Key clinical point: Patients with pediatric-onset multiple sclerosis (MS) are more likely than those with adult-onset MS to have cognitive impairment in adulthood.
Major finding: At age 35 years, the mean Symbol Digit Modalities Test score for patients with adult-onset MS was 61, whereas for patients with pediatric-onset MS it was 51. By age 40 years, the mean score was 58 for adult-onset MS versus 46 for pediatric-onset MS.
Study details: A Swedish population-based, longitudinal cohort study of 5,704 patients with MS, 300 of whom had pediatric-onset MS (5%).
Disclosures: The study was supported by the Swedish Research Council, the Swedish Brain Foundation, and by postdoctoral awards from the Canadian Institutes of Health Research and European Committee for Treatment and Research in Multiple Sclerosis, both to Dr. McKay. Coauthors reported receiving honoraria for speaking and serving on advisory boards for various pharmaceutical companies, as well as receiving research funding from agencies, foundations, and pharmaceutical companies.
McKay KA et al. JAMA Neurol. 2019 Jun 17. doi: 10.1001/jamaneurol.2019.1546.
The study by McKay et al. indicates that onset of multiple sclerosis (MS) during childhood or adolescence has long-term effects, Lauren B. Krupp, MD, and Leigh E. Charvet, PhD, wrote in an accompanying editorial.
In early adulthood, patients with pediatric-onset MS initially may perform better on the Symbol Digit Modalities Test, compared with patients with adult-onset MS. “However, the two groups diverged by the time the [pediatric-onset MS] patients reached 30 years of age, with slower performance in the [pediatric-onset MS] group relative to the [adult-onset MS] group, a difference that persisted over time,” Dr. Krupp and Dr. Charvet wrote. The findings remained even when the researchers adjusted for disease duration.
“Despite initial resiliency and age-based advantages, the study’s findings suggest greater deleterious long-term consequences from developing MS during a period of ongoing brain development,” they wrote.
The effect of slowed cognitive processing on quality of life is unclear, however. “The key question for future research is whether those with [pediatric-onset MS] attain their anticipated educational and occupational achievements in a manner comparable to those with [adult-onset MS],” Dr. Krupp and Dr. Charvet concluded.
Dr. Krupp and Dr. Charvet are affiliated with the Multiple Sclerosis Comprehensive Care Center at New York University. These comments are adapted from an editorial accompanying the article by McKay et al. ( JAMA Neurol. 2019 Jun 17. doi: 10.1001/jamaneurol.2019.1546 ). Dr. Krupp reported receiving grants from the National Multiple Sclerosis Society; grants and personal fees from Biogen; and personal fees from Novartis, Sanofi Aventis, Sanofi Genzyme, Shire Pharmaceuticals, Roche, and RedHill Biopharma outside the submitted work. Dr. Charvet reported receiving grants and personal fees from Biogen, grants from the National Multiple Sclerosis Society, and research funding from Novartis and Biogen outside the submitted work.