Neuroanatomy for PsychiatristsNeuroanatomy for Psychiatrists

Dr Rohit ShankarDr Rohit ShankarMBBS, MD, MRCPsych, CCT, PGC Cl. ResearchMBBS, MD, MRCPsych, CCT, PGC Cl. Research

Consultant in Adult Developmental NeuropsychiatryConsultant in Adult Developmental Neuropsychiatry

Why should we know any Neurology?Why should we know any Neurology?

Brain Behaviour connectionBrain Behaviour connection

Man made divideMan made divide

2000 years of togetherness2000 years of togetherness

Hippocrates (460-377BC) Humours theory and Triad of mental illnessHippocrates (460-377BC) Humours theory and Triad of mental illness

Plato – divine inspired and physical inspired mental illnessPlato – divine inspired and physical inspired mental illness

Inter canon of the yellow emperorInter canon of the yellow emperor

Johann Christian Reil 1808Johann Christian Reil 1808

Reintegration – biological underpinningsReintegration – biological underpinnings

Golden RulesGolden Rules

Adhere to the routineAdhere to the routine

A good History is more useful than a good examinationA good History is more useful than a good examination

Usually well practiced testing would take 20 minutes then come back to Usually well practiced testing would take 20 minutes then come back to any areas of deficitsany areas of deficits

Don’t ‘Scan’ before you ‘Can’ physically examineDon’t ‘Scan’ before you ‘Can’ physically examine

Hoof beats are usually more likely to be from horses as opposed to Hoof beats are usually more likely to be from horses as opposed to Zebras, Hemiparesis is more likely from a stroke as opposed to an Zebras, Hemiparesis is more likely from a stroke as opposed to an unwitnessed seizureunwitnessed seizure

Motor System – Motor System – Limb strength Limb strength spasticity, flaccidity and fasciculationspasticity, flaccidity and fasciculationAbnormal movements – e.g.. Chorea and tremorsAbnormal movements – e.g.. Chorea and tremors

Reflexes – Reflexes – DTRs – biceps, triceps, Quadriceps, Achilles DTRs – biceps, triceps, Quadriceps, Achilles Pathological reflexes – Babinski, frontal release signsPathological reflexes – Babinski, frontal release signs

Sensation –Sensation –Position, vibration, stereognosis, PainPosition, vibration, stereognosis, Pain

Cerebellar –Cerebellar –Finger – Nose, Heel – Toe, Rapid alternating movements, GaitFinger – Nose, Heel – Toe, Rapid alternating movements, Gait

The Neurological ExamThe Neurological Exam

The Neurological ExamThe Neurological ExamMental Status – Mental Status – GCS, orientation, Language, higher intellectual functions (arithmetic)GCS, orientation, Language, higher intellectual functions (arithmetic)

Cranial Nerves –Cranial Nerves –I SmellI SmellII Visual acuity, visual field, optic fundiII Visual acuity, visual field, optic fundi

Ocular motility nerves:Ocular motility nerves:III,IV,VI pupil size and reactivity, extra ocular motion III,IV,VI pupil size and reactivity, extra ocular motion

cerebello-pontine angle nerves:cerebello-pontine angle nerves:V corneal reflex and facial sensationV corneal reflex and facial sensationVII upper and lower facial muscle strength, tasteVII upper and lower facial muscle strength, tasteVIII hearingVIII hearing

Others:Others:IX - XI articulation, palate movement, gag reflexIX - XI articulation, palate movement, gag reflexXII tongue movements XII tongue movements

THE LAST SUPPERTHE LAST SUPPER

DETAILSDETAILS LIE IN BEHOLDER’S LIE IN BEHOLDER’S OBSERVATIONS!OBSERVATIONS!

Detail of the Da Vinci's The Last Supper by Giacomo Raffaelli

Diagnostic PathwayDiagnostic Pathway

Be RitualisticBe Ritualistic

The formulation:The formulation:Symptoms, Signs, Localization and DiagnosisSymptoms, Signs, Localization and Diagnosis

Localization:Localization:Where is the lesion?Where is the lesion?CNS, PNS or MusclesCNS, PNS or Muscles

What is the lesion?What is the lesion?Diffuse or DiscreteDiffuse or Discrete

Diagnosis:Diagnosis:Common conditions arise commonly – Common conditions arise commonly – Hoof beats are usually more likely to be from horses as opposed to ZebrasHoof beats are usually more likely to be from horses as opposed to ZebrasHemiparesis is more likely from a stroke as opposed to an unwitnessed Hemiparesis is more likely from a stroke as opposed to an unwitnessed

seizureseizure

The LobesThe Lobes

Job AllocationJob Allocation

Division of LabourDivision of Labour

Lobe FunctionLobe Function

Frontal Lobe DysfunctionFrontal Lobe Dysfunction The primary motor cortexThe primary motor cortex Contra lateral motor controlContra lateral motor control

The medial frontal cortex The medial frontal cortex Arousal and motivation – Abulic (Apathy & inattention)Arousal and motivation – Abulic (Apathy & inattention)

The orbital frontal cortex The orbital frontal cortex Modulate Behaviour -Labile, euphoric, facetious, vulgarModulate Behaviour -Labile, euphoric, facetious, vulgar

The left postero-inferior frontal cortex (Broca's)The left postero-inferior frontal cortex (Broca's) Language – expressive AphasiaLanguage – expressive Aphasia

The dorsolateral frontal cortex The dorsolateral frontal cortex Working memory & dysexecutive syndromeWorking memory & dysexecutive syndrome

Parietal Lobe DysfunctionParietal Lobe Dysfunction The primary somatosensory cortexThe primary somatosensory cortex Integrates somesthetic stimuli for recognition and recall of form, texture, and Integrates somesthetic stimuli for recognition and recall of form, texture, and

weight - Contralateral astereognosisweight - Contralateral astereognosis

Posterolateral - Postcentral gyrusPosterolateral - Postcentral gyrus visual-spatial relationships and proprioceptionvisual-spatial relationships and proprioception

Midparietal lobe (dominant)Midparietal lobe (dominant) calculation, writing, left-right orientation, and finger recognition - Gerstmann's calculation, writing, left-right orientation, and finger recognition - Gerstmann's

syndromesyndrome

The nondominant parietal lobe The nondominant parietal lobe Contralateral environmental awareness, drawing – Anosognosia, Contralateral environmental awareness, drawing – Anosognosia,

Hemiasomatognosia, spatial ApraxiaHemiasomatognosia, spatial Apraxia

Temporal Lobe DysfunctionTemporal Lobe Dysfunction Auditory perception, receptive components of Auditory perception, receptive components of

language, visual memory, declarative (factual) language, visual memory, declarative (factual) memory, and emotionmemory, and emotion

Right temporal lobe lesions - interpret nonverbal Right temporal lobe lesions - interpret nonverbal auditory stimuli (e.g. music)auditory stimuli (e.g. music)

Left temporal lobe lesions interfere greatly with the Left temporal lobe lesions interfere greatly with the recognition, memory, and formation of language recognition, memory, and formation of language

medial limbic - emotional parts & TLE medial limbic - emotional parts & TLE

Occipital Lobe DysfunctionOccipital Lobe Dysfunction

Primary visual cortex and visual association Primary visual cortex and visual association areas areas

Anton Babinski SyndromeAnton Babinski Syndrome

Occipital Seizures – C/L Visual HallucinationOccipital Seizures – C/L Visual Hallucination

Prosopagnosia - Face blindnessProsopagnosia - Face blindness

Conscious pain, temperature, crude touch & pressure

Lateral and an anterior tract

Thalamus (all conscious sensations) projection to areas of the cerebral cortex

This tract carries unconscious proprioception (muscle sense) to the cerebellum which is responsible for muscle coordination

They innervate the cerebellum on the same side

Corticospinal tract cerebral cortex – Localised voluntary motor controlTwo branches, the lateral and the anterior The lateral crosses in the medulla at the ‘pyramids’ The anterior does not crossCommon signs: DTR abnormalities, Motor Paresis, Babinski

The Basal GangliaThe Basal Ganglia

Located Sub corticallyLocated Sub cortically

Modulates the Corticospinal tractModulates the Corticospinal tract

Regulates muscle tone, motor activity and Regulates muscle tone, motor activity and generates postural reflexgenerates postural reflex

Confined to the brain, no role on LMNs or Spinal Confined to the brain, no role on LMNs or Spinal CordCord

Caudate Nucleus, Corpus Striatum, Lentiform Caudate Nucleus, Corpus Striatum, Lentiform Nucleus (Globus Pallidus + Putamen), Subthalamic Nucleus (Globus Pallidus + Putamen), Subthalamic Nuclei, Substantia NigraNuclei, Substantia Nigra

IC (white matter) runs between the CN and the LN = Corpus StriatumArtery of StrokePure damage to Basal Ganglia = No corticospinal symptoms, No neuropsychological dysfunction, No cognitive Dysfunction, contra lateralResult of biochemical not usually structural, B/L, slow progressCerebrum + BG = inv Mov + cognitive &/or psychiatric Sx

Basal Ganglia and Limbic SystemBasal Ganglia and Limbic System

Hippocampal Formation & AmygdalaHippocampal Formation & AmygdalaHippocampal FormationHippocampal Formation

Dentate gyrus + the hippocampus proper + SubiculumDentate gyrus + the hippocampus proper + Subiculum

Memory, spatial navigation and attentionMemory, spatial navigation and attention

Amygdala Amygdala

Via hypothalamus activates the ANSVia hypothalamus activates the ANS

Activation of NeurotransmittersActivation of Neurotransmitters

Emotional Learning – ConditioningEmotional Learning – Conditioning

Memory modulationMemory modulation

Kluver Bucy Syndrome – Docility: diminished fear responses, dietary Kluver Bucy Syndrome – Docility: diminished fear responses, dietary changes, Hyperorality, Hypersexuality, Visual Agnosia, changes, Hyperorality, Hypersexuality, Visual Agnosia, Hypermetamorphosis: irresistible impulse to notice and react to everything, Hypermetamorphosis: irresistible impulse to notice and react to everything, memory lossmemory loss

Papez CircuitPapez Circuit

Function of the Limbic SystemFunction of the Limbic System

Affective functionsAffective functions

Playful moods Playful moods

Emotions and feelings, Emotions and feelings, like wrath, fright, like wrath, fright, passion, love, hate, joy passion, love, hate, joy and sadnessand sadness

self preservation self preservation

Dopamine PathwaysDopamine Pathways

VTAHT

Serotonin PathwaysSerotonin Pathways

Serotonin and DepressionSerotonin and Depression

Serotonin transmission - Caudal raphe nuclei Serotonin transmission - Caudal raphe nuclei and Rostal raphe nuclei is reduced in and Rostal raphe nuclei is reduced in depression depression

Increasing the levels of serotonin in these Increasing the levels of serotonin in these pathways, by reducing serotonin reuptake = pathways, by reducing serotonin reuptake = treatmenttreatment

Serotonin in SchizophreniaSerotonin in Schizophrenia Dorsal raphe nuclei - Substantia Nigra Dorsal raphe nuclei - Substantia Nigra

Rostral raphe nuclei - cerebral cortex, limbic regions Rostral raphe nuclei - cerebral cortex, limbic regions and basal gangliaand basal ganglia

The up-regulation of Serotonin pathways leads to the The up-regulation of Serotonin pathways leads to the

hypofunction dopamine pathways = negative hypofunction dopamine pathways = negative symptomssymptoms

The serotonergic nuclei in the brainstem that give rise The serotonergic nuclei in the brainstem that give rise

to descending serotonergic axons remain unaffected to descending serotonergic axons remain unaffected in schizophrenia in schizophrenia

Serotonin and DepressionSerotonin and Depression

Serotonin and SchizophreniaSerotonin and Schizophrenia

Brain StemBrain Stem Brain Stem: Midbrain, Pons, MedullaBrain Stem: Midbrain, Pons, Medulla

Contains CNs, CS Tract and other ‘long’ TractsContains CNs, CS Tract and other ‘long’ Tracts

Positive evidence of localization and negative Positive evidence of localization and negative evidence of cerebral injuryevidence of cerebral injury

Example – Diplopic but no effect on visual acuity or Example – Diplopic but no effect on visual acuity or fieldsfields

Brain stem injures -Massive infarcts, Overdoses etcBrain stem injures -Massive infarcts, Overdoses etc

Simultaneous damage of BS and Cerebrum RARE Simultaneous damage of BS and Cerebrum RARE exceptions: MS, tumours etc exceptions: MS, tumours etc

CerebellumCerebellum Controls the coordination of movements/limbs – Controls the coordination of movements/limbs –

IpsilateralIpsilateral

Muscle Hypotonia and Pendular DTRsMuscle Hypotonia and Pendular DTRs

No obvious cognitive roleNo obvious cognitive role

Intentional TremorIntentional Tremor

Gait Ataxia, Scanning speech, tandem gait failureGait Ataxia, Scanning speech, tandem gait failure

Cognitive Impairment?Cognitive Impairment?

Alcohol – Thiamine, AIDS, toxins, Vitamin E, Alcohol – Thiamine, AIDS, toxins, Vitamin E, PhenytoinPhenytoin

Psychiatry and NeurologyPsychiatry and Neurology Psychogenic Paresis and Hoover’s SignPsychogenic Paresis and Hoover’s Sign

La Belle IndifferenceLa Belle Indifference

MSMS

Sleep DisordersSleep Disorders

Parkinsonism, Huntington, Wilson’s diseaseParkinsonism, Huntington, Wilson’s disease

Frontal Lobe issues, DementiaFrontal Lobe issues, Dementia

Seizures of Non epileptic origin and NEADs, Seizures of Non epileptic origin and NEADs, Sensory seizuresSensory seizures

CASE STUDY 1CASE STUDY 1

An elderly man has left ptosis and a dilated and An elderly man has left ptosis and a dilated and unreactive left pupil with external deviation of the unreactive left pupil with external deviation of the left eye, right hemiparesis, right sided hyperactive left eye, right hemiparesis, right sided hyperactive DTRs and positive Babinski, no aphasia or DTRs and positive Babinski, no aphasia or hemianopia where is the lesion?hemianopia where is the lesion?

CerebrumCerebrum CerebellumCerebellum PonsPons MidbrainMidbrain MedullaMedulla None of the aboveNone of the above

CASE STUDY 2CASE STUDY 2

A 20 year old woman reports having lost all vision A 20 year old woman reports having lost all vision in her right eye and right hemi-sensory loss. Pupil in her right eye and right hemi-sensory loss. Pupil and DTRs are normal. She does not press down and DTRs are normal. She does not press down with her left leg while attempting to lift her right leg. with her left leg while attempting to lift her right leg. where is the lesion?where is the lesion?

CerebrumCerebrum CerebellumCerebellum PonsPons MidbrainMidbrain MedullaMedulla None of the aboveNone of the above

CASE STUDY 3CASE STUDY 3

50 yr old man with mild dementia has absent 50 yr old man with mild dementia has absent reflexes, loss of position and vibration sense and reflexes, loss of position and vibration sense and ataxia. Which areas are affected?ataxia. Which areas are affected?

The CNSThe CNS The CNS and the PNSThe CNS and the PNS The Cerebrum and the posterior columnsThe Cerebrum and the posterior columns The ANSThe ANS

CASE STUDY 4CASE STUDY 4

After having suffered from increasing severe After having suffered from increasing severe depression for 3 years the psychiatrist finds the 55 depression for 3 years the psychiatrist finds the 55 year old woman to have right sided optic atrophy year old woman to have right sided optic atrophy and left sided papilledema. Where is the lesion?and left sided papilledema. Where is the lesion?

Occipital LobeOccipital Lobe Frontal LobeFrontal Lobe Parietal LobeParietal Lobe Temporal LobeTemporal Lobe None of the aboveNone of the above

QUESTIONQUESTION

Where is the primary damage in Wilson's disease, Where is the primary damage in Wilson's disease, Huntington's Chorea and Choreiform Cerebral Huntington's Chorea and Choreiform Cerebral Palsy?Palsy?

Extra pyramidal systemExtra pyramidal system Pyramidal systemPyramidal system Entire CNSEntire CNS Cerebellar outflow tractsCerebellar outflow tracts None of the aboveNone of the above

SOME CORRECTIONSSOME CORRECTIONS

EMI -2EMI -2