1. From the Department of Neurosurgery (J. Goldberg, D.S., W.Z., A.R., J.B., C.F.), Inselspital, Bern University Hospital, University of Bern, Switzerland.
2. Department of Diagnostic and Interventional Neuroradiology (P.M., J. Gralla), Inselspital, Bern University Hospital, University of Bern, Switzerland.