Data of 249 Pediatric-onset MS patients were assessed. Mean age at onset and mean disease duration were 15.06 and 11.78 years, respectively. In 10.8% of children, the first symptoms appeared at the age of <12 years. At the last follow-up visits, most of patients (83.5%) remained in a relapsing-remitting phenotype, while 10% had secondary progressive MS (SPMS) and only 1 case (0.4%) was diagnosed as primary progressive MS (PPMS). Twelve patients (4.8%) continued to be labelled as clinical isolated syndrome.
The most frequent presentation at onset was of brainstem/cerebellar manifestations, (34.9%), followed by spinal symptoms (29.3%). At the baseline visit, EDSS was 2.26, as compared to the last follow up visit, which significantly decreased to 1.95, (p<0.001). The ARR was 0.18 during the first 2 years while on treatment. About 43.4% of the patients were on interferon/copaxone prior treatment escalation to high efficacy medications. Escalation to high efficacy DMTs was due to disease breakthrough in 36.1% of patients, and 9.6% of others due to adverse events on prior DMT.
POMS has a unique clinical, where brainstem/ cerebellar symptoms was the most frequent first symptoms present. Pediatric patients are less likely to develop PPMS or SPMS and more likely to follow a relapsing–remitting course. Disease breakthrough is common in POMS, especially when using platform therapies.