Changes in disability in people with multiple sclerosis: a 10-year prospective study

BACKGROUND: Little is known about the long-term course of disability in relation with disease severity in people with multiple sclerosis (PwMS). OBJECTIVE: To explore changes in a broad spectrum of disability over 10 years in relation with disease severity in PwMS. METHODS: We conducted a longitudinal study of 155 PwMS who attended the MS Centre at Karolinska University Hospital, Stockholm. Disease severity was determined by the use of the Expanded Disability Status Scale (EDSS) and classified as mild MS (EDSS score 0–3.5) or moderate/severe MS (EDSS score 4–9.5). Ten-year changes in perceived physical and psychological impacts of MS, walking, cognition, manual dexterity, participation in social/lifestyle activities, and signs of depression were compared between PwMS with mild and moderate/severe MS at baseline. RESULTS: Although walking, manual dexterity, and cognition declined in both groups, only the moderate/severe group demonstrated that long-term increased physical impact of MS, increased wheel-chair dependency, and reduced participation in social/lifestyle activities. Perceived psychological impact of MS declined in both groups, while signs of depression were experienced by fewer in the mild group and remained unaltered in the moderate/severe group. CONCLUSION: We found a more pronounced increase in disability across 10 years in individuals with moderate/severe MS compared to mild MS. These findings accentuate the importance of developing a variety of interventions that can be applied across the spectrum of disease severity.