1. Department of Clinical Neurophysiology; University Medical Center Göttingen; Göttingen Germany
2. Paracelsus-Elena-Klinik; Kassel Germany
3. Department of Neurology; Philipps-University Marburg; Marburg Germany
4. Department of Medical Statistics; University Medical Center Göttingen; Göttingen Germany
5. Department of Neurosurgery; University Medical Center Göttingen; Göttingen Germany