Karolinska Institutet - Department of Clinical Neuroscience, University of Copenhagen - Department of Pediatrics, Karolinska Institutet - Neuroimmunology Unit, Karolinska Institutet, Aarhus University Hospital - Department of Neurology, University of Southern Denmark - MS Clinic Southern Denmark, University of Copenhagen - Rigshospitalet, University of Copenhagen - Rigshospitalet, Karolinska Institutet - Department of Clinical Neuroscience and Sahlgrenska University Hospital - Department of Neurology