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CORTICAL FUNCTION
dr. Paulus Anam Ong Sp.Sdr. Yustiani Dikot Sp.S(K)
Bagian I.P. Saraf RSHS FKUP
CEREBRUM / FOREBRAIN
CONSIST OF 2 HEMISPHERE WHICH IS NOT SYMETRICAL IN SHAPE AND FUNCTION
THE LARGEST PART OF THE HUMAN BRAIN
COVERED BY GRAY MATTER CALLED CORTEX WHICH WAS FOLDED MADE GYRI AND SULCI
Part Of Cerebral Cortex
CEREBRAL CORTEX
CONSIST OF SIX LAYERS, THE THICHNESS VARIES IN DIFFERENT
REGIONS
VIEWED LATERALLY COMPOSED OF FOUR LOBES, BROODMAN
DEVIDED IN 47 AREAS WHICH SPECIFIC PART RESPECT FOR A
CERTAIN ASPECT OF FUNCTION
FUNCTION ARE INTEGRATION IN DISCRIMINATIVE AND
COGNITIVE PROCESSES RELATING TO AFFECTIVE BEHAVIOR,
MOTOR FUNCTION, SOMATOSENSORY PERCEPTION,
INTEGRATION AND MEMORY FUNCTION PERCEPTION MOTIVATION MOVEMENT
Functional Areas of The Cerebrum
INTEGRATION FIBRES
INTEGRATION IN ONE HEMISPHERE
ASSOCIATION FIBRES
INTEGRATION BETWEEN TWO HEMISPHERE
COMMISURE FIBRES/CORPUS CALLOSUM
INTEGRATION WITH OTHER PART OF CNS
PROJECTION FIBRES
Right and Left Hemisphere Function
Right and Left Hemisphere Function
THE 47 AREAS
Consist of
PRIMARY / PRINCIPLE RECEPTIVE AREA
ASSOCIATION AREA
INTEGRATION WITH OTHER PART OF
THE HEMISPHERE / BRAIN
Homonculus Cerebri
The Lateral Aspect of Cerebrum
The Medial Aspect of Cerebrum
Frontal Lobe Parts
FRONTAL LOBE FUNCTION
1. PRECENTRAL GYRUS (MOTOR CORTEX)
• Contralateral movement face, arm, leg, trunk
2. BROCA’S AREA (DOMINANT HEMISPHERE)
• Expressive centre for speech
3. A.SUPPLEMENTORY MOTOR AREA and B. frontal eye field
A.More involved in providing drive for initiation of movement than executing movement
B.Voluntary eyes movement on opposite stimulation
4. PREFRONTAL AREAS
• Personality and Initiative
5. PRECENTRAL LOBULE
• Cortical Inhibition of bladder and bowel voiding
IMPAIREMENT OF FRONTAL LOBE FUNCTION
1. PRECENTRAL GYRUS
Monoplegia or hemiplegia depending on extent of damage
2. BROCA’S AREA
Broca’s dysphasia
3. SUPPLEMENTARY MOTOR AREA and frontal eye field
Lack of initiation and Paralysis of head and eye movement to
opposite site
5. PRECENTRAL GYRUS
Incontinence of urine and fecal
Loss of cortical inhibition
A.ORBITOFRONTAL SYNDROME 1. Poor judgement2. Disinhibition3. Emotional lability
B. FRONTAL CONVEXITY SYNDROME Apathy Indifference Poor abstract thought
C. MEDIAL FRONTAL SYNDROME Akinetic Incontinent Sparse verbal output
Associated with :1. Primitive reflexes (gasp,pout, etc.)2. Disturbance of gait (gait apraxia)3. Resistance to passive movements of the limbs
(paratonia)
4. PREFRONTAL AREASChange personality with antisocial behavior / loss of inhibition
Parietal Lobe Parts
PARIETAL LOBES FUNCTION
1. POSTCENTRAL GYRUS (primary sensory Cortex) and Superior Parietal Lobule (secondary sensory association area)
• Receives afferent pathways for appreciation of posture, touch and passive movement
• Coordination, integration and refinement of sensory input, tactile localization, discrimination, sterognosis
2. Inferior parietal lobule: posterior tertiarry are that combines information from 3 posterior lobes: parietal, temporal, occipital
SUPRAMARGINAL AND ANGULAR GYRI
• DOMINANT HEMISPHERE
• Language: From wernicke’s language area Integration of auditory and visual aspects comprehension in
• Skill of handling numbers/calculation
• NON-DOMINANT HEMISPHERE
1. Concept of body imaged and the awareness of the external environment and ability to construct shape
PARIETAL LOBE IMPAIRMENT
1. DISTURBED in• Postural sensation• Sensation of passive movement• Accurate localisation of light touch• Two point discrimination
2. WERNICKE’S DYSPHASIANON-DOMINANT
• Anosognosia• Dressing apraxia• Geographical apraxia• Constructional apraxia
DOMINANT : (Gertman’s Syndrome)• Right and left limbs disorientation• Finger agnosia• Acalculation• Agraphia
Temporal Lobe Parts
LOBUS TEMPORAL FUNCTION
1.Primary AUDITORY CORTEX (Heschl’s gyrus, BA 41,42)• Dominant Hearing of Language• Non-Dominant Hearing of sound, rhythm and music
2 Wernicke area: stretch over tertiary association of parietal, temporal, occipital
Dominant: language comprehension Non dominant: perception of music
2.THE MIDDLE AND INFERIOR TEMPORAL GYRI• Learning and Memory
3. THE LIMBIC LOBE• Sensation of olfaction, Emosional, Affective behavior
4.VISUAL PATHWAY
TEMPORAL LOBE IMPAIRMENT
1. AUDITORY CORTEX (Cortical deafness)• DOMINANT Difficulty in hearing spoken sounds• NON-DOMINANT Amusia• Auditory hallucinations
2. MIDDLE AND INFERIOR TEMPORAL GYRI • Disturbed memory / learning
3. LIMBIC LOBE• Olfactory hallucination with complex partial seizures• Aggressive or antisocial behavior• Inability to establish new memories
4. OPTIC RADIATION• Upper homonymous qudrantanopia
Occipital Lobe Parts
OCCIPITAL LOBE FUNCTION
Perception of vision (The visual cortex)
Lies along the banks of the calcarine sulcus
1. The Striate cortex: Primary visual cortex (BA 17)2. Parastriate cortex: Association visual cortex (BA 18): Synthesize visual impression, integrate them with other
sensory modalities and aid in formation of visual memory traces.
Area where parietal and occipital lobes meet: perception of spatial relationship,
visuokinesthetic motor engrams
prepositional consruction in language comprehension and
speech
OCCIPITAL LOBE IMPAIRMENT
1. HOMONIMOUS HEMIANOPSIA2. CORTICAL BLINDNESS
• Extensive bilateral cortical lesions of the striate cortex3. ANTON’S SYNDROME
• Involvement of both the striate and the parastriate cortices affects the interpretation of vision
• Unaware of the visual loss and denies its presence4. BALINT’S SYNDROME
• Simultanagnosia5. VISUAL HALLUCINATIONS
• Elementary – unformed – appearing as patterns6. VISUAL ILLUSIONS (Non-dominant)
• Micropsia / macropsia• Disappearance of colour
7. PROSOPAGNOSIA• Able to see a familiar face but cannot named it
Balint’s syndrome
Synonim: Balinnt-Holmes syndrome
(1909), Occularr apraxia ; optic ataxia
Bilateral parieto-occipital disease
Inability to direct the eyes to a certain
point in the visual field despite intact eye
movement.
End of Session
Mental Status
5 basic element that build mental status
1.1. Arousal Mechanism ( alertness, attention, Arousal Mechanism ( alertness, attention, concentration)concentration)
2.2. OrientationOrientation
3.3. LanguageLanguage
4.4. MemoryMemory
5.5. Higher cortical functionHigher cortical function
Basic element of mental status
Higher cortical function
Memory
Concentration
Attentioni
Arousal
Language
Basic element of cogntion (Marshall,Mayer.1997)
• Arousal mechanism
• Bahasa & memori: well developed and localized basic element elemen
• Higher cortical function: depend on the 3 basic element
Language The basic tool of human communication and
crucial in assessing most cognitive abilities
Must be establish early in the course of mental status testing due to most of the mental test are verbal oriented e.g verbal memory test, oral calculation, proverb test
Terminology Dysarthria: specific disorder of articulation in which
basic language (grammar, comprehension & word choice) is intact
Dysprosody: an interruption of speech melody (inflection and rhyme) that caused monotonal, halting, can at times mimic a foreign accent
Aphasia: a true deficit of higher integrative language processing, patient produces errors of grammar and word choice or has a defect in comprehension
Terminology Alexia: loss of (any level of) reading ability in
previously literate person. Dyslexia: a specific developmental learning disorders
of children who have normal intelligence, yet experience unusual difficult in learning to read
Agraphia: an acquired disturbance in writing. Specifically refers to errors of language and not to problem with the actual formation of letter or poor handwriting
Aphasia Def: an acquired language impairment due to
damage to language areas of the brain (left hemisphere)
Characterized by defects of: Word selection language production language comprehension
Affect not only spoken, but also written language both comprehension (alexia) and production (agraphia)
Etiology of aphasia Acute
ischemic stroke (embolic/ thrombotic) in the distribution of middle cerebral artery
Cerebral hemorhage (hipertension, AVM, Aneurysm, Trauma
Slowly progressive: brain tumor Degenerative process: Alzheimer disease, Primary
Progressive Aphasia Transient: TIA, epileptic seizures
Aphasia 95% result from left hemisphere lesions
‘cause 95% of right handed individual and 70% of left handed are left hemisphere dominant for language
Crossed aphasia: aphasia after lesion of right hemisphere in a right handed individual
Primary Language Area(perisylvian area)
Area Broca Area Wernicke
Fasikulus Arcuatus
Girus postsentralis
Girus temporalis superiorSulkus lateralis
Girus presentralis
Language model of Wernicke-Geswind
kanankiri
Perisylvian area Aphasia most often caused by damage of
perisylvian language, that comprises of: Broca’s area: motor programming of speech Broca
aphasia Wernicke’s area: critical for auditory comprehension of
spoken words Wernicke aphasia Arcuate fasciculus: links Broca’s and Wernicke’s areas,
important for repetition Conduction aphasia
Extra perisylvian aphasias Aphasia may also caused by lesions that
do not directly damage the perisylvian language area, but isolate them from brain regions involved in semantic processing and production of volitional speech Transcortical aphasias
Clinical evaluation Fluency Naming Repetition Auditory comprehesion
Fluency Fluent aphasias
plentiful verbal output, well articulated, easy produced utterances of relatively normal length and prosody (i.e., variation of pitch, loudness, rhythm).
Lesions: post Rolandic cortex Non Fluent aphasia:
sparse, effortful utterances of short phrase length and disrupted prosody
Lesion: pre-Rolandic cortex
Naming All aphasic patients exhibit naming
impairment, or anomia, usually in combination with other language deficits
Isolated anomia anomic aphasia
Auditory comprehension Most aphasic patients show auditory
processing defective Anterior lesions result in relatively mild
auditory comprehension impairment, whereas posterior lesions (esp. Wernicke’s area) result in significant impairment of auditory processing
Repetition Requires intact perisylvian language area Perisylvian aphasias: repetition distrubed Extra-perisylvian aphasia: preserved of
repetition
Classification of Aphasia
Broca’s AreaExecutive or motor for
production of language
Broca’s dysphasia Motor dysphasia
Nonfluent / hesitant speech Telegraphic speech Comprehension – relative
preserved Repetition – poor Handwriting- poor
Wernick’s Area–Receptive Area
Wernicke’s dysphasia Comprehension – Impaired Speech fluent but nonsensical Neologism Paraphasia – half right words Patient unaware of language
problems Repetition: relative preserved Hand writing poor
Conduction Aphasia
Speech nonsensical but fluent
Comprehension - normal Repetition - poor
Global Aphasia
Non-fluent speech Comprehension impaired Repetition - poor
Boston Aphasia ClassificationAphasia syndromes Fluency Naming Repetition Auditory
Comprehension
Broca aphasia Non-fluent - - +
Wernicke aphasia Fluent - - -
Conduction aphasia Fluent - - +
Gobal aphasia Non-fluent - - -
Transcortical motor aphasia Non-fluent - + +
Transcortical sensory aphasia Fluent - + -
Mixed transcortical aphasia Non-fluent - + -
Anomia aphasia Fluent - + +
+: relatively preserved -: relatively disturbed
Memory
Memory
Involves :1. Recognition2. Registration3. Recall – Retrieval
Anatomical basis of memory Hippocampus
The Anatomical Basis of Memory
Test of Memory1. Immediate memory2. Recent memory3. Remote memory
Disorder of Memory(Amnesia Syndrome)
1. Retrograde amnesia Impairment of memory for events that
antedate illness or injury
2. Anterograde amnesia Inability to learn new verbal or non-verbal
information from onset of illness or injury
Disorders of Memory Retrieval Senescence – AAMI (Age Associated Memory
Impairment) –retrieval of stored memory slow but accurate
Depression – disorder in motivation and concentration
Dementia – especially recent memories MCI- mild cognitive impairment amnestic type; a
pre-dementia stage
Constructional ability Capacity to draw or construct two or three
dimensional figures or shapes Task
Copying line drawing Drawing to command Reconstructing block designs
Parietal lobe dysfunction Right hemisphere produces higher inciden and severity
than the left.
Constructional Abilities
Stimulus Results
Copying Figures
Constructional Abilities
Copying Figures
Higher Cortical Function Attention Language Memory
Consists of : Manipulation of well learned material Abstract thinking Arithmatic computation etc
Basic buiding blocks for
development of higher
cortical function
1. Evaluation
1. The fund of acquired information or the store of knowlegde
• Assessed by :1. Simple verbal test of vocabulary2. General information/ knowledge3. Proverb interpretation
2. Manipulation of old knowledge
Ability to apply information to new or unfamiliar situations
Assessed by :1. Calculation2. Similarities and Differences3. Conceptual Series completion4. Social comprehension
Related cortical functions Apraxia Right-Left disorientation Acalculia Agraphia Finger Agnosia Visual agnosia Geographic disorientation
Gerstmann’s
Syndrome
APRAXIA
Loss of ability to carry out skilled movement despite adequate
understanding of task and normal motor power
Ideomotor apraxia Separation of idea of movement from execution• Dominant hemisphere lesion• Unable to carry out commands:
• Buccofacial apraxia: “Show me how to blow out a match” ; “drink through a straw” –
• Limb apraxia: “flipping a coin”, “saluting”, “kicking a ball”
• Truncal apraxia: “stand like a boxer”
Task: fail in command imitating real object
Apraxia Ideomotor
Ideational apraxia Inability to carry out a sequence of movements Higher order of complex motor planning than
ideomotor apraxia Difficulty in manipulating real object Sometimes show object agnosia: e.g. striking
candle to match box Bilateral diffuse cortex lesions especially parietal
cortexTask: “ folding a letter, placing it in an envelope, sealing
it, and placing a stamp on the envelop”
Other apraxias
3. Constructional apraxia and dressing apraxia (Non
dominant parietal disease)
4. Gait apraxia (Frontal lobe/anterior corpus callosum
disease)
5. Occulomotor apraxia (Parieto-occipital disease)
DISCONNECTION PATHWAY1. INTRAHEMISPHERIC
• Linking part of the same hemisphere
2. INTERHEMISPHERE • Corpus callosum link related parts of the two
hemisphere
Intrahemisphere Dysconnection Syndrome
Lesion of the arcuate fasciculus
Fluent dysphasia speech good comprehension,
poor repetitionBroca’s speech area
Wernicke’s speech area
CONDUCTION APHASIA
Lesion beetween the primary auditory cortex (Heschl’s gyrus) and auditory association cortex)
Impaired comprehension of spoken word, self initiated is normal
Patient seems deaf but audiometry is normal
Intrahemisphere Dysconnection Syndrome
PURE WORD DEAFNESS
No connection between the two hemisphere
Failure to name an object presented visually or by touch to the non-dominant hemisphere
INTERHEMISPHERE DISCONNECTION SYNDROME
AGENESIS OF THE CORPUS CALLOSUM
Involves the links between left and right association motor cortices
Right brachiofacial weakness and apraxia of tongue, lip and left limb movements
Premotor motor cortex Broca’s area
Interhemisphere Dysconnection Syndrome
BUCCAL LINGUAL and SYMPATHETIC APRAXIA
INTERHEMISPHERE DISCONNECTION SYNDROME
Lesion of the anterior corpus callosum
Apraxia of the left sided limb move-ment
LEFT SIDE APRAXIA
Lesion of the posterior corpus callosum and dominat occipital lobe (primary visual area)
Inability to read, to name colours, to copy writing and the ability to identify colours Inability to read letter (literal alexia) Inability to read word (verbal alexia)
INTERHEMISPHERE DISCONNECTION SYNDROME
ALEXIA WITHOUT AGRAPHIAPURE WORD BLINDNESS
Alexia without agraphia
Pure alexia Hemi alexia
