Brain glymphatic system impairment in multiple sclerosis patients based on diffusion tensor imaging

Motivation: Glymphatic abnormalities have been reported in several neurodegenerative disorders. However, glymphatic function has not been thoroughly investigated in multiple sclerosis, especially its relationship with clinical fatigue. Goal(s): We aimed to investigate glymphatic system function in multiple sclerosis and to evaluate its association with clinical fatigue. Approach: We prospectively enrolled 36 multiple sclerosis patients and 31 healthy controls. All subjects underwent diffusion tensor imaging, and the along perivascular space (ALPS) indexes were calculated. Correlations between ALPS indexes and clinical fatigue parameters were analyzed. Results: The brain glymphatic system is impaired in multiple sclerosis. Impaired glymphatic function was associated with multiple sclerosis-related fatigue. Impact: Non-invasive diffusion-based imaging approach could be used as a proxy for displaying an impaired glymphatic system in multiple sclerosis patients, suggesting that glymphatic impairment may be a pathological mechanism underpinning clinical fatigue.