Mediation effects of white matter abnormalities in the associations between cerebral small vessel disease burden and cognitive impairment

Motivation: Different cerebral small vessel disease (CSVD) burden may be an important factor affecting CSVD. Goal(s): To characterize white matter (WM) microstructural abnormalities in CSVD subjects with different CSVD burden and further to investigate the exactly mechanism for how different CSVD burden influences cognitive decline in CSVD subjects. Approach: WM diffusion changes among groups were analyzed using diffusion tensor imaging (DTI) -derived tract-based spatial statistic. Results: CSVD subjects with severe CSVD burden (CSVD-s) exhibits extensive WM microstructural deterioration and cognitive dysfunction. Changes of brain WM diffusion biomarkers played a significant mediating role in the relationship between CSVD burden and cognitive impairment. Impact: Combining DTI-derived diffusivity and anisotropy metrics can provide complementary information for assessing WM alterations associated with cognitive dysfunction, which helps us to understand the mechanism of cognitive impairment in CSVD-s.