Analyzing the Differences Between Adolescent and Adult Multiple Sclerosis

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Pediatric-onset multiple sclerosis (POMS), defined as disease onset before 18 years of age, accounts for approximately 2% to 5% of all MS cases.¹ The condition most commonly presents during adolescence, though onset can also occur in early childhood. Compared with adult-onset multiple sclerosis (MS), POMS is associated with higher inflammatory activity, more frequent early relapses, and a longer cumulative disease burden over a patient’s lifetime.²

In May 2018, fingolimod (Gilenya, Novartis) became the first FDA-approved drug to treat relapsing MS in pediatric patients, expanding on its 2010 indication for adults with the condition. Further clinical trials evaluating pediatric patients aged 10 to 17 years substantiated an expanded approval for these patients.³ The safety and effectiveness of fingolimod in pediatric patients aged 10 and older have been established, but there is no data pertaining to pediatric patients below the age of 10.

At the 2026 Americas Committee for Treatment and Research in Multiple Sclerosis (ACTRIMS) Forum, held February 5–7 in San Diego, California, a dedicated session examined MS across the lifespan. Within that session, POMS was explored as a distinct and impactful disease subtype. The presentation was delivered by Yael Hacohen, MD, PhD, pediatric neurologist at the UCL Institute of Neurology in London, England, who evaluated POMS through the lens of its long-term implications for people living with MS. To gain further insight, NeurologyLive spoke with Hacohen following her presentation.

In the interview, Hacohen explained some of the differences between pediatric-onset MS and adult-onset MS, noting that age strongly influences the balance between inflammation, neurodegeneration, and repair capacity. The discussion also highlighted that brain atrophy is more difficult to interpret in pediatric populations because the brain is still developing, requiring age-adjusted modeling to accurately assess neurodegeneration. Above all, Hacohen underscored that pediatric demyelinating events are far more likely to represent MS mimics, such as MOG antibody–associated disease, than true MS.

For more ACTRIMS 2026 coverage, click here.

REFERENCES
1. Boster A, Endress C, Hreha S, Caon C, Perumal J, Khan O. Pediatric-Onset Multiple Sclerosis in African-American Black and European-Origin White Patients. Pediatric Neurology. 2029;40(1):31-33 doi:doi.org/10.1016/j.pediatrneurol.2008.09.004.
2. Chitnis T, Glanz B, Jaffin S, Healy B. Demographics of pediatric-onset multiple sclerosis in an MS center population. Neurology. 2009;72(1):39–44.
3. FDA expands approval of Fingolimod to treat multiple sclerosis in pediatric patients. FDA website. Updated May 11, 2018. Accessed August 22, 2018. https://www.fda.gov/newsevents/newsroom/pressannouncements/ucm607501.htm?rel=0"