Functional and structural MRI correlates of executive functions in multiple sclerosis

Area of Science:

• Neuroimaging
• Neuroscience
• Neurology

Background:

• Executive dysfunction affects 15%-28% of multiple sclerosis (MS) patients, impacting attention, working memory, planning, and inhibition.
• Understanding the neurobiological underpinnings of these deficits is crucial for effective management.

Purpose of the Study:

• To investigate the relationship between structural and functional magnetic resonance imaging (MRI) abnormalities and executive function (EF) deficits in MS patients.
• To identify specific brain networks and white matter tracts associated with impaired EF in MS.

Main Methods:

• 116 MS patients and 65 controls underwent resting-state (RS) and diffusion-weighted MRI scans.
• Neuropsychological testing, including the Wisconsin Card Sorting Test (WCST), assessed EF.
• Analysis included deriving brain RS cognitive networks and fractional anisotropy (FA) from white matter tracts, and investigating associations with WCST scores.

Main Results:

• Lower corpus callosum (CC) FA and altered working-memory network (WMN) and executive control network (ECN) functional connectivity (FC) predicted working memory deficits.
• Reduced CC genu FA and altered WMN/default-mode network (DMN) FC were associated with attention impairments.
• Lower CC genu and superior cerebellar peduncle (SCP) FA, along with altered WMN/ECN FC, predicted deficits in shifting and inhibition.

Conclusions:

• Microstructural damage in the CC and SCP contributes to executive dysfunction in MS.
• Abnormalities in resting-state functional connectivity (FC) within cognitive networks are linked to executive function frailty in MS patients.