Volumetric MRI Comparing Longitudinal Change in MOGAD to NMOSD, MS and Healthy Controls, and Disability Associations.

OBJECTIVES

To examine volumetric magnetic resonance imaging (vMRI) in myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD), compared to multiple sclerosis (MS), neuromyelitis optica spectrum disorder (NMOSD), and healthy controls (HC).

METHODS

Standardized vMRI in MOGAD were compared to age, sex, and disease duration matched MS (5:1), and non-matched NMOSD and HC, in mixed linear models with time and group interactions. Disability assessments included; patient determined disease steps (PDDS), manual dexterity (MDT), walking speed (WST), processing speed (PST), and contrast sensitivity tests (CST). Correlations between vMRI and disability in MOGAD were examined.

RESULTS

A total of 293 patients were included; 32 MOGAD, 160 MS, 49 NMOSD, and 52 HC. MOGAD had a faster rate of volume loss in all brain regions compared to HC (p < 0.05). At baseline, MOGAD had preserved thalamic (0.000507, p = 0.005), caudate (0.000287, p = 0.004), and putamen (0.000341, p = 0.007) fractions than MS. Longitudinally, MOGAD had increased lateral ventricle fraction (LVF) (-0.000645, p = 0.032), but less hippocampal (0.000031, p = 0.044) and upper cervical cord area (UCCA) loss (1.482887, p = 0.005), compared to NMOSD. MOGAD had increased LVF (0.00529, p < 0.001), but less UCCA loss (0.538656, p = 0.042) longitudinally compared to MS. Among MOGAD, UCCA was associated with PDDS (-0.72, p = 0.004) and CST (0.60, p = 0.014). Whole brain fraction (WBF) was associated with PDDS (-0.66, p = 0.01) and PST (0.52, p = 0.019). LVF was associated with PDDS (0.78, p < 0.001).

INTERPRETATION: MOGAD showed longitudinal brain volume loss compared to HC. Deep gray matter was relatively preserved compared to MS, while MS and NMOSD had greater UCCA loss, indicating regional differences in atrophy. Despite less overall atrophy, volume loss in MOGAD was associated with disability. ANN NEUROL 2025;98:1044-1056.