Transient Ischaemic Attack (TIA)

Question 1

What is the definition of a TIA?

Answer 1

A rapidly developing focal disturbance of brain function of presumed vascular origin that resolves completely within 24 hours.

Question 2

Explain the aetiology of TIAs?

Answer 2

• It is usually EMBOLIC but may be thrombotic
• Most common source of emboli = CAROTID atherosclerosis
• Emboli can also arise from the heart:
  Atrial fibrillation
  Mitral valve disease
  Atrial myxoma

NOTE: clots from the right side of the circulation can cause a stroke if there is a septal defect (e.g. PFO)

Question 3

What are the risk factors involved with TIAs?

Answer 3

Hypertension

Smoking

Diabetes mellitus

Heart disease (valvular, ischaemic, atrial fibrillation)

Peripheral arterial disease

Polycythaemia rubra vera

COCP

Hyperlipidaemia

Alcohol

Clotting disorders

Question 4

What is the epidemiology of TIAs?

Answer 4

More common with increasing age

More common in men

15% of stroke patients would have experienced a previous TIA

Question 5

What should be done to any patient suspected of a TIA?

Answer 5

ANY PATIENT presenting with acute neurological symptoms that resolve completely within 24 hours (i.e. a suspected TIA) should be given 300 mg aspirin immediately and assessed urgently within 24 hours

Question 6

How long do TIAs normally last?

Answer 6

TIAs usually last 10-15 mins (but can be anything from a few minutes to 24 hours)

Question 7

What are the clinical features of TIAs

Answer 7

Clinical features depend on the part of the brain affected:

Carotid Territory:

• Unilateral
• Most often affect the MOTOR AREA: weakness an arm, leg or one side of the face
• Dysarthria
• Broca’s dysphasia (if Broca’s area is involved)
• Amaurosis fugax (painless fleeting loss of vision caused by retinal ischaemia)

Vertebrobasilar Territory:

• Homonymous hemianopia (if ophthalmic cortex is involved)
• May be bilateral visual impairment
• May be hemiparesis, hemisensory symptoms, diplopia, vertigo, vomiting, dysarthria, dysphagia or ataxia
• Ask about weakness, facial drooping, gait disturbance, confusion, memory loss, dysarthria or abnormal behaviour
• Check for simultaneous cardiac symptoms (e.g. palpitations)

Question 8

What are the signs of TIA on physical examination?

Answer 8

Neurological examination may be NORMAL because the TIA may have resolved by the time you do it

Check pulse for irregular rhythm (AF)

Auscultate the carotids to check for bruits (carotid atherosclerosis)

Question 9

What investigations may be appropriate when suspecting TIA?

Answer 9

In primary care the following investigations can be requested:

• Urinalysis (check for glycosuria)
• FBC, U&Es, Lipids, LFTs, TSH
• ECG (check for AF or previous MI)

Secondary care investigations can involve an unenhanced CT - if there’s a possibility of a haemorrhage (eg if patient is anticoagulated or has a bleeding disorder)

Lastly you can investigate for the source of emboli

• ECG (24 hr tape or cardiac monitoring may be considered if paroxysmal atrial fibrillation is suspected)
• Doppler ultrasound of carotid and vertebral arteries

Question 10

What is the management plan for TIAs?

Answer 10

• Patients with acute neurological symptoms that resolve completely within 24 hrs should be given 300 mg aspirin immediately and assessed urgently within 24 hrs
• Patients with confirmed TIA should receive:
  Clopidogrel - 300 mg loading dose and 75 mg thereafter
  High-Intensity Statin Therapy - e.g. atorvastatin 20-80 mg
  ——————————————
  Secondary prevention can involve:
  Antiplatelets
  Antihypertensives
  Lipid-modifying treatments
  Management of AF
  ——————————————–
  Assesment of future stroke risk in TIA pts = ABCD2 score

Question 11

What are the potential complications of TIAs?

Answer 11

Recurrent TIAs

Strokes

Question 12

What is the prognosis of patients with TIAs

Answer 12

VERY HIGH RISK of STROKE in the first month after the TIA and up to 1 year afterwards