Progress in Cerebrovascular Disease Management of Patients with Established ("Completed") Cerebral Infarction

BY ARBITRARY DEFINITION, focal neurological deficit due to vascular disease which resolves in less than 24 hours is called a transient ischemic attack (TIA); one that exceeds this length of time is attributed to infarction or hemorrhage. Some neurologists distinguish another category, in which a neurological deficit lasting more than 24 hours eventually resolves completely — usually within 3 weeks. This has been termed a reversible ischemic neurological deficit (RIND). It is postulated that this situation results from sustained ischemia not severe enough to produce infarction. To be considered as established, or completed, an infarction in the brain supplied by the carotid system must be static for at least 24 hours; one in the brain supplied by the vertebrobasilar arterial system, for 72 hours. If new symptoms or signs develop during this period, the original episode is regarded as an evolving (progressing) infarction. Established or completed refers to the sequence of events and does not imply that a neurological deficit is as severe as it can become, but indicates that infarction has remained unchanged. For example, in a righthanded patient with an established infarction in the distribution of the left middle cerebral artery there may be no asphasia. Because it is still possible for the infarction to extend within this vascular bed, the question is whether prophylaxis following the first episode can prevent this. These definitions are retrospective and arbitrary but because they form a framework with which to link pathophysiology and clinical events, they are important when one is comparing groups of patients and