[1] Asklepios Hosp Hamburg N, Dept Neurol, D-22417 Hamburg, Germany
[2] Aschaffenburg Hosp, Dept Neurol, Aschaffenburg, Germany
[3] Univ Hosp Schleswig Holstein, Dept Neurol, Lubeck, Germany
[4] Univ Hosp Schleswig Holstein, Dept Neuroradiol, Lubeck, Germany
[5] Univ Hosp Schleswig Holstein, Inst Med Biometry & Stat, Lubeck, Germany