HIGHER CORTICAL FUNCTIONNEUROLOGY DEPARTMENTMUHAMMAD HOESIN GENERAL HOSPITAL2015

Higher Cortical FunctionsMental FunctionsClinical NeuropsychologyBehavioural Neurology

BRAIN

Cerebral Cortex ComponentsInitiation of movement (Motoric)

Sensation from the body and the special sensory organs (Sensoric)

The cerebral cortex is also the substrate for functions that convey comprehension,cognition, and communication

Cerebral Components of Higher Cortical FunctionsCortex Cerebri (Cytoarchitectonic).Limbic System.Reticular Formation.Diencephalon.Associated Projection.Non-Specific Afferent System (collateral network to cortex).

Cytoarchitectonic

Area 4Motor cortexArea 6Supplementary motor cortexArea 22Wernickes areaArea 44, 45 Brocas area

CEREBRAL CORTEX

Lateral organization (Left & Right brain) Sperry (1970)Left Hemisphere Lingual HemisphereRight Hemisphere Non Lingual Hemisphere

Non-Dominan Hemisphere SyndromeLeft HemisphereAphasia.Apraxia.Alexia.Agraphia.Gerstmann Syndrome.Left-right Disorganization.Acalculia.Finger Agnosia.Agraphia.Right HemisphereAttention & Emotion disturbances.Visuospatial Disturbances :Construction Apraxia.Dressing Apraxia.Prosopagnosia Amusia.

Frontal Lobe SyndromeCaused by brain tumor, head trauma, etc.Bilateral lesions.Sign and symptoms :Behavioral changes (labile, irritable, apathetic, inattentive, akinesia syndrome).Impaired intellectual and cognitive function.Alteration in personality and mood.

Parietal Lobe SyndromeApraxia. Agnosia.Disorientation.Impaires Body Image.Hemiparesis, Hemihipesthesia.Hemianopsia.

HCF

The High Cortical Functions areMemoryOrientationConcentrationLanguagePerformance of learned skilled movements (eq. Apraxia)Recognition of Stimuli (eq. Agnosia)Regular Assesment

MENTAL STATUS EXAMINATION

MMSE RESULT

MEMORYMemory is the ability to revive past thoughts and sensory experiences.RegistrationThe ability to perceive, recognise, and establish information in CNSRetentionThe ability to retain registered informationRecall the ability to retrieve stored information at will

Tests of MemoryShort-term Memory Recall of material within a period of up to 30 secsLong-Term MemoryRecent Memory :events occuring during past few hours to the past few monthsRemote Memory : events occuring in past years

ORIENTATIONOrientation in TimeOrientation in PlaceOrientation in Person

ATENTION (CONCENTRATION)Attention is a multifaceted mental function, but in general, it denotes the capacity of an individual to focus the mind (pay attention to) some aspect of the environment or the contents of the mind itself.

Tests of AttentionHistory and ConversationSubstractionReversing Components

LANGUAGESpontaneous VerbalComprehensionNamingRepetitionReading AbilityWriting Ability

Alexia Inability to read.Alexia with agraphia : impairment of reading and writing, caused by lesions at the angular gyrus.Alexia without agraphia : unable to read, although writing is not impaired, caused by lesions at left visual cortex and the splenium of corpus callosum.

Aphasia Refers to loss or impairment of language function as a result of brain damage.

Type of aphasia result from lesions in specific regions of the cerebral hemisphere.

Types of Aphasia

TypeFluencyComprehension NamingRepetitionBrocas-++-Wernickes+---Global ----Conduction+++-Motor Transcortical-+-+Sensory Transcortical+--+Mixed Transcortical---+Anomic ++-+

ApraxiaThe inability to carry out motor acts correctly despite intact motor and sensory pathways, intact comprehension, and full cooperation.Caused by cortical association disturbances. Ideational apraxia, ideomotor apraxia, kinetic apraxia, dressing apraxia, constructional apraxia.

CONSTRUCTIONAL APHASIAIn the testing situation the patient is asked to copy a drawing on paper or an arrangement of blocks, or other physical objects.

The Rey Osterrieyh Complex Figure

INTERLOCKING TEST FINGERThe IFT is the 1st bed-side/office test of the parietal lobe to be described in many decades. It probably entails limb praxis, visual-spatial, and visuoconstructional skills, and poor performace is highly correlated with parietal lobe pathology.

Agnosia Difficulty in identification or recognition.Caused by disturbances in the association functions of the cerbral cortex.Astereognosis : failure of tactile recognition.Visual agnosia.Prosopagnosia : inability to recognize familiar faces.Unilateral neglect : fail to respond to stimuli in one half of space.Anosognosia : lack of awareness of disease or denial of illness.

Unilateral Neglect Unilateral (left-sided) neglect in a patient with a right hemispheric lesion.

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