Abstract
BACKGROUND/OBJECTIVES: Pediatric-onset multiple sclerosis (POMS) accounts for 3-10% of all multiple sclerosis (MS) cases and represents the earliest manifestation of chronic autoimmune demyelination of the central nervous system. While increasing incidence rates have been reported in Europe, no regional data exist for Austria. This study aimed to determine the incidence, prevalence, and clinical characteristics of POMS in Tyrol, Austria, over a 10-year period. METHODS: All patients diagnosed with MS before 18 years of age between 1 January 2015 and 31 December 2024, were included. Diagnoses were confirmed according to the 2010 and 2017 McDonald criteria and re-evaluated using the 2024 revisions. Demographic, clinical, cerebrospinal fluid (CSF), and MRI data were systematically reviewed. Incidence and prevalence rates were calculated with 95% confidence intervals (CI) using the exact Clopper-Pearson method. RESULTS: Twenty-nine patients were newly diagnosed with POMS (26 female; median age 15 years, range 11-17), corresponding to a pooled 10-year incidence of 2.19 per 100,000 person-years (95% CI 1.47-3.14) and a point prevalence of 6.7 per 100,000 children (95% CI 3.1-12.8) as of 31 December 2024. Sensory (55%) and visual (31%) symptoms predominated at onset. Pleocytosis was found in 93%, and all CSF samples showed positive oligoclonal bands. MRI revealed supratentorial lesions in 97%, infratentorial in 69%, and spinal in 73%. The median annualized relapse rate was 0.67, and all patients had an EDSS of 0 at last follow-up. CONCLUSIONS: This first regional analysis of pediatric-onset MS in Austria demonstrates a higher incidence than most previously reported European cohorts, positioning Tyrol within the upper European range. The findings highlight the impact of early recognition, structured diagnostics, and timely initiation of disease-modifying therapy on favorable short-term outcomes.