White matter volume and microstructural integrity are associated with fatigue in relapsing multiple sclerosis

Area of Science:

• Neuroscience
• Neurology
• Radiology

Background:

• Multiple sclerosis (MS) is a neurological disorder characterized by inflammation and demyelination.
• Fatigue is a common and debilitating symptom in MS, but its underlying mechanisms are not fully understood.
• Fatigue also occurs in other neurological conditions and healthy individuals, highlighting the need to differentiate its causes.

Purpose of the Study:

• To investigate the relationship between brain structure and fatigue in people with relapsing MS (PwRMS).
• To identify specific brain regions associated with general and cognitive fatigue in PwRMS.
• To explore potential differences in fatigue mechanisms between PwRMS and healthy controls.

Main Methods:

• Cross-sectional analysis of 32 PwRMS and 29 healthy controls reporting fatigue.
• Magnetic Resonance Imaging (MRI) including T1-weighted and diffusion-weighted imaging.
• Statistical analysis using Bayesian LASSO and Spike-and-Slab LASSO regression models.

Main Results:

• Significant associations were found between fatigue scores and brain structures in PwRMS.
• Reduced white matter volume was observed in regions like the cingulate gyrus, inferior frontal gyrus, and banks of the superior temporal sulcus.
• Compromised microstructural integrity in these areas correlated with fatigue severity in PwRMS.

Conclusions:

• Alterations in specific brain regions, particularly white matter, play a critical role in the manifestation of fatigue in MS.
• These findings may help distinguish general fatigue mechanisms from those specific to MS.
• Understanding these neuroanatomical correlates could inform the development of targeted therapeutic strategies for MS-related fatigue.