Transient ischaemic attacks: evaluation and management

Transient ischaemic attacks (TIAs) are temporary focal cerebral or retinal deficits that resolve within 24 hours. Attention should be given to the tempo and localisation of the clinical syndrome, as multiple and hemispheric TIAs are associated with the greatest incidence of early stroke. Evaluation of TIAs depends on the clinical symptoms, physical examination and investigations. Attention should be given to clinical evidence of generalised atherosclerotic disease, as death due to the complications of ischaemic heart disease is the commonest outcome in patients with TIA. Early attention should focus on risk factor modification, with emphasis on the treatment of hypertension and smoking cessation. Antiplatelet therapy should be instituted. Aspirin is the first-line treatment but, if not tolerated, clopidogrel is effective in preventing vascular complications. Anticoagulants are generally reserved for patients with atrial fibrillation and are associated with a significant reduction of stroke risk. The use of statins is becoming more widespread, with emerging evidence of their efficacy in reducing stroke risk. The risk of stroke is greatest in the weeks following TIA and patients should be referred for carotid duplex ultrasonography. Carotid endarterectomy for symptomatic internal carotid artery high grade stenosis virtually abolishes stroke risk in that vascular territory over subsequent years. TIAs should be regarded as an emergency requiring early diagnosis and prompt referral.