Emergency treatment of acute ischemic stroke: expanding the time window.

Intravenous thrombolysis has been shown to improve outcome in patients with ischemic stroke if given within the first 3 hours. This benefit extends into a 4.5-hour time window when applied in a more selected patient population. Strokes from large-vessel intracranial occlusion carry high morbidity and respond poorly to intravenously administered thrombolytics. Endovascular therapy should therefore be considered in patients who fail or have contraindications for intravenous thrombolysis, or who present within a time window of 4.5 to 8 hours, and perhaps up to 12 to 24 hours for basilar occlusions.