1. Division of Neuroscience, Department of Basic & Clinical Neuroscience, King's College London Institute of Psychiatry, Psychology & Neuroscience London United Kingdom
2. Parkinson Foundation Centre of Excellence at King's College Hospital NHS Foundation Trust London United Kingdom
3. Department of Neurology, Centre of Expertise for Parkinson & Movement Disorders, Donders Institute for Brain, Cognition and Behaviour Radboud University Medical Center Nijmegen The Netherlands
4. Department of Clinical and Movement Neurosciences UCL Institute of Neurology, University College London London United Kingdom
5. Center for Networked Biomedical Research in Neurodegenerative Diseases (CIBERNED) Carlos III Institute of Health Madrid Spain
6. Department of Psychiatry and Neurology Perelman School of Medicine at the University of Pennsylvania Philadelphia PA USA
7. Parkinson's Disease Research, Education and Clinical Center (PADRECC) Philadelphia Veterans Affairs Medical Center Philadelphia PA USA