1. From the Stroke Institute (M.A.J., T.G., A.M.M., V.R., R.L., J.I.O., S.Z., L.R.W., T.G.J.) and Department of Neurosurgery (B.J., M.H.), University of Pittsburgh Medical Center, Pittsburgh, Pa; Memorial Hospital (F.Z.), Northwestern University, Chicago, Ill; and Department of Medicine (A.A.), Universitat Autonoma de Barcelona, and Department of Medicine (G.R.-A.) University Hospital La Paz, Madrid, Spain.