what is a stroke?
ACUTE onset of focal neurological symptoms and signs due to DISRUPTION OF BLOOD SUPPLY
= end organ complication of poor vascular health
what are the 2 types of stroke?
1) haemorrhagic
2) ischaemic
what happens haemorrhagic stroke?
= when bleeding occurs in inside or around brain tissue
what happens in ischaemic stroke?
= a clot blocks blood flow to an area of the brain
what type of blood pressure causes haemorrhagic shock?
raised high blood pressure
= HYPERTENSION
what does a haemorrhagic shock to the vessel walls?
= weakening and rupturing blood vessel walls
in haemorrhagic shock, what causes the weakened blood vessels?
what 3 things happen in ischaemic stroke?
1) thrombotic
2) embolic
3) hypo perfusion
what is a thrombosis, in iscahemic stroke?
= clot blocking the artery AT SITE OF OCCLUSION
what is an embolic, in iscahemic stroke?
= clot blocking artery that has TRAVELLED to an artery to occlude from somewhere more proximal in the arteries of the heart
what causes hypo perfusion in ischaemic stroke?
= due to reduced flow of blood due to stenosed artery rather than occlusion of artery
what are the 3 components that encompass thrombosis?
1) endothelial injury
2) circulatory stasis
3) hyper-coagulable state
what is the mechanism of athero- thrombotic stroke?
1) atherogenesis
2) plaque
3) platelet aggregation
4) thrombosis
5) ischaemia
what 2 things can happen between plaque and platelet aggregation?
1) plaque rupture
2) vessel stenosis
what does vessel stenosis cause?
causes low blood flow
what are the non-modifiable risk factors for stroke?
what are the modifiable risk factors for stroke?
how can improvement in hypertension improve stroke?
= a 10mm reduction in systolic BP reduces risk of CV events
- isolated systolic hypertension canincrease stroke risk
how can smoking affect stroke?
= doubles risk of ishaemic stroke
when should statins be used?
NOT RECOMENDED in haemorrhagic stroke
what are the 3 essential questions to ask yourself when investigating a stroke?
1) is this a stroke?
2) what kind of stroke is it?
3) what has caused this?
what is a stroke mimic?
= conditions that present acutely with focal neurological signs but aren’t due to interrupted blood flow
give examples of what might be the causes of stroke mimics?
what is the only way to differentiate between ischaemic and hemorrhagic stroke?
= imaging