1. From the UPMC Stroke Institute (A.M.M., N.A.V., R.L., S.F.Z., A.A., M.A.J., V.K.R., M.D.H., L.R.W., T.G.J.), University of Pittsburgh Medical Center, Pittsburgh, PA; Swedish Neuroscience Institute (A.M.M.), Swedish Medical Center, Seattle, WA; the Souers Stroke Institute and Center for Cerebrovascular Disease and Skull Base Surgery (N.A.V.), St Louis University, St Louis, MO; and the Department of Neurosurgery (B.T.J., M.B.H.), University of Pittsburgh Medical Center, Pittsburgh, PA.