Brain. Cerebral white matter. Brain cortex. Frontal lobe. Frontal lobe Brain cortex

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1 Brain Brain cortex Layer (stratum) of grey matter which cover hemisphers Longitudinal fissure - 2 hemispheres Enlargement of neocortex folding the brain surface into convolutions (gyri) separated by groves sulci, fissures. Cerebral white matter Projection fibers Efferent Afferent Association fibers Commisural fibers corpus callosum Brain cortex From the functional point of view, cortex is divided to: Primary cortical fields Unimodal Association areas Multimodal Association areas Frontal lobe Froma parietal lobe sulcus centralis Rolandi 3 horizontal gyri frontal superior gyrus frontal medial gyrus frontal inferior gyrus 1 vertical gyrus precentral gyrus Frontal lobe 1

2 Temporal lobe Temporal lobe From parietal lobe Sylvia s fissura 3 horizontal gyri temporal superior gyrus temporal middle gyrus temporal inferior gyrus On the inner part - temporal transversal gyri, Heschl gyrus Parietal lobe Parietal lobe From occipital lobe parietooccipital fissura Postcentral gyrus - vertical Posterior part (interparietal sulcus) lobulus parietal superior and inferior, which is divided to supramarginal gyrus and angular gyrus Occipital lobe Occipital lobe Behind the parietooccipital fissura On the medial side fissura calcarina 2

3 The basic functional unit is analyser which consists from Periferal perception apparatus Neuronal pathways Perception neurons in brain cortex Each perception apparatus has in brain cortex projection nucleus of analyser Cortical parts are overlaping for analysis and syntesis of impulses In cortical part of each analyser area cortical projection area projection areas Motor projection area for muscles of contralateral part of the body precentral gyrus projection areas Area for movements of the eyes in front of precentral gyrus postreior part of middle frontal lobe (area 8) - irritation movement of the eyes on the contralateral side Center for involuntary movements occipital lobe projection areas Somatosensory projection area endings of somatosensory pathways postcentral gyrus Visual projection area in the inner part of fissura calcarina of occipital lobe Auditory projection area in Heschl s transversal gyrus of temporal lobe 3

4 projection areas Vestibular projection area in temporal medial gyrus Projection area for smell in uncus gyri hippocampi the basis of temporal lobe Projection area for taste posterior part of inzula near the projection area of tongue mental and cognitive functions which are located in specific brain regions. in expressive part expression by speech and writing in perceptive part understanding of speech and reading Projection areas for hearing, smell, taste have bilateral connections The most of them are connected with dominant hemisphere They include also gnosia and praxia Praxia higher form of motor function - dominant hemisphere Gnosia analysis and syntesis in the region of somatosensory analysers, we can recognize the things arround us Gnosia Stereognosia recognize subjects by touch Auditory gnosia recognise objects by sounds Visual gnosia - recognize according look, ability to read Gnosia of smell and taste Non-fluent (Expressive or motor) aphasia expression in speech is affected, while understanding of speech is preserved Frontalis inferior gyrus dominant h. Non-fluency the reduced rate of word production Perseveration repeating of words Amnestic aphasia unable to recall the words Agrammatism - faults of speech are grammatical Fluent (Sensory or perceptive) aphasia unability to understand the speech, unability to recognize words leads to a disorder of both comprehension and expression of meaning by spoken words Temporalis superior gyrus dom. h. Speech is fluent patient does not know his faults, logorrhoe 4

5 Patient does not understand his own speech he is talking nonsense jargon aphasia Paraphasia patient use the words in other sense (meaning) Agraphia unability to write, moving with write upper extremity is possible Praxia Frontal medial gyrus dom. h. Pure agraphia is very rare, usually is with expressive aphasia Broca s aphasia Alexia unability to read, to recognize words, letters, colors Angular gyrus dom. h. (between visual and auditory analysers) Splenium corporis callosi connection of visual centres Visual agnosia unability to recognize objects which sb. clearly sees bilateral lesion Parieto - occipital lobe left hemisphere Subjects identify objects by touch Avoid obstacles, but objects does not recognize 5

6 Visual agnosia space agnosia patientt does not recognize the space its left part if the lesion is in the right hemisfere + P lobe Acalculia unability to realise basic calculation Amusia upper temporal gyrus Astereognosia unability recognise objects by touch Parietal lobe Not in dominant hemisphere Autotopagnosia failure to recognize part of the body Gerstmann s sy angular gyrus dom.h. Agnosia of fingers to select fingers Failure to discriminate between right and left Agraphia Acalculia Anosognosia the patient dose not percieve his own defect Right parietal lobe left side lesion Apraxia inability to carry out a purposive movement the nature of which patient understands Ideativ (sensoric) apraxia Ideomotoric (motoric) apraxia Senzoric apraxia lesion of gnostic part (visual, touching) Parietal lobe, supramarginal gyrus The patient does not know what to do with object Motoric apraxia Frontal lobe near precentral gyrus The patient does not know realise the movement, he knows function of it Prefrontal syndrom In front of precentral gyrus Psychical problems decreased of spontaneity and iniciation apathy, sleeping, coma frontale euphoria, joking gatizm loos the social behavour 6

7 Prefrontal syndrom Frontal ataxia - astazia and abazia lesion of frontopontocerebellar pathways Deliberation grasoing reflex saccing reflex Rolandic syndromes Motoric rolandic syndrom - precentral gyrus - kontralateral central monoplegia - crural, brachial, facial - diplegia spastica - parasagital proces - kontralateral signs of iritation - seizures of tonic clonic convlusions - facial,brachial, crural type (Jackson motoric epilepsy) Rolandic syndromes Retrorolandic syndrom - postcentral gyrus - iritative signs - paresthesia kontralateral (Jackson sensitive epilepsy ) - hypofunction - kontralateral hypesthesia or anesthesia - crural, brachial type problem with epikritic sensitivity Parietal syndromes Symbolic disturbances astereognosia autotopagnosia anozognosia senzoric apraxia Temporal syndromes Symbolic defects - senzoric aphasia, amusia Psychical defects - dreamy states, paroxysmal (defect of putting experience to the memory) illusion de ja vu, de j aime vu Temporal syndromes Uncinat crisis - smell, taste pseudohalucination iritation of uncus gyri hippocampi Auditory disturbances auditory pseudohalucination Vestibular defects - subjective dizziness Visual defects - kvadrant kontralateral hemianopsy 7

8 Occipital syndromes Iritation signs blinking fosfens, scotoma scintilans, visual pseudohalucination Hypofunction defects skotoms fissura calcarina - homonymous hemianopia global, kvadrant - Cortical blindness lesion of all projection area bilateral Visual agnosia Disconnection syndromes Interruption of corpus callosum Incapacity to transfer visual or tactile information or information concerning language from one hemisphere to the other Patient does not give name to object which was recognized by sesnse with representation in right hemisphere Recognize object by left hand, does not know to give him name Sensitivity LUE representation in right hemisphere Representation of speech in left hemisphere Subjects recognized by RUE possible to give names 8