1. From the Department of Neurology (R.W., Y.G., A.K.B., O.A.W.) and G.H. Sergievsky Center (Y.G.), Vagelos College of Physicians and Surgeons, Columbia University Irving Medical Center; Department of Epidemiology (Y.G.), Joseph P. Mailman School of Public Health, and the Taub Institute for Research in Alzheimer's Disease and the Aging Brain, Columbia University, New York.