Brief episode of neurological dysfunction due to temporary focal cerebral or retinal ischaemia without infarction, e.g. a weak limb, aphasia or loss of vision, usually lasting seconds or minutes with complete recovery; symptoms last less than ~24 hours

Aetiology

• Usually the result of microemboli

Risk factors

• Hypertension
• Diabetes mellitus
• High cholesterol
• Atrial fibrillation
• Carotid stenosis
• Smoking
• Previous history of cardio-embolic events
• Family history of cardiovascular disease/stroke

Clinical features

Patients typically present with a sudden onset of focal neurological deficits which may include:

• Speech difficulty (dysphasia)
• Arm or leg weakness
• Sensory changes
• Ataxia, vertigo or loss of balance
• Visual disturbance: Homonymous hemianopia, diplopia
• Amaurosis fugax - sudden transient loss of vision in one eye
  • A TIA causing an episode of amaurosis fugax is often the first clinical evidence of internal carotid artery stenosis - a warning sign of incipient ICA territory stroke