Background: White matter (WM) damage could be observed in both vascular cognitive disorder predementia (VCD-P) and amnestic mild cognitive impairment (aMCI). In the period of VCD-P, the degree of cognitive decline was similar to aMCI, but they are different in the specific cognitive domains. However whether the differences in cognitive domains are related to the pattern of WM impairment hasn’t been illustrated.
Hypothesized: The region or degree of WM impairment differs from VCD-P to aMCI.
Methods: All subjects include 28 patients with VCD-P, 34 aMCI and 39 normal controls (NC) underwent a comprehensive neuropsychological assessment and DTI. We compared fractional anisotropy (FA), mean diffusivity (MD) and axial diffusivity (AxD) of whole brain WM regions. Then the diffusion tensor was reconstructed, analyzed by tract-based spatial statistics.
Results: Patient groups exhibited significant differences in FA, MD and AxD, the VCD-P group has a lower FA, higher MD and AxD. The different FA and MD region between VCD-P and aMCI was in left anterior limb of internal capsule, bilateral corona radiata, corpus callosum, cerebral peduncle, external capsule, posterior limb of internal capsule, fornix, inferior longitidinal fasciculus, inferior and superior fronto-occipital fasciculus, whereas in AxD it was showed in bilateral corona radiata, internal capsule, external capsule, corpus callosum, posterior thalamic radiation and superior longitudinal fasciculus.
Conclusion: Our findings suggest that VCD-P and aMCI have divergent topography of WM microstructural changes in the degree and the region, the WM integrity was impaired more severe in VCD-P. The differences in regions may illustrate the clinical and neuropsychological features characterized by executive or memory deficit. These findings provide insights into the biological mechanism of cognitive disorders and highlight the potential of DTI as the imaging biomarker for diagnosis. All authors report no conflicts of interest. This work was supported by the National Natural Science Funds of China (Grant No. 81301188).