1. Institute of Diagnostic and Interventional Neuroradiology (T.D., E.I.P., N.S., J.K., J.G., P.M.), Inselspital, University Hospital of Bern, Switzerland.
2. Department of Neurology (B.V., T.R.M., M.A., U.F., S.J., M.R.H), Inselspital, University Hospital of Bern, Switzerland.
3. Department of Neurology, University of Erlangen-Nuremberg, Germany (B.V.).
4. Department of Interventional, Pediatric and Diagnostic Radiology (N.S., J.K.), Inselspital, University Hospital of Bern, Switzerland.