Long-term disability progression of pediatric-onset multiple sclerosis

OBJECTIVE: To evaluate long-term disability progression in pediatric-onset multiple sclerosis (POMS) and compare to adult-onset multiple sclerosis (AOMS). METHODS: This was a retrospective cohort study using prospectively collected clinical information from the Swedish MS Registry. Clinical features were compared and Kaplan-Meier and Cox proportional hazards regression were used to assess the risk of reaching sustained Expanded Disability Status Scale (EDSS) 3, 4, and 6 in POMS (multiple sclerosis [MS] onset <18 years) and AOMS (MS onset ≥18 years). RESULTS: A total of 12,482 persons were included; 549 (4.4%) were classified as POMS. The POMS cohort took longer to reach all 3 disability milestones from their MS onset, but did so at a younger age than the AOMS cohort. Primary progressive course (hazard ratio [HR] 4.63; 95% confidence interval [CI] 1.46–14.7), higher relapse rate in the first 5 years of disease (HR 5.35; 95% CI 3.37–8.49), and complete remission from the initial relapse (HR 0.41; 95% CI 0.18–0.94) were associated with an altered risk of progression to EDSS 4 among POMS cases. The same pattern emerged for the risk of reaching EDSS 3 and 6. CONCLUSIONS: Patients with pediatric-onset MS follow a distinctive clinical course, which should be considered in the treatment and management of the disease.