A. Viswanathan, MD, PhD, S. M. Rakich, BS, C. Engel, BA, R. Snider, BS, J. Rosand, MD, MSc, S. M. Greenberg, MD, PhD and E. E. Smith, MD, FRCPC From the Stroke Service and Neurology Clinical Trials Unit, Department of Neurology, Massachusetts General Hospital, Boston. Address correspondence and reprint requests to Dr Smith, VBK 802, MGH Stroke Service, Massachusetts General Hospital, 55 Frui