Transient Ischaemic Attack

Question 1

Define

Answer 1

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

Question 2

Causes

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

Risk factors

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

Epidemiology

Answer 4

More common with increasing age

More common in men

15% of stroke patients would have experienced a previous TIA

Question 5

Symptoms

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

History

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

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 6

Signs

Answer 6

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 7

Investigations

Answer 7

Primary Care Investigations

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

Secondary Care

• Unenhanced CT - if there is a possibility of a haemorrhage (e.g. if the patient is anticoagulated or has a bleeding disorder)

Investigate for Source of Emboli

Question 8

Management

Answer 8

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

• Antiplatelets
• Antihypertensives
• Lipid-modifying treatments
• Management of AF

Assessment of future stroke risk in TIA patients: ABCD2 score

Question 9

Complications

Answer 9

Recurrence

Stroke

Question 10

Prognosis

Answer 10

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