1. Blizard Institute, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, London, UK
2. Department of Neurology, Hospital Universitario Fundación Santa Fe de Bogotá, Bogotá, Colombia
3. School of Medicine, Universidad de los Andes, Bogotá, Colombia
4. Multiple Sclerosis Centre of Catalonia (Cemcat), Neurology Department, Vall d’Hebron Univeristy Hospital, Barcelona, Spain
5. Preventive Medicine and Epidemiology Department, Hospital Universitari Vall d’Hebron, Barcelona, Spain
6. Vall d’Hebron Institut de Recerca (VHIR), Universitat Autònoma de Barcelona, Barcelona, Spain