance and genetic anticipation particularly if inherited mutated allele is paternal
The mutation responsible is on chromosome 4p163 and consists of a CAG trineucleotide repeat
The usual 10-30 copies are amplified to greater than 36 and the greater the number of repeats the earlier the age of onset
RADIOGRAPHIC FEATURES
MRI
The most striking and best known feature is that of caudate head atrophy resulting in enlargement of the frontal horns often giving them a box like configuration
This can be quantified by an number of measurements
bullfrontal horn width to intercaudate distance ratio (FHCC)
bullintercaudate distance to inner table width ratio (CCIT)
Juvenile form
putamen are also atrophied and demonstrate increased T2 signal
basal ganglia may show decrease T2 signal and blooming on SWI in keeping with iron deposition
Generalised age inappropriate cortical volume loss is also recognised
FHCC ratio normal mean 22 to 26 (this ratio decreases with ageing as a result of enlargement of the frontal horns of the lateral ventricles)
CCIT ratio normal mean 009 to 012
AMYOTROPHIC LATERAL SCLEROSISalso known as Lou Gehrig disease or Charcot disease
Primary degeneration of the motor neurons within the brain brain stem and spinal cord
Patients typically present with progressive muscle weakness and limb and truncal atrophy combined with signs of spasticity
Mean age at the time of diagnosis is 55 years
RADIOGRAPHIC FEATURES
MRI
The earliest MR manifestation is hyperintensity on T2WI in the corticospinal tracts seen earliest in the internal capsule
Iron deposition in the cortex is demonstrated as loss of signal most evident on T2 weighted sequences
IS IT ATROPHY OR HYDROCEPHALUS
Abnormal accumulation of CSF in Ventricular system
Results from Structural or functional block to normal flow Of CSF
In effect all are obhstructive
Difficult to differentiate Atrophy from Hydrocephalus gt60yrs
Initially show increased ICT
Later stages may reach Equillibrium and Becomes NP hYdrocephalus
Types
Obstructive
Communicating
NPH ndash seen typically in old patients Diagnosis is more based on clinical feature
Dementia urinary incontinence and gait apraxias + Hydrocephalus = NPH
Radiologically w
1 degeree of ventricular dilatation is more with Thinning and bowing of CC
2 Sulcal effacement is invariable seen Hydrocephalus
3 dilatation or rounding of the Temporal Horns
4 Rounding and enlargement of the frontal horns
5 Enlargement and ballooning of 3rd
ventricle
6 Enlargement of fourth ventricle
SPOTTERS
THANK YOU
RADIOGRAPHIC FEATURES
MRI
MRI findings may be bilateral or unilateral and symmetric or asymmetric and include
T2 hyperintensity
obasal ganglia (putamen and caudate)
othalamus ( hockey stick sign and pulvinar sign)
ocortex most common early manifestation
owhite matter
persistent restricted diffusion on DWI (considered the most sensitive sign)
Review of sequential studies also typically demonstrates rapidly progressive cerebral atrophy
hypometabolism on 18FDG-PET studies
TREATMENT AND PROGNOSIS
here is currently no curative treatment and the disease is invariably fatal with a mean survival of only 7 months for most cases
PROGRESSIVE SUPRANUCLEARPALSYlso known as the Steele-Richardson-Olszewski syndrome
Progressive supranuclear palsy typically becomes clinically apparent in the 6th decade of life
Progresses to death usually within a decade (2-17 years from diagnosis)
Progressive supranuclear palsy is characterised
decreased cognition
abnormal eye movements (supranuclear vertical gaze palsy)
postural instability and falls
as well as parkinsonian features and speech disturbances
RADIOGRAPHIC FEATURESMRI
midbrain atrophy
reduction of anteroposterior midline midbrain diameter at the level of the superior colliculi on axial imaging (from interpeduncular fossa to the intercolicular groove lt12mm 8) which can give a mickey mouse appearance
reduced area of the midbrain on midline sagittal and reduced midbrain to pons area ratio approx 012 (normal approx 024) on midline sagittal
Loss of the lateral convex margin of the tegmentum of midbrain has been described as the morning glory sign
hummingbird sign also known as the penguin sign The key is a flattening or concave outline to the superior aspect of the midbrain which should be upwardly convex
bullT2 diffuse high-signal lesions in
bull pontine tegmentum
bull tectum of the midbrain
bull inferior olivary nucleus
MICKEY MOUSE APPEARANCE
THE PENGUIN SIGN
MULTIPLE SYSTEM ATROPHY
sporadic neurodegenerative disease
Typically symptoms begin between 40 and 60 years of age
Clinical presentation is variable but typically presents in one of three patterns (initially described as separate entities)
Shy-Drager syndrome is used when autonomic symptoms predominate
striatonigral degeneration shows predominant parkinsonian features
olivopontocerebellar atrophy demonstrates primarily cerebellar dysfunction
MSA has been divided clinically into 2 forms according to the dominant non-autonomic symptoms
MSA-C predominance of cerebellar symptoms (olivopontocerebellar atrophy)
MSA-P predominance of parkinsonian signs and symptoms (striatonigraldegeneration)
RADIOGRAPHIC FEATURES
bullT2 hyperintensities typically present in the pontocerebellar tractsbull pons hot cross bun sign (MSA-C)
bull middle cerebellar peduncles
bull Cerebellum
putaminal findings in MSA-P reduced volume
reduced GRE and T2 signal relative to globus pallidus
reduced GRE and T2 signal relative to red nucleus
abnormal disruption of the normal high T2 linear rim
bullMSA-Cbull disproportionate atrophy of the cerebellum and brainstem (especially olivary nuclei and middle
cerebellar peduncle)
NUCLEAR MEDICINE
SPECT and PET studies tend to demonstrate hypometabolism in the superior parietal and superior frontal areas in the basal ganglia
HUNTINGTON DISEASE
autosomal dominant neurodegenerative disease
a loss of GABAergic neurons of the basal ganglia
especially atrophy of the caudate nucleus and putamen
Huntington disease has a prevalence of 5-10 per 100000 and is typically diagnosed between 30 and 50 years of age
In approximately 1-6 symptoms occur before the age of 20 so-called juvenile form
Presentation is typically with progressive rigidity choreoathetosis dementia psychosis and emotional lability
The juvenile form has a different presentation with cerebellar symptoms rigidity and hypokinesia being prominent
it is a autosomal dominant with complete penetrance and genetic anticipation particularly if inherited mutated allele is paternal
The mutation responsible is on chromosome 4p163 and consists of a CAG trineucleotide repeat
The usual 10-30 copies are amplified to greater than 36 and the greater the number of repeats the earlier the age of onset
RADIOGRAPHIC FEATURES
MRI
The most striking and best known feature is that of caudate head atrophy resulting in enlargement of the frontal horns often giving them a box like configuration
This can be quantified by an number of measurements
bullfrontal horn width to intercaudate distance ratio (FHCC)
bullintercaudate distance to inner table width ratio (CCIT)
Juvenile form
putamen are also atrophied and demonstrate increased T2 signal
basal ganglia may show decrease T2 signal and blooming on SWI in keeping with iron deposition
Generalised age inappropriate cortical volume loss is also recognised
FHCC ratio normal mean 22 to 26 (this ratio decreases with ageing as a result of enlargement of the frontal horns of the lateral ventricles)
CCIT ratio normal mean 009 to 012
AMYOTROPHIC LATERAL SCLEROSISalso known as Lou Gehrig disease or Charcot disease
Primary degeneration of the motor neurons within the brain brain stem and spinal cord
Patients typically present with progressive muscle weakness and limb and truncal atrophy combined with signs of spasticity
Mean age at the time of diagnosis is 55 years
RADIOGRAPHIC FEATURES
MRI
The earliest MR manifestation is hyperintensity on T2WI in the corticospinal tracts seen earliest in the internal capsule
Iron deposition in the cortex is demonstrated as loss of signal most evident on T2 weighted sequences
IS IT ATROPHY OR HYDROCEPHALUS
Abnormal accumulation of CSF in Ventricular system
Results from Structural or functional block to normal flow Of CSF
In effect all are obhstructive
Difficult to differentiate Atrophy from Hydrocephalus gt60yrs
Initially show increased ICT
Later stages may reach Equillibrium and Becomes NP hYdrocephalus
Types
Obstructive
Communicating
NPH ndash seen typically in old patients Diagnosis is more based on clinical feature
Dementia urinary incontinence and gait apraxias + Hydrocephalus = NPH
Radiologically w
1 degeree of ventricular dilatation is more with Thinning and bowing of CC
2 Sulcal effacement is invariable seen Hydrocephalus
3 dilatation or rounding of the Temporal Horns
4 Rounding and enlargement of the frontal horns
5 Enlargement and ballooning of 3rd
ventricle
6 Enlargement of fourth ventricle
SPOTTERS
THANK YOU
hypometabolism on 18FDG-PET studies
TREATMENT AND PROGNOSIS
here is currently no curative treatment and the disease is invariably fatal with a mean survival of only 7 months for most cases
PROGRESSIVE SUPRANUCLEARPALSYlso known as the Steele-Richardson-Olszewski syndrome
Progressive supranuclear palsy typically becomes clinically apparent in the 6th decade of life
Progresses to death usually within a decade (2-17 years from diagnosis)
Progressive supranuclear palsy is characterised
decreased cognition
abnormal eye movements (supranuclear vertical gaze palsy)
postural instability and falls
as well as parkinsonian features and speech disturbances
RADIOGRAPHIC FEATURESMRI
midbrain atrophy
reduction of anteroposterior midline midbrain diameter at the level of the superior colliculi on axial imaging (from interpeduncular fossa to the intercolicular groove lt12mm 8) which can give a mickey mouse appearance
reduced area of the midbrain on midline sagittal and reduced midbrain to pons area ratio approx 012 (normal approx 024) on midline sagittal
Loss of the lateral convex margin of the tegmentum of midbrain has been described as the morning glory sign
hummingbird sign also known as the penguin sign The key is a flattening or concave outline to the superior aspect of the midbrain which should be upwardly convex
bullT2 diffuse high-signal lesions in
bull pontine tegmentum
bull tectum of the midbrain
bull inferior olivary nucleus
MICKEY MOUSE APPEARANCE
THE PENGUIN SIGN
MULTIPLE SYSTEM ATROPHY
sporadic neurodegenerative disease
Typically symptoms begin between 40 and 60 years of age
Clinical presentation is variable but typically presents in one of three patterns (initially described as separate entities)
Shy-Drager syndrome is used when autonomic symptoms predominate
striatonigral degeneration shows predominant parkinsonian features
olivopontocerebellar atrophy demonstrates primarily cerebellar dysfunction
MSA has been divided clinically into 2 forms according to the dominant non-autonomic symptoms
MSA-C predominance of cerebellar symptoms (olivopontocerebellar atrophy)
MSA-P predominance of parkinsonian signs and symptoms (striatonigraldegeneration)
RADIOGRAPHIC FEATURES
bullT2 hyperintensities typically present in the pontocerebellar tractsbull pons hot cross bun sign (MSA-C)
bull middle cerebellar peduncles
bull Cerebellum
putaminal findings in MSA-P reduced volume
reduced GRE and T2 signal relative to globus pallidus
reduced GRE and T2 signal relative to red nucleus
abnormal disruption of the normal high T2 linear rim
bullMSA-Cbull disproportionate atrophy of the cerebellum and brainstem (especially olivary nuclei and middle
cerebellar peduncle)
NUCLEAR MEDICINE
SPECT and PET studies tend to demonstrate hypometabolism in the superior parietal and superior frontal areas in the basal ganglia
HUNTINGTON DISEASE
autosomal dominant neurodegenerative disease
a loss of GABAergic neurons of the basal ganglia
especially atrophy of the caudate nucleus and putamen
Huntington disease has a prevalence of 5-10 per 100000 and is typically diagnosed between 30 and 50 years of age
In approximately 1-6 symptoms occur before the age of 20 so-called juvenile form
Presentation is typically with progressive rigidity choreoathetosis dementia psychosis and emotional lability
The juvenile form has a different presentation with cerebellar symptoms rigidity and hypokinesia being prominent
it is a autosomal dominant with complete penetrance and genetic anticipation particularly if inherited mutated allele is paternal
The mutation responsible is on chromosome 4p163 and consists of a CAG trineucleotide repeat
The usual 10-30 copies are amplified to greater than 36 and the greater the number of repeats the earlier the age of onset
RADIOGRAPHIC FEATURES
MRI
The most striking and best known feature is that of caudate head atrophy resulting in enlargement of the frontal horns often giving them a box like configuration
This can be quantified by an number of measurements
bullfrontal horn width to intercaudate distance ratio (FHCC)
bullintercaudate distance to inner table width ratio (CCIT)
Juvenile form
putamen are also atrophied and demonstrate increased T2 signal
basal ganglia may show decrease T2 signal and blooming on SWI in keeping with iron deposition
Generalised age inappropriate cortical volume loss is also recognised
FHCC ratio normal mean 22 to 26 (this ratio decreases with ageing as a result of enlargement of the frontal horns of the lateral ventricles)
CCIT ratio normal mean 009 to 012
AMYOTROPHIC LATERAL SCLEROSISalso known as Lou Gehrig disease or Charcot disease
Primary degeneration of the motor neurons within the brain brain stem and spinal cord
Patients typically present with progressive muscle weakness and limb and truncal atrophy combined with signs of spasticity
Mean age at the time of diagnosis is 55 years
RADIOGRAPHIC FEATURES
MRI
The earliest MR manifestation is hyperintensity on T2WI in the corticospinal tracts seen earliest in the internal capsule
Iron deposition in the cortex is demonstrated as loss of signal most evident on T2 weighted sequences
IS IT ATROPHY OR HYDROCEPHALUS
Abnormal accumulation of CSF in Ventricular system
Results from Structural or functional block to normal flow Of CSF
In effect all are obhstructive
Difficult to differentiate Atrophy from Hydrocephalus gt60yrs
Initially show increased ICT
Later stages may reach Equillibrium and Becomes NP hYdrocephalus
Types
Obstructive
Communicating
NPH ndash seen typically in old patients Diagnosis is more based on clinical feature
Dementia urinary incontinence and gait apraxias + Hydrocephalus = NPH
Radiologically w
1 degeree of ventricular dilatation is more with Thinning and bowing of CC
2 Sulcal effacement is invariable seen Hydrocephalus
3 dilatation or rounding of the Temporal Horns
4 Rounding and enlargement of the frontal horns
5 Enlargement and ballooning of 3rd
ventricle
6 Enlargement of fourth ventricle
SPOTTERS
THANK YOU
TREATMENT AND PROGNOSIS
here is currently no curative treatment and the disease is invariably fatal with a mean survival of only 7 months for most cases
PROGRESSIVE SUPRANUCLEARPALSYlso known as the Steele-Richardson-Olszewski syndrome
Progressive supranuclear palsy typically becomes clinically apparent in the 6th decade of life
Progresses to death usually within a decade (2-17 years from diagnosis)
Progressive supranuclear palsy is characterised
decreased cognition
abnormal eye movements (supranuclear vertical gaze palsy)
postural instability and falls
as well as parkinsonian features and speech disturbances
RADIOGRAPHIC FEATURESMRI
midbrain atrophy
reduction of anteroposterior midline midbrain diameter at the level of the superior colliculi on axial imaging (from interpeduncular fossa to the intercolicular groove lt12mm 8) which can give a mickey mouse appearance
reduced area of the midbrain on midline sagittal and reduced midbrain to pons area ratio approx 012 (normal approx 024) on midline sagittal
Loss of the lateral convex margin of the tegmentum of midbrain has been described as the morning glory sign
hummingbird sign also known as the penguin sign The key is a flattening or concave outline to the superior aspect of the midbrain which should be upwardly convex
bullT2 diffuse high-signal lesions in
bull pontine tegmentum
bull tectum of the midbrain
bull inferior olivary nucleus
MICKEY MOUSE APPEARANCE
THE PENGUIN SIGN
MULTIPLE SYSTEM ATROPHY
sporadic neurodegenerative disease
Typically symptoms begin between 40 and 60 years of age
Clinical presentation is variable but typically presents in one of three patterns (initially described as separate entities)
Shy-Drager syndrome is used when autonomic symptoms predominate
striatonigral degeneration shows predominant parkinsonian features
olivopontocerebellar atrophy demonstrates primarily cerebellar dysfunction
MSA has been divided clinically into 2 forms according to the dominant non-autonomic symptoms
MSA-C predominance of cerebellar symptoms (olivopontocerebellar atrophy)
MSA-P predominance of parkinsonian signs and symptoms (striatonigraldegeneration)
RADIOGRAPHIC FEATURES
bullT2 hyperintensities typically present in the pontocerebellar tractsbull pons hot cross bun sign (MSA-C)
bull middle cerebellar peduncles
bull Cerebellum
putaminal findings in MSA-P reduced volume
reduced GRE and T2 signal relative to globus pallidus
reduced GRE and T2 signal relative to red nucleus
abnormal disruption of the normal high T2 linear rim
bullMSA-Cbull disproportionate atrophy of the cerebellum and brainstem (especially olivary nuclei and middle
cerebellar peduncle)
NUCLEAR MEDICINE
SPECT and PET studies tend to demonstrate hypometabolism in the superior parietal and superior frontal areas in the basal ganglia
HUNTINGTON DISEASE
autosomal dominant neurodegenerative disease
a loss of GABAergic neurons of the basal ganglia
especially atrophy of the caudate nucleus and putamen
Huntington disease has a prevalence of 5-10 per 100000 and is typically diagnosed between 30 and 50 years of age
In approximately 1-6 symptoms occur before the age of 20 so-called juvenile form
Presentation is typically with progressive rigidity choreoathetosis dementia psychosis and emotional lability
The juvenile form has a different presentation with cerebellar symptoms rigidity and hypokinesia being prominent
it is a autosomal dominant with complete penetrance and genetic anticipation particularly if inherited mutated allele is paternal
The mutation responsible is on chromosome 4p163 and consists of a CAG trineucleotide repeat
The usual 10-30 copies are amplified to greater than 36 and the greater the number of repeats the earlier the age of onset
RADIOGRAPHIC FEATURES
MRI
The most striking and best known feature is that of caudate head atrophy resulting in enlargement of the frontal horns often giving them a box like configuration
This can be quantified by an number of measurements
bullfrontal horn width to intercaudate distance ratio (FHCC)
bullintercaudate distance to inner table width ratio (CCIT)
Juvenile form
putamen are also atrophied and demonstrate increased T2 signal
basal ganglia may show decrease T2 signal and blooming on SWI in keeping with iron deposition
Generalised age inappropriate cortical volume loss is also recognised
FHCC ratio normal mean 22 to 26 (this ratio decreases with ageing as a result of enlargement of the frontal horns of the lateral ventricles)
CCIT ratio normal mean 009 to 012
AMYOTROPHIC LATERAL SCLEROSISalso known as Lou Gehrig disease or Charcot disease
Primary degeneration of the motor neurons within the brain brain stem and spinal cord
Patients typically present with progressive muscle weakness and limb and truncal atrophy combined with signs of spasticity
Mean age at the time of diagnosis is 55 years
RADIOGRAPHIC FEATURES
MRI
The earliest MR manifestation is hyperintensity on T2WI in the corticospinal tracts seen earliest in the internal capsule
Iron deposition in the cortex is demonstrated as loss of signal most evident on T2 weighted sequences
IS IT ATROPHY OR HYDROCEPHALUS
Abnormal accumulation of CSF in Ventricular system
Results from Structural or functional block to normal flow Of CSF
In effect all are obhstructive
Difficult to differentiate Atrophy from Hydrocephalus gt60yrs
Initially show increased ICT
Later stages may reach Equillibrium and Becomes NP hYdrocephalus
Types
Obstructive
Communicating
NPH ndash seen typically in old patients Diagnosis is more based on clinical feature
Dementia urinary incontinence and gait apraxias + Hydrocephalus = NPH
Radiologically w
1 degeree of ventricular dilatation is more with Thinning and bowing of CC
2 Sulcal effacement is invariable seen Hydrocephalus
3 dilatation or rounding of the Temporal Horns
4 Rounding and enlargement of the frontal horns
5 Enlargement and ballooning of 3rd
ventricle
6 Enlargement of fourth ventricle
SPOTTERS
THANK YOU
PROGRESSIVE SUPRANUCLEARPALSYlso known as the Steele-Richardson-Olszewski syndrome
Progressive supranuclear palsy typically becomes clinically apparent in the 6th decade of life
Progresses to death usually within a decade (2-17 years from diagnosis)
Progressive supranuclear palsy is characterised
decreased cognition
abnormal eye movements (supranuclear vertical gaze palsy)
postural instability and falls
as well as parkinsonian features and speech disturbances
RADIOGRAPHIC FEATURESMRI
midbrain atrophy
reduction of anteroposterior midline midbrain diameter at the level of the superior colliculi on axial imaging (from interpeduncular fossa to the intercolicular groove lt12mm 8) which can give a mickey mouse appearance
reduced area of the midbrain on midline sagittal and reduced midbrain to pons area ratio approx 012 (normal approx 024) on midline sagittal
Loss of the lateral convex margin of the tegmentum of midbrain has been described as the morning glory sign
hummingbird sign also known as the penguin sign The key is a flattening or concave outline to the superior aspect of the midbrain which should be upwardly convex
bullT2 diffuse high-signal lesions in
bull pontine tegmentum
bull tectum of the midbrain
bull inferior olivary nucleus
MICKEY MOUSE APPEARANCE
THE PENGUIN SIGN
MULTIPLE SYSTEM ATROPHY
sporadic neurodegenerative disease
Typically symptoms begin between 40 and 60 years of age
Clinical presentation is variable but typically presents in one of three patterns (initially described as separate entities)
Shy-Drager syndrome is used when autonomic symptoms predominate
striatonigral degeneration shows predominant parkinsonian features
olivopontocerebellar atrophy demonstrates primarily cerebellar dysfunction
MSA has been divided clinically into 2 forms according to the dominant non-autonomic symptoms
MSA-C predominance of cerebellar symptoms (olivopontocerebellar atrophy)
MSA-P predominance of parkinsonian signs and symptoms (striatonigraldegeneration)
RADIOGRAPHIC FEATURES
bullT2 hyperintensities typically present in the pontocerebellar tractsbull pons hot cross bun sign (MSA-C)
bull middle cerebellar peduncles
bull Cerebellum
putaminal findings in MSA-P reduced volume
reduced GRE and T2 signal relative to globus pallidus
reduced GRE and T2 signal relative to red nucleus
abnormal disruption of the normal high T2 linear rim
bullMSA-Cbull disproportionate atrophy of the cerebellum and brainstem (especially olivary nuclei and middle
cerebellar peduncle)
NUCLEAR MEDICINE
SPECT and PET studies tend to demonstrate hypometabolism in the superior parietal and superior frontal areas in the basal ganglia
HUNTINGTON DISEASE
autosomal dominant neurodegenerative disease
a loss of GABAergic neurons of the basal ganglia
especially atrophy of the caudate nucleus and putamen
Huntington disease has a prevalence of 5-10 per 100000 and is typically diagnosed between 30 and 50 years of age
In approximately 1-6 symptoms occur before the age of 20 so-called juvenile form
Presentation is typically with progressive rigidity choreoathetosis dementia psychosis and emotional lability
The juvenile form has a different presentation with cerebellar symptoms rigidity and hypokinesia being prominent
it is a autosomal dominant with complete penetrance and genetic anticipation particularly if inherited mutated allele is paternal
The mutation responsible is on chromosome 4p163 and consists of a CAG trineucleotide repeat
The usual 10-30 copies are amplified to greater than 36 and the greater the number of repeats the earlier the age of onset
RADIOGRAPHIC FEATURES
MRI
The most striking and best known feature is that of caudate head atrophy resulting in enlargement of the frontal horns often giving them a box like configuration
This can be quantified by an number of measurements
bullfrontal horn width to intercaudate distance ratio (FHCC)
bullintercaudate distance to inner table width ratio (CCIT)
Juvenile form
putamen are also atrophied and demonstrate increased T2 signal
basal ganglia may show decrease T2 signal and blooming on SWI in keeping with iron deposition
Generalised age inappropriate cortical volume loss is also recognised
FHCC ratio normal mean 22 to 26 (this ratio decreases with ageing as a result of enlargement of the frontal horns of the lateral ventricles)
CCIT ratio normal mean 009 to 012
AMYOTROPHIC LATERAL SCLEROSISalso known as Lou Gehrig disease or Charcot disease
Primary degeneration of the motor neurons within the brain brain stem and spinal cord
Patients typically present with progressive muscle weakness and limb and truncal atrophy combined with signs of spasticity
Mean age at the time of diagnosis is 55 years
RADIOGRAPHIC FEATURES
MRI
The earliest MR manifestation is hyperintensity on T2WI in the corticospinal tracts seen earliest in the internal capsule
Iron deposition in the cortex is demonstrated as loss of signal most evident on T2 weighted sequences
IS IT ATROPHY OR HYDROCEPHALUS
Abnormal accumulation of CSF in Ventricular system
Results from Structural or functional block to normal flow Of CSF
In effect all are obhstructive
Difficult to differentiate Atrophy from Hydrocephalus gt60yrs
Initially show increased ICT
Later stages may reach Equillibrium and Becomes NP hYdrocephalus
Types
Obstructive
Communicating
NPH ndash seen typically in old patients Diagnosis is more based on clinical feature
Dementia urinary incontinence and gait apraxias + Hydrocephalus = NPH
Radiologically w
1 degeree of ventricular dilatation is more with Thinning and bowing of CC
2 Sulcal effacement is invariable seen Hydrocephalus
3 dilatation or rounding of the Temporal Horns
4 Rounding and enlargement of the frontal horns
5 Enlargement and ballooning of 3rd
ventricle
6 Enlargement of fourth ventricle
SPOTTERS
THANK YOU
RADIOGRAPHIC FEATURESMRI
midbrain atrophy
reduction of anteroposterior midline midbrain diameter at the level of the superior colliculi on axial imaging (from interpeduncular fossa to the intercolicular groove lt12mm 8) which can give a mickey mouse appearance
reduced area of the midbrain on midline sagittal and reduced midbrain to pons area ratio approx 012 (normal approx 024) on midline sagittal
Loss of the lateral convex margin of the tegmentum of midbrain has been described as the morning glory sign
hummingbird sign also known as the penguin sign The key is a flattening or concave outline to the superior aspect of the midbrain which should be upwardly convex
bullT2 diffuse high-signal lesions in
bull pontine tegmentum
bull tectum of the midbrain
bull inferior olivary nucleus
MICKEY MOUSE APPEARANCE
THE PENGUIN SIGN
MULTIPLE SYSTEM ATROPHY
sporadic neurodegenerative disease
Typically symptoms begin between 40 and 60 years of age
Clinical presentation is variable but typically presents in one of three patterns (initially described as separate entities)
Shy-Drager syndrome is used when autonomic symptoms predominate
striatonigral degeneration shows predominant parkinsonian features
olivopontocerebellar atrophy demonstrates primarily cerebellar dysfunction
MSA has been divided clinically into 2 forms according to the dominant non-autonomic symptoms
MSA-C predominance of cerebellar symptoms (olivopontocerebellar atrophy)
MSA-P predominance of parkinsonian signs and symptoms (striatonigraldegeneration)
RADIOGRAPHIC FEATURES
bullT2 hyperintensities typically present in the pontocerebellar tractsbull pons hot cross bun sign (MSA-C)
bull middle cerebellar peduncles
bull Cerebellum
putaminal findings in MSA-P reduced volume
reduced GRE and T2 signal relative to globus pallidus
reduced GRE and T2 signal relative to red nucleus
abnormal disruption of the normal high T2 linear rim
bullMSA-Cbull disproportionate atrophy of the cerebellum and brainstem (especially olivary nuclei and middle
cerebellar peduncle)
NUCLEAR MEDICINE
SPECT and PET studies tend to demonstrate hypometabolism in the superior parietal and superior frontal areas in the basal ganglia
HUNTINGTON DISEASE
autosomal dominant neurodegenerative disease
a loss of GABAergic neurons of the basal ganglia
especially atrophy of the caudate nucleus and putamen
Huntington disease has a prevalence of 5-10 per 100000 and is typically diagnosed between 30 and 50 years of age
In approximately 1-6 symptoms occur before the age of 20 so-called juvenile form
Presentation is typically with progressive rigidity choreoathetosis dementia psychosis and emotional lability
The juvenile form has a different presentation with cerebellar symptoms rigidity and hypokinesia being prominent
it is a autosomal dominant with complete penetrance and genetic anticipation particularly if inherited mutated allele is paternal
The mutation responsible is on chromosome 4p163 and consists of a CAG trineucleotide repeat
The usual 10-30 copies are amplified to greater than 36 and the greater the number of repeats the earlier the age of onset
RADIOGRAPHIC FEATURES
MRI
The most striking and best known feature is that of caudate head atrophy resulting in enlargement of the frontal horns often giving them a box like configuration
This can be quantified by an number of measurements
bullfrontal horn width to intercaudate distance ratio (FHCC)
bullintercaudate distance to inner table width ratio (CCIT)
Juvenile form
putamen are also atrophied and demonstrate increased T2 signal
basal ganglia may show decrease T2 signal and blooming on SWI in keeping with iron deposition
Generalised age inappropriate cortical volume loss is also recognised
FHCC ratio normal mean 22 to 26 (this ratio decreases with ageing as a result of enlargement of the frontal horns of the lateral ventricles)
CCIT ratio normal mean 009 to 012
AMYOTROPHIC LATERAL SCLEROSISalso known as Lou Gehrig disease or Charcot disease
Primary degeneration of the motor neurons within the brain brain stem and spinal cord
Patients typically present with progressive muscle weakness and limb and truncal atrophy combined with signs of spasticity
Mean age at the time of diagnosis is 55 years
RADIOGRAPHIC FEATURES
MRI
The earliest MR manifestation is hyperintensity on T2WI in the corticospinal tracts seen earliest in the internal capsule
Iron deposition in the cortex is demonstrated as loss of signal most evident on T2 weighted sequences
IS IT ATROPHY OR HYDROCEPHALUS
Abnormal accumulation of CSF in Ventricular system
Results from Structural or functional block to normal flow Of CSF
In effect all are obhstructive
Difficult to differentiate Atrophy from Hydrocephalus gt60yrs
Initially show increased ICT
Later stages may reach Equillibrium and Becomes NP hYdrocephalus
Types
Obstructive
Communicating
NPH ndash seen typically in old patients Diagnosis is more based on clinical feature
Dementia urinary incontinence and gait apraxias + Hydrocephalus = NPH
Radiologically w
1 degeree of ventricular dilatation is more with Thinning and bowing of CC
2 Sulcal effacement is invariable seen Hydrocephalus
3 dilatation or rounding of the Temporal Horns
4 Rounding and enlargement of the frontal horns
5 Enlargement and ballooning of 3rd
ventricle
6 Enlargement of fourth ventricle
SPOTTERS
THANK YOU
bullT2 diffuse high-signal lesions in
bull pontine tegmentum
bull tectum of the midbrain
bull inferior olivary nucleus
MICKEY MOUSE APPEARANCE
THE PENGUIN SIGN
MULTIPLE SYSTEM ATROPHY
sporadic neurodegenerative disease
Typically symptoms begin between 40 and 60 years of age
Clinical presentation is variable but typically presents in one of three patterns (initially described as separate entities)
Shy-Drager syndrome is used when autonomic symptoms predominate
striatonigral degeneration shows predominant parkinsonian features
olivopontocerebellar atrophy demonstrates primarily cerebellar dysfunction
MSA has been divided clinically into 2 forms according to the dominant non-autonomic symptoms
MSA-C predominance of cerebellar symptoms (olivopontocerebellar atrophy)
MSA-P predominance of parkinsonian signs and symptoms (striatonigraldegeneration)
RADIOGRAPHIC FEATURES
bullT2 hyperintensities typically present in the pontocerebellar tractsbull pons hot cross bun sign (MSA-C)
bull middle cerebellar peduncles
bull Cerebellum
putaminal findings in MSA-P reduced volume
reduced GRE and T2 signal relative to globus pallidus
reduced GRE and T2 signal relative to red nucleus
abnormal disruption of the normal high T2 linear rim
bullMSA-Cbull disproportionate atrophy of the cerebellum and brainstem (especially olivary nuclei and middle
cerebellar peduncle)
NUCLEAR MEDICINE
SPECT and PET studies tend to demonstrate hypometabolism in the superior parietal and superior frontal areas in the basal ganglia
HUNTINGTON DISEASE
autosomal dominant neurodegenerative disease
a loss of GABAergic neurons of the basal ganglia
especially atrophy of the caudate nucleus and putamen
Huntington disease has a prevalence of 5-10 per 100000 and is typically diagnosed between 30 and 50 years of age
In approximately 1-6 symptoms occur before the age of 20 so-called juvenile form
Presentation is typically with progressive rigidity choreoathetosis dementia psychosis and emotional lability
The juvenile form has a different presentation with cerebellar symptoms rigidity and hypokinesia being prominent
it is a autosomal dominant with complete penetrance and genetic anticipation particularly if inherited mutated allele is paternal
The mutation responsible is on chromosome 4p163 and consists of a CAG trineucleotide repeat
The usual 10-30 copies are amplified to greater than 36 and the greater the number of repeats the earlier the age of onset
RADIOGRAPHIC FEATURES
MRI
The most striking and best known feature is that of caudate head atrophy resulting in enlargement of the frontal horns often giving them a box like configuration
This can be quantified by an number of measurements
bullfrontal horn width to intercaudate distance ratio (FHCC)
bullintercaudate distance to inner table width ratio (CCIT)
Juvenile form
putamen are also atrophied and demonstrate increased T2 signal
basal ganglia may show decrease T2 signal and blooming on SWI in keeping with iron deposition
Generalised age inappropriate cortical volume loss is also recognised
FHCC ratio normal mean 22 to 26 (this ratio decreases with ageing as a result of enlargement of the frontal horns of the lateral ventricles)
CCIT ratio normal mean 009 to 012
AMYOTROPHIC LATERAL SCLEROSISalso known as Lou Gehrig disease or Charcot disease
Primary degeneration of the motor neurons within the brain brain stem and spinal cord
Patients typically present with progressive muscle weakness and limb and truncal atrophy combined with signs of spasticity
Mean age at the time of diagnosis is 55 years
RADIOGRAPHIC FEATURES
MRI
The earliest MR manifestation is hyperintensity on T2WI in the corticospinal tracts seen earliest in the internal capsule
Iron deposition in the cortex is demonstrated as loss of signal most evident on T2 weighted sequences
IS IT ATROPHY OR HYDROCEPHALUS
Abnormal accumulation of CSF in Ventricular system
Results from Structural or functional block to normal flow Of CSF
In effect all are obhstructive
Difficult to differentiate Atrophy from Hydrocephalus gt60yrs
Initially show increased ICT
Later stages may reach Equillibrium and Becomes NP hYdrocephalus
Types
Obstructive
Communicating
NPH ndash seen typically in old patients Diagnosis is more based on clinical feature
Dementia urinary incontinence and gait apraxias + Hydrocephalus = NPH
Radiologically w
1 degeree of ventricular dilatation is more with Thinning and bowing of CC
2 Sulcal effacement is invariable seen Hydrocephalus
3 dilatation or rounding of the Temporal Horns
4 Rounding and enlargement of the frontal horns
5 Enlargement and ballooning of 3rd
ventricle
6 Enlargement of fourth ventricle
SPOTTERS
THANK YOU
MICKEY MOUSE APPEARANCE
THE PENGUIN SIGN
MULTIPLE SYSTEM ATROPHY
sporadic neurodegenerative disease
Typically symptoms begin between 40 and 60 years of age
Clinical presentation is variable but typically presents in one of three patterns (initially described as separate entities)
Shy-Drager syndrome is used when autonomic symptoms predominate
striatonigral degeneration shows predominant parkinsonian features
olivopontocerebellar atrophy demonstrates primarily cerebellar dysfunction
MSA has been divided clinically into 2 forms according to the dominant non-autonomic symptoms
MSA-C predominance of cerebellar symptoms (olivopontocerebellar atrophy)
MSA-P predominance of parkinsonian signs and symptoms (striatonigraldegeneration)
RADIOGRAPHIC FEATURES
bullT2 hyperintensities typically present in the pontocerebellar tractsbull pons hot cross bun sign (MSA-C)
bull middle cerebellar peduncles
bull Cerebellum
putaminal findings in MSA-P reduced volume
reduced GRE and T2 signal relative to globus pallidus
reduced GRE and T2 signal relative to red nucleus
abnormal disruption of the normal high T2 linear rim
bullMSA-Cbull disproportionate atrophy of the cerebellum and brainstem (especially olivary nuclei and middle
cerebellar peduncle)
NUCLEAR MEDICINE
SPECT and PET studies tend to demonstrate hypometabolism in the superior parietal and superior frontal areas in the basal ganglia
HUNTINGTON DISEASE
autosomal dominant neurodegenerative disease
a loss of GABAergic neurons of the basal ganglia
especially atrophy of the caudate nucleus and putamen
Huntington disease has a prevalence of 5-10 per 100000 and is typically diagnosed between 30 and 50 years of age
In approximately 1-6 symptoms occur before the age of 20 so-called juvenile form
Presentation is typically with progressive rigidity choreoathetosis dementia psychosis and emotional lability
The juvenile form has a different presentation with cerebellar symptoms rigidity and hypokinesia being prominent
it is a autosomal dominant with complete penetrance and genetic anticipation particularly if inherited mutated allele is paternal
The mutation responsible is on chromosome 4p163 and consists of a CAG trineucleotide repeat
The usual 10-30 copies are amplified to greater than 36 and the greater the number of repeats the earlier the age of onset
RADIOGRAPHIC FEATURES
MRI
The most striking and best known feature is that of caudate head atrophy resulting in enlargement of the frontal horns often giving them a box like configuration
This can be quantified by an number of measurements
bullfrontal horn width to intercaudate distance ratio (FHCC)
bullintercaudate distance to inner table width ratio (CCIT)
Juvenile form
putamen are also atrophied and demonstrate increased T2 signal
basal ganglia may show decrease T2 signal and blooming on SWI in keeping with iron deposition
Generalised age inappropriate cortical volume loss is also recognised
FHCC ratio normal mean 22 to 26 (this ratio decreases with ageing as a result of enlargement of the frontal horns of the lateral ventricles)
CCIT ratio normal mean 009 to 012
AMYOTROPHIC LATERAL SCLEROSISalso known as Lou Gehrig disease or Charcot disease
Primary degeneration of the motor neurons within the brain brain stem and spinal cord
Patients typically present with progressive muscle weakness and limb and truncal atrophy combined with signs of spasticity
Mean age at the time of diagnosis is 55 years
RADIOGRAPHIC FEATURES
MRI
The earliest MR manifestation is hyperintensity on T2WI in the corticospinal tracts seen earliest in the internal capsule
Iron deposition in the cortex is demonstrated as loss of signal most evident on T2 weighted sequences
IS IT ATROPHY OR HYDROCEPHALUS
Abnormal accumulation of CSF in Ventricular system
Results from Structural or functional block to normal flow Of CSF
In effect all are obhstructive
Difficult to differentiate Atrophy from Hydrocephalus gt60yrs
Initially show increased ICT
Later stages may reach Equillibrium and Becomes NP hYdrocephalus
Types
Obstructive
Communicating
NPH ndash seen typically in old patients Diagnosis is more based on clinical feature
Dementia urinary incontinence and gait apraxias + Hydrocephalus = NPH
Radiologically w
1 degeree of ventricular dilatation is more with Thinning and bowing of CC
2 Sulcal effacement is invariable seen Hydrocephalus
3 dilatation or rounding of the Temporal Horns
4 Rounding and enlargement of the frontal horns
5 Enlargement and ballooning of 3rd
ventricle
6 Enlargement of fourth ventricle
SPOTTERS
THANK YOU
THE PENGUIN SIGN
MULTIPLE SYSTEM ATROPHY
sporadic neurodegenerative disease
Typically symptoms begin between 40 and 60 years of age
Clinical presentation is variable but typically presents in one of three patterns (initially described as separate entities)
Shy-Drager syndrome is used when autonomic symptoms predominate
striatonigral degeneration shows predominant parkinsonian features
olivopontocerebellar atrophy demonstrates primarily cerebellar dysfunction
MSA has been divided clinically into 2 forms according to the dominant non-autonomic symptoms
MSA-C predominance of cerebellar symptoms (olivopontocerebellar atrophy)
MSA-P predominance of parkinsonian signs and symptoms (striatonigraldegeneration)
RADIOGRAPHIC FEATURES
bullT2 hyperintensities typically present in the pontocerebellar tractsbull pons hot cross bun sign (MSA-C)
bull middle cerebellar peduncles
bull Cerebellum
putaminal findings in MSA-P reduced volume
reduced GRE and T2 signal relative to globus pallidus
reduced GRE and T2 signal relative to red nucleus
abnormal disruption of the normal high T2 linear rim
bullMSA-Cbull disproportionate atrophy of the cerebellum and brainstem (especially olivary nuclei and middle
cerebellar peduncle)
NUCLEAR MEDICINE
SPECT and PET studies tend to demonstrate hypometabolism in the superior parietal and superior frontal areas in the basal ganglia
HUNTINGTON DISEASE
autosomal dominant neurodegenerative disease
a loss of GABAergic neurons of the basal ganglia
especially atrophy of the caudate nucleus and putamen
Huntington disease has a prevalence of 5-10 per 100000 and is typically diagnosed between 30 and 50 years of age
In approximately 1-6 symptoms occur before the age of 20 so-called juvenile form
Presentation is typically with progressive rigidity choreoathetosis dementia psychosis and emotional lability
The juvenile form has a different presentation with cerebellar symptoms rigidity and hypokinesia being prominent
it is a autosomal dominant with complete penetrance and genetic anticipation particularly if inherited mutated allele is paternal
The mutation responsible is on chromosome 4p163 and consists of a CAG trineucleotide repeat
The usual 10-30 copies are amplified to greater than 36 and the greater the number of repeats the earlier the age of onset
RADIOGRAPHIC FEATURES
MRI
The most striking and best known feature is that of caudate head atrophy resulting in enlargement of the frontal horns often giving them a box like configuration
This can be quantified by an number of measurements
bullfrontal horn width to intercaudate distance ratio (FHCC)
bullintercaudate distance to inner table width ratio (CCIT)
Juvenile form
putamen are also atrophied and demonstrate increased T2 signal
basal ganglia may show decrease T2 signal and blooming on SWI in keeping with iron deposition
Generalised age inappropriate cortical volume loss is also recognised
FHCC ratio normal mean 22 to 26 (this ratio decreases with ageing as a result of enlargement of the frontal horns of the lateral ventricles)
CCIT ratio normal mean 009 to 012
AMYOTROPHIC LATERAL SCLEROSISalso known as Lou Gehrig disease or Charcot disease
Primary degeneration of the motor neurons within the brain brain stem and spinal cord
Patients typically present with progressive muscle weakness and limb and truncal atrophy combined with signs of spasticity
Mean age at the time of diagnosis is 55 years
RADIOGRAPHIC FEATURES
MRI
The earliest MR manifestation is hyperintensity on T2WI in the corticospinal tracts seen earliest in the internal capsule
Iron deposition in the cortex is demonstrated as loss of signal most evident on T2 weighted sequences
IS IT ATROPHY OR HYDROCEPHALUS
Abnormal accumulation of CSF in Ventricular system
Results from Structural or functional block to normal flow Of CSF
In effect all are obhstructive
Difficult to differentiate Atrophy from Hydrocephalus gt60yrs
Initially show increased ICT
Later stages may reach Equillibrium and Becomes NP hYdrocephalus
Types
Obstructive
Communicating
NPH ndash seen typically in old patients Diagnosis is more based on clinical feature
Dementia urinary incontinence and gait apraxias + Hydrocephalus = NPH
Radiologically w
1 degeree of ventricular dilatation is more with Thinning and bowing of CC
2 Sulcal effacement is invariable seen Hydrocephalus
3 dilatation or rounding of the Temporal Horns
4 Rounding and enlargement of the frontal horns
5 Enlargement and ballooning of 3rd
ventricle
6 Enlargement of fourth ventricle
SPOTTERS
THANK YOU
MULTIPLE SYSTEM ATROPHY
sporadic neurodegenerative disease
Typically symptoms begin between 40 and 60 years of age
Clinical presentation is variable but typically presents in one of three patterns (initially described as separate entities)
Shy-Drager syndrome is used when autonomic symptoms predominate
striatonigral degeneration shows predominant parkinsonian features
olivopontocerebellar atrophy demonstrates primarily cerebellar dysfunction
MSA has been divided clinically into 2 forms according to the dominant non-autonomic symptoms
MSA-C predominance of cerebellar symptoms (olivopontocerebellar atrophy)
MSA-P predominance of parkinsonian signs and symptoms (striatonigraldegeneration)
RADIOGRAPHIC FEATURES
bullT2 hyperintensities typically present in the pontocerebellar tractsbull pons hot cross bun sign (MSA-C)
bull middle cerebellar peduncles
bull Cerebellum
putaminal findings in MSA-P reduced volume
reduced GRE and T2 signal relative to globus pallidus
reduced GRE and T2 signal relative to red nucleus
abnormal disruption of the normal high T2 linear rim
bullMSA-Cbull disproportionate atrophy of the cerebellum and brainstem (especially olivary nuclei and middle
cerebellar peduncle)
NUCLEAR MEDICINE
SPECT and PET studies tend to demonstrate hypometabolism in the superior parietal and superior frontal areas in the basal ganglia
HUNTINGTON DISEASE
autosomal dominant neurodegenerative disease
a loss of GABAergic neurons of the basal ganglia
especially atrophy of the caudate nucleus and putamen
Huntington disease has a prevalence of 5-10 per 100000 and is typically diagnosed between 30 and 50 years of age
In approximately 1-6 symptoms occur before the age of 20 so-called juvenile form
Presentation is typically with progressive rigidity choreoathetosis dementia psychosis and emotional lability
The juvenile form has a different presentation with cerebellar symptoms rigidity and hypokinesia being prominent
it is a autosomal dominant with complete penetrance and genetic anticipation particularly if inherited mutated allele is paternal
The mutation responsible is on chromosome 4p163 and consists of a CAG trineucleotide repeat
The usual 10-30 copies are amplified to greater than 36 and the greater the number of repeats the earlier the age of onset
RADIOGRAPHIC FEATURES
MRI
The most striking and best known feature is that of caudate head atrophy resulting in enlargement of the frontal horns often giving them a box like configuration
This can be quantified by an number of measurements
bullfrontal horn width to intercaudate distance ratio (FHCC)
bullintercaudate distance to inner table width ratio (CCIT)
Juvenile form
putamen are also atrophied and demonstrate increased T2 signal
basal ganglia may show decrease T2 signal and blooming on SWI in keeping with iron deposition
Generalised age inappropriate cortical volume loss is also recognised
FHCC ratio normal mean 22 to 26 (this ratio decreases with ageing as a result of enlargement of the frontal horns of the lateral ventricles)
CCIT ratio normal mean 009 to 012
AMYOTROPHIC LATERAL SCLEROSISalso known as Lou Gehrig disease or Charcot disease
Primary degeneration of the motor neurons within the brain brain stem and spinal cord
Patients typically present with progressive muscle weakness and limb and truncal atrophy combined with signs of spasticity
Mean age at the time of diagnosis is 55 years
RADIOGRAPHIC FEATURES
MRI
The earliest MR manifestation is hyperintensity on T2WI in the corticospinal tracts seen earliest in the internal capsule
Iron deposition in the cortex is demonstrated as loss of signal most evident on T2 weighted sequences
IS IT ATROPHY OR HYDROCEPHALUS
Abnormal accumulation of CSF in Ventricular system
Results from Structural or functional block to normal flow Of CSF
In effect all are obhstructive
Difficult to differentiate Atrophy from Hydrocephalus gt60yrs
Initially show increased ICT
Later stages may reach Equillibrium and Becomes NP hYdrocephalus
Types
Obstructive
Communicating
NPH ndash seen typically in old patients Diagnosis is more based on clinical feature
Dementia urinary incontinence and gait apraxias + Hydrocephalus = NPH
Radiologically w
1 degeree of ventricular dilatation is more with Thinning and bowing of CC
2 Sulcal effacement is invariable seen Hydrocephalus
3 dilatation or rounding of the Temporal Horns
4 Rounding and enlargement of the frontal horns
5 Enlargement and ballooning of 3rd
ventricle
6 Enlargement of fourth ventricle
SPOTTERS
THANK YOU
MSA has been divided clinically into 2 forms according to the dominant non-autonomic symptoms
MSA-C predominance of cerebellar symptoms (olivopontocerebellar atrophy)
MSA-P predominance of parkinsonian signs and symptoms (striatonigraldegeneration)
RADIOGRAPHIC FEATURES
bullT2 hyperintensities typically present in the pontocerebellar tractsbull pons hot cross bun sign (MSA-C)
bull middle cerebellar peduncles
bull Cerebellum
putaminal findings in MSA-P reduced volume
reduced GRE and T2 signal relative to globus pallidus
reduced GRE and T2 signal relative to red nucleus
abnormal disruption of the normal high T2 linear rim
bullMSA-Cbull disproportionate atrophy of the cerebellum and brainstem (especially olivary nuclei and middle
cerebellar peduncle)
NUCLEAR MEDICINE
SPECT and PET studies tend to demonstrate hypometabolism in the superior parietal and superior frontal areas in the basal ganglia
HUNTINGTON DISEASE
autosomal dominant neurodegenerative disease
a loss of GABAergic neurons of the basal ganglia
especially atrophy of the caudate nucleus and putamen
Huntington disease has a prevalence of 5-10 per 100000 and is typically diagnosed between 30 and 50 years of age
In approximately 1-6 symptoms occur before the age of 20 so-called juvenile form
Presentation is typically with progressive rigidity choreoathetosis dementia psychosis and emotional lability
The juvenile form has a different presentation with cerebellar symptoms rigidity and hypokinesia being prominent
it is a autosomal dominant with complete penetrance and genetic anticipation particularly if inherited mutated allele is paternal
The mutation responsible is on chromosome 4p163 and consists of a CAG trineucleotide repeat
The usual 10-30 copies are amplified to greater than 36 and the greater the number of repeats the earlier the age of onset
RADIOGRAPHIC FEATURES
MRI
The most striking and best known feature is that of caudate head atrophy resulting in enlargement of the frontal horns often giving them a box like configuration
This can be quantified by an number of measurements
bullfrontal horn width to intercaudate distance ratio (FHCC)
bullintercaudate distance to inner table width ratio (CCIT)
Juvenile form
putamen are also atrophied and demonstrate increased T2 signal
basal ganglia may show decrease T2 signal and blooming on SWI in keeping with iron deposition
Generalised age inappropriate cortical volume loss is also recognised
FHCC ratio normal mean 22 to 26 (this ratio decreases with ageing as a result of enlargement of the frontal horns of the lateral ventricles)
CCIT ratio normal mean 009 to 012
AMYOTROPHIC LATERAL SCLEROSISalso known as Lou Gehrig disease or Charcot disease
Primary degeneration of the motor neurons within the brain brain stem and spinal cord
Patients typically present with progressive muscle weakness and limb and truncal atrophy combined with signs of spasticity
Mean age at the time of diagnosis is 55 years
RADIOGRAPHIC FEATURES
MRI
The earliest MR manifestation is hyperintensity on T2WI in the corticospinal tracts seen earliest in the internal capsule
Iron deposition in the cortex is demonstrated as loss of signal most evident on T2 weighted sequences
IS IT ATROPHY OR HYDROCEPHALUS
Abnormal accumulation of CSF in Ventricular system
Results from Structural or functional block to normal flow Of CSF
In effect all are obhstructive
Difficult to differentiate Atrophy from Hydrocephalus gt60yrs
Initially show increased ICT
Later stages may reach Equillibrium and Becomes NP hYdrocephalus
Types
Obstructive
Communicating
NPH ndash seen typically in old patients Diagnosis is more based on clinical feature
Dementia urinary incontinence and gait apraxias + Hydrocephalus = NPH
Radiologically w
1 degeree of ventricular dilatation is more with Thinning and bowing of CC
2 Sulcal effacement is invariable seen Hydrocephalus
3 dilatation or rounding of the Temporal Horns
4 Rounding and enlargement of the frontal horns
5 Enlargement and ballooning of 3rd
ventricle
6 Enlargement of fourth ventricle
SPOTTERS
THANK YOU
RADIOGRAPHIC FEATURES
bullT2 hyperintensities typically present in the pontocerebellar tractsbull pons hot cross bun sign (MSA-C)
bull middle cerebellar peduncles
bull Cerebellum
putaminal findings in MSA-P reduced volume
reduced GRE and T2 signal relative to globus pallidus
reduced GRE and T2 signal relative to red nucleus
abnormal disruption of the normal high T2 linear rim
bullMSA-Cbull disproportionate atrophy of the cerebellum and brainstem (especially olivary nuclei and middle
cerebellar peduncle)
NUCLEAR MEDICINE
SPECT and PET studies tend to demonstrate hypometabolism in the superior parietal and superior frontal areas in the basal ganglia
HUNTINGTON DISEASE
autosomal dominant neurodegenerative disease
a loss of GABAergic neurons of the basal ganglia
especially atrophy of the caudate nucleus and putamen
Huntington disease has a prevalence of 5-10 per 100000 and is typically diagnosed between 30 and 50 years of age
In approximately 1-6 symptoms occur before the age of 20 so-called juvenile form
Presentation is typically with progressive rigidity choreoathetosis dementia psychosis and emotional lability
The juvenile form has a different presentation with cerebellar symptoms rigidity and hypokinesia being prominent
it is a autosomal dominant with complete penetrance and genetic anticipation particularly if inherited mutated allele is paternal
The mutation responsible is on chromosome 4p163 and consists of a CAG trineucleotide repeat
The usual 10-30 copies are amplified to greater than 36 and the greater the number of repeats the earlier the age of onset
RADIOGRAPHIC FEATURES
MRI
The most striking and best known feature is that of caudate head atrophy resulting in enlargement of the frontal horns often giving them a box like configuration
This can be quantified by an number of measurements
bullfrontal horn width to intercaudate distance ratio (FHCC)
bullintercaudate distance to inner table width ratio (CCIT)
Juvenile form
putamen are also atrophied and demonstrate increased T2 signal
basal ganglia may show decrease T2 signal and blooming on SWI in keeping with iron deposition
Generalised age inappropriate cortical volume loss is also recognised
FHCC ratio normal mean 22 to 26 (this ratio decreases with ageing as a result of enlargement of the frontal horns of the lateral ventricles)
CCIT ratio normal mean 009 to 012
AMYOTROPHIC LATERAL SCLEROSISalso known as Lou Gehrig disease or Charcot disease
Primary degeneration of the motor neurons within the brain brain stem and spinal cord
Patients typically present with progressive muscle weakness and limb and truncal atrophy combined with signs of spasticity
Mean age at the time of diagnosis is 55 years
RADIOGRAPHIC FEATURES
MRI
The earliest MR manifestation is hyperintensity on T2WI in the corticospinal tracts seen earliest in the internal capsule
Iron deposition in the cortex is demonstrated as loss of signal most evident on T2 weighted sequences
IS IT ATROPHY OR HYDROCEPHALUS
Abnormal accumulation of CSF in Ventricular system
Results from Structural or functional block to normal flow Of CSF
In effect all are obhstructive
Difficult to differentiate Atrophy from Hydrocephalus gt60yrs
Initially show increased ICT
Later stages may reach Equillibrium and Becomes NP hYdrocephalus
Types
Obstructive
Communicating
NPH ndash seen typically in old patients Diagnosis is more based on clinical feature
Dementia urinary incontinence and gait apraxias + Hydrocephalus = NPH
Radiologically w
1 degeree of ventricular dilatation is more with Thinning and bowing of CC
2 Sulcal effacement is invariable seen Hydrocephalus
3 dilatation or rounding of the Temporal Horns
4 Rounding and enlargement of the frontal horns
5 Enlargement and ballooning of 3rd
ventricle
6 Enlargement of fourth ventricle
SPOTTERS
THANK YOU
NUCLEAR MEDICINE
SPECT and PET studies tend to demonstrate hypometabolism in the superior parietal and superior frontal areas in the basal ganglia
HUNTINGTON DISEASE
autosomal dominant neurodegenerative disease
a loss of GABAergic neurons of the basal ganglia
especially atrophy of the caudate nucleus and putamen
Huntington disease has a prevalence of 5-10 per 100000 and is typically diagnosed between 30 and 50 years of age
In approximately 1-6 symptoms occur before the age of 20 so-called juvenile form
Presentation is typically with progressive rigidity choreoathetosis dementia psychosis and emotional lability
The juvenile form has a different presentation with cerebellar symptoms rigidity and hypokinesia being prominent
it is a autosomal dominant with complete penetrance and genetic anticipation particularly if inherited mutated allele is paternal
The mutation responsible is on chromosome 4p163 and consists of a CAG trineucleotide repeat
The usual 10-30 copies are amplified to greater than 36 and the greater the number of repeats the earlier the age of onset
RADIOGRAPHIC FEATURES
MRI
The most striking and best known feature is that of caudate head atrophy resulting in enlargement of the frontal horns often giving them a box like configuration
This can be quantified by an number of measurements
bullfrontal horn width to intercaudate distance ratio (FHCC)
bullintercaudate distance to inner table width ratio (CCIT)
Juvenile form
putamen are also atrophied and demonstrate increased T2 signal
basal ganglia may show decrease T2 signal and blooming on SWI in keeping with iron deposition
Generalised age inappropriate cortical volume loss is also recognised
FHCC ratio normal mean 22 to 26 (this ratio decreases with ageing as a result of enlargement of the frontal horns of the lateral ventricles)
CCIT ratio normal mean 009 to 012
AMYOTROPHIC LATERAL SCLEROSISalso known as Lou Gehrig disease or Charcot disease
Primary degeneration of the motor neurons within the brain brain stem and spinal cord
Patients typically present with progressive muscle weakness and limb and truncal atrophy combined with signs of spasticity
Mean age at the time of diagnosis is 55 years
RADIOGRAPHIC FEATURES
MRI
The earliest MR manifestation is hyperintensity on T2WI in the corticospinal tracts seen earliest in the internal capsule
Iron deposition in the cortex is demonstrated as loss of signal most evident on T2 weighted sequences
IS IT ATROPHY OR HYDROCEPHALUS
Abnormal accumulation of CSF in Ventricular system
Results from Structural or functional block to normal flow Of CSF
In effect all are obhstructive
Difficult to differentiate Atrophy from Hydrocephalus gt60yrs
Initially show increased ICT
Later stages may reach Equillibrium and Becomes NP hYdrocephalus
Types
Obstructive
Communicating
NPH ndash seen typically in old patients Diagnosis is more based on clinical feature
Dementia urinary incontinence and gait apraxias + Hydrocephalus = NPH
Radiologically w
1 degeree of ventricular dilatation is more with Thinning and bowing of CC
2 Sulcal effacement is invariable seen Hydrocephalus
3 dilatation or rounding of the Temporal Horns
4 Rounding and enlargement of the frontal horns
5 Enlargement and ballooning of 3rd
ventricle
6 Enlargement of fourth ventricle
SPOTTERS
THANK YOU
HUNTINGTON DISEASE
autosomal dominant neurodegenerative disease
a loss of GABAergic neurons of the basal ganglia
especially atrophy of the caudate nucleus and putamen
Huntington disease has a prevalence of 5-10 per 100000 and is typically diagnosed between 30 and 50 years of age
In approximately 1-6 symptoms occur before the age of 20 so-called juvenile form
Presentation is typically with progressive rigidity choreoathetosis dementia psychosis and emotional lability
The juvenile form has a different presentation with cerebellar symptoms rigidity and hypokinesia being prominent
it is a autosomal dominant with complete penetrance and genetic anticipation particularly if inherited mutated allele is paternal
The mutation responsible is on chromosome 4p163 and consists of a CAG trineucleotide repeat
The usual 10-30 copies are amplified to greater than 36 and the greater the number of repeats the earlier the age of onset
RADIOGRAPHIC FEATURES
MRI
The most striking and best known feature is that of caudate head atrophy resulting in enlargement of the frontal horns often giving them a box like configuration
This can be quantified by an number of measurements
bullfrontal horn width to intercaudate distance ratio (FHCC)
bullintercaudate distance to inner table width ratio (CCIT)
Juvenile form
putamen are also atrophied and demonstrate increased T2 signal
basal ganglia may show decrease T2 signal and blooming on SWI in keeping with iron deposition
Generalised age inappropriate cortical volume loss is also recognised
FHCC ratio normal mean 22 to 26 (this ratio decreases with ageing as a result of enlargement of the frontal horns of the lateral ventricles)
CCIT ratio normal mean 009 to 012
AMYOTROPHIC LATERAL SCLEROSISalso known as Lou Gehrig disease or Charcot disease
Primary degeneration of the motor neurons within the brain brain stem and spinal cord
Patients typically present with progressive muscle weakness and limb and truncal atrophy combined with signs of spasticity
Mean age at the time of diagnosis is 55 years
RADIOGRAPHIC FEATURES
MRI
The earliest MR manifestation is hyperintensity on T2WI in the corticospinal tracts seen earliest in the internal capsule
Iron deposition in the cortex is demonstrated as loss of signal most evident on T2 weighted sequences
IS IT ATROPHY OR HYDROCEPHALUS
Abnormal accumulation of CSF in Ventricular system
Results from Structural or functional block to normal flow Of CSF
In effect all are obhstructive
Difficult to differentiate Atrophy from Hydrocephalus gt60yrs
Initially show increased ICT
Later stages may reach Equillibrium and Becomes NP hYdrocephalus
Types
Obstructive
Communicating
NPH ndash seen typically in old patients Diagnosis is more based on clinical feature
Dementia urinary incontinence and gait apraxias + Hydrocephalus = NPH
Radiologically w
1 degeree of ventricular dilatation is more with Thinning and bowing of CC
2 Sulcal effacement is invariable seen Hydrocephalus
3 dilatation or rounding of the Temporal Horns
4 Rounding and enlargement of the frontal horns
5 Enlargement and ballooning of 3rd
ventricle
6 Enlargement of fourth ventricle
SPOTTERS
THANK YOU
it is a autosomal dominant with complete penetrance and genetic anticipation particularly if inherited mutated allele is paternal
The mutation responsible is on chromosome 4p163 and consists of a CAG trineucleotide repeat
The usual 10-30 copies are amplified to greater than 36 and the greater the number of repeats the earlier the age of onset
RADIOGRAPHIC FEATURES
MRI
The most striking and best known feature is that of caudate head atrophy resulting in enlargement of the frontal horns often giving them a box like configuration
This can be quantified by an number of measurements
bullfrontal horn width to intercaudate distance ratio (FHCC)
bullintercaudate distance to inner table width ratio (CCIT)
Juvenile form
putamen are also atrophied and demonstrate increased T2 signal
basal ganglia may show decrease T2 signal and blooming on SWI in keeping with iron deposition
Generalised age inappropriate cortical volume loss is also recognised
FHCC ratio normal mean 22 to 26 (this ratio decreases with ageing as a result of enlargement of the frontal horns of the lateral ventricles)
CCIT ratio normal mean 009 to 012
AMYOTROPHIC LATERAL SCLEROSISalso known as Lou Gehrig disease or Charcot disease
Primary degeneration of the motor neurons within the brain brain stem and spinal cord
Patients typically present with progressive muscle weakness and limb and truncal atrophy combined with signs of spasticity
Mean age at the time of diagnosis is 55 years
RADIOGRAPHIC FEATURES
MRI
The earliest MR manifestation is hyperintensity on T2WI in the corticospinal tracts seen earliest in the internal capsule
Iron deposition in the cortex is demonstrated as loss of signal most evident on T2 weighted sequences
IS IT ATROPHY OR HYDROCEPHALUS
Abnormal accumulation of CSF in Ventricular system
Results from Structural or functional block to normal flow Of CSF
In effect all are obhstructive
Difficult to differentiate Atrophy from Hydrocephalus gt60yrs
Initially show increased ICT
Later stages may reach Equillibrium and Becomes NP hYdrocephalus
Types
Obstructive
Communicating
NPH ndash seen typically in old patients Diagnosis is more based on clinical feature
Dementia urinary incontinence and gait apraxias + Hydrocephalus = NPH
Radiologically w
1 degeree of ventricular dilatation is more with Thinning and bowing of CC
2 Sulcal effacement is invariable seen Hydrocephalus
3 dilatation or rounding of the Temporal Horns
4 Rounding and enlargement of the frontal horns
5 Enlargement and ballooning of 3rd
ventricle
6 Enlargement of fourth ventricle
SPOTTERS
THANK YOU
RADIOGRAPHIC FEATURES
MRI
The most striking and best known feature is that of caudate head atrophy resulting in enlargement of the frontal horns often giving them a box like configuration
This can be quantified by an number of measurements
bullfrontal horn width to intercaudate distance ratio (FHCC)
bullintercaudate distance to inner table width ratio (CCIT)
Juvenile form
putamen are also atrophied and demonstrate increased T2 signal
basal ganglia may show decrease T2 signal and blooming on SWI in keeping with iron deposition
Generalised age inappropriate cortical volume loss is also recognised
FHCC ratio normal mean 22 to 26 (this ratio decreases with ageing as a result of enlargement of the frontal horns of the lateral ventricles)
CCIT ratio normal mean 009 to 012
AMYOTROPHIC LATERAL SCLEROSISalso known as Lou Gehrig disease or Charcot disease
Primary degeneration of the motor neurons within the brain brain stem and spinal cord
Patients typically present with progressive muscle weakness and limb and truncal atrophy combined with signs of spasticity
Mean age at the time of diagnosis is 55 years
RADIOGRAPHIC FEATURES
MRI
The earliest MR manifestation is hyperintensity on T2WI in the corticospinal tracts seen earliest in the internal capsule
Iron deposition in the cortex is demonstrated as loss of signal most evident on T2 weighted sequences
IS IT ATROPHY OR HYDROCEPHALUS
Abnormal accumulation of CSF in Ventricular system
Results from Structural or functional block to normal flow Of CSF
In effect all are obhstructive
Difficult to differentiate Atrophy from Hydrocephalus gt60yrs
Initially show increased ICT
Later stages may reach Equillibrium and Becomes NP hYdrocephalus
Types
Obstructive
Communicating
NPH ndash seen typically in old patients Diagnosis is more based on clinical feature
Dementia urinary incontinence and gait apraxias + Hydrocephalus = NPH
Radiologically w
1 degeree of ventricular dilatation is more with Thinning and bowing of CC
2 Sulcal effacement is invariable seen Hydrocephalus
3 dilatation or rounding of the Temporal Horns
4 Rounding and enlargement of the frontal horns
5 Enlargement and ballooning of 3rd
ventricle
6 Enlargement of fourth ventricle
SPOTTERS
THANK YOU
FHCC ratio normal mean 22 to 26 (this ratio decreases with ageing as a result of enlargement of the frontal horns of the lateral ventricles)
CCIT ratio normal mean 009 to 012
AMYOTROPHIC LATERAL SCLEROSISalso known as Lou Gehrig disease or Charcot disease
Primary degeneration of the motor neurons within the brain brain stem and spinal cord
Patients typically present with progressive muscle weakness and limb and truncal atrophy combined with signs of spasticity
Mean age at the time of diagnosis is 55 years
RADIOGRAPHIC FEATURES
MRI
The earliest MR manifestation is hyperintensity on T2WI in the corticospinal tracts seen earliest in the internal capsule
Iron deposition in the cortex is demonstrated as loss of signal most evident on T2 weighted sequences
IS IT ATROPHY OR HYDROCEPHALUS
Abnormal accumulation of CSF in Ventricular system
Results from Structural or functional block to normal flow Of CSF
In effect all are obhstructive
Difficult to differentiate Atrophy from Hydrocephalus gt60yrs
Initially show increased ICT
Later stages may reach Equillibrium and Becomes NP hYdrocephalus
Types
Obstructive
Communicating
NPH ndash seen typically in old patients Diagnosis is more based on clinical feature
Dementia urinary incontinence and gait apraxias + Hydrocephalus = NPH
Radiologically w
1 degeree of ventricular dilatation is more with Thinning and bowing of CC
2 Sulcal effacement is invariable seen Hydrocephalus
3 dilatation or rounding of the Temporal Horns
4 Rounding and enlargement of the frontal horns
5 Enlargement and ballooning of 3rd
ventricle
6 Enlargement of fourth ventricle
SPOTTERS
THANK YOU
AMYOTROPHIC LATERAL SCLEROSISalso known as Lou Gehrig disease or Charcot disease
Primary degeneration of the motor neurons within the brain brain stem and spinal cord
Patients typically present with progressive muscle weakness and limb and truncal atrophy combined with signs of spasticity
Mean age at the time of diagnosis is 55 years
RADIOGRAPHIC FEATURES
MRI
The earliest MR manifestation is hyperintensity on T2WI in the corticospinal tracts seen earliest in the internal capsule
Iron deposition in the cortex is demonstrated as loss of signal most evident on T2 weighted sequences
IS IT ATROPHY OR HYDROCEPHALUS
Abnormal accumulation of CSF in Ventricular system
Results from Structural or functional block to normal flow Of CSF
In effect all are obhstructive
Difficult to differentiate Atrophy from Hydrocephalus gt60yrs
Initially show increased ICT
Later stages may reach Equillibrium and Becomes NP hYdrocephalus
Types
Obstructive
Communicating
NPH ndash seen typically in old patients Diagnosis is more based on clinical feature
Dementia urinary incontinence and gait apraxias + Hydrocephalus = NPH
Radiologically w
1 degeree of ventricular dilatation is more with Thinning and bowing of CC
2 Sulcal effacement is invariable seen Hydrocephalus
3 dilatation or rounding of the Temporal Horns
4 Rounding and enlargement of the frontal horns
5 Enlargement and ballooning of 3rd
ventricle
6 Enlargement of fourth ventricle
SPOTTERS
THANK YOU
RADIOGRAPHIC FEATURES
MRI
The earliest MR manifestation is hyperintensity on T2WI in the corticospinal tracts seen earliest in the internal capsule
Iron deposition in the cortex is demonstrated as loss of signal most evident on T2 weighted sequences
IS IT ATROPHY OR HYDROCEPHALUS
Abnormal accumulation of CSF in Ventricular system
Results from Structural or functional block to normal flow Of CSF
In effect all are obhstructive
Difficult to differentiate Atrophy from Hydrocephalus gt60yrs
Initially show increased ICT
Later stages may reach Equillibrium and Becomes NP hYdrocephalus
Types
Obstructive
Communicating
NPH ndash seen typically in old patients Diagnosis is more based on clinical feature
Dementia urinary incontinence and gait apraxias + Hydrocephalus = NPH
Radiologically w
1 degeree of ventricular dilatation is more with Thinning and bowing of CC
2 Sulcal effacement is invariable seen Hydrocephalus
3 dilatation or rounding of the Temporal Horns
4 Rounding and enlargement of the frontal horns
5 Enlargement and ballooning of 3rd
ventricle
6 Enlargement of fourth ventricle
SPOTTERS
THANK YOU
IS IT ATROPHY OR HYDROCEPHALUS
Abnormal accumulation of CSF in Ventricular system
Results from Structural or functional block to normal flow Of CSF
In effect all are obhstructive
Difficult to differentiate Atrophy from Hydrocephalus gt60yrs
Initially show increased ICT
Later stages may reach Equillibrium and Becomes NP hYdrocephalus
Types
Obstructive
Communicating
NPH ndash seen typically in old patients Diagnosis is more based on clinical feature
Dementia urinary incontinence and gait apraxias + Hydrocephalus = NPH
Radiologically w
1 degeree of ventricular dilatation is more with Thinning and bowing of CC
2 Sulcal effacement is invariable seen Hydrocephalus
3 dilatation or rounding of the Temporal Horns
4 Rounding and enlargement of the frontal horns
5 Enlargement and ballooning of 3rd
ventricle
6 Enlargement of fourth ventricle
SPOTTERS
THANK YOU
Radiologically w
1 degeree of ventricular dilatation is more with Thinning and bowing of CC
2 Sulcal effacement is invariable seen Hydrocephalus
3 dilatation or rounding of the Temporal Horns
4 Rounding and enlargement of the frontal horns
5 Enlargement and ballooning of 3rd
ventricle
6 Enlargement of fourth ventricle
SPOTTERS
THANK YOU
SPOTTERS
THANK YOU
THANK YOU