1. From the Department of Medicine (Neurology) (D.T.L.), Duke University, Durham, NC; the Department of Neurology (S.E.K.), University of Pennsylvania, Philadelphia Pa; the Department of Neurology (J.S.), UCLA Medical Center, Los Angels, Calif; the Department of Neurology (K.S.R.), University of Louisville, Louisville, Ky; and the Department of Neurosciences (E.C.J.), Medical University of South Carolina, Charleston, SC.