Stroke

Question 0

TIA is

Answer 0

Transient ischaemic attack

Stroke symptoms which resolve completely within 24hrs

Question 1

Stroke is

Answer 1

A cerebrovascular accident (CVA)
Rapidly developing loss of brain function due to disturbance in blood supply
Stroke requires neurological deficit persisting longer than 24hrs
If it resolves completely before that then it is a TIA

Question 2

Causes of stroke

Answer 2

80% are ischaemic, may be
- Atherothrombo-embolic (40%) - Small vessel CV disease (20%)
- Systemic hypoperfusion, Venous thrombosis & other (20%)
20% are haemorrhagic, can be
- Intracerebral (15%) - Subarachnoid (5%)

Question 3

Haemorrhagic strokes can occur in which spaces

Answer 3

Subdural
Subarachnoid
Intracranial

Question 4

Incidence of stroke

Answer 4

1-1.3 per 100 people in the UK per year
Only 25% in people of working age
Incidence doubles with every decade over 55 and is double in black people
1/4 men and 1/5 women will have had a stroke by 85

Question 5

Incidence of TIA

Answer 5

Similar to stroke in people younger than 55
Incidence stable from 55-85, thus far fewer than strokes overall
This is due to likelihood of recovery in 24hrs decreasing as age increases

Question 6

National Mortality of stroke

Answer 6

12% of all deaths in UK, 9% of male and 13% of female
3rd greatest cause of death after cancer and IHD
56,000 people in 1999

Question 7

Personal mortality of stroke

Answer 7

At 1yr: 33% dead, 22% dependant on care, 45% independent
In survivors: 1/2 hemiparesis, 1/3 depressed, 1/5 unable to walk, 1/5 aphasic
Risk of recurrence: At 1yr 7%, at 5yrs 16% and at 10yrs 25%
Mortality is 3% lower in women

Question 8

Disease burden of stroke

Answer 8

6% of total healthcare budget
Occupy 1/5 acute hospital beds and 1/4 long term beds
900,000 people are living in the UK with effects of stroke

Question 9

Changes in stroke mortality

Answer 9

Steep decline in developed countries, 2% per yr
40% drop in UK from 1981 to 2004 and 30% in US from 1995 to 2005
Attributed to risk factor modification
Ageing of population will counter is and keep numbers stable

Question 10

Risk factors for stroke

Answer 10

Starting with the largest
1. Hypertension 2. Reduced physical activity 3. Waist to hip ratio
4. Cholesterol 5. Smoking 6. Diet risk score
INTERSTROKE study lancet 2010

Question 11

Hypertension and stroke risk

Answer 11

Accounts for 35-50% of risk
Lowering BP is effective at reducing risk, a population wide lowering of 3-5mmHg would reduce stroke numbers by 40%
Larger reductions are even more effective

Question 12

Cholesterol and stroke risk

Answer 12

Unclear now important cholesterol is in stroke risk
But statins are very effective at reducing stroke
They may exert effect through other mechanisms, such as improvements in endothelial function

Question 13

Physical activity and stroke risk

Answer 13

Protective against stroke in both sexes

Multiple possible mechanisms of action

Question 14

Alcohol and stroke risk

Answer 14

Heavy alcohol consumption is an independent risk factor for stroke
Modest consumption may be protective

Question 15

Strategies for stroke prevention

Answer 15

High risk individuals - reduce risk factors particularly BP
- increase physical activity
Whole Population - dietary change and reducing salt in food etc
In both cases modify risk factors

Question 16

Cerebral arteries

Answer 16

Anterior and middle come off the internal carotid artery
Posterior comes from the vertebrobasilar circulation
Connected by circle of Willis

Question 17

Classification systems for stroke syndromes

Answer 17

Oxfordshire community stroke project classification –> 4 clinical syndromes based on location, which can be either ischaemic (I) or haemorrhagic (H)
TOAST classification –> 5 categories based on underlying pathology

Question 18

Oxfordshire community stroke classification

Answer 18

TAC - Total anterior circulation PAC - Partial anterior circulation
LAC - Lacunar stroke (Deep brain) POC - Posterior circulation
Four letter is I/H depending on ischaemic or haemorrhagic cause

Question 19

TOAST classification of stroke aetiology

Answer 19

1. Large artery atherosclerosis
2. Cardio-embolism
3. Small-vessel occlusion (lacunae)
4. Stroke of other determined aetiology
5. Stroke of undetermined aetiology

Question 20

Clinical signs that neurological deficit is vascular in origin

Answer 20

If the symptoms are focal and negative with sudden onset which are maximal at onset—> likely a vascular event
If they are non-focal, including positive symptoms with a gradual or progressive onset—> unlikely a vascular event

Question 21

Non-stroke signs

Answer 21

Fainting, dizziness or syncope
Generalised muscle weakness
Urinary or faecal incontinence
Confusion and disorientation
4-5% of events thought to be stroke are not

Question 22

Differentials for non-stroke neurological symptoms

Answer 22

Tumours
Peripheral neuropathies and MS
Hypoglycaemia
Complicated migraine
Post-Ictal states

Question 23

Causes of missed strokes

Answer 23

Unusual clinical presentations - hemiballismus (basal ganglia damage causing lack of suppression of unwanted movements)
Fluent aphasias (Wernicke’s)
Aboulia (disorder of diminished motivation due to frontal damage)
Severe co-morbidity or sedation

Question 24

Intracerebral haemorrhage

Answer 24

Rupture of blood vessels within the brain
30-day mortality 30-55%
May be caused traumatically or by spontaneous rupture
Spontaneous rupture due to vascular changes due to RFs
Small vessel disease, aneurysms or arteriovenous malformation

Question 25

Locations of Intracerebral haemorrhage

Answer 25

Basal ganglia - 42%
Lobar - 40%
Cerebellum - 8%
Brainstem - 6%
Thalamus - 4%

Question 26

Mortality of Intracerebral haemorrhage

Answer 26

Estimated based on - GCS on presentation (0,1,2)
- volume of haemorrhage over 30ml (0,1)
- any intraventricular haemorrhage (0,1)
- infratentorial origin (0,1)
Score (mortality %): 1(13), 2(26), 3(72), 4(97), 5(100)

Question 27

Treatment of haemorrhagic stroke

Answer 27

Acutely stabilise and admit to stroke unit/