[1] Haukeland Univ Hosp HUS, Norwegian Multiple Sclerosis Competence Ctr, Dept Neurol, Bergen, Norway
[2] Sogn & Fjordane Cent Hosp, Dept Neurol, Forde, Norway
[3] Sogn & Fjordane Univ Coll, Fac Hlth Studies, Forde, Norway
[4] Univ Bergen, Dept Clin Med, KG Jebsen Ctr MS Res, Bergen, Norway
[5] Haukeland Hosp, Norwegian Multiple Sclerosis Registry & Biobank, Dept Neurol, N-5021 Bergen, Norway