1. From the Department of Neurology (H.P.A., E.C.L.), Carver College of Medicine and the Department of Epidemiology (J.C.T.), College of Public Health, University of Iowa, Iowa City, Iowa; Centocor Research (E.B., L.P.), Malvern, Pa; Eli Lilly and Company (M.B.E.), Indianapolis, Ind; and the Department of Neurology (W.H.), University of Heidelberg, Heidelberg, Germany.