Stroke Flashcards
What is a stroke
A stoke is a sudden event producing a disturbance of CNS function due to vascular disease
Also known as a cerebrovascular accident
Symptoms are for >24hrs for a stroke, <24hrs is a TIA
What are the catagories of stroke
Cerebral infarction - caused by thromboemboli
Cerebral haemorrhage
Other - dissection, venous sinus thrombosis, hypoxic brain injury
What are the two main types of cerebral haemorrhage causing a stroke and briefly describe the two
Intracerebral haemorrhage - associated with hypertensive vessel damage. May result from Charcot-Bouchard aneurysms. Produces a space occupying lesion - RICP
Subarachnoid haemorrhage - caused by rupture of a berry aneurysm. Risk increased if male, hypertensive, atheromatous. Can be fatal due to cerebral vasospasm of arteries in the circle of Willis
What are the main causes of a cerebral infarction stroke
Embolism from heart, atheromatous debris, thrombus over ruptured atheromatous plaque, aneurym (causes a thrombus)
Thrombus - over atheromatous plaque
What are the symptoms seen in an anterior cerebral artery infarct
Unilateral contralateral weakness in legs
Unilateral contralateral paraesthesia in legs
Urinary incontinence - paracentral lobes on medial surface of hemispheres
Apraxia - inability to complete motor planning
Dysarthria - ischaemia of premotor cortex
Corpus callosum involvement causes complex syndromes
What are the symptoms of a middle cerebral artery infarct
Contralateral hemiparesis of rest of homunculus - homunculus not supplied by ACA
Contralateral hemisensory of rest of homunculus
Hemianopia - usually homonymous without macular sparing
Aphasia - occurs with dominant hemispehre infarction
Hemispatial neglect - non-dominant hemisphere infarction
How do the symptoms of a middle cerebral artery infarct change depending on where the infarct is in the artery
Proximal infarction will affect MCA territory and internal capsule thorugh lenitculostriate arteries so have full hemiparesis. Also affects all optic tract causing contralateral homonymous hemianopia
Distal infarction spares internal capsule so no full hemiparesis. Distal occlusion may only affect part of optic radiations causing contalateral quadrantanopia
Superior division of MCA - Broca’s aphasia
Inferior division of MCA - Wernicke’s aphasia
What does an occlusion of a lenticulostriate artery cause and what structures does it affect
Occlusion of lenticulostriate arteries causes subcortical stroke
Affects internal capsule +/- basal ganglia
Spares the cortex
What are the symptoms of a posterior cerebral artery infarct
Contralateral homonymous hemianopia with macular sparing
Contralateral sensory loss as thalamus invovled
What are the symptoms of a cerebellar infarct
Non-specific symptoms - nausea, vomiting, headache, dizziness
Ipsilateral cerebellar signs - dysdiadochokinesia, ataxia, nystagmus, intention tremour, slurred speech (dysarthria), hypotonia
Ipsilateral brainstem signs
What are the symptoms of a brainstem infarct
Crossed deficits - are due to contralateral ascending and descending tracts
Have motor deficit on one side and sensory on the other
What are the two syndromes seen with a basilar artery infarct
Top of the basilar syndrome - if infarct in distal basilar artery
Locked in syndrome - if infarct in proximal basilar artery
What are the symptoms of top of the basilar syndrome
Visual and oculomotor defects
Behavioural abnormalities
Somnolence, hallucinations, dreamlike behaviour
What are the symptoms of locked in syndrome
Complete loss of movement
Preserved consciousness
Preserved ocular movement
What are the catagories in the Bramford/Oxford classification of strokes
Total anterior circulation stokre
Partial anterior circulation stroke
Posterior circulation stroke
Lacunar syndrome
