1. Danish Multiple Sclerosis Center, Department of Neurology, University of Copenhagen and Rigshospitalet, Copenhagen, Denmark
2. Department of Neurology, University Hospital, Medical Faculty, Heinrich-Heine-University, Düsseldorf, Germany
3. Department of Neurology, Hospital General Universitari Vall D’Hebron, Cemcat, Barcelona, Spain
4. Division of Neurology, University of Toronto, St. Michael’s Hospital, Toronto, Canada
5. Department of Neurology and Institute of Experimental Neurology, San Raffaele Hospital, Vita-Salute San Raffaele University, Milan, Italy