1 Parkinson's Disease & Movement Disorders Unit, Hospital Clínic Barcelona, Barcelona, Spain.
2 DIBAPS-Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Spain.
3 Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Madrid, Spain.
4 Universitat de Barcelona, Catalonia, Spain.
5 Nuclear Medicine Department, Hospital Clínic Barcelona & Biomedical Research Networking Center in Bioengineering, Biomaterials and Nanomedicine (CIBER-BBN), Barcelona, Spain.