1. From the Department of Neurology and Neuroscience (B.B.N., H.K.), Weill Cornell Medical College, New York, NY; Department of Neurology (M.P.S., A.W.G., S.N.P., S.A.J., S.C.J., A.S.K.), University of California, San Francisco, CA; California Pacific Medical Center (C.W.), San Francisco, CA; Department of Emergency Medicine (W.D.W.), University of California, San Francisco, CA; Department of Epidemiology and Biostatistics (S.C.J.), University of California, San Francisco, CA.