Transient ischaemic attack (N)

Question 1

Define transient ischaemic attack.

Answer 1

Temporary, focal cerebral ischaemia that results in reversible neurological deficits without acute infarction that resolves completely within 24h

Question 2

What demographics does transient ischaemic attack happen in commonly? (2)

Answer 2

• M>F
• incidence increases with age

Question 3

What are some risk factors for transient ischaemic attack? (7)

Answer 3

• AF (most common)
• valvular disease
• carotid stenosis
• congestive heart failure
• hypertension
• DM
• smoking

Question 4

What are transient ischaemic attack usually?

Answer 4

Usually embolic, may be thrombotic

Question 5

What are some causes of transient ischaemic attack? (3)

Answer 5

• carotid atherosclerosis
• cardioembolism - mural thromboembolism post-MI/AF, mitral valve disease, atrial myxoma, prosthetic valve
• clots from right side of circulation can cause stroke if there is a septal defect (PFO)

Question 6

If there is infarction on imaging in suspected transient ischaemic attack, what does this suggest?

Answer 6

If infarction on imaging, stroke NOT transient ischaemic attack

Question 7

When should we suspect TIA?

Answer 7

In anyone with sudden-onset focal neurological deficit that has completely resolved within 24h and cannot be explained by another condition e.g. hypoglycaemia

Question 8

How long do TIAs usually last?

Answer 8

10-15 minutes, but can be anywhere from a few minutes to 24h

Question 9

What are the main clinical features of TIA? (6)

Answer 9

• sudden-onset and brief duration of Sx (most resolve within 1h)
• unilateral weakness or paralysis
• dysphasia (left-sided ischaemia)
• ataxia, vertigo or loss of balance (posterior TIA)
• homonymous hemianopia
• diplopia

Question 10

What are the features of an anterior TIA (carotid territory)? (5)

Answer 10

• unilateral
• most often affect the motor area - weakness in arm, leg or one side of face
• dysarthria
• Broca’s dysphasia (if LHS)
• amaurosis fugax (painless fleeting loss of vision caused by retinal ischaemia)

Question 11

What are the features of a posterior TIA (vertebrobasilar territory)? (4)

Answer 11

• homonymous hemianopia (if ophthalmic cortex involved)
• may have bilateral vision impairment
• may be hemiparesis, hemisensory Sx, diplopia, vertigo, vomiting, dysarthria, dysphagia or ataxia
• ask about unilateral weakness, facial drooping, gait disturbance, confusion, memory loss, dysarthria or abnormal behaviour

Question 12

What does dysphasia indicate in TIA?

Answer 12

Left-sided ischaemia

Question 13

What does ataxia, vertigo or loss of balance indicate in TIA?

Answer 13

Posterior TIA (vertebrobasilar territory)

Question 14

What might you check for on examination in TIA? (2)

Answer 14

• check pulse for AF
• auscultate carotids for bruits (carotid atherosclerosis)

Question 15

What investigation do we order for all patients with TIA?

Answer 15

Urgent carotid doppler

Question 16

What scans can we do for TIA? (3)

Answer 16

• CT head - urgently needed if patient has bleeding disorder or is on anticoagulation to exclude haemorrhage
• MRI brain with diffusion-weighted imaging - to determine location
• ECG - evaluate for AF and rule out myocardial ischaemia

Question 17

If there is infarction on imaging, what does this suggest in suspected TIA?

Answer 17

If infarction of imaging –> STROKE not TIA

Question 18

What bloods can we do for TIA and why? (2)

Answer 18

• blood glucose - exclude hypoglycaemia as cause of sudden neurological Sx
• PT, APTT, INR - exclude coagulopathy

Question 19

What score do we calculate in TIA and why?

Answer 19

ABCD2 score - estimates future stroke risk in TIA patients

Question 20

When is stroke risk highest after TIA?

Answer 20

In first 7 days following TIA –> start secondary prevention therapy immediately once TIA confirmed

Question 21

What are some differential diagnoses for TIA? (9)

Answer 21

• stroke (>24h)
• hypoglycaemia (BGC<3.3mmol/mol)
• seizure with post-seizure paralysis
• complex migraine
• space occupying lesion (intracranial haemorrhage, abscess or mass)
• labyrinthine disorders (BPPV, Meniere’s, labyrinthitis)
• MS
• peripheral neuropathy (Bell’s palsy non-forehead sparing, Ramsay-Hunt may show vesicles near tympanic membrane)
• global hypoperfusion/syncope

Question 22

How do we manage patients with acute neurological symptoms that resolve completely within 24 hours?

Answer 22

300mg aspirin immediately + urgent assessment within 24h

Question 23

What do we do in suspected TIA if patient is on anticoagulant, or has a bleeding disorder?

Answer 23

Urgent CT head to rule out haemorrhage

Question 24

What is the gold standard treatment for TIA?

Answer 24

• dual antiplatelet therapy (followed by clopidogrel for life):
  
  • aspirin 300mg loading dose, followed by 75mg for 21d
  • clopidogrel 300mg loading dose, followed by 75mg for 21d
  • then clopidogrel 75mg for life
• high-intensity statin therapy (atorvastatin 20-80mg)

Question 25

When do we treat BP in TIA?

Answer 25

Only if >220/120 or other indication

Question 26

What do we do if patients with TIA present within vs after 7 days of episode?

Answer 26

- within 7d: specialist review within 24h - after 7d: specialist review within 7d

Question 27

What antiplatelet therapy do we provide in TIA (gold standard)?

Answer 27

Dual antiplatelet therapy for 21d, followed by clopidogrel monotherapy for life - aspirin 300mg loading dose --> 75mg for 21 days - clopidogrel 300mg loading dose --> 75mg for 21 days - clopidogrel 75mg monotherapy for life

Question 28

What medication can be used for secondary long-term prevention of TIA?

Answer 28

Atorvastatin 80mg + antihypertensives

Question 29

What if a patient with TIA has carotid artery stenosis?

Answer 29

Carotid endarterectomy (if carotid artery stenosis >70%)

Question 30

In AF patients with TIA, what anticoagulant do we give?

Answer 30

DOAC or LMWH

Question 31

What do we give for TIA with cardiac emboli present?

Answer 31

Warfarin

Question 32

What can patients not do for at least 1 month after TIA?

Answer 32

Drive

Question 33

When is stroke risk highest post-TIA?

Answer 33

Risk of recurrent stroke is high in the first 7 days following a TIA --> start secondary prevention therapy (dual antiplatelet + statin) immediately

Question 34

What are some complications of TIA? (2)

Answer 34

- stroke - MI

Question 35

Describe the prognosis of TIA.

Answer 35

By definition, a patient with a TIA has no residual symptoms from the primary event; however patients have increased risk of future ischaemic stroke