Corpus callosum damage predicts disability progression and cognitive dysfunction in primary-progressive MS after five...

Area of Science:

• Neuroimaging
• Neurology
• Multiple Sclerosis Research

Background:

• Primary-progressive multiple sclerosis (PPMS) is characterized by gradual neurological decline.
• Predicting disability progression and cognitive dysfunction in PPMS is crucial for patient management.
• White matter (WM) and grey matter (GM) integrity are implicated in MS pathophysiology.

Purpose of the Study:

• To identify specific WM and GM regions that predict disability progression and cognitive dysfunction over five years in early PPMS patients.
• To investigate the relationship between baseline imaging metrics and clinical outcomes.
• To understand the role of interhemispheric pathways in PPMS.

Main Methods:

• Longitudinal study of 32 early PPMS patients with 5-year follow-up.
• Assessment of Expanded Disability Status Scale (EDSS) and neuropsychological tests.
• Baseline imaging included diffusion tensor imaging (DTI) and T1-weighted volumetric MRI.
• Voxel-based morphometry and tract-based spatial statistics were used to analyze imaging data.
• Voxelwise linear regression analyses correlated imaging metrics with clinical outcomes.

Main Results:

• Lower fractional anisotropy (FA) in the splenium of the corpus callosum (CC) predicted greater EDSS progression.
• Lower FA throughout the CC predicted poorer performance in verbal memory, attention, processing speed, and executive function.
• Baseline grey matter volume did not predict clinical outcomes.
• Damage to interhemispheric callosal pathways is associated with long-term physical and cognitive disability in PPMS.

Conclusions:

• Damage to the corpus callosum (CC) is a significant predictor of both physical disability and cognitive impairment in primary-progressive multiple sclerosis (PPMS).
• The findings underscore the importance of interhemispheric pathway integrity for motor and cognitive function in PPMS.
• Disruption of these pathways may lead to a disconnection syndrome contributing to long-term disability in PPMS patients.