1. Department of Neurology, Haukeland University Hospital, Bergen, Norway
2. Haematology Section, Department of Medicine, Haukeland University Hospital, Bergen, Norway
3. Department of Immunology and Transfusion Medicine, Haukeland University Hospital, Bergen, Norway
4. Department of Neurology, Akershus University Hospital, Oslo, Norway
5. Institute of Clinical Medicine, University of Oslo, Oslo, Norway
6. Department of Neurology, Sørlandet Hospital Kristiansand, Kristiansand, Norway
7. Department of Clinical Medicine, University of Bergen, Bergen, Norway