Correlation Between Visual Network Integrity and Visual Function in Multiple Sclerosis Patients
Vanessa Dias Veloso1, Jonadab Dos Santos Silva1, Viviane Carvalho2, Sarita Walvekar1, Luciana Schermann Azambuja3, Adriana Gutterres Pereira3, Giordani Rodrigues dos Passos3, Douglas Kazutoshi Sato3, Jefferson Becker3
1Neurology, Yale New Haven Hospital/Yale University, 2Federal Fluminense University, 3Instituto do Cerebro, Pontificia Universidade Catolica do Rio Grande do Sul (PUCRS)
Objective:
This study aimed to pinpoint cortical nodes in the visual network whose functional integrity is associated with visual disability in MS.
Background:
Visual dysfunction is a disabling symptom in multiple sclerosis (MS), traditionally linked to demyelination of the anterior visual pathways. However, the role of cortical network integrity, specifically in higher-order visual association areas, in clinical visual impairment is not fully understood.
Design/Methods:
Cross-sectional study with 20 MS patients. Resting-state functional MRI (rs-fMRI) was used to assess intrinsic brain activity. The visual resting-state network was identified using group-level Independent Component Analysis (ICA). To examine the relationship between the visual network's intrinsic connectivity and clinical visual function, measured by the Functional Systems Visual (FS Visual) score of the Expanded Disability Status Scale (EDSS), a whole-brain, voxel-wise regression analysis was conducted. Age and sex were covariates.
Results:
The analysis revealed a significant negative correlation between intrinsic connectivity and FS Visual scores, localized to a single cluster in the right hemisphere. This statistically significant cluster (p-FDR = 0.035) was centered in the right posterior inferior temporal gyrus (pITG) (MNI coordinates: +48, -24, -24). The negative correlation means that reduced functional connectivity in this region was associated with worse visual function. A data-driven meta-analysis confirmed the right pITG's robust association with higher-order visual processing, including functions like reading and face recognition.
Conclusions:
Reduced functional integrity of the right pITG, a key node in the ventral visual stream, is a neural correlate of visual impairment in MS. The pathophysiology of visual disability in MS extends beyond damage to the anterior visual pathways to include cortical dysfunction in areas responsible for complex visual interpretation. The observed hypoconnectivity linked to worse function supports a model of maladaptive neuroplasticity or "network collapse" within the visual system, making the right pITG a potential imaging biomarker for higher-order component of visual disability in MS.
Disclaimer: Abstracts were not reviewed by Neurology® and do not reflect the views of Neurology® editors or staff.