Long-term prognostic features of pediatric-onset multiple sclerosis: A large cohort from Türkiye

This study aimed to characterize demographic features, clinical presentations, and long-term outcomes of pediatric-onset multiple sclerosis (POMS) patients in a Turkish tertiary MS center.

We retrospectively analyzed 143 patients diagnosed with multiple sclerosis (MS) before age 16, based on the 2017 McDonald criteria, and clinically monitored between 1981 and 2018. Demographic and clinical data, including age at onset, initial symptoms, relapse history, and Expanded Disability Status Scale (EDSS) scores, were collected. Disability milestones (EDSS 4 and 6) and conversion to secondary progressive MS (SPMS) were examined using Kaplan-Meier survival analysis and Cox regression.

We followed 143 POMS patients for a median of 11 years (69.2% female; median onset age: 14.6 years). By study completion, 22.4% reached EDSS 4 and 16.8% converted to SPMS. Onset before age 14 was associated with a longer time to EDSS 4 (p < 0.001) and SPMS-free survival (p = 0.03). In multivariate analysis, male sex, onset after age 14, higher baseline EDSS, and incomplete recovery from the first attack independently predicted disability progression. Delayed disease modifying therapy initiation (≥12 months) was also associated with increased risk of reaching EDSS 4. SPMS conversion was predicted by onset after age 14, higher baseline EDSS, brainstem onset, and incomplete recovery from the first attack.

In this large Turkish POMS cohort, onset after age 14, brainstem involvement, and poor recovery from the first attack were associated with earlier disability milestones. These findings highlight the prognostic role of early disease characteristics and emphasize the importance of optimizing treatment strategies in pediatric MS.