Pediatric Multiple Sclerosis in Rio de Janeiro: Secondary Progression and Disability

The onset of multiple sclerosis (MS) in 2% to 10% of cases occurs prior to 18 years of age. Early age onset appears to affect some aspects of multiple sclerosis. The objective of our study was to evaluate the prevalence, the clinical and demographic characteristics, and the disease progression in a sample of pediatric multiple sclerosis patients from a mixed population.

In a cross-sectional design, the prevalence, demographic characteristics, and initial clinical forms were compared between 75 cases of pediatric multiple sclerosis (PMS) and 689 adults with MS. Sixty-five PMS patients with complete data and 260 randomly selected adults with relapsing-remitting multiple sclerosis were compared. A Kaplan-Meier analysis was conducted to compare the age at and time to Expanded Disability Status Scale (EDSS) 3, EDSS 6, and secondary progressive multiple sclerosis (SPMS).

A total of 9.8% of all MS cases with available data were PMS. All cases of PMS consisted of relapsing-remitting multiple sclerosis. Brazilians of African descent comprised 34.6% of the sample, and the female-to-male ratio was 2.4:1. At the first attack, motor alterations were more common. Benign forms were more common in PMS (84.6% versus 62.2%). Fewer PMS patients reached EDSS 6 (11.6% versus 25.4%) (P = 0.0017) and SPMS (11.1% versus 28.1%) (P = 0.005). PMS patients took longer to reach EDSS 3 (P = 0.017), EDSS 6 (P = 0.001), and SPMS (P < 0.001); however, they reached EDSS 3 earlier (P < 0.001).

In this mixed cohort, the prevalence of PMS was similar to that reported in other studies, and the pediatric patients had a more benign course than adults with MS.