Whole Brain MRI Reveals that Children with Acute Disseminated Encephalomyelitis have Enlarged Brain Ventricles at Disease Onset

Pediatric patients with acute disseminated encephalomyelitis (ADEM) are at risk of long-term neurocognitive consequences. We investigated a multi-center cohort of ADEM patients with serial whole brain MRI, to distinguish transient reversible expansion of brain ventricle volume (BVV) from persistent changes. Using the automated brain segmentation tool SynthSeg, we observed that ADEM patients had significantly enlarged BVV relative to sex- and age-matched pediatric control subjects, already at the first clinical presentation, before any steroid treatment. Most ADEM patients developed even greater BVV expansion over the observation period. The majority of patients recovered, though some showed persistent BVV enlargement, suggesting brain atrophy.