Objective: Many researches have indicated that the default-mode network (DMN) and hippocampus were vulnerable to Alzheimer's disease (AD). However, the changes in resting-state functional connectivity (rsFC) patterns of the two systems vary across the progression of AD. We aimed to use meta analysis to explore rsFC changes of AD and mild cognitive impairment (MCI) based on the DMN and hippocampus as seeds. Materials and Methods: A standardized meta analysis procedure was adopted to systematically review articles from PubMed and Web of Science. A total of 12 seed-based whole-brain voxel-wise rsFC studies were finally entered into meta analysis by using signed differential mapping (SDM). Results: Compared with healthy controls (HC), we found AD show significantly decreased rsFC in the medial prefrontal cortex (MPFC) by using the hippocampus as the seed region. Using DMN regions as the seed, we found AD show decreased rsFC in the MPFC, rolandic operculum, hippocampus and parahippocampus; while MCI show decreased rsFC in right posterior cingulate cortex (PCC), also with increased connectivity in the right precentral gyrus. Conclusions: Reduced rsFC between the hippocampus and MPFC of anterior DMN is an important imaging feature for AD, while MCI mostly impairs the connectivity of the PCC in the posterior DMN and shows compensatory enhancement in the precentral gyrus (sensorimotor area). The results clarified the different rsFC patterns of DMN and hippocampus alterations in AD and MCI, and provided imaging reference for the recognition of AD and the evaluation of intervention effect.

目的 以往研究表明海马和默认网络(default-mode network,DMN)易受阿尔茨海默病(Alzheimer′s disease,AD)的影响，而这两个系统的静息态功能连接(resting-state functional connectivity,rsFC)随AD进程表现出不同的变化模式。本文采用Meta分析方法研究AD及其早期轻度认知障碍(mild cognitive impairment,MCI)基于DMN和海马为种子点的rsFC变化特征。材料与方法 基于Meta分析标准化程序对PubMed和Web of Science数据库进行全面检索，采用标记差异映射分析(signed differential mapping,SDM)对纳入12篇基于种子点的全脑体素rsFC研究进行分析。结果 以海马为种子点，AD患者内侧前额叶(medial prefrontal cortex,MPFC) rsFC较健康对照组(healthy controls,HC)显著下降。以DMN脑区为种子点，AD患者MPFC、中央沟盖、海马和海马旁回等区域rsFC下降；MCI患者右侧后扣带回(posterior cingulate cortex,PCC) rsFC下降，而右侧中央前回rsFC增强。结论 海马和DMN前部MPFC之间rsFC下降是AD的重要影像学特征，而MCI主要损伤DMN后部PCC，同时在中央前回(感觉运动区)表现出代偿性增强。该结果明确了DMN和海马在AD和MCI的不同变化模式，可为AD的识别和干预效果评估提供影像学参考。

国家自然科学基金(61673374、62177004)~~