[1] Hannover Med Sch, Dept Neurol, D-30623 Hannover, Germany
[2] Univ Duisburg Essen, Dept Neurol, Essen, Germany
[3] Nordstadt Klinikum Hannover, Dept Neurol, Hannover, Germany
[4] Kreisklinikum Siegen, Dept Neurol, Siegen, Germany
[5] Boehringer Ingelheim Pharma GmbH & Co KG, Ingelheim, Germany
[6] Boehringer Ingelheim GmbH & Co KG, Ingelheim, Germany
[7] Univ Hosp Schleswig Holstein, Dept Neurol, Kiel, Germany
[8] Univ Gottingen, Dept Neurol, D-3400 Gottingen, Germany
[9] Stadt Klinikum Munchen GmbH, Dept Neurol, Klinikum Harlaching, Munich, Germany