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STROKE - Coggle Diagram
STROKE
ischaemic stroke
embolic stroke
plaque/clot forming outside skull and travelling to brain to occlude artery i.e. coagulopathy involved
larger infarct size
multiple simultaneous lesions within ≥1 vascular territories
cortical
(can only be embolic)
lacunar stroke
occlusion of small penetrating artery
small infarct size
only 1 lesion associated with single clinical event
if multiple events occur, can become confluent
deep white matter
most common
often asymptomatic (so minority of clinical)
haemodynamic stroke
intracranial haemorrhage
intracerebral
presents like ischaemic stroke
acute intracerebral haemorrhages bright in imaging
located in
basal ganglia
if large enough it can enter ventricle (poor prognosis)
microhaemorrhages
if located in basal ganglia, due to HT
if lobar location, most likely amyloid angiopathy
susceptibility-weighted MRI (dark spots)
subarachnoid
usually caused by rupture of cerebral artery aneurysm
extends into SAS, covering brain
subdural
usually caused by tears in bridging emissary veins
recurrent falls/head injury
located mainly along superior sagittal sinus
in FLARE MRI, crescent-shaped hyperintensity
very young or old
epidural
usually caused by skull fractures/traumatic head injury
damage to middle meningeal artery
on MRI, presents as D-shaped highly localised haemorrhage pressing on brain
sinus vein thrombosis
obstruction of venous outflow from brain
rare
usually in young females
risk factors
non-modifiable: age, male, Fhx
modifiable: HT, sedentary/obese, diabetes, high cholesterol, alcohol, AF, dissection, migraine with aura (in combination with OCP), Moyamoya disease (proximal occlusion of IC/MCA)
DDx: seizure, toxic, hypoglycaemia, sepsis, syncope, delirium, vestibular dysfunction, peripheral/cranial nerve lesion, migraine
clinical signs
acute onset weakness/numbness (most common)
ACA stroke - legs more affected
MCA strokes - arms more affected
Visual symptoms
monocular vision loss
caused by occlusion of opthalmic artery
if transient, called amaurosis fugax
hemianopia
homonymous hemianopia if stroke affects post-chiasm
mostly caused by PCA stroke (possibly MCA)
diplopia
eyes no longer synchronised
mostly caused by brainstem stroke
brainstem stroke also causes dysarthria, weakness, sensory deficits
Wallenberg syndrome
(dorsolateral medulla)
caused by PICA stroke
ipsilateral Horner syndrome
diplopia
ipsilateral ataxia
nystagmus
dysphagia/dysphonia and dysarthria
constricted pupil
contralateral dissociated sensory deficit (position/temp)
vertigo
Horner syndrome
most commonly caused by carotid artery dissection (common in young people)
loss of sympathetic innervation (damage to plexus on IC)
partial ptosis
miosis (constricted pupil)
enophthalmos
anhidrosis
vertigo
caused by inner ear or vestibular dysfunction usually, but also BPPV, migraine, labyrinthitis, Meiner's disease, stroke
Hallpike test
aphasia
non-fluent aphasia
understanding intact but incoherent sentences
Brocas's area affected
fluent aphasia
speech sounds normal but understanding affected
Wernicke's area affected
Imaging
non-contrast CT, CT-angiogram (CT-A), CT-perfusion (CT-P)
CTs good for detecting haemorrhages but not at identifying stroke in first few hours
identify penumbra (likely to be infarcted but salvageable)
Management
rTPA (recombinant tissue plasminogen activator) i.e. thrombolysis
binds to plasminogen at lysine binding site to cause fibrinolysis
benefit only ≤4.5 hours after onset
ineffective at dissolving large clots or may not be able to reach if vessel is occluded
stent clot retrieval
effective for large vessel stroke