1. The National Hospital; Queen Square and University College London; London UK
2. Neurology Service, Hospital Clínic de Barcelona; Universitat de Barcelona, IDIBAPS, Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas; Barcelona Catalonia Spain
3. Departments of Neurology and Neuroscience; Mount Sinai School of Medicine, New York; New York USA