Stroke and TIA

Question 1

What % of stroke/TIA survivors go on to have a further stroke in less than 5 years?

Answer 1

20%

Question 2

What is the global burden of stroke?

Answer 2

20 million/year

2nd leading cause of death

Question 3

Describe the “FAST” system for approach to stroke recognition

Answer 3

F: facial weakness

A: arm weakness

S: speech difficulty

T: time to act fast

Question 4

Associated features of stroke

Answer 4

Weakness, numbness or paralysis of face or limbs

Difficulty speaking or understanding

Dizziness and loss of balance

Loss of vision

Headache (may be severe and abrupt)

Difficulty swallowing

Question 5

What are the 3 assessments to make in the Cincinnati pre-hospital stroke scale?

Answer 5

Facial droop: smile

Arm drift: close eyes and hold out arms

Speech: say “you can’t teach an old dog new tricks” or similar familiar saying

Question 6

Define stroke

Answer 6

Brief episodes

Question 7

Define TIA

Answer 7

Brief neurological episodes (usually less than 24 hours) without damage on imaging

Question 8

63 year old Mrs Faul with PHx of smoking and untreated HTN experiences sudden onset speech difficulties and R sided weakness with confusion

O/E (90 mins after onset of Sx): alert, BP 170/100, irregular pulse, expressive dysphasia, moderate R hemiparesis, appears frustrated

What should be done next?

Answer 8

Code stroke:

1) Urgent triage and high priority for stroke patient
2) Mobilise stroke team
3) Establish IV access and test glucose, routine biochem, FBE
4) ECG
5) Accurate clinical Dx (exclude mimics)
6) Urgent CT

Question 9

List 11 recognised stroke mimics

Answer 9

Seizure

Sepsis

Toxic/metabolic

Space-occupying lesion

Syncope/presyncope

Acute confusional state

Vestibular dysfunction

Acute mononeuropathy

Dementia

Migraine

Spinal cord lesion

Question 10

List 4 clinical features which suggest stroke over some other mimic

Answer 10

Exact time of onset

Patient could recall exactly what they were doing at symptom onset

Well in the last week

Definite focal symptoms or signs, worse NIHSS

Question 11

List 5 clinical features which suggest stroke mimic over a stroke

Question 12

What is the NIHSS and what does it assess?

Answer 12

National Institute of Health Stroke Scale

Assesses 11 aspects and provides a score from 0-42 (stratifies as no stroke Sx, minor stroke, moderate, moderate to severe, severe stroke)

Assesses level of consciousness, horizontal eye movement, visual field test, facial palsy, motor (UL, LL), limb ataxia, sensory function, language, speech, extinction and inattention

Question 13

What is shown on this DWI MRI?

Answer 13

Lightbulb sign

Question 14

What does this CT show?

Answer 14

Early (4.5 hours) ischaemic changes in a R MCA infarct

Question 15

What does this scan show?

Answer 15

Deep putamenal ICH

Question 16

What are the 3 major stroke types?

Answer 16

Ischaemic stroke (cerebral infarction)

Intracerebral haemorrhage (ICH)

Subarachnoid haemorhage (SAH)

Question 17

What are the 3 main causes of ischaemic stroke?

Answer 17

Large artery thromboembolism

Cardiogenic embolism

Small vessel (lacunar) infarct

Question 18

What are the most common sites for intracerebral haemorrhage?

Answer 18

Deep HTNive location

Lobar

Question 19

What are the most common causes of SAH?

Answer 19

Ruptured aneurysm

AVM

Question 20

What is the most common underlying cardiac cause of a cardiogenic embolism?

Answer 20

AF

Question 21

What cerebral region is affected in a lacunar infarct?

Answer 21

Subcortical

Question 22

List 4 rarer causes of ischaemic stroke

Answer 22

Arterial dissection

Drugs

Vasculitis

Rarer arteriopathies (e.g. Moyamoya disease)

Question 23

What is the most lethal subtype of stroke?

Answer 23

ICH: mortality is 30-40%, patients have worse functional outcomes

Question 24

How is ICH classified? What sites are affected in each and what is the typical offending pathology?

Answer 24

Deep: affects putamen, thalamus, brainstem, cerebellum, and usually due to HTN and rupture of deep penetrating arteries

Lobar: superficial, often secondary to amyloid angiopathy, tumour, AVM, aneurysm

Question 25

What is the aim of therapies for ischaemic stroke and ICH?

Answer 25

Limiting stroke growth (rescuing the penumbra)

Question 26

Mx for ischaemic stroke

Answer 26

Thrombolysis: IV tPA Admission to stroke unit Ix for underlying cause (e.g. AF, large artery stenosis)

Question 27

Why are TIA and ischaemic stroke patients considered high-risk?

Answer 27

5-10% of TIA patients have a stroke at 1/52, 10-20% at 3/12 Even higher recurrence rate if DWI performed Probably similar for ischaemic stroke Patients with CVD are at high risk of CHD and vascular death

Question 28

List 5 non-modifiable RFs for ischaemic stroke

Answer 28

Age Gender FHx Ethnicity Contraceptive use

Question 29

List 9 established modifiable RFs for stroke

Answer 29

HTN DM Smoking AF/heart disease Hyperlipidaemia EtOH consumption Prothrombotic factors Prior TIA Prior stroke

Question 30

List 9 possible modifiable RFs for stroke

Answer 30

Physical inactivity Obesity Dietary factors Oral Lack of HRT Infection Stress Sleep apnoea SES

Question 31

What are the main modifiable RFs for stroke and how can these be managed?

Answer 31

RFs: smoking, HTN, DM, obesity Mx: smoking cessation, weight loss, increased physical activity, healthy diet, anti-HTN, in high risk of CVD consider aspirin (but no clear indication for antiplatelet treatment in low risk or intermediate risk - i.e. uncomplicated DM, HTN, hyperlipidaemia - of stroke)

Question 32

By what % do anti-HTN drugs reduce risk of primary stroke?

Answer 32

Up to 40%

Question 33

Give 3 examples of NOACs and their mechanisms of action

Answer 33

Direct thrombin inhibitors: dabigatran Factor Xa inhibitors: rivaroxaban, apixaban

Question 35

When are NOACs indicated in stroke prevention?

Answer 35

Prevention of stroke (or systemic embolism) in non-valvular AF in a patient with one or more RFs for developing stroke

Question 36

What is the risk of haemorrhage with oral anticoagulation?

Answer 36

1-1.5% per annum (greater if over 80 years old)

Question 37

CHADS2

Answer 37

Cardiac failure HTN Age \>75 DM Previous Stroke or TIA (2 points) If 1 or more, recommend oral anticoagulant If 0, undertake a more comprehensive risk assessment (e.g. VASc)

Question 38

By what % do oral antiocoagulants reduce the risk of stroke in people with AF?

Answer 38

Risk of stroke reduced by 60%

Question 39

What is the recurrent stroke risk after a first stroke?

Answer 39

4% per annum

Question 40

ABCD^2 score

Answer 40

AGE: 60 or above - 1 BP: SBP 140 or above, DBP 90 or above - 1 CLINICAL: focal weakness - 2, speech impairment without focal weakness - 1 DURATION: 60 min or more - 2, 10-59 min - 1 DM - 1 Low risk = 0-3, moderate risk = 4-5, high risk = 6-7

Question 41

What are the principles of secondary prevention in stroke?

Answer 41

BP lowering Cholesterol lowering and statins Antiplatelet therapy AF and anticoagulation Carotid revascularisation (endarterectomy and stenting)

Question 42

At what level should BP and cholesterol lowering medications be initiated post-stroke?

Answer 42

ANY level; any reduction is beneficial

Question 43

What is the polypill and what is its expected impact on CVD rates?

Answer 43

Statin, 3 BP drugs (e.g. thiazide, B blocker, ACEI), aspirin, folic acid

Question 44

What is the effect of aspirin on risk of subsequent stroke and all vascular events?

Answer 44

Reduces risk of subsequent stroke by ~13% Reduces risk of all vascular events by 20%

Question 45

When is dipyridamole + aspirin indicated over aspirin alone?

Answer 45

If patient at moderate to severe absolute risk, or in cases of recurrent stroke SE of headache common

Question 46

When is clopidogrel recommended post-stroke over aspirin?

Answer 46

Modestly more effective than aspirin in prevention of serious high risk vascular events so prescribed in these contexts

Question 47

When might there be a role for aspirin + clopidogrel post-stroke?

Answer 47

In first 90 days after stroke or TIA

Question 48

List 4 complications of CEA

Answer 48

Death or stroke Cranial nerve palsy Wound complications CVS complications

Question 49

What are some of the limitations of CEA?

Answer 49

Only marginal benefits on annual rates of ipsilateral stroke for patients with asymptomatic or moderate lesions; dramatic benefit is only seen for high-grade (above 70%) symptomatic stenoses Benefits are time-linked to last symptomatic event (best within 30 days) Risk of complications

Question 50

What is more effective at reducing risk of ipsilateral stroke and perioperative death in patients with advanced symptomatic carotid artery disease: CEA or medical therapy?

Answer 50

CEA

Question 51

Mrs Faul has had an ischaemic stroke secondary to carotid artery thromboembolism, managed with thrombolysis (to which she had a good response) Post-stroke Mx for Mrs Faul?

Answer 51

Lifestyle issues: smoking cessation, regular exercise, weight reduction and maintenance BP: reduce to 120/80 Statin CEA or stenting Long-term anticoagulation with dabigatran or other NOAC

Question 52

Summarise important principles of secondary prevention for stroke

Answer 52

High-risk patients benefit from BP and cholesterol reduction regardless of baseline Antiplatelet therapy is routine if patient not anticoagulated Warfarin for AF may be replaced by NOAC CEA proven therapy for carotid artery stenosis, but carotid stenting may be equivalent for patients less than 70 years old

Question 53

Dipyridamole

Answer 53

Inhibits PDE which normally breaks down cAMP (increasing cellular cAMP levels and blocking the platelet aggregation response to ADP), and/or cGMP (resulting in added benefit when given together with nitric oxide or statins) Inhibits cellular reuptake of adenosine into platelets, RBCs and endothelial cells leading to increased extracellular concentrations of adenosine