Stroke

Question 1

How is a stroke defined?

Answer 1

A sudden onset of neurological dysfunction caused by an alteration in cerebrovascular blood supply

Question 2

Characteristics of a stroke?

Answer 2

Rapid, acute onset
Focal neurological deficit: almost always some sort of hemiplegia

Question 3

What is hemiplegia?

Answer 3

paralysis on one side of the body

Question 4

What is hemiparesis?

Answer 4

Weakness on one side of the body

Question 5

3 stroke classifications

Answer 5

Haemorrhage- 10-20%
Brain ischaemia (infarct)- 80-90%
TIA

Question 6

What is a TIA?

Answer 6

Symptoms completely resolve within 24 hours.

Ischaemia without infarct

Question 7

Causes of a TIA?

Answer 7

Usually microemboli (80%)
Temporary reduced blood flow e.g. massive postural hypotension or stenosed artery

Question 8

How long does it take for clinical effects of a stroke to reach maximum?

Answer 8

Usually within 6 hours of onset

Question 9

Prognosis

Answer 9

20% mortality in first 2 months, then roughly 10% per year
<40% of stroke (not TIA) patients make full recovery

Question 10

Which brain arteries do arterial embolisms arise from?

Answer 10

Carotids, vertebral or basilar arteries

Heart valves in endocarditis (vegetations (clumps of blood cells and bacteria) form in heart)

Question 11

How much does the blood flow to brain have to drop by for damage to occur?

Answer 11

50% of the normal value

Question 12

What time of day are strokes most common?

Answer 12

Morning because the bp usually rises in the morning- this could dislodge an embolism

Question 13

Risk factors for ischaemic stroke

Answer 13

hypertension (damages artery walls- increased risk of thrombus formation)

smoking (increases bp + damages artery walls)

exercise and diet

atrial fibrillation

diabetes (increases bp and atherosclerosis)

cholesterol (statins reduce risk by 1/3)

carotid artery stenosis

heart disease

valve disease

Question 14

Risk factors for SAH?

Answer 14

hypertension
smoking
age

Question 15

Risk factors for intracerebral haemorrhage?

Answer 15

hypertension
smoking
atrial fibrillation
obesity
cerebral aneurysm!

Question 16

Anterior circulation stroke:
where is the thrombus coming from?
Affects which part of brain?

Answer 16

Likely from carotid system
Affects cerebral function

Question 17

Features of an anterior circulation stroke?

Answer 17

Aphasia/dysphasia
Hemiparesis
Amaurosis fugax
Sensory loss (hemi)
Hemianopic visual loss

Question 18

What is hemianopia?

Answer 18

loss of half of visual fields in one or both eyes

Question 19

What is amaurosis fugax?
What causes it?

Answer 19

sudden loss of vision in one eye
Caused by infarct in the retinal artery

Question 20

Posterior circulation:
where is the thrombus from?
Which part of brain is affected?

Answer 20

Vertebrobasilar arteries

Brainstem/cerebellum

Question 21

Does a TIA cause a headache?

Answer 21

Not usually. This can be helpful to distinguish it from a migraine (migraine also has confusion and visual disturbance)

Question 22

Immediate management for a TIA?

Answer 22

300mg aspririn

Question 23

Causes of cerebral infarct?

Answer 23

Atherosclerosis
Disease of vessels in the brain
Valvular heart disease

Question 24

Most common artery occluded in a stroke?

Answer 24

Middle cerebral artery (similar symptoms to internal carotid occlusion)

Question 25

Symptoms of MCA occlusion?

Answer 25

Contralateral:

hemiparesis
hemiplegia
floppy limbs (reduced reflexes)
facial weakness
hemianopia