Alterations of White Matter Microstructure in Subcortical Vascular Mild Cognitive Impairment with and without Depressive Symptoms

Background: Depressive symptoms were thought to increase the risk of vascular dementia. Previous studies reported widespread white matter damages in the subcortical vascular mild cognitive impairment (svMCI), but little is known about the mechanism of depressive symptoms in svMCI. Objective: In the current study, we aim to explore the white matter microstructural alterations in svMCI with depressive symptoms, and their associations with clinical measurements. Methods: Fifty-eight subjects including 18 svMCI with depression (svMCI+D), 17 svMCI without depression (svMCI-D), and 23 normal controls (NC) were included in the study. Voxel-based analyses were performed on fractional anisotropy (FA) and mean diffusivity (MD). Results: Compared to NC, both svMCI groups showed decreased FA in the bilateral insula and the left precentral gyrus, and increased MD in the cerebellum. Compared to svMCI-D, svMCI+D showed increased FA in left precentral gyrus. Moreover, svMCI+D showed significant correlation between the increased MD in the cerebellum and the Hamilton Depression Rating Scale (HAMD) scores. Conclusion: Our findings of white matter alterations might be associated with executive function and memory performance in the svMCI patients. Moreover, the structural alterations in the cerebellum might underlie the mechanism of depressive symptoms in svMCI patients.