[1] Tech Univ Munich, Klinikum Rechts Isar, Neurol, D-80290 Munich, Germany
[2] Univ Basel Hosp, Neurol, CH-4031 Basel, Switzerland
[3] Tech Univ Munich, Klinikum Rechts Isar, Neuroradiol, D-80290 Munich, Germany
[4] Tech Univ Munich, Klinikum Rechts Isar, Neurol, D-80290 Munich, Germany