Stroke Flashcards
What is the definition of a stroke?
Acute onset of focal neurological symptoms and signs due to disruption of blood supply.
What are the 2 types of stroke?
Haemorrhagic (15-20%) - bleeding occurs inside or around brain tissue.
Ischaemic (80-85%) - a clot blocks blood flow to an area of the brain.
What is the pathogenesis of haemorrhagic stroke?
Raised blood pressure, weakened blood vessel wall due to structural abnormalities like aneurysm, arteriovenous malformation (AVM) or inflammation of the vessel wall (vasculitis).
What are the 3 types of ischaemic stroke?
Thrombotic - clot blocking artery at the site of occlusion.
Embolic - clot blocking artery has travelled to artery it occludes from somewhere more proximal in the arteries or the heart.
Hypoperfusion - due to reduced blood flow due to stenosed artery rather than occlusion of artery.
What type of stroke is statin therapy recommended in?
Ischaemic.
Give some examples of the rarer causes of stroke (especially in young patients).
Homocysteinemia; vascultiis, antiphospholipid antibody syndrome; protein S, C and antithrombin III deficiency; paradoxical embolism (venous clot to arterial side) through patent foramen ovale or pulmonary AV shunts
Many more
What are stroke mimics?
Hypoglycaemia, seizure (posticatal states), migrane, hyperglycaemia, hyponatrema, space occupying lesions like brain tumours, functional hemiparesis (weakness affecting one side of body).
What is the only way to differentiate between ischaemic and haemorrhagic stroke?
Brain imaging.
Give some examples of brain imaging.
Brain CT with angiography, MRI with DWI (diffusion weighted imaging) and angiography, MRI with SWI (susceptibility weighted imaging) - looks for old haemosiderin deposits (old bleed).
What sort of investigations would be carried out for suspected ischaemic stroke?
Blood tests - glucose, lipids, thrombophilia screen in young patients. Assess for hypertension. Look for signs of blood vessel disease.
What are the 2 types of embolism involved in ischaemic stroke?
Atheroembolism (platelet rich clots, infarct same side as affected coronary artery).
Cardioembolism (embolism from a clot formed in heart (usually left atrium), clotting factor rich, infarcts in more than one arterial territory, bilateral).
How would you tell if it was an atheroemoblism?
Carotid scanning, CT/MR angiography of aortic arch.
How would you tell if it was a cardioembolism?
Look at ECG for AF, old ischaemic changes, LVH.
Echocardiogram.
24 hour-5day ECG to look for paroxysmal AF.
Where are haemorrhagic strokes located and what causes them?
Deep in brain in older patients - hypertensin.
Young, not hypertensive and lobar (superficial) haemorrhage - underlying aneurysm or ateriovenous malformation (AVM).
Multiple haemorrhages - vasculitis, Moya Moya disease, central amyloid angiopathy.
What are the 2 treatments for ischaemic stroke?
Thrombolysis: up to 4.5 hours from onset of treatment (very effective treatment in stroke).
Thrombectomy: up to 6 hours from symptom onset, usually after having started thrombolysis.
