1. Sobell Department of Motor Neuroscience and Movement Disorders; University College London (UCL) Institute of Neurology; London United Kingdom
2. Neurology Clinic; Attiko Hospital, University of Athens; Greece
3. Department of Molecular Neuroscience; UCL Institute of Neurology; London United Kingdom
4. Department of Clinical Neurophysiology; National Hospital for Neurology and Neurosurgery; London United Kingdom
5. Department of Neurology; University of Kiel; Kiel Germany
6. Department of Neurology; Kantonsspital St. Gallen St. Gallen Switzerland