Regional brain atrophy in children with multiple sclerosis

► CNS atrophy in pediatric patients with multiple sclerosis is not yet characterized. ► Z-scoring against healthy children is needed to account for age-expected brain size. ► TBM identified reduced volumes for thalamus and splenium of corpus callosum. ► Splenium atrophy correlated with disease load; optic pathway atrophy, with duration. ► Focal inflammatory lesions may be an important cause of tract degeneration.