Disease Progression in Pediatric Multiple Sclerosis: A Narrative Review

OBJECTIVES: The occurrence of multiple sclerosis (MS) before the age of 18 years is relatively rare and approximately 2-10% of MS patients have their first manifestation before adulthood. There is limited evidence on progression of disease in pediatric onset MS (POMS) and how it is different from adult onset MS (AOMS), therefore our objective is to compare clinical and long-term outcomes in POMS vs. AOMS. METHODS: MEDLINE, Embase, the Cochrane Database of Systematic Reviews were queried using the OVID platform to identify publications related to disease progression in POMS. Studies published in the English language, between 2007 and March 2017 were included. RESULTS: Search generated 2,238 records, and 313 full-text articles were reviewed and of these, 42 were included in the review. Female preponderance was observed in both POMS and AOMS. Twenty-one studies reported data on disability accumulation as measured by EDSS and almost all reported a slower development of irreversible disability in POMS. However, POMS patients reached disability milestones at a younger age than AOMS. Ten studies reported data on relapse outcomes and, of these> four reported a comparison between AOMS and POMS.Three of them reported that relapses w^rp more frequent in POMS than AOMS. A slightly higher number of relapses were observed in patients with MS onset before 11 years of age. Relapse frequency in early phase of disease showed some correlation with the development of disability in patients. Two studies comparing cognitive outcomes for AOMS and POMS showed that cognitive impairment was higher in POMS as measured on Symbol Digit Modalities Test and Paced Auditory Serial Additional Test. CONCLUSIONS: Even though accrual of physical disability is slower in POMS than AOMS, cognitive decline in combination with progressive disability may have a severe impact on a child's ability to achieve and perform in later life.