let’s break this down
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Let’s break this down. Neuroscience: 20/180 Geriatrics + Ethics + immunology: 60/180 Faster to learn Straightforward What is 1 MEQ then? 20/180 =0.11 0.11/2*100 = 5.56 (assuming MEQ is 50%) 5.56*60/100 = 3.33 MARKS for THEORY MD2140. So…. - PowerPoint PPT PresentationTRANSCRIPT
Let’s break this down
Neuroscience: 20/180
Geriatrics + Ethics + immunology: 60/180 Faster to learn Straightforward
What is 1 MEQ then? 20/180 =0.11 0.11/2*100 = 5.56 (assuming MEQ is 50%) 5.56*60/100 = 3.33 MARKS for THEORY MD2140
So….
If you haven’t finish stuff like systemic patho or pharmaco, and have no time to do neuroscience
Ditch it
Or just study stroke and hope you luck out
Go learn why old people are prone to falls
However… If you got spare time and are already ethical
Neuroscience is FUN
It’s more understanding and less memorizing If you are memorizing more than you understand, you
are doing it wrong I’m NOT talking about the ‘HOW DO YOU _____’ lectures
It forms the corner-stone of every neuro-exam you gonna have in clinical years.
It’s gonna be super important in future. But maybe not for M2 pros.
Drugs Used in CNS
Pharma Qns
Mode of Action
Indications
Side Effects
Drug Types
Anxiolytic + hypnotic
Anti-depressant
Anti-psychotic
Examples?
Anxiolytic + Hypnotic
Benzodiazepine (BZD) Short acting: Midazolam Intermediate acting: Lorazepam, Alprazolam Long Acting: Diazepam
Benzodiazepine (BZD)
Mode of Action?
Benzodiazepine (BZD)
Mode of Action Binds to specific BZD sites in the CNS and potentiates
GABA (an inhibitory neurotransmitter) action by increasing frequency of chloride channel opening
Increase Cl- Influx
Increase neuron hyperpolarization
Sedation
Drug action dependent on GABA OD doesn’t kill
Benzodiazepine (BZD)
Indications? Think of 3
Benzodiazepine (BZD)
Indications Convulsion, seizure (IV) Anxiety disorder Insomnia
‘Date-rape’
Benzodiazepine (BZD)
Side Effect? Think of 3 classes and some examples
Benzodiazepine (BZD) Side Effect
CNS: increase sedation decrease motor skills slower reaction time Anterograde Amnesia (esp with IV)
CVS Decrease BP, decrease respiration rate
Paradoxical symptoms Hallucination, irritability, violent tendency, excitement
Floppy Child syndrome (contra-indicated in pregnancy)
TOLERANCE, DEPENDENCE, WITHDRAWAL
Non-BZD hypnotics
Zolpidem, Zopiclone
Depression
Theory for Depression: Deficiency in monoamines in the synaptic cleft Deficiency of neurotransmitters to effect it’s action
on the post synaptic membrane
Anti-depressants
2 types?
SSRI
MOA? Related to the name
SSRI
MOA: Binds to serotonin reuptake transporter in the
presynaptic cell membrane Increase concentration of serotonin in the synaptic
cleft
Name: Fluoxetine, escitalopram
OD WILL NOT DIE!!!
SSRI
Adverse Effect? Think of 3
SSRI
Adverse Effect: Anxiety Weight loss/gain Headache Sexual dysfunction
TCA –amitriptyline, imipramine TCA blocks both serotonin reuptake transporter
and norepinephrine reuptake transporter
Gold standard treatment
BUT OD can lead to death Depressed people tend to want to die more Easy way to commit suicide
TCA
Side Effect: Cardiac rhythm: Tachycardia, arrhythmia Postural hypotension Anticholinergic effects CNS: sedation, fatigue
Antipsychotics
Broad classes?
Mode of action?
Antipsychotic - Haloperidol
Typical antipsychotic
Blocks: Dopaminergic receptors Serotonic receptors Histaminic receptors Cholinergic receptors Alpha adrenergic
Haloperidol
Side effects?
Haloperidol
Side effect: Extrapyramidal side effects:
Acute dystonia Parkinsonism Akathisia Malignant syndrome Tardive dyskinesia
CNS Pathology
Quick Start
What’s the mean ICP? 7 to 15 mmHg
How much blood does the brain need? 150ml/100g/min
What can cause acute rise in ICP? (think of 2) Hemorrhagic stroke, Intracranial Hemorrhage
Quick Start
What can cause gradual focal deficits and also increase in ICP? (Think of 2) Tumor, infection
What are the 2 different types of hydrocephalus? Name 2 etiology of each. Non-communicating vs communicating NC: SOL(medulloblastoma), meningitis (TB meningitis, scarring),
congenital (Arnold Chiari malformation) C: Subarachnoid hemorrhage, NPH, meningitis
What are the presentations and complications of raised ICP? Papilloedema, headache, nausea, HERNIATION (most dangerous
form of herniation is?)
Keep going… What are the 4 most common tumors in children? Where are
they found? Medulloblastoma (posterior fossa/infratentorial) Pilocytic Astrocytoma (Glioma, anywhere in the brain
parenchyma) Ependymoma (para/intra-ventricular) Germ Cell tumor (Mid-line)
What are the presentation of a slow-growing Meningioma? SOL Focal deficits and raised ICP
What type of CNS tumor (that we’ve learned) cross the midline and forms a butterfly shape lesion? What grade is it? Glioblastoma Multiforme (Grade IV)
Keep going… What must you suspect if you find primary lymphoma in
the brain? HIV Immunosuppression
What can be the possible diagnoses when there are multiple SOL in the brain? Lymphoma, Abscess, METASTASIS
What are the acute, chronic, and pregnant complications of drinking alcohol? (Name 1 each) Acute: Respiratory depression -> Death Chronic: cerebellar atrophy, cortical atrophy, Wernicke’s
encephalopathy, Korsakoff syndrome Pregnant: fetal alcohol syndrome (growth retardation)
Almost there… What histological changes of the brain can you see in
Alzheimer’s disease? Amyloid plagues / Neurofibrillary tangles (tau protein in
neurons) These cannot be digested. Leads to reactive gliosis and
neuronal damage and progressive cognitive decline
Which lobe is most affect in AD – Smaller, atrophied brain? Temporal Lobe
What are the clinical features of Parkinson’s Disease? TRAP – asymmetric Mask-like face Gait abnormality Respond to Levo Dopa (for 5 to 7 years)
Almost there… What are the 2 broad groups of meningitis?
Bacterial vs Aseptic What’s the difference in Cell/Glucose/Protein?
What are the top 3 cause of meningitis in neonates? E coli, Listeria monocytogenes, Streptococcal agalactiae
What are the other few bacteria that cause meningitis in pediatrics? (young children) Nisseria meningitidis, Streptococcal pneumonia, Hemophilus
influenza type B THEY ALL HAVE CAPSULE!!!!!!!!!
HYPERTENSION AND IT’S ASSOCIATED HYPERTENSIVE CEREBRAL VASCULAR DISEASE IS IMPORTANT!!!!!!!
Localising Lesions
Revision DCML
Spino-thalamic
Corticospinal
Spino-cerebellar
General route, Decussation, Function?
UMN VS LMN
What is UMN and LMN?
How does it help in localizing the level of the lesion? Understand: Inverted supinator jerk and Inverted
knee jerk Where is the level of the lesion?
UMN vs LMN
Inverted Supinator Jerk Weak biceps jerk (C5, 6) Weak brachioradialis jerk (C5,6) Brisk triceps Jerk (C7, 8) (Brisk flexion of the fingers)
Will this guy be able to breathe?
Inverted Knee Jerk Weak knee jerk (L3) Brisk ankle jerk (S1)
What’s wrong with this guy?
Brown Sequard Syndrome
Where is the Lesion? T2 to L2
How to narrow down further? Strength of Hip Flexion Cremasteric reflex Superficial Abdominal Reflex
What are the OTHER clinical signs? UMN signs… WHICH SIDE? Loss of proprioception and touch… WHICH SIDE?
Brown Sequard Syndrome
Hemisection of the spinal cord
What are some SOL in the spinal cord that can cause hemicord syndrome? Tumor (meningioma, lymphoma), Abscess
Can syringomyelia/hydromyelia cause brown sequard?
Revision
What is somatotopy? Of the Brain Of the Spinal Cord
Ascending weakness
What are the causes of ascending weakness? Guillain-Barre syndrome Myelopathy (compression, vascular, inflammation)
What are some microbes that can cause Guillain-Barre syndrome? Campylobacter jejuni CMV Influenza Varicella
How will a syringomyelia present? (usually grows laterally and anteriorly)
Stroke
What are the 2 different type of infarct? “An artery can either _____ or ______.”
What are the risk factors for each? (name at least 5)
What are the etiologies? (at least 2 for each)
Stroke Ischemic infarct vs hemorrhagic infarct
What are the risk factors? Hypertension, Diabetes, hyperlipidemia, TIA,
Hypercoagulable state, Atrial Fibrillation, RHD, Vascular malformations (Berry aneurysm, Charcot-Bouchard Aneurysm, AVM, moya-moya)
What are the etiologies? Ischemic: Shock, acute plague change, thromboembolism Hemorrhagic: Rupture of aneurysm, trauma, tumor,
malignant hypertension
Revision
What clinically important areas does the superior branch of the middle cerebral artery supply?
How about the inferior branch of the MCA?
MCA Superior
Frontal Lobe: Broca(left), FEF, Primary Motor Cortex(UL and Face) Parietal lobe: Somatosensory cortex (UL and Face)
Inferior Parietal lobe: Wernicke’s Area(left), Somatosensory cortex(UL and Face) Parietal and Temporal Lobe: Optic Radiation(contralateral homonymous
hemianopia)
Internal Capsule (lenticulostriate arteries, LL and lots of other stuff)
What about the PCA and ACA?
UMN VS LMN
What are 6 things to look out for when testing for UMN vs LMN?
UMN vs LMN
Tone Atrophy Fasiculations Deep tendon reflex Clonus Plantar reflex
THE EYES!
What is the difference between a destructive and irritative lesion involving the FEF?
What side does the eye gaze in a left sided pontine lesion? (PPRF lesion)
What is internuclear opthalmoplegia?
What is a possible clinical presentation of the eye in an Uncal lesion?
Which motor nerve to the eye has the longest course between the brainstem and the eye?
The MyoNeuro-axis Muscle NMJ Peripheral nerves Plexus Roots Spinal cord Brain stem Brain
Cerebellar Basal ganglia Extra-pyramidal Cranial nerves
What are their hallmarks?
Muscle Proximal weakness Gower’s sign Muscular dystrophy
Creatinine kinase, rhabdomyolysis
NMJ Severe fatigability, especially in muscles that usually does
not gets tired Gets better with rest Gets better with ice Gets better with Acetylcholinesterase inhibitor (tensilon
test)
Peripheral Nerves/Diffuse polyneuropathy Glove and stocking deficits (distal weakness) Length dependent Usually a systemic problem (bilaterally affected) Weakness and wasting (Pes Cavus), Sensory abnormality Denervated muscles become completely dead in 18 month
Mononeuropathy (nerve entrapment) Patchy sensory abnormality Motor and sensory loss follows specific nerve innervation
pattern
What disease affects peripheral nerve?
Plexopathy Involvement of multiple areas supplied by different
nerves, but distribution fits into the supply from trunks/cords of the plexus
Weakness + wasting + sensory deficits (patchy) Somewhat like a peripheral nerve problem, but
more extensive, and NOT length dependent
Radiculopathy Deficits will present in a myotomal/dermatomal
pattern No longer length dependent
Anterior Horn Cell Non-length dependent pattern of weakness Wasting FASCICULATIONS
“Dramatic dying of the cell body, crying and screaming, anyhow firing”
Spinal Cord
UMN vs LMN signs
What test can you do to localize the level of the lesion?
If patient has a hemiplegia + speech defect, where is the level of the lesion?
Brain Stem and the Rule of 4
Rule of 4 – What is this?
Speech deficits What’s the difference between bulbar and pseudobulbar
palsy?
Facial droop (UMN VS LMN) What other cranial nerve is unilaterally supplied? Half face paralysis + contralateral hemiparesis – Level?
Ocular muscle weakness What happens in a 3rd nerve palsy? 3rd Nerve palsy + contralateral hemiparesis – Level?
Brain
When is the lesion LEAST LIKELY to be in the brain?
Brain
When is the lesion LEAST LIKELY to be in the brain? Bilaterally affected (tetraplegia) Ascending weakness Glove and Stocking deficits NO UMN signs
What about a guy with just a unilateral LL weakness?
Explain the following….
Sudden right Hemiparesis Expressive aphasia Ipsilateral gaze shift towards the lesion
Seizure
Reactive Gliosis -> Glial Scar -> predispose to uncoordinated firing of neurons
Destructive lesion vs Irritative lesion of the FEF
Harlem Shake?
No….. Definitely Ballismus