Cortical lesions in children with multiple sclerosis.

Double inversion recovery (DIR) sequences have improved the detection of cortical lesions (CLs) in adult patients with multiple sclerosis (MS). We evaluated the presence and frequency of CLs in pediatric patients with relapsing-remitting MS (RRMS) in comparison to adult patients with MS with the same clinical phenotype. Using a 3.0-T scanner, brain DIR, dual-echo, and 3-dimensional T1-weighted scans were acquired from 24 pediatric patients with RRMS, 15 adult patients with RRMS, and 10 pediatric healthy controls. CLs and white matter (WM) lesions were identified, and their volumes measured. Brain gray matter and WM volumes were also calculated. Between-group comparisons were performed using χ(2), Mann-Whitney, and analysis of variance tests. Poisson regressions for count data were used to model the number of lesions of the 2 groups of patients. Compared to adults, pediatric patients had shorter disease duration and lower disability. WM lesion number and volume did not differ between pediatric and adult patients with MS. CLs were detected in 2 (8%) pediatric and 10 (66%) adult patients. Median CL volume was lower in pediatric than adult patients with RRMS (p = 0.0003). Regression analysis showed that pediatric patients had a lower number of CLs than adults (p = 0.0003), after adjusting for age, gender, Expanded Disability Status Scale score, and disease duration. CLs are rare in pediatric patients with MS. Since pediatric patients with MS have a clinical onset closer to the biological onset of the disease than adult patients with MS, our findings indicate that CL formation is likely not to be an initial event in this disease.