Academic outcomes before and after clinical onset of acquired demyelinating syndromes in children: a matched cohort data linkage study.

It is unknown if cognition is impaired before clinical onset of paediatric acquired demyelinating syndromes. We conducted a matched cohort study using prospectively collected educational data in multiple sclerosis (MS) and myelin oligodendrocyte glycoprotein antibody disease (MOGAD) patients (n = 60) and controls (pooled n = 449,553). Academic performance at ages 10-11 was impaired in MOGAD (-1.27 adjusted z-score [95% CI: -1.81 to -0.73], P < 0.001) and preclinical MS (-0.40 [-0.80 to -0.0003], P = 0.0498). Moderate/high-efficacy MS treatment was associated with better final academic performance (0.92 [0.28-1.57], P = 0.005). After clinical onset MS patients missed 8.7% of school (controls 2.9%, P < 0.001) and MOGAD patients 11.9% (controls 2.0%, P < 0.001).