1. J. R. Marler is associate director for Clinical Trials, National Institute of Neurological Disorders and Stroke, Bethesda, MD 20817, USA.
2. L. B. Goldstein is with the Department of Medicine (Neurology), Duke Center for Cerebrovascular Disease, and the Stroke Policy Program, Center for Clinical Health Policy Research, Duke University and the VA Medical Center, Durham, NC 27710, USA.