1. Department of Neurology, Hannover Medical School, Carl-Neuberg Strasse 1, Hannover 30625, Lower Saxony, Germany
2. Department of Neurology, Hannover Medical School, Hannover, Germany
3. Department of Anesthesiology, Hannover Medical School, Hannover, Germany
4. Department of Neuroradiology, Hannover Medical School, Hannover, Germany