1. Department of Neurology, Medical Faculty, Heinrich-Heine-University, Düsseldorf, Germany/Brain and Mind Centre, University of Sydney, Sydney, NSW, Australia; Department of Neurology, Medical University of Vienna, Vienna, Austria
2. Department of Neurology, Medical Faculty, Heinrich-Heine-University, Düsseldorf, Germany
3. Queen Square MS Centre, UCL Institute of Neurology, London, UK