Association between Changes in White Matter Microstructure and Cognitive Impairment in White Matter Lesions

Area of Science:

• Neuroimaging
• Neurology
• Biomarkers

Background:

• Cerebral small vessel disease frequently causes white matter lesions (WMLs).
• WMLs are associated with cognitive impairment, including vascular cognitive impairment non-dementia and vascular dementia.
• Understanding the microstructural basis of cognitive decline in WMLs is crucial.

Purpose of the Study:

• To investigate cognitive impairment characteristics in patients with WMLs.
• To identify corresponding changes in white matter (WM) microstructures using diffusion tensor imaging (DTI).
• To explore the relationship between WM microstructural integrity and cognitive function.

Main Methods:

• Collected DTI data from 50 patients with WMLs and 37 healthy controls.
• Categorized patients into vascular cognitive impairment non-dementia and vascular dementia groups.
• Utilized tract-based spatial statistics to analyze WM microstructural integrity.

Main Results:

• Patients with WMLs exhibited significantly altered DTI metrics (lower fractional anisotropy, higher mean, axial, and radial diffusivity) in major WM tracts compared to controls.
• Significant differences in DTI metrics were observed across all analyzed fiber bundles.
• DTI metrics of most fiber bundles significantly correlated with Montreal Cognitive Assessment scores, except for axial diffusivity in the forceps major and inferior longitudinal fasciculus.

Conclusions:

• Patients with WMLs demonstrate widespread changes in WM microstructure, detectable by DTI.
• Quantifiable alterations in WM microstructure are a primary pathological basis for cognitive impairment in WMLs.
• WM microstructural changes may serve as valuable biomarkers for WMLs and associated cognitive deficits.