Introduction: The balance between excitatory and inhibitory (E/I) neural processes is a fundamental principle of brain function, and its disruption has been implicated in the pathophysiology of multiple sclerosis (MS). In vivo assessment of E/I balance has traditionally relied on electrophysiological measures, and despite the abundance of fMRI data on MS, no fMRI-based technique has so far been presented to measure E/I balance in MS.Methods: Recently, a novel MRI-based method has been introduced to estimate E/I balance by integrating functional MRI and diffusion weighted imaging data. We use this approach to study E/I balance in MS at a global (over the whole head) and at the local level of specific resting state networks affected by MS: the somatomotor and Default Mode network (DMN). Furthermore, we perform the analysis using three different atlases: the Schaefer atlas, which is functionally defined, and the Automatic Anatomical Labeling (AAL) and Desikan Killany (DK) atlas, which are defined based on structural features.Results: Our findings reveal a significant alteration in E/I balance within the somatomotor and default mode networks when using the functionally defined Schaefer atlas, suggesting a network-specific dysfunction in MS. We also find that the E/I balance inferred within the somatomotor network correlates with motor fatigue.Conclusions: This study demonstrates a promising framework for investigating E/I balance alterations in neurological disorders and paves the way for validation in larger cohorts.
Zin, G, Nagels, G, Van Schependom, J & Manos, T 2026 'Altered excitation-inhibition balance in the somatomotor and default mode network in multiple sclerosis'.
Zin, G., Nagels, G., Van Schependom, J., & Manos, T. (2026). Altered excitation-inhibition balance in the somatomotor and default mode network in multiple sclerosis.
@techreport{0d3003517cc04f08985a9766085aa82e,
title = "Altered excitation-inhibition balance in the somatomotor and default mode network in multiple sclerosis",
abstract = "Introduction: The balance between excitatory and inhibitory (E/I) neural processes is a fundamental principle of brain function, and its disruption has been implicated in the pathophysiology of multiple sclerosis (MS). In vivo assessment of E/I balance has traditionally relied on electrophysiological measures, and despite the abundance of fMRI data on MS, no fMRI-based technique has so far been presented to measure E/I balance in MS.Methods: Recently, a novel MRI-based method has been introduced to estimate E/I balance by integrating functional MRI and diffusion weighted imaging data. We use this approach to study E/I balance in MS at a global (over the whole head) and at the local level of specific resting state networks affected by MS: the somatomotor and Default Mode network (DMN). Furthermore, we perform the analysis using three different atlases: the Schaefer atlas, which is functionally defined, and the Automatic Anatomical Labeling (AAL) and Desikan Killany (DK) atlas, which are defined based on structural features.Results: Our findings reveal a significant alteration in E/I balance within the somatomotor and default mode networks when using the functionally defined Schaefer atlas, suggesting a network-specific dysfunction in MS. We also find that the E/I balance inferred within the somatomotor network correlates with motor fatigue.Conclusions: This study demonstrates a promising framework for investigating E/I balance alterations in neurological disorders and paves the way for validation in larger cohorts.",
keywords = "Multiple sclerosis, multimodal MRI, functional connectivity",
author = "Gaia Zin and Guy Nagels and {Van Schependom}, Jeroen and Manos, {Thanos (Athanasios)}",
year = "2026",
language = "English",
type = "WorkingPaper",
}