Stroke Flashcards
Stroke definition
Acute, focal, neurological deficit of cerebrovascular origin that persists >24h
Transient ischaemic attack definition
Acute, focal neurological deficit of cerebrovascular origin that persists <1h
MRI: no signs of cerebral infarction
High risk of stroke within 4w of a TIA
Amaurosis fugax definition
Sudden transient loss of vision in one eye
Often occurs with TIAs
Can be 1st clinical sign of inferior cerebral artery stenosis
Can occur due to ocular disease, migraine
Irreversible risk factors for ischaemic stroke
Age
Personal/family history
Hyper-coagulable states
AF
Reversible risk factors for ischaemic stroke
Hypertension Hypercholesterolaemia DM Smoking Alcohol Poor diet Low exercise Increased weight Endocarditis Migraine Polycythaemia APL syndrome Vasculitis Amyloidosis
Risk factors for haemorrhagic stroke
Family history Uncontrolled hypertension Vascular abnormalities: aneurysms, atriovenous malformation, hereditary haemorrhagic telangiectasia Coagulopathies/anticoagulant therapy Recent heavy alcohol intake
Types of cerebral ischaemia
Regional infarction: thrombosis/embolus in large vessels, usually cortical areas
Lacunar infarction: microinfarcts caused by arteriosclerosis, ususally sub-cortical, can be asymptomatic –> pseudoparkinsonism/vascular dementia
Global ischaemia: infarcts at arterial boundary zones due to severe hypotension (watershed infarct)
Severe: cortical laminar necrosis in 24h = vegetative state
Zones of cerebral ischaemic damage
Infarct core: tissue almost certain to die
Oligaemic periphery: tissue that will survive due to collateral supply
Ischaemic pneumbra: tissue in between
Clinical features of ischaemic stroke
Contralateral limb weakness/hemiplegia: first flaccid, then hyperreflexia, weakness recovers gradually over weeks/months Facial weakness Higher dysfunction Visual disturbances Epileptic fit (rare)
Higher dysfunction in ischaemic stroke
Expressive aphasia: Broca’s
Receptive aphasia: Wernicke’s
Apraxia: difficulty performing tasks despite intact motor function
Asterognosis: inability to recognise objects, persons, sounds, shapes or smells despite senses/memory being intact
Inattention: inability to attend to stimuli despite intact senses
Subarachnoid haemorrhage clinical presentation
‘Thunderclap headache’: comes on in seconds, high intensity, often occipital, during transient hypertension
Vomiting: post-headache
Photophobia
Increasing drowsiness/coma
Focal signs: may help locate lesion, may reflect raised ICP / cerebral vasospasm
Neck stiffness
Kernig’s sign +ve
Papilloedema: + retinal haemorrhages
Prior ‘sentinel headache’: small warning leak from offending aneurysm
Subarachnoid haemorrhage predisposing abnormalities
Berry aneurysm (70%) Arteriovenous malformations (AVM - 10%) No lesion found (20%)
Berry aneurysm locations
Developmental (not congenital)
In circle of Willis and adjacent arteries…
Anterior communicating artery (most common)
Posterior communicating artery: at bifurcation from inferior cerebral artery
Middle cerebral artery: at bi/trifurcation
Berry aneurysm risk factors
Polycystic kidney disease Family history Smoking Hypertension Ehlers-Danlos/Marfans
Arteriovenous malformation pathology
Congenital collection of abnormal arteries/veins
10% rebleed annually
Can cause focal epilepsy
