To investigated how white matter microstructural integrity and structural network connectivity are related to recognition functions in a community-based sample.

Evidences showed that the disconnection of cortical-subcortical linkages plays a role in cognitive impairment in neurodegenerative disease and aging populations. Whereas this disconnection could not be comprehensively displayed via white matter damage visible on conventional imaging. Thus, exploring patterns of microstructural integrity and network connectivity would give important indications for the pathogenic mechanisms of cognitive dysfunction.

Participants (age ≥35 years) from the community-based Shunyi Study were included to investigate the association between white matter metrics and cognition cross-sectionally. Cognitive functions were assessed using Fuld Object Memory (FOM), digit span, trail making test (TMT)-A, and TMT-B. Fractional anisotropy (FA), mean diffusivity (MD), and structural network connectivity parameters were calculated based on diffusion tensor imaging.

Of the 974 participants included, the mean (SD) age was 56.02(9.18)years, and the mean (SD) education level was 6.60 (3.29) years. Poor performance in digit span, TMT-A, and TMB-B were associated with lower FA and higher MD in skeleton voxels of bilateral internal and external capsules left upper and lower longitudinal fascicles (TFCE corrected P<0.05), independent of age, sex and education level. FOM scores was significantly correlated with the connectivity strength of the bilateral cingulate gyrus and precuneus (unadjusted p < 0.01), while digit span scores significantly correlated with connectivity strength of the bilateral frontal gyrus and medial temporal lobe (unadjusted p < 0.01). TMT-A performance was significantly related to the nodal efficiency of the frontal motor area (FDR corrected p<0.05).

In a large community-based aging population, widespread disrupted white matter integrity is related to poor cognition functions. Limbic-occipital and frontal-temporal linkage contribute to visual physical memory and working memory respectively, while frontal network dysconnectivity is engaged in executive function impairment.