1. Sobell Department of Motor Neuroscience and Movement disorders; UCL Institute of Neurology; London United Kingdom
2. Second Department of Neurology, Attiko Hospital; University of Athens; Athens Greece
3. Neurology Clinic; Philipps-University; Marburg Germany
4. Department of Neurology; University of Kiel; Kiel Germany
5. Department of Neurology; Medical University of Graz; Graz Austria