Intravenous Thrombolysis Plus Hypothermia for Acute Treatment of Ischemic Stroke

A stroke is usually caused by a blockage in one of the arteries that carries blood to the brain. Research has shown that tissue plasminogen activator (tPA)-a naturally occurring protein that opens blocked arteries by dissolving blood clots-activates the body's ability to dissolve recently formed blood clots and reduces or prevents the brain damage caused by a stroke. The Food and Drug Administration (FDA) has approved the use of tPA for people having a stroke when taken within 3 hours of stroke onset, but not for those who arrive at the hospital more than 3 hours after stroke onset. Researchers believe that a lower body temperature (hypothermia) may be beneficial while a stroke is happening because hypothermia may prevent further brain injury, or may make the stroke less damaging. In particular, hypothermia may make it possible to use tPA later than 3 hours after a stroke begins. This study will determine if it is safe to use tPA within 6 hours of the start of a stroke when combined with hypothermia. Patients will receive a standard stroke evaluation, which includes blood tests, a computed tomography (CT) scan, complete physical and neurological examinations, and an electrocardiogram (EKG) to determine eligibility for the study. Participants will be randomly assigned to a study group based on when their stroke began. Those who arrive at the hospital less than 3 hours from stroke onset will receive tPA alone or tPA with cooling (hypothermia). Those who arrive at the hospital 3 to 6 hours after stroke onset will be assigned to 1 of 4 groups-receiving either tPA alone, tPA with cooling, cooling alone, or standard medical care. Length of participation (including observation after the patient leaves the hospital) is 90 days. This study is part of the Specialized Program of Translational Research in Acute Stroke (SPOTRIAS), which allows researchers to enhance and initiate translational research that ultimately will benefit stroke patients by treating more patients in less than 2 hours, and finding ways to treat additional patients later.