Glymphatic system impairment in multiple sclerosis: relation with brain damage and disability

Area of Science:

• Neuroscience
• Radiology
• Immunology

Background:

• The glymphatic system facilitates central nervous system waste clearance.
• Glymphatic dysfunction is implicated in neurodegenerative diseases like Alzheimer's and Parkinson's.
• Its role in multiple sclerosis (MS), a condition with both inflammatory and neurodegenerative aspects, remains underexplored.

Purpose of the Study:

• To investigate glymphatic system function in MS patients.
• To assess the association between glymphatic function and clinical disability, disease course, demyelination, and neurodegeneration.
• To compare glymphatic function across different MS subtypes and with healthy controls.

Main Methods:

• Retrospective study including 71 MS patients and 32 healthy controls.
• Utilized advanced MRI techniques (high-resolution T1, T2, DIR, DWI, SWI) to assess glymphatic function via diffusion along perivascular space (dPVS) index.
• Quantified clinical disability, disease duration, lesion volumes, and normal-appearing white matter microstructural damage.

Main Results:

• MS patients exhibited significantly lower dPVS index compared to healthy controls.
• Progressive MS patients showed more pronounced glymphatic impairment than relapsing-remitting MS patients.
• Lower dPVS index was associated with greater clinical disability, longer disease duration, increased lesion load, and more severe white matter microstructural damage.

Conclusions:

• Glymphatic system impairment is evident in multiple sclerosis, particularly in progressive stages.
• Impaired glymphatic function is linked to key pathological features of MS, including demyelination and neurodegeneration.
• Glymphatic dysfunction may represent a significant pathological mechanism contributing to MS progression and clinical severity.