Thrombolysis in acute ischaemic stroke

The primary deficit in acute ischaemic stroke is one of impaired blood flow. Part of the cerebral circulation is occluded either by in situ thrombosis, or embolism from the heart or a more proximal artery (for example, the ipsilateral internal carotid artery). Angiographic studies of the cerebral circulation in acute stroke demonstrate occluding thrombus in up to 80% of patients. The aim of thrombolytic therapy therefore is to lyse an occluding thrombus or embolus and reduce the volume of cerebral tissue irreversibly damaged. Such an approach is of course successfully employed in the treatment of acute myocardial infarction. However a major complication of thrombolysis in stroke is cerebral haemorrhage which could oVset any beneficial eVects. Here we review the available evidence for thrombolysis in acute stroke and suggest imaging methods that could be used to aid future selection of patients who are most likely to benefit from such treatment.