Differences in resting state functional connectivity relative to multiple sclerosis and impaired information...

Area of Science:

• Neuroscience
• Medical Imaging
• Cognitive Science

Background:

• Multiple sclerosis (MS) frequently causes cognitive impairment (CI), particularly affecting information processing speed (IPS), impacting daily life.
• Neural underpinnings of IPS deficits in MS remain unclear, necessitating advanced neuroimaging techniques.
• Resting-state functional magnetic resonance imaging (fMRI) offers a window into brain function alterations in MS.

Purpose of the Study:

• To investigate functional connectivity (FC) differences in individuals with MS compared to healthy controls (HC).
• To compare FC in MS patients with cognitive impairment (MS-CI) and those cognitively preserved (MS-CP) against HC.
• To explore FC variations between MS-CI and MS-CP groups and their correlation with cognitive performance.

Main Methods:

• 107 MS patients and 94 HC underwent resting-state fMRI and the Symbol Digit Modalities Test (SDMT).
• Participants were categorized into MS-CI (SDMT z-score < -1.5) and MS-CP (SDMT z-score ≥ 0) groups.
• Whole-brain ROI-to-ROI analysis was conducted, with specific contrasts and regression analyses.

Main Results:

• Individuals with MS exhibited altered FC in the cerebellum, visual/language areas, thalamus, hippocampus, and basal ganglia compared to HC.
• The MS-CI group showed significant FC differences in the cerebellum, visual/language areas, thalamus, and caudate compared to their matched HC.
• FC between the cerebellum and lateral occipital cortex correlated with SDMT scores in the MS group.

Conclusions:

• Functional connectivity alterations in cerebellar, visual, and language-associated regions are prominent in MS.
• These FC changes are evident across all MS participants, the MS-CI subgroup, and correlate with cognitive performance.
• Future research on MS-related IPS impairments should prioritize these identified brain regions.