10.1 Stroke Flashcards
define stroke
serious life threatening condition occurring when blood supply to brain is cut off, signs and symptoms last more than 24 hours
emergency management of stroke
-CT/MRI to see if there’s a bleed
-if no bleed, and within 4 hours = thrombolysis
explain why ACA infarct could lead to urinary incontinence
ACA supplies paracentral lobules of motor and sensory cortices, which supply perineal area.
so less of control
explain why ACA infarct could lead to apraxia
ACA supplies left frontal lobe, so leads to ineffective motor planning
what type of motor loss is seen in proximal MCA infarct?
contralateral full hemiparesis, as internal capsule fibres mixed to leg, arm and fa ce
what type of visual loss is seen in proximal MCA infarct? why?
contralateral homonymous hemianopia without macular sparing, as both inferior and superior optic radiations (temporal and parietal lobes) destroyed
what type of visual loss is seen in distal MCA infarct? why?
quadranatopia, as maybe only superior OR inferior optic radiations affected
how to distinguish lenticulostriate infarct from others
no cortical features e.g. neglect, aphasia
types of lacunar strokes
pure motor
-IC motor fibres affected
pure sensory
-IC sensory fibres affected
sensorimotor
-boundary between motor and sensory fibres IC
features of distal MCA stroke, superior division
lateral frontal lobe affected
-contralateral face, arm weakness, expressive (Broca’s) aphasia if L
features of distal MCA stroke, inferior division
lateral parietal lobe, superior temporal
-contrlateral sensory change face, arm
-receptive (wernicke’s) aphasia if L
-contralateral homonymous hemianopia without macular sparing
PCA stroke features
-contralateral homonymous hemianopia with macular sparing (collateral supply from MCA)
-contralateral sensory loss due to thalamus damage
cerebellar infarct features
-ipsilateral cerebella signs: DANISH
-ipsilateral CN signs
-ipsilateral Horner’s
why does cerebellar infarct cause ipsilateral Horner’s?
sympathetic pathways descend in brainstem to spinal cord, and cerebellar arteries normally supply brainstem as they loop round cerebellum
features of distal basilar artery occlusion
-visual and cocculomotor deficits
-behavioural abnormalities
-somnolencde, hallucinations, dreamlike (as brainstem contains reticular activating system importune for consciousness)
why is motor function often OK in distal (superior) basilar artery occlusion)?
cerebral peduncles can et blood from PCAs in turn from posterior communicating arteries
features of proximal basilar artery occlusion
locked in syndrome
bilateral pontine branches occluded
-eyes move OK as midbrain supply from PCAs
-preserved consciousness as midbrain reticular formation intact
Total Anterior Circulation Syndrome
hemiparesis+
higher cortical dysfunction+
homonymous hemianopia
Partial Anterior Circulation Syndrome
hemiparesis+
homonymous hemianopia
OR
higher cortical dysfunction
POsterior Circualtion Syndrome
isolated hemianopia
or
cerebellar syndromes
what type of stroke is basilar artery occlusion?
POCS
what type of stroke is brainstem stroke?
POCS
what type of stroke is cerebellar infarct?
POCS
what type of stroke is PCA infarct?
POCS
