Radiologically isolated syndrome in children: Clinical and radiologic outcomes.

OBJECTIVE: To describe clinical and radiologic outcomes of children with incidental findings on neuroimaging suggestive of CNS demyelination (termed "radiologically isolated syndrome" or RIS). METHODS: Clinical and radiologic data were obtained from a historical cohort of children with no symptoms of demyelinating disease who had MRI scans that met the 2010 MRI criteria for dissemination in space for MS. RESULTS: We identified 38 children (27 girls and 11 boys) with RIS now being prospectively followed at 16 sites in 6 countries. The mean follow-up time was 4.8 ± 5.3 years. The most common reason for initial neuroimaging was headache (20/38, 53%). A first clinical event consistent with CNS demyelination occurred in 16/38 children (42%; 95% confidence interval [CI]: 27%-60%) in a median of 2.0 years (interquartile range [IQR] 1.0-4.3 years). Radiologic evolution developed in 23/38 children (61%; 95% CI: 44%-76%) in a median of 1.1 years (IQR 0.5-1.9 years). The presence of ≥2 unique oligoclonal bands in CSF (hazard ratio [HR] 10.9, 95% CI: 1.4-86.2, p = 0.02) and spinal cord lesions on MRI (HR 7.8, 95% CI: 1.4-43.6, p = 0.02) were associated with an increased risk of a first clinical event after adjustment for age and sex. CONCLUSIONS: We describe the clinical characteristics and outcomes of children with incidental MRI findings highly suggestive of CNS demyelination. Children with RIS had a substantial risk of subsequent clinical symptoms and/or radiologic evolution. The presence of oligoclonal bands in CSF and spinal cord lesions on MRI were associated with an increased risk of a first clinical event.