[1] Univ Med Ctr Hamburg Eppendorf, Dept Neurol, D-20246 Hamburg, Germany
[2] Univ Med Ctr Hamburg Eppendorf, Dept Med Biometry & Epidemiol, D-20246 Hamburg, Germany
[3] Neurol Outpatient Clin Parkinsons Dis & Deep Brai, D-07551 Gera, Germany
[4] Univ Med Ctr Hamburg Eppendorf, Dept Neurophysiol & Pathophysiol, D-20246 Hamburg, Germany
[5] Univ Med Ctr Hamburg Eppendorf, Dept Neurosurg, D-20246 Hamburg, Germany