Stroke Flashcards
What is a stroke?
Infarction or bleeding in the brain
List the causes of stroke
Small vessel occlusion/cerebral microangiography or thrombosis in situ Cardiac emboli (AF, endocarditis, MI) Atherothromboembolism (from carotids) CNS bleeds - HTN, anticoagulation, thrombolysis, aneurysm rupture, trauma Sudden drop in BP >40mmHg Carotid artery dissection Vasculitis Subarachnoid haemorrhage Venous sinus thrombosis Antiphospholipid syndrome Thrombophilia Fabry disease CADSIL
List some modifiable risk factors of stroke
HTN DM Lipids Heart disease - valvular, AF, ischaemic Alcohol use Smoking PVD COCP Syphilis
When are signs of stroke at their worst?
At onset
List some signs which unreliably favour haemorrhage
Meningism
Severe headache
Coma
List some signs which suggest ischaemia
Carotid bruit
AF
Past TIA
IHD
Describe the presentation of a cerebral infarct
Depending on the site, there may be contralateral sensory loss or hemiplegia - initially flaccid but becomes spastic, dysphasia, homonymous hemianopia, visuo-spatial defect
Describe the presentation of a brainstem infarct
Varied
Quadriplegia
Disturbances of gaze and vision
Locked in syndrome
Describe the presentation of lacunar infarcts
Ataxic hemiparesis Pure motor Pure sensory Sensorimotor Dysarthria/clumsy hand Cognition/consciousness are intact except in thalamic strokes
What brain structures are classed as lacunar?
Basal ganglia
Internal capsule
Thalamus
Pons
Describe the acute management of stroke
Protect the airway
Maintain homeostasis - keep glucose between 4 and 11mmol/L. Only treat BP if hypertensive emergency or thrombolysis considered (aim for <185/110 as treating even high BP may impair cerebral perfusion)
Screen swallow - keep NBM till this is done but maintain hydration
CT/MRI within 1 hour - essential if thrombolysis is considered or high risk of haemorrhage or unusual presentation. Otherwise within 24 hours. Diffusion weighted MRI is the most sensitive for an acute infarct but CT helps rule out primary haemorrhage
Antiplatelet agent - once haemorrhage has been ruled out, give aspirin 300mg (continue for 2 weeks then switch to long term anti-thrombotic treatment)
Thrombolysis - consider this as soon as haemorrhage has been excluded provided onset of symptoms was within 4.5hrs ago and the benefits of thrombolysis outweigh the risks. Alteplase is the drug of choice.
CT post lysis to identify bleeds
Thrombectomy - intra-arterial mechanical thrombectomy provides additional benefit for those with large artery occlusion in the proximal anterior circulation
What is primary prevention of stroke
Preventing a stroke happening before one has ever happened
What is secondary prevention of stroke
Preventing a further stroke from happening after one has already happened
Describe ways of primary prevention of strokes
Treat HTN Manage DM Treat hyperlipidaemia Stop smoking Exercise Lifelong anticoagulation in AF and prosthetic heart valves
Describe ways of secondary prevention of strokes
Treat risk factors
Antiplatelets after stroke - If no primary haemorrhage, 300mg aspirin for 2 weeks then switch to long term Clopidogrel monotherapy. If not tolerated or is CI then lifelong low dose aspirin plus slow release dipyridamole
Anticoagulation with warfarin or DOAC
