Transient Ischaemic Attack

Question 1

Definition

Answer 1

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

Question 2

Aetiology

Answer 2

• It is usually EMBOLIC but may be thrombotic
• Most common source of emboli = CAROTID atherosclerosis

• Emboli can also arise from the heart:
o Atrial fibrillation
o Mitral valve disease
o 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

o Hypertension
o Smoking
o Diabetes mellitus
o Heart disease (valvular, ischaemic, atrial fibrillation)
o Peripheral arterial disease
o Polycythaemia rubra vera
o COCP
o Hyperlipidaemia
o Alcohol
o 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

Presenting 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
o 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

Question 6

Presenting symptoms (located in carotid territory)

Answer 6

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)

Question 7

Presenting symptoms (located in vertebrobasilar territory)

Answer 7

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

Signs 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

Investigations (primary care)

Answer 9

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

Question 10

Investigations (secondary care)

Answer 10

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

Question 11

Investigations (to find source of emboli)

Answer 11

o ECG (24 hr tape or cardiac monitoring may be considered if paroxysmal atrial fibrillation is suspected)

o Doppler ultrasound of carotid and vertebral arteries

Question 12

Management plan (acute)

Answer 12

• 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:
o Clopidogrel - 300 mg loading dose and 75 mg thereafter
o High-Intensity Statin Therapy - e.g. atorvastatin 20-80 mg

Question 13

Management plan (prevention)

Answer 13

• Secondary Prevention
o Antiplatelets
o Antihypertensives
o Lipid-modifying treatments
o Management of AF

• Assessment of future stroke risk in TIA patients: ABCD2 score

Question 14

Possible complications

Answer 14

• Recurrence

* Stroke

Question 15

Prognosis

Answer 15

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