1. From the Department of Neurology (J.O., J.L.S., J.R.A., S.S., M.C.L., G.D., R.J., P.V., J.P.V., F.V., C.S.K.), Stroke Center (J.L.S., S.S., M.C.L., R.J., P.V., C.S.K.), Department of Radiology (J.R.A, G.D. J.P.V., F.V.), Department of Emergency Medicine (S.S.), and Department of Neurosurgery (P.V.), UCLA Medical Center, Los Angeles, Calif, and Department of Radiology (P.G.), New York Presbyterian-Weill Cornell Medical College, New York.