Abstract

A transient ischaemic attack (TIA), perhaps better referred to as transient brain ischaemia, may be defined as an ischaemic focal disturbance of brain function lasting less than 24 hours; most attacks last less than 30 minutes. The attacks need to be distinguished from focal or temporal lobe epilepsy or the premonitory symptoms before a migrainous headache. The ischaemia may occur in either the carotid or vertebro-basilar territory. Attacks tend to recur, and can herald an impending stroke. Transient ischaemia is usually due to embolism from an atheromatous lesion. Concomitant conditions such as anaemia¹ and polycythaemia² make attacks more likely, a fact too often ignored in reports on the treatment of transient brain ischaemia.