1. Parkinson's Disease and Movement Disorders Unit Institut Clínic de Neurociències Hospital Clinic de Barcelona Barcelona Spain
2. Centre for Networked Biomedical Research on Neurodegenerative Diseases (CIBERNED) Madrid Spain
3. The National CJD Research & Surveillance Unit Centre for Clinical Brain Sciences University of Edinburgh Edinburgh EH4 2XU United Kingdom
4. Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS) University of Barcelona (UB) Barcelona Spain