Telencephalon- clinical cerebral cortex Flashcards
agranular layer is in which gyrys?
post central gyrus
which gyrus is the granular layer?
precentral
which cortical projection does interhemispheric connections?
commissural
what does the anterior commissure connect? what does the corpus callosum connect?
ant commissure connects middle and inferior temporal gyri
CC connects about everything else
which cortical projection connects intracortical areas?
association- uncinate, arcuate, superior longitudinal, inf longitudinal, cingulum
which cortical projection descends to subcortical regions?
projection
a lesion in the commissural pathways would manifest in a deficit in the…
homologous region in the opposite hemisphere
infarct vs penumbra
penumbra is potential site for spread of infarction, but not yet irreversibly damaged
deficits associated with left hemisphere damage
right sided sensory and motor deficit, aphasia, alexia, gerstmann’s syndrome, tactile agnosia, apraxia (movement deficit), verbal memory impairment, executive reasoning
deficits associated with right hemisphere damage
elft sided sensory and motor deficits, arousal, orientation, awareness deficits, neglect of left space, constructional and dressing apraxia, aprosodia
each hemisphere’s spatial awareness capabilities
LH- only right spatial awareness
RH- left and right spatial awareness (so loss of RH could still have right spatial awareness)
what is alexia without agraphia? what location would the lesions be in? what artery could be blocked?
unable to read written info, even if they write it themselves. damage to visual cortex in the left hemisphere and the splenium of the corpus callosum
-left posterior cerebral artery supplies these
the somatosensory areas of the brain. what are the primary sensations that are processed here?
areas 3, 1, 2; touch, proprioception; stimulation produces tingling, numbness
damage to the somatosensory areas causes..
contralateral hyperesthesia
astereognosis
the somatosensory association cortices
superior parietal areas 5 and 7 (input from 3, 1, 2 and visual area 7)
supramarginal gyrus area 40 (sensory, auditory, and visual input)
damage to superior parietal association results in
contralateral loss of tactile discrimination (astereognosis) and inability to recognize forms and body position
damage to supramarginal gyrus results in
apraxia, aphasia, spatial neglect
inability to see more than 1 object at a time (usually bilateral damage)
simultanagnosia
deficit in reaching under visual guidance that cannot be explained by motor, sensory, visual field defects
optic ataxia
decreased awareness for the side of the body or objects in space located contralateral to brain injury// what location is commonly damaged and causes this?
hemispatial neglect
right parietal lobe
what location of lesion is visual agnosia more commonly associated with?
inferior temporal lobe and adjacent visual cortex
*components of Balint’s syndrome
psychic paralysis of gaze with haphazard scanning
optic ataxia
simultanagnosia
what causes Balint’s syndrome?
bilateral lesions in parieto-occipital cortex due to stroke, trauma, or degenerative disease
presentation of hemispatial neglect
eyes and head deviate ipsilaterally
eat food on left side of plate, fail to dress left side of body, fail to acknowledge people on the left
tests for diagnosing hemispatial neglect
line bisection, line cancellation
right posterior parietal cortex lesion results in unilateral visual neglect of what side?
left side (neglect is frequently the result of damage to the right hemisphere!)
functions of the inferior areas of the left hemisphere parietal lobe
language, skilled movement, simple math
fucntions of the right side inferior parietal lobe
spatial and non-spatial cognition, attention, memory
superior areas of parietal lobe on both sides mediates..
reaching, grasping, tactile exploration, oculomotor function, visually guided action and intentions to perform movemnts
primary and secondary visual areas
primary- 17
secondary-18, 19
destruction of area 17 results in…. destruction of areas 18 and 19 results in…..
17-visual field defects
18,19- hallucinations, agnosia, alexia
describe Anton’s syndrome/ what typically causes it
form of cortical blindness in which px denies visual impairment
confabulation is common
caused by bilateral damage to occipital lobe extending from primary visual cortex to association cortex
gyrus for visual association; where do inputs come from?; what does damage result in?
angular gyrus area 39
receives heteromodal input
optic radiation damage results in contralateral hemianopia
left hemisphere destruction of angular gyrus (visual association) is associated with this syndrome
Gerstmann’s syndrome
right hemisphere destruction of angular gyrus (visual association) is associated with this deficit
hemi-neglect
4 symptoms of gerstmann’s syndrome
agnosia (cant ID things), left-right confusion, agraphia, acalculia
may or may not have visual field defects
a deficit in visual object recognition
visual agnosia
rare inability to copy, recognize, or discriminate shapes
apperceptive visual agnosia
more common- has shape perception and can draw objects but can’t associate the visual object with its meaning; can’t name objects or show recognition b y pointing
associate visual agnosia
location of lesion that usually causes associative visual agnosia
inferior temporal lobes
which plays bigger role in spatial processing and spatially directed movements: occipital cortex or superior partietal lobes?
superior parietal lobes
what and where pathways: which is dorsal and goes to posterior parietal lobe? which is ventral and goes to inferior temporal lobe?
where goes to posterior parietal
what goes to inferior temporal
difference between magno and parvocellular pathways/location?
magno cells have large bodies- operates quickly
parvo cells have small bodies- operate slowly with more details
LGN
auditory areas/what gyrus? input?
41, 42; heschl’s gyrus; input from MGN; destruction results in partial deafness
association cortex area? location? destruction of LH vs RH?
association cortex is area 22 in posterior superior temporal gyrus
LH damage results in Wernicke’s aphasia
RH damage results in sensory dysprosodia
motor areas and their locations
primary- area 4 (precentral gyrus) - hemiparesis
premotor- area 6; precentral gyrus - apraxia, dystonia
prefrontal cortex damage results in
impaired social behavior, decreased initiation, suck and grasp responses, incontinence, abulia, mutism
