1. Department of Neurology, University Medical Center Groningen, University of Groningen, The Netherlands
2. Parkinson’s Foundation International Centre of Excellence, King’s College Hospital, London, UK
3. Psychology & Neuroscience, King’s College Institute of Psychiatry, London, UK
4. Parkinson and Movement Disorders Unit, Study Center on Neurodegeneration (CESNE), Department of Neuroscience, Padua University, Padua, Italy
5. Department of Neurology, Movement Disorder Clinic, University Hospital of Bispebjerg, Copenhagen, Denmark
6. Department of Neurology, University Medical Centre Ljubljana, Slovenia, Faculty of Medicine, University of Ljubljana, Slovenia