Published in:
17-04-2023 | Multiple Sclerosis | Original Communication
Multiple sclerosis optic neuritis and trans-synaptic pathology on cortical thinning in people with multiple sclerosis
Authors:
Ranjani Ganapathy Subramanian, Robert Zivadinov, Niels Bergsland, Michael G. Dwyer, Bianca Weinstock-Guttman, Dejan Jakimovski
Published in:
Journal of Neurology
|
Issue 8/2023
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Abstract
Background
The multi-order visual system represents an excellent testing site regarding the process of trans-synaptic degeneration. The presence and extent of global versus trans-synaptic neurodegeneration in people with multiple sclerosis (pwMS) is not clear.
Objective
To explore cross-sectional and longitudinal relationships between retinal, thalamic and cortical changes in pwMS with and without MS-related optic neuritis (pwMSON and pwoMSON) using MRI and optical coherence tomography (OCT).
Methods
162 pwMS and 47 healthy controls (HCs) underwent OCT and brain MRI at baseline and 5.5-years follow-up. Peripapillary retinal nerve fiber layer (pRNFL) and macular ganglion cell inner plexiform layer (mGCIPL) thicknesses were determined. Global volume measures of brain parenchymal volume (BPV)/percent brain volume change (PBVC), thalamic volume and T2-lesion volume (LV) were derived using standard analysis protocols. Regional cortical thickness was determined using FreeSurfer. Cross-sectional and longitudinal relationship between the retinal measures, thalamic volume and cortical thickness were assessed using age, BPV/PBVC and T2-LV adjusted correlations and regressions.
Results
After age, BPV and T2-LV adjustment, the thalamic volume explained additional variance in the thickness of pericalcarine (R2 increase of 0.066, standardized β = 0.299, p = 0.039) and lateral occipital (R2 increase of 0.024, standardized β = 0.299, p = 0.039) gyrii in pwMSON. In pwoMSON, the thalamic volume was a significant predictor only of control (frontal) regions of pars opercularis. There was no relationship between thalamic atrophy and cortical thinning over the follow-up in both pwMS with and without MSON. While numerically lower in the pwMSON group, the inter-eye difference was not able to predict the presence of MSON.
Conclusions
MSON can induce a measurable amount of trans-synaptic pathology on second-order cortical regions.