Tao Wuhai, Li Xin, Zhang Junying, Chen Yaojing, Ma Chao, Liu Zhen, Yang Caishui, Wang Wenxiao, Chen Kewei, Wang Jun, Zhang Zhanjun
State Key Laboratory of Cognitive Neuroscience and Learning and IDG/McGovern Institute for Brain Research, Beijing Normal University, Beijing, P. R. China.
BABRI Centre, Beijing Normal University, Beijing, P. R. China.
J Alzheimers Dis. 2017;60(2):679-690. doi: 10.3233/JAD-170252.
The alteration of the default mode network (DMN) functional connectivity (FC) has been reported in patients with amnestic mild cognitive impairment (aMCI) as a predictor of Alzheimer's disease (AD). However, no studies exist that examined stage-dependent DMN FC changes throughout the course of aMCI. The present study aims to characterize patterns of DMN FC over three aMCI stages as first defined. Utilizing the extreme groups approach on the performance of memory tasks, aMCI subjects were divided into mild, moderate, and severe stages. Independent component analysis was used to assess DMN for individual patients in each of the three cross-sectionally defined stages. Instead of finding that continued monotonic decline was the case for the hippocampus volume, which we also investigated in this study, we observed an increase in DMN functional connectivity from mild aMCI to moderate aMCI and a decrease to severe aMCI, mainly in the left precuneus and superior parietal lobe. Moreover, the FC was significantly associated with cognitive performance. Though a longitudinal study is needed to confirm these results, our cross-sectional finding is that non-linear FC changes in DMN could be a characteristic of prodromal early disease development.
遗忘型轻度认知障碍（aMCI）患者的默认模式网络（DMN）功能连接（FC）改变已被报道，可作为阿尔茨海默病（AD）的预测指标。然而，尚无研究考察aMCI病程中DMN FC的阶段依赖性变化。本研究旨在描述首次定义的三个aMCI阶段的DMN FC模式。利用极端组方法对记忆任务表现进行分析，将aMCI受试者分为轻度、中度和重度阶段。采用独立成分分析评估三个横断面定义阶段中每个阶段个体患者的DMN。本研究还对海马体积进行了调查，并未发现其持续单调下降，而是观察到从轻度aMCI到中度aMCI，DMN功能连接增加，到重度aMCI时减少，主要发生在左侧楔前叶和顶上叶。此外，FC与认知表现显著相关。尽管需要纵向研究来证实这些结果，但我们的横断面研究发现，DMN中非线性FC变化可能是前驱期早期疾病发展的一个特征。
