Divergent Roles of Vascular Burden and Neurodegeneration in the Cognitive Decline of Geriatric Depression Patients and Mild Cognitive Impairment Patients

Abstract

Both geriatric depression and mild cognitive impairment (MCI) confer an increased risk for the development of dementia. The mechanisms underlying the development of cognitive impairment in geriatric depression patients remain controversial. The present study aimed to explore the association of cognitive decline with vascular risk, white matter hyperintensity (WMH) burden and hippocampal volume in both remitted geriatric depression (RGD) subjects and amnestic mild cognitive impairment (aMCI) subjects. Forty-one RGD subjects, 51 aMCI subjects, and 64 healthy elderly subjects underwent multimodal MRI scans and neuropsychological tests at both baseline and a 35-month follow-up. According to the changing patterns (declining or stable) of global cognitive function during the follow-up period, each group was further divided into a declining subgroup and a stable subgroup. The Framingham 10-year cardiovascular risk, WMH volume and hippocampal volume were measured to assess vascular pathology and neurodegeneration, respectively. The RGD declining group displayed a higher vascular risk and greater WMH volume than the RGD stable group, whereas no such difference was found in the aMCI subjects. In contrast, the aMCI declining group displayed a smaller left hippocampal volume than the aMCI stable group, whereas no such difference was found in the RGD subjects. Furthermore, greater increases in the WHM volume correlated with greater decreases in global cognitive function in the RGD declining group, and greater decreases in the left hippocampal volume correlated with greater decreases in global cognitive function in the aMCI declining group. In conclusion, the cognitive decline in RGD patients is associated with vascular burden, whereas the cognitive decline in aMCI patients is associated with neurodegeneration. These findings could contribute to a better understanding of the specific mechanisms of the development of dementia in each condition.

White Matter Hyperintensities Quantification in Healthy Adults: A Systematic Review and Meta‐Analysis

“…From the initial search, 162 articles were retrieved with 38 of them being analyzed 19,21–57 . All included studies were prospective; five had an intraindividual study design with two 21,24,31,40 or three study groups 19 that were examined separately. In those cases, study groups were considered to be independent, resulting in a total of 44 study groups from the 38 articles.…”

“…Seventeen articles with a total of 21 study groups reported quantitative data for WMH volume as mean ± SD and were therefore included in the meta‐analysis 19,21,23,26–28,31,33,37,39,42,43,46,48,49,52,57 . The total number of healthy subjects included in the meta‐analysis was 2743.…”

Enhanced Regional Homogeneity and Functional Connectivity in Subjects With White Matter Hyperintensities and Cognitive Impairment

“…As described in our previous study (Ye et al, 2017), brain volume was assessed using the VBM8 toolbox for SPM12. First, the T 1 images were segmented into gray matter, white matter and cerebrospinal fluid.…”

Depression, Anxiety, and Apathy in Mild Cognitive Impairment: Current Perspectives

“…In MCI patients, new onset of depression was associated with deep subcortical cerebral white matter hyperintensity severity (Kim et al, 2016). Another study showed that the cognitive decline was associated with vascular burden (white matter hyperintensity) in remitted geriatric depression patients but neurodegeneration (left hippocampal volume) in aMCI patients (Ye et al, 2017). A cohort with 35,791 participants that were followed up for 13 years showed that individuals with depression had a higher risk of dementia, and that, furthermore, depression had a more significant effect on participants with incident stroke or newly diagnosed hypertension, which indicated that targeting vascular disorders might lower dementia risk (Köhler et al, 2015).…”