1. From the Stroke Prevention Research Unit (E.T., P.M.R.), University Department of Clinical Neurology, Radcliffe Infirmary, Oxford, England; Faculté de Médecine René Descartes (E.T.), Université Paris 5, France; and the Department of Clinical Neuroscience (C.P.W.), Edinburgh University, Western General Hospital, Crewe Road, Edinburgh, England.