3.13.14 28 Clinical Cerebral Cortex Flashcards
What areas are associated with the primary somatosensory cortex? What manifests with lesions of these areas?
3, 1, 2
Contralateral hypesthesia and astereognosis
What area is associated with the association cortex? The secondary somatosensory cortex? What results from lesions?
5, 7
- Contralateral astereognosis
- Inability to recognize forms and body position (primarily a right hemispheric lesion)
What area is associated with the supramarginal gyrus? Why is this area important? What results from lesions?
40
- Somatosensory, auditory, and visual input
- Apraxia, aphasia, neglect (primarily a right hemispheric lesion)
What areas are associated with the superior parietal lobe?
5, 7
What area is associated with simultanagnosia, optic ataxia, and hemispatial neglect?
Posterior parietal cortex
What is simultanagnosia?
Inability to see more than one object at a time
What is optic ataxia?
Deficit in directing reach under visual guidance;
Cannot be explained by motor, somatosensory, or field deficits
What is hemispatial neglect?
Decreased awareness for the side of the body contralateral to the lesion; typically a right parietal lobe lesion, affecting the left body
What is associated with posterior parietal cortex lesions?
Simultanagnosia
Optic ataxia
Hemispatial neglect (typically in right hemisphere)
What type of lesion typifies Balint’s Syndrome?
Bilateral lesions in parieto-occipital cortex
What symptoms are characteristic of Balint’s Syndrome?
Psychic paralysis of gaze (difficulty directing gaze; pt will often move head to view objects)
Optic ataxia (difficulty reaching)
Simultanagnosia (difficulty seeing more than one object)
What areas are associated with the inferior parietal lobe?
40 (supramarginal area) and 39 (angular area)
What abilities/behaviors is the inferior area of the left parietal lobe associated with?
Language
Skilled movement
Simple math
What abilities/behaviors is the inferior area of the right parietal lobe associated with?
Spatial and non-spatial cognition
Attention/arousal
Memory
What abilities/behaviors are the superior areas of the left AND right parietal lobes associated with?
Reaching, grasping, tactile exploration
Oculomotor function
Visually-guided action
Intention to perform movements
What is the primary visual area (#)? What geniculate nucleus/body is it associated with?
Area 17
Lateral geniculate body
What is the secondary visual (visual association) area? What results from lesions to this area?
Areas 18 and 19
Visual hallucinations (uninhibited imagination)
Agnosia (can’t associate objects)
Alexia (can’t read)
What is Anton’s Syndrome? What is the cause?
aka Anton-Babinski Syndrome
Cortical blindness with denial of visual impairment (uninhibited imagination)
Bilateral damage to occipital lobes (from primary visual cortex to association cortex)
What is the area for the angular gyrus (#)? What is its importance? What is associated with damage to the angular gyrus and sub-angular optic radiations of the left hemisphere? Right hemisphere?
39
Receives heteromodal (multiple modes) input
Blends visual, tactile, spatial, and auditory input
Left: Gerstmann’s syndrome
Right: Hemi-neglect
Either: contralateral hemianopia
What is Gerstmann’s syndrome? What lesion causes it?
Agnosia (can't ID by sight) Left-Right confusion Agraphia (can't write) Acalculia (can't solve math problems) Caused by left hemisphere damage to angular gyrus (area 39)
What is apperceptive visual agnosia?
What is Associative visual agnosia?
Which is more common?
Apperceptive: rare; impairment of shape perception and ability to copy, recognize, or discriminate shapes
Associative: more common; inability to associate visual object with its meaning (can copy images, but cannot tell what they are)
What causes associative visual agnosia?
Localized damage to inferior temporal lobes and adjacent occipital cortex (inferior longitudinal fasciculus, or the ventral/”what” visual pathway)
What are the two visual pathways?
Dorsal = posterior parietal = fronto-occipital fasciculus = “where” pathway
Ventral = Inferior temporal = Inferior longitudinal fasciculus = “what” pathway
What are the two main cell types of the lateral geniculate nucleus/body?
Magno cells = large cell bodies with quick operation, but low detail
Parvo cells = small cell bodies with slow operation, but more detailed information
What are the primary auditory areas? Another name?
Receive information from which geniculate nucleus/body?
41 and 42
Located in Heschl’s gyrus
Medial geniculate nucleus
What is the auditory association cortex area? What is the result of left hemisphere lesion? Right?
22; superior temporal gyrus
Left: Wernicke’s aphasia
Right: sensory dysprosodia (inability to perceive of speech intonations, emotion)
What is the primary motor area? What is the premotor area?
4, 6
What is the supplementary motor cortex area? What is its purpose?
6
Programs complex motor sequences and bilateral movements
What is the frontal eye field area? What is its purpose?
8
Control gaze in contralateral direction
What is the are for the prefrontal cortex? What results from lesions (famous patient)?
9-12, important for working memory Impaired social behavior Decreased initiation Suck and grasp responses Incontinence Abulia (lack of will or motivation) Mutism
