Stroke Flashcards
Stroke definition?
Acute onset of focal neurological symptoms and signs due to disruption of blood supply
Stroke effects?
People don’t often die from initial stroke but can come out of it severely disabled
How many types of stroke? and what are they called?
Ischaemic
Haemorrhagic
Reason for haemorrhagic stroke?
Raised BP
Weakened blood vessel wall due to structural abnormalities
-aneurism
-Atriovenous malformation
Inflammation of vessel walls (vasculitis)
Reason for ischaemic stroke?
Thrombotic- clot blocking artery at site of occlusion
Embolic- Clot blocking artery has traveled to artery, it occludes from somewhere more proximal in arteries or heart
Hypoperfusion- Due to reduced blood flow due to stenosed artery rather than occlusion of artery
Non-modifiable risk factors for stroke?
Age Family History Gender Race- south Asians Previous stroke
Potentially modifiable risk factors for stroke?
Hypertension Smoking Hyperlipidaemia Smoking Prior history of TIA Atrial fibrillation Diabetes Congestive heart Failure Alcohol excess Obesity Physical Inactivity Poor socioeconomic status
Smoking________ risk of ischaemic stroke
Doubles
What type of stroke are statins recommended for?
Ischaemic
Rarer causes of stroke?
Homocysteinemia
Vasculitis,
Antiphospholipid antibody syndrome
Protein S, C, Antithrombin III deficiency
Paradoxical embolism(venous clot to arterial side) through patent foramen ovale
Pulmonary AV shunts(these are openings large enough between arterial and venous circulations)
Genetic- Factor V Leiden mutation, common prothrombin mutation, MELAS, CADASIL,Fabry’s disease
Cardioembolic- mural thrombi, infective endocarditis, myxoma
Cervical artery dissection
Behavioral modification of stroke prevention?
Diet
Exercise
Smoking cessation
Weight control
Approach to managing stroke?
Present- fixing the problem? thrombolysis or thrombectomy in ischaemic stroke
Stopping further strokes in future - identify and treat cause
Helping patient adjust to disability- rehab
Questions to ask when managing a stroke?
Is it a stroke?
What kind?
Cause?
Appropriate secondary prevention?
What conditions does a stroke mimic?
Hypoglycaemia
Seizure - part of brain may not function temporarily after
Migraine
Metabolic- hyperglycaemia or Hyponatremia
Brain tumors- space occupying lesions
Functional hemiparesis
Only way of differentiating between different types of stroke?
Brain Imaging
Types of brain imaging for stroke?
CT brain +- angiography
MRI with DWI +-angiography
MRI with SWI (looks for old bleeds)
Arheroebolism?
embolism from a thrombus forming on a atherosclerotic plaque- platelet rich clots
infarcts in same side as affected carotid artery
Cardioembolism?
Embolism from a clot formed in the heart(usually left atrium)
- clotting factor rich clots
infarcts in more than one arterial territory, bilateral
Tests to see for atheroembolism?
Carotid scanning
CT/MRI angiography of aortic arch
Tests to see for carioembolism?
Echocardiogram
ECG
24 hour 5 day ECG monitor tests
AF
Investigating cause of bleeding in haemorrhagic stroke?
Hypertensive- deep in brain usually
If young, not hypertension and superficial haemorrhage- aneurism
Multiple haemorrhages- vasculitis, moya moya disease
Reversing disability in ischaemic stroke?
Thrombolysis - up to 4.5 hours from onset of symptoms
Thrombectomy- Up to 6 hours from symptom onset
How thrombolysis works?
Clot forms
tPA injected intravenously
Blood clot dissolves
Restored blood flow
When are thrombectomies indicated?
Large arterial proximal occlusions
Process of thrombectomy?
Blood clots restricts blood to affected area of brain
Stent retriever is navigated to side of blocked blood vessel. Retriever is advanced through clot and expands and integrates into it
Retriever and clot are retracted into catheter and removed
Surgical management of stroke?
- Haematoma evacuation
- Relief of raised intracranial presure : obstructive hydrocephalus, large total MCA infarctions
- Carotid endarterectomy
Explain TIAs?
Patients who present like a stroke but within a few minutes are better
Temporary neurological symptoms due to occlusion of artery stopping blood flow - because arteries are capable of dissolving clots
Risk of TIA after stroke
TIA definition?
focal neurological symptoms that resolve within 24 hrs
Investigations used to find causes of thrombosis or embolism in ischaemic stroke?
Blood tests- glucose, lipids, thrombophillia
Assess for hypertension
What does medical management to prevent next stroke depend on?
What caused it
If a stroke was atheroembolic or due to thrombus prevent another one by?
Antiplatelets (aspirin) Statins to treat high lipids Diabetes management Hypertension management Lifestyle advice
If a stroke is due to atrial fibrillation prevent further stroke by?
Anticoagulate ASAP
- Warfarin (Vit K antagonists)
- Direct acting oral coagulants
- Rivaroxaban, Dabigatran, apixaban, edoxaban
-Antihypertensives- more important in stroke than in CHD or PAD
