9/26 Stroke Syndromes - Glendinning Flashcards
stroke/CVA
cerebrovascular accident
focal neurological deficit of vascular origin due to abrupt incidence of vascular insufficiency and/or bleeding in regions in/immediately adjacent to brain
in US, 87% ischemic, 10% hemorrhagic, 3% subarachnoid hemorrhagic
predicted deficits in diff regions of cortex:
- motor cortex
- somatosensory cortex
- frontal eye fields
- primary visual cortex
- primary auditory cortex
- Broca’s area (dominant)
- Wernicke’s area (dominant)
- parietal association cortex (R)
motor cortex: contralateral hemiparesis
somatosensory cortex: contralat sensory loss or “cortical sensory” loss (graphesthesia, sterognosis)
frontal eye fields; paralysis of contralat horizontal gaze
primary visual cortex: contralat homonymous hemianopsia
primary auditory cortex: diminished localization of auditory inputs
Broca’s area (dominant, L): motor aphasia
Wernicke’s area (dominant, L): sensory aphasia
R parietal association cortex: contralat hemineglect
Frontal Association Cortex signs
perseveration: getting stuck when asked to view a changing pattern
impersistence: loss of sustained movement (sticking out tongue, holding up arms)
frontal release signs: grasp, root, suck, snouth
Gegenhalten: increased voluntary tone
personality changes
- disinhibition → orbitofrontal lesion
- abulia (loss of motivation/action) → dorsolateral convexity
mood changes:
- left → depression
- right → manic
magnetic gait: shuffling
incontinence (with bilateral medial lesions)
circulation terminology
ant vs post
Circle of Willis
anterior circulation arises from internal carotid artery
- MCA
- ACA
posterior circulation arises from vertebral artery
- PCA
Circle of Willis references the circular formation of interconnected PCA/int carotid/MCA/ACA arteries via anterior and posterior communicating arteries
- gives potential for recovery in cases where proximal artery is blocked
anterior cerebral artery
mainly supplies:
- medial portion of frontal lobe
- medial portion of parietal lobe
- ventral basal ganglia (near point of entry into brain)
cortical areas supplied:
- medial portions of frontal lobe and anterior parietal lobe → lower limb motor/sensory portions
ACA stroke
expected issues
left-sided ACA strokes?
right-sided ACA strokes?
hits medial frontal/parietal lobe (pre and post central gyri)
- contralateral hemiparesis
- contralateral sensory deficit
- LEGS > arms in both
possibilities:
- L ACA stroke: transcortical motor aphasia
- R ACA stroke: hemineglect
deep branches of ACA
what do they supply?
what is the effect of a stroke in these branches?
recurrent arteries of Heubner
supply:
- anterior limb of internal capsule (frontopontine and caudate-putamen)
- head of caudate nucleus
strokes in ACA branches dont usually produce specific deficits
why? collateral circ! MCA branches and Circle of Willis handle it
middle cerebral artery
largest cerebral artery, most prone to strokes
- travels to lateral cortex with several branches supplying subcortical regions
deficits depend on portion of artery occluded!
- base: stem aka M1
- gives off lenticulostriate aa. perfusing basal ganglia and internal capsule
- continues onward to insula/operculum
- MCA superior div
- MCA inferior div
lenticulostriate arteries
deep penetrating branches off M1 of MCA supplying basal ganglia, internal capsule
- prone to narrowing, esp in patients with longstanding HTN
- common site of lacunar infarct → contralateral hemiplegia (“pure motor”), poss basal ganglia signs
- can also see “pure sensory” or “motor/sensory deficits”
deficits
- L MCA deep territory: right pure motor hemiparesis of UMN
- R MCA deep territory: left pure motor hemiparesis of UMN
superior and inferior divisions of MCA
what do they serve?
what functions are represented?
superior → region anterior to central sulcus
- motor to contralateral body (upper > lower) and face
- horizontal gaze to opposite side (FEF)
- L side: speech motor (Broca’s aphasia)
- R side: attention
inferior → region posterior to central sulcus & temporal regions
- sensory to contralateral body (upper > lower)
- visual field projections (optic radiations)
- L side: speech sensory (Wernicke’s aphasia)
- R side: attention
MCA stroke in the STEM
end up hitting everything
- severe sensorimotor deficit in contralateral body (pre-, post-central gyri, internal capsule)
- transient paralysis of horizontal gaze to opposite side → gaze preference to side of lesion!
- L sided? global aphasia (speech areas)
- R sided? overall neglect (parietal assoc cortex)
- visual field deficits (visual projections)
*confusion from temporal lobe damage can occur
MCA strokes and aphasias
superior branch of MCA → Broca’s aphasia
- no repetition
- comprehension
- disfluent speech
inferior branch of MCA → Wernicke’s aphasia
- no repetition
- no comprehension
- fluent speech
stem of MCA → global aphasia
- no rep
- no comprehension
- disfluent aphasia
cortical vs subcortical lesions
LOOK for CORTICAL DEFICITS
- visual
- higher cortical
- oculomotor
- language
- apraxia
“pure motor” hemiparesis? prob lesion in internal capsule, ventral pons, cerebral crus
+ associated cortical signs? lesion in cortex!
anterior choroidal artery
anterior choroidal artery syndrome
deep branch from internal carotid
- ICA gives off MCA, ACA, and…
- ophthalmic a → eye
- anterior choroidal artery → optic tract and internal capsule below optic tract
syndrome:
- contralat homonymous hemianopsia (optic tract), no macular sparing
- contralat hemiplegia: “pure motor” hemiparesis (post limb of int capsule)
- contralat hemianasthesia possible
- possible basal ganglia signs
posterior cerebral artery
- supplies: midbrain, thalamus, medial temporal, medial occipital lobe
- cortical supply: mainly medial surface, also incl temporal/occipital/parietal regions
deficits:
- damage to primary visual area → contralateral homonymous hemianopsia
- L side: transcortical sensory aphasia
- repetition/fluency intact, but comprehension problem (like Wernicke’s except rep intact)
MCA-ACA watershed infarcts
“man in a barrel” syndrome
- sensory and motor loss of proximal upper limbs
- LITTLE EFFECT on legs
transcortical motor aphasia
- nonfluent
- comprehension
- repetition
