Antibody-mediated demyelinating disease – A voxel-based morphology analysis

Identifying magnetic resonance imaging (MRI) markers in myelin-oligodendrocytes-glycoprotein antibody-associated disease (MOGAD) and neuromyelitis optica spectrum disorder-aquaporin-4 positive (NMOSD-AQP4) is essential for establishing objective outcome measures.

The primary aim was to explore differences within the brain morphology changes through the voxel-based-morphology (VBM) between MOGAD and NMOSD-AQP4 patients during the remission stage with healthy controls (HC).

In this cross-sectional study, 27 patients with MOGAD, 27 with NMOSD-AQP4, and 30 healthy subjects were recruited from 2018 to 2020. All 84 participants were scanned with the same standardized MRI-protocol on a 3-Tesla MRI-scanner. Structural T1-weighted images were processed and analyzed using the Computational Anatomy Toolbox (CAT12) (Gaser, C. Structural Brain Mapping, Group, Jena University Hospital, Jena, Germany; https://www.neuro.uni-jena.de/cat/) implemented in Statistical Parametric Mapping (SPM12; Wellcome Trust Centre for Neuroimaging, London, UK; https://www.fil.ion.ucl.ac.uk/spm/software/ spm12/). Processing and analysis steps were followed according to the pre-set parameters with the standard protocol described in the manual (https://www. neuro.uni-jena.de/cat12/CAT12-Manual.pdf).

Compared to the HC, MOGAD patients demonstrated grey matter volume reduction in the left ventral superior frontal gyrus and left superior temporooccipital (p<0.001). NMOSD-AQP4 showed a greater extension of cerebral volume reduction, more significantly in the subependymal areas (adjacent to third ventricle and bilateral periatrial) and the left lingual cortex (p<0.001).

In conclusion, MOGAD and NMOSD-AQP4 patients, during the remission stage, exhibited distinct patterns of brain volume reduction. Our findings could be explained, at least in part, by the differences in pathophysiology between these diseases. Although we conducted a group analysis, these results can support the transition of future studies analyzing the potential use of VBM analysis as a surrogate tool at the individual level.