Vanishing MS T2-bright lesions before puberty: A distinct MRI phenotype?

Abstract

Background Multiple sclerosis (MS) onset before puberty may have a distinct clinical presentation. Pediatric patients with MS may less often meet MRI diagnostic criteria for adults. Whether initial MRI presentation is distinct in prepubertal patients is unknown. Methods We queried the UCSF MS database for pediatric patients with MS (onset or=11 years) pediatric MS. The next available brain MRI scan was used to evaluate lesion resolution. Results Thirteen children with EOPMS (median age 8.90 years, range [3.58-10.98], 38% girls) and 18 with LOPMS (median age 14.47 years, range [11.78-18.00], 61% girls) were identified. While the overall number of T2-bright lesions was similar in the two groups, patients with EOPMS had fewer well-defined ovoid T2-bright lesions (median = 7, range [0-29] vs 21.5, [4-100]; p = 0.004) and more often had confluent lesions (31% of patients vs 0%; p = 0.02) on their first MRI compared with patients with LOPMS. Ninety-two percent of patients with EOPMS had a reduction in the number of T2-bright lesions on the second scan compared to 29% of patients with LOPMS (p = 0.002). Conclusions The distinct prepubertal multiple sclerosis (MS) MRI phenotype suggests that underlying biologic processes may differ in earlier-onset pediatric MS compared to later-onset pediatric MS. These findings may delay diagnosis in that age range. MRI criteria for MS diagnosis may need to be revised before puberty.