CVA - 2b Stroke Syndromes Flashcards
what are common presentations seen specific to a posterior circulation stroke
deficits in:
- balance
- brainstem w CNs (funky eye movements, n/v, vertigo)
what is the path of the homunculus from the cerebral cortex
down corticospinal tract -> internal capsule -> midbrain and pons and down SC
what structures does ACA specifically supply
med and ant portion of cerebral hemispheres (frontal and parietal)
subcortical structures:
- basal ganglia (ant internal capsule, inferior caudate nucleus)
- ant corpus callosum
what role does the basal ganglia play in deficits seen in ACA
motor apraxia
- impaired initiation of movement via BG
what is the significance of the ant communicating artery in ACA syndrome
more collateral blood flow
most common clinical features to ACA syndrome
contra hemiplegia and hemisensory loss LE>UE
parietal cortex = apraxia
prefrontal = abulia
supplemental motor area = expressive aphasia (in L ACA - broca’s aphasia)
what is abulia? how do we treat this?
no motor drive
- even if have motor and sensory capacity, no will to initiate movement –> poorer outcomes
flat affect
benefit from a neuropsych eval -> use pharm to improve initiation
what is apraxia
problems w motor planning and executing purposeful movements (sequencing problem)
- not attributable to motor, sensory, or peripheral issues
damage to what structures typically lead to apraxia
L hemisphere brain damage
- parietal
- BG
- premotor frontal cortex
how does damage to parietal, BG, premotor frontal cortex structures lead to apraxia
defect in pathways that contain memory of learned patterns of movement
- pts can’t retrieve models of stored, skilled movements
what is a differential dx for apraxia and what can help w this
abulia
- neuropsych consult can help us differientiate
what are 3 types of apraxia and what are the main 2
- ideomotor **
- ideational **
- constructional
damage to what structure often results in ideomotor apraxia
L parietal
what is ideomotor apraxia
unable to imitate movements or produce movement on verbal command
- but can move automatically w habitual movements
damage to what structure results in ideational apraxia
L > R parietal
what is ideational apraxia
unable to produce movement either on command or automatically
how will someone w ideational apraxia often present outside the apraxia
usually very fidgety w things
- not sure what to do w things
what structure results in constructional apraxia
R > L parietal
what is constructional apraxia
inability to draw pictures or construct simple configurations
ex: draw a clock, assemble something
what artery is the most common site of occlusion
MCA
what type of stroke syndrome are we most likely to see and treat
MCA
- most common site of occlusion
- low mortality rate
what specific structures does the MCA supply
entire lateral aspect of cerebral hemisphere - frontal, temporal, and parietal
subcortical structures:
- post internal capsule
- globus pallidus
- caudate nucleus
- putamen
aka basal ganglia
why are worse outcomes associated w a proximal occlusion of MCA vs distal
inc edema and less collaterals available
why do you see global aphasia w MCA and not ACA
MCA feeds Wernicke and Broca’s areas
- get both expressive and receptive aphasias