1. From the Department of Epidemiology (M.J.R., J.G.), Michigan State University, East Lansing, Mich; College of Education (K.S.M.), Michigan State University, East Lansing, Mich; Department of Neurology (J.P.B., C.J.M.), University of Cincinnati, Ohio; Department of Neurology (M.F.), Emory University, Atlanta, Ga; Massachusetts PRO (K.A.L.), Waltham, Mass; Department of Neurology (L.S.), Massachusetts General Hospital, Boston, Mass.