1. From the Department of Neurology (P.J.L., L.S., R.O.R., T.T., O.H., M.T, M. Kaste) and Neuroscience Program, Biomedicum Helsinki (P.J.L., T.T.); Department of Radiology (O.S.); and Helsinki Emergency Medical Services (M. Kuisma), Helsinki University Central Hospital, Helsinki, Finland.