Stroke

Question 1

What is a stroke?

Answer 1

Acute onset of focal neurological symptoms and signs due to disruption of blood supply
(a clinical diagnosis)

Question 2

What are the 2 types of stroke?

Answer 2

Haemorrhagic (15-20%) - bleeding occurs inside or around brain tissue
Ischaemic (80-85%) - a clot blocks blood flow to an area of the brain

Question 3

What predisposes to a haemorrhagic stroke?

Answer 3

Raised BP
weakened blood vessel wall due to stuctural abnormalities like aneurysm, ateriovenous malformation (AVM) or inflammation of the vessel walls (vasculitis)

Question 4

Types of ischemic stroke

Answer 4

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 flow of blood due to stenosed artery rather than occlusion of artery

Question 5

What is the cause of arterial clots?

Answer 5

atherosclerotic disease

Question 6

Non-modifiable risk factors for stroke

Answer 6

Age
Family history of stroke
Gender
Race
Previous stroke

Question 7

Risk factors for strokes which are potentially modifiable

most important at top down to AF

Answer 7

Hypertension            
Hyperlipidaemia
Smoking
Prior history of TIA especially if recent and recurrent
Atrial fibrillation
Diabetes
Congestive heart failure
Alcohol excess
Obesity 
Physical inactivity
Poor socioeconomic status

Question 8

Why are statins not given to people who’ve had a haemorrhagic stoke

Answer 8

They have the effect of increasing the risk of haemorrhagic stroke

Question 9

Rare causes of clots

Answer 9

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

Question 10

Aims of stroke management

Answer 10

minimising disability
stopping further strokes
through rehab helping the patient to adjust

Question 11

What is the relation of hypertension to stroke risk?

Answer 11

even a 10 mm reduction in SBP reduces risk of cardiovascular events by over 20%
even isolated systolic hypertension can increase stroke risk

Question 12

What is the relationship between smoking and risk of stroke?

Answer 12

smoking doubles the risk of stroke

Question 13

What is the relationship between hyperlipidaemia and risk of stroke?

Answer 13

Statin therapy recommended in everyone with ischaemic stroke and not recommended for hemorrhagic stroke

Question 14

Other conditions which present similarly to stroke

Answer 14

Hypoglycaemia
Seizure- postictal states
Migraine
Other metabolic –hyperglycaemia, hyponatremia
Space occupying lesions like brain tumours
Functional hemiparesis

Question 15

How do you determine whether the stoke is hemorrhagic or ischemic?

Answer 15

Brain imaging
CT brain
MRI with DWI
MRI with SWI (looks for old haemosiderin - old bleeds)

Question 16

What further investigations are used in ischaemic stroke?

Answer 16

Blood tests (glucose, lipids, thrombophillia screen in young patients
Assess for hypertension
any clues the patient has any blood vessel diseases

Question 17

What investigations are used to look for the cause of the bleeding in hemorrhagic stroke?

Answer 17

Hypertensive - tend to be deep in the brain and in older patients
In young people tends to be an aneurysm or malformed blood vessel (tends to be lobar haemorrhage)
If multiple haemorrhages look into
vasculitis
moya moya disease
cerebral amyloid angiopathy

Question 18

Treatment of ischemic stroke

Answer 18

Thrombolysis - within 4.5 hrs from symptom onset

Thrombectomy within 6 hrs from symptom onset usually follows thrombolysis

Question 19

What is a thrombectomy?

Answer 19

passing a wire into the clot and pulling it out

Question 20

How do you prevent further strokes in someone who has had a atheroembolic stroke?

Answer 20

Antiplatelets(Aspirin 75 mg + Dipyridamole MR 200 mg twice daily/Clopidogrel 75 mg daily)
Statins to treat high lipids
Diabetes management
Hypertension management
Lifestyle advice

Question 21

How do you prevent further strokes in someone who has had stroke due to AF?

Answer 21

Warfarin (Vitamin K antagonist)
Direct acting oral anticoagulants (act by inhibiting clotting factors directly like factor X and thrombin)
Rivaroxaban, Dabigatran, Apixaban, Edoxaban

Question 22

It is more important to control hypertension in stroke than in CHD what are some medications recommended

Answer 22

perindopril + indapamide (even in normotensive patients)

Question 23

What is an atheroembolism?

Answer 23

It is from a thrombus forming on a atherosclerotic plaque, rich in blood platelets, the infarct will be on the same side as the carotid artery

Question 24

What is cardioembolism?

Answer 24

embolism from a clot formed in the heart (usually the left atrium)
infarct will be in more than one artery territory - bilateral

Question 25

What do you investigations do you in a large vessel stroke suspected to be an atheroembolism?

Answer 25

carotid scanning

CT/MRI angiography of the aortic arch

Question 26

What do you investigations do you in a large vessel stroke suspected to be an cardiooembolism?

Answer 26

ECG
Echocardiogram
24hr, 5 day ECG monitor tests