3 Department of Neurology, University of Kiel, Kiel, Germany.
4 Hospital General de Agudos Jose Maria Ramos Mejia, Departamento de Neurología, Universidad de Buenos Aires, Buenos Aires, Argentina.
5 The Edmond J. Safra Program in Parkinson's Disease and the Morton and Gloria Shulman Movement Disorders Clinic, University of Toronto, Toronto, Ontario, Canada.
6 National Center of Epidemiology and CIBERNED, Carlos III Institute of Health, Madrid, Spain.
7 Parkinson's Disease and Movement Disorders Center, Division of Neurology, Department of Medicine, The Ottawa Hospital Research Institute, University of Ottawa, Ottawa, Ontario, Canada.
8 George Huntington Institute and Dept. of Clinical Radiology, University of Muenster, Muenster, and Dept. of Neurodegenerative Diseases and Hertie Institute for Clinical Brain Research, University of Tuebingen, Tuebingen, Germany.
9 Center for the Study of Movement, Cognition, and Mobility, Tel Aviv Sourasky Medical Center; Department of Physical Therapy, Sackler Faculty of Medicine and Sagol School of Neuroscience, Tel Aviv University, Israel; Rush Alzheimer's Disease Center and Department of Orthopaedic Surgery, Rush University Medical Center, Chicago, Illinois, USA.
10 Department of Neurology and Center for Health + Technology, University of Rochester Medical Center, Rochester, New York, USA.
11 Discipline of Physiotherapy, Faculty of Health Sciences, University of Sydney, Sydney, Australia.
12 Department of Biomedical Informatics, University of Cincinnati College of Medicine, Cincinnati, Ohio, USA.
13 CHDI Foundation/ CHDI Management, Inc., Princeton, New Jersey, USA.
14 Department of Physical Medicine & Rehabilitation, Spaulding Rehabilitation Hospital, Harvard Medical School, Charlestown, Massachusetts, USA.
15 Division of Neurology and the Mah Pooi Soo & Tan Chin Nam Centre for Parkinson's & Related Disorders, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia.
16 Radboud University Medical Center, Donders Institute for Brain, Cognition and Behaviour, Department of Neurology, Nijmegen, The Netherlands.
17 The Michael J. Fox Foundation for Parkinson's Research, New York, New York, USA.
18 Jeff and Diane Ross Movement Disorders Clinic at ATC/Baycrest Health Sciences, Division of Neurology Department of Medicine University of Toronto, Toronto, Ontario, Canada.
19 Biogen, Cambridge, Massachusetts, USA.
20 Department of Molecular Neurology, Movement Disorder Unit, University Hospital Erlangen, Friedrich-Alexander-University Erlangen-Nürnberg, Erlangen, Germany.
21 Department of Neurological Sciences, Rush University Medical Center, Chicago, Illinois, USA.