Stroke

Question 1

What is a stroke?

Answer 1

Acute onset of focal neurological symptoms and signs due to disruption of blood supply

Question 2

What does it mean if symptoms are focal?

Answer 2

should be able to tell which part of brain is affected by symptoms

Question 3

What are the types of stroke and which is most common?

Answer 3

Haemorrhagic and Ischaemic

15-20% and 80-85%

Question 4

Describe the differences between a haemorrhagic and ischaemic stroke.

Answer 4

H: bleeding occurs in, or around, brain tissue - tissue tear.
I: a clot blocks flow to an area of brain - tissue blockage.

Question 5

Causes of brain haemorrhage?

Answer 5

raised BP

weakened vessel walls; structural abnormalities and inflammation

Question 6

What structural abnormalities could cause a brain bleed?

Answer 6

aneurysm 
arteriovenous malformation (AVM) - bypasses capillaries

Question 7

An example of inflammation that could cause brain haemorrhage?

Answer 7

vasculitis - vessel walls inflamed and weakened

Question 8

Causes of ischaemic stroke?

Answer 8

Thrombotic - clot blocking artery AT site of occlusion
Embolic - clot has traveled to occluded artery from proximal artery or the heart
Hypo-perfusion - due to reduced blood flow - STENOSED artery rather than occluded

Question 9

What are the points of Virchow’s triad?

Answer 9

Hyper-coagulable state
Endothelial injury
Circulatory stasis

Question 10

Every 8mmHg of diastolic pressure >85 doubles risk of stroke.
True/False?

Answer 10

true

Question 11

What effect does smoking having on risk of ischaemic stroke?

Answer 11

double risk

Question 12

Statin therapy is recommended in all patients with a stroke.

True/False?

Answer 12

False

Not recommended in haemorrhagic stroke

Question 13

What are some mimic presentations of stroke?

Answer 13

hypoglycaemia - confusion, sweating
seizure
migrane
tumours

Question 14

What is the only way to differentiate between an ischaemic and haemorrhagic stroke?

Answer 14

brain imaging;
CT brain ± angiography
MRI with DWI ± angio
MRI with SWI

Question 15

What does MRI with SWI indicate?

Answer 15

old haemosiderin deposits (old bleed)

Question 16

What is an atheroembolism?

Answer 16

an embolism from a thrombus forming on an atherosclerotic plaque
infarcts on the SAME side as affected carotid artery

Question 17

What is a cardioembolism?

Answer 17

Embolism from clot formed in heart (usually LA)

infarcts in more than one arterial territory - bilateral

Question 18

Which type of embolism is platelet-rich?

Answer 18

atheroembolism

Question 19

Which type of embolism is clotting factor-rich?

Answer 19

cardioembolism

Question 20

What is a thrombectomy?

Answer 20

used in ischaemic stroke - ‘unplugging’ procedure - usually after starting thrombolysis

Question 21

What are the indications for thrombectomy?

Answer 21

only for large proximal arteries

up to 6hrs from onset of symptoms

Question 22

when would you do thrombolysis?

Answer 22

ischaemic stroke - up to 4.5 hrs from onset of symptoms

Question 23

How would prevent the next stroke in a patient, if the first was caused by a thrombus?

Answer 23

Anti-platelets - aspirin + dipyridamole/Clopidogrel
Statins - to treat high lipids
Diabetes management
Hypertension management
Lifestyle advice

Question 24

How would you prevent the next stroke in a patient, if the first was due to AF?

Answer 24

Anti-coagulate ASAP; warfarin, rivaroxaban

Anti-hypertensives

Question 25

What is a TIA?

Answer 25

Transient Ischaemic Attack

Temporary neurological symptoms due to occlusion of artery, stopping flow of blood

Question 26

Why is a TIA temporary?

Answer 26

arteries are capable of dissolving small clots

Question 27

Why is TIA an emergency?

Answer 27

high risk of stroke afterward

Question 28

How long do TIA symptoms last?

Answer 28

24hrs

Question 29

which arteries supply the brains?

Answer 29

internal carotids and vertebral arteries

Question 30

What is the purpose of the Circle of Willis and which arteries are involved?

Answer 30

To maintain perfusion even if one carotid artery is obstructed.
Basilar & carotid arteries anastomose.
(Basilar formed by two vertebral arteries)

Question 31

What does auto-regulation of cerebral blood flow ensure?

Answer 31

prevents MABP change outwit 60-160mmHg

Question 32

What happens to vessels supplying brain if MABP falls?

Answer 32

resistance vessels dilate to maintain blood flow

Question 33

What is the minimum MABP needed before you faint?

Answer 33

50mmHg

Question 34

Normal intracranial pressure (ICP)?

Answer 34

8-13mmHg

Question 35

What is cerebral perfusion pressure (CPP) equal to?

Answer 35

CPP = MAP - ICP

Question 36

What is the result of hypoxaemia due to blood loss on cerebral flow and vessels?

Answer 36

less O2 = increased BP and HR
increased MABP = increased CPP
cerebral arterioles constrict to prevent CPP getting too high