Correlates of long-term clinical outcomes in pediatric multiple sclerosis: A 12-year study

Background: Identifying long-term outcome substrates in pediatric multiple sclerosis (Ped-MS) can inform treatment selection. We investigated clinical/magnetic resonance imaging (MRI) correlates over a median 12.3-year follow-up. Methods: Fifty-two Ped-MS patients and 23 healthy controls underwent baseline 3.0 T MRI. Neurological evaluations were performed every 6 months. MRI metrics included regional lesion burden, brain and choroid plexus (CP) volumes, diffusion tensor-derived fractional anisotropy (FA), averaged in normal-appearing white matter (NAWM). Multivariable Cox, Andersen–Gill, linear regression models identified long-term outcome correlates. Results: At follow-up, 69% relapsed, 21% had 6-month confirmed disability worsening (6m-CDW), and 35% showed EDSS worsening. Infratentorial lesion number (hazard ratio (HR) = 1.09, 95% confidence interval (CI) = 1.02 to 1.18), spinal cord lesion presence (HR = 2.45, 95% CI = 1.18 to 5.10), and thalamic volume (HR = 0.77, 95% CI = 0.60 to 0.99) were associated with shorter time to first relapse; high-efficacy treatment (HET) exposure with longer (HR = 0.20, 95% CI = 0.06 to 0.68), and CP volume (HR = 1.58, 95% CI = 0.93 to 2.68) was associated marginally. WM lesion volume (HR = 1.04, 95% CI = 1.01 to 1.06) and HET exposure (HR = 0.21, 95% CI = 0.11 to 0.40) were associated with higher/lower overall relapse risk, respectively; baseline EDSS (HR = 1.29, 95% CI = 0.96 to 1.73), spinal cord lesion presence (HR = 1.52, 95% CI = 0.95 to 2.44), and CP volume (HR = 1.35, 95% CI = 1.00 to 1.83) contributed marginally. Younger age (HR = 0.82, 95% CI = 0.68 to 0.98) and NAWM FA (HR = 0.67, 95% CI = 0.51 to 0.88) were associated with earlier 6m-CDW; NAWM FA with EDSS worsening (β = −0.26, 95% CI = −0.50 to −0.03). Conclusion: Advanced MRI markers and HET exposure associate with long-term outcomes in Ped-MS.