1. Department of Neurology, Zuyderland Medical Center, 6130 MB Sittard, The Netherlands
2. Department of Neurosciences, S. Camillo Forlanini Hospital, Rome, Italy
3. Department of Clinical Neuroscience, Institute of Neuroscience and Physiology, Sahlgrenska Academy and Department of Neurology, Sahlgrenska University Hospital, Gothenburg, Sweden
4. Center of Clinical Neuroscience, Carl Gustav Carus University Clinic, Technical University of Dresden, Dresden, Germany
5. REVAL, Faculty of Rehabilitation Sciences, Hasselt University, Diepenbeek, Belgium; UMSC Hasselt, Pelt, Belgium
6. Biogen, Cambridge, MA, USA
7. Biogen, Baar, Switzerland
8. Plymouth University Peninsula Schools of Medicine and Dentistry, Plymouth Hospitals NHS Trust, Plymouth, UK