Alteration of functional connectivity network in population of objectively-defined subtle cognitive decline
Xinyi Zhang, Qingze Zeng, Yanbo Wang, Yu Jin, Tiantian Qiu, Kaicheng Li, Xiao Luo, Shuyue Wang, Xiaopei Xu, Xiaocao Liu, Shuai Zhao, Zheyu Li, Luwei Hong, Jixuan Li, Siyan Zhong, Tianyi Zhang, Peiyu Huang, Baorong Zhang, Minming Zhang, Yanxing Chen,- Neurology
- Cellular and Molecular Neuroscience
- Biological Psychiatry
- Psychiatry and Mental health
Abstract
The objectively-defined subtle cognitive decline individuals had higher progression rates of cognitive decline and pathological deposition than healthy elderly, indicating a higher risk of progressing to Alzheimer’s disease. However, little is known about the brain functional alterations during this stage. Thus, we aimed to investigate the functional network patterns in objectively-defined subtle cognitive decline cohort.
Forty-two cognitive normal, 29 objectively-defined subtle cognitive decline and 55 mild cognitive impairment subjects were included based on neuropsychological measures from the Alzheimer's Disease Neuroimaging Initiative dataset. Thirty cognitive normal, 22 objectively-defined subtle cognitive decline and 48 mild cognitive impairment had longitudinal MR data. The degree centrality and eigenvector centrality for each participant were calculated by using resting-state functional MRI. For cross-sectional data, analysis of covariance (ANCOVA) was performed to detect between-group differences of degree centrality and eigenvector centrality after controlling age, sex, and education. For longitudinal data, repeated measurement ANCOVA was used for comparing the alterations during follow-up period among three groups. In order to classify the clinical significance, we correlated degree centrality and eigenvector centrality values to Alzheimer’s disease biomarkers and cognitive function.
The results of ANCOVA showed significant between-group differences of eigenvector centrality and degree centrality in left superior temporal gyrus and left precuneus respectively. Across groups, the eigenvector centrality value of left superior temporal gyrus was positively related with recognition scores in auditory verbal learning test, whereas the degree centrality value of left precuneus was positively associated with Mini-mental State Examination total score. For longitudinal data, the results of repeated measurement ANCOVA indicated objectively-defined subtle cognitive decline group had the highest declined rate of both eigenvector centrality and degree centrality values than other groups.
Our study showed an increased brain functional connectivity in objectively-defined subtle cognitive decline individuals at both local and global level, which were associated with Alzheimer’s disease pathology and neuropsychological assessment. Moreover, we also observed a faster declined rate of functional network matrix in objectively-defined subtle cognitive decline individuals during the follow-ups.