1Department of Surgery, Klinikum Grosshadern, Ludwig-Maximilian University, Marchioninistrasse 15, D-81377 Munich, Germany, Germany
2Department of Neurology, Klinikum Grosshadern, Ludwig-Maximilian University, Marchioninistrasse 15, D-81377 Munich, Germany, Germany
3Department of Radiology, Klinikum Grosshadern, Ludwig-Maximilian University, Marchioninistrasse 15, D-81377 Munich, Germany, Germany
4Department of Clinical Neurosciences, Western General Hospitals NHS Trust, University of Edinburgh, Crewe Road, Edinburgh EH4 XU, UK, UK