1. From the Department of Neurology (S.S.K., E.S., B.C., C.G., G.T.), University Medical Center Hamburg-Eppendorf, Germany
2. Department of Neurology, University Hospital Essen, University of Duisburg-Essen, Germany (U.B.).
3. Department of Diagnostic and Interventional Neuroradiology (J.F.), University Medical Center Hamburg-Eppendorf, Germany