Acute ischaemic stroke: part I. The carotid circulation.

OBJECTIVE To review recent advances in the management of acute ischaemic stroke in a two part presentation. DATA SOURCES Articles and a review of studies reported from 1990 to 2000 and identified through a MEDLINE search of the English language literature on acute ischaemic stroke. SUMMARY OF REVIEW An acute ischaemic stroke is characterised clinically by the rapid development of a neurological deficit caused by a thrombus or embolus in the carotid (i.e. anterior) circulation or vertebrobasilar (i.e. posterior) circulation. Management requires urgent computed tomography to differentiate it from a haemorrhagic stroke. Ancillary investigations of echocardiography and thrombophilia screen may also be required if a cardiac embolic condition or hypercoagulable state is suspected, respectively. Cerebral magnetic resonance imaging, angiography and duplex ultrasonography with Doppler analysis of cerebral blood flow are becoming increasingly useful in determining the site and extent of the ischaemic lesion. Lumbar puncture is rarely required. Treatment with aspirin (150-300 mg) within the first 48 hr as well as management in a specialised unit focusing on resuscitation and prevention of complications (e.g. maintaining hydration and nutrition, and preventing aspiration and pressure sores, etc), has reduced morbidity and mortality associated with acute ischaemic strokes. However, while therapy to improve cerebral blood flow using thrombolytics, anticoagulants, glycoprotein IIb/IIIa inhibitors or fibrinogen depleting agents or neuroprotective agents to reduce further neuronal damage (e.g. solfotel, eliprodil, lubeluzole) have shown promise experimentally and in specific clinical circumstances, they have not produced consistent improvement in morbidity or mortality. CONCLUSIONS An acute ischaemic stroke in the distribution of the carotid circulation requires aspirin 150-300 mg daily and management in an acute stroke unit. Thrombolytic therapy (with rt-PA within the first three hours) to improve cerebral blood flow has limited application, and current neuroprotective agents have not yet been shown to be of benefit.