FN: Stroke: Causes and investigation

Question 1

Definition

Answer 1

Rapid onset, focal neruological deficit due to a vascular lesion lasting >24hrs

Question 2

Pathogenesis

Answer 2

Infarction due to ischaemia (80%) or intracerebra haemorrhage (20%)

Question 3

Ischaemic strokes 2 types

Answer 3

Atheroma (large e.g. MCA) or small vessel perforators (lacunar)

Embolism:

1. Cardiac (30% of strokes):AF, endocarditis, MI
2. Atherothromboembolism e.g. from carotids

Question 4

Haemorrhage (20%)

Answer 4

1. High BP
2. Trauma
3. Aneurysm rupture
4. Anticoagulation
5. thrombolysis

Question 5

Rarer Causes

Answer 5

1, Watershed stroke: sudden drop in BP e.g. sepsis

2. CArotid artery dissection
3. Vasculitis: PAN, HIV
4. Cerebral vasospasm secondary to SAH
5. Venous sinus thrombosis
6. Anti-phospholipid syndrome, thrombophilia

Question 6

Risk Factors

Answer 6

Hypertension
Smoking, DM, raised lipids, FH
Cardiac AF

Question 7

Cardiac causes of stroke

Answer 7

AF:4.5%/yr
External cardioversion:1-3%
Prosthetic valves
Acute MI: esp. large anterior
Paradoxical systemic emboli
Cardiac surgery
Valve vegetations

Question 8

Investigations

Answer 8

ID risk factors for further strokes

Question 9

HTN

Answer 9

Retinopathy
Nephropathy
Bigh heart on CXR
(Dont treat acutely)

Question 10

Cardiac emboli

Answer 10

ECG ± 24hr tape: AF

Echo: mural thrombus, hypokinesis, valve lesions, ASD, VSD (paradoxical emboli)

Question 11

Carotid artery stenosis

Answer 11

Dopper US ± angio

Endarterectomy beneficial if >70% symptomatic stensosi

Question 12

Bleeding/thrombotic tendency

Answer 12

Thrombophilia screen

Thrombocytopenia

Question 13

Hyperviscosity

Answer 13

Polycythaemia
SCD
Myeloma

Question 14

Metabolic

Answer 14

High or low glucose
Raised lipids
Hyperhomocystinaemia

Question 15

Vasculitis

Answer 15

Raised ESR

ANA