B leeding R isk A nalysis in S troke I maging Before Thrombo L ysis (BRASIL)

Abstract
Background and Purpose— There has been speculation that the risk of secondary symptomatic intracranial hemorrhage (SICH) may be increased after thrombolytic therapy in ischemic stroke patients who have cerebral microbleeds (CMBs) on T2*-weighted magnetic resonance imaging. Because of this concern, some centers withhold potentially beneficial thrombolytic therapy from these patients. Methods— We analyzed magnetic resonance imaging data acquired within 6 hours after symptom onset from 570 ischemic stroke patients treated with intravenous tissue plasminogen activator in 13 centers in Europe, North America, and Asia. Baseline T2*-weighted magnetic resonance images were evaluated for the presence of CMBs. The primary end point was SICH, defined as clinical deterioration with an increase in the National Institutes of Health Stroke Scale score by ≥4 points, temporally related to a parenchymal hematoma on follow-up-imaging. Results— A total of 242 CMBs were detected in 86 of 570 patients (15.1%). The number of CM...