[1] Univ Gottingen, Dept Clin Neurophysiol, D-37075 Gottingen, Germany
[2] Westeinde Ziekenhuis, Dept Clin Neurophysiol, The Hague, Netherlands
[3] Westeinde Ziekenhuis, Sleepctr, MCHaaglanden, The Hague, Netherlands
[4] Univ Marburg, Dept Neurol, Marburg, Germany
[5] Ctr Parkinsonism & Movement Disorders, Paracelsus Elena Klin, Kassel, Germany
[6] SEIN Zwolle, Sleepctr, Zwolle, Netherlands
[7] SEIN Zwolle, Dept Clin Neurophysiol, Zwolle, Netherlands