Supplementary Material for: Alterations in Intra- and Interregional Intrinsic Brain Connectivity Are Differentially Associated with Memory Performance in Amnestic Mild Cognitive Impairment

Background: Previous research has separated spatial patterns of intra- and interregional intrinsic brain connectivity, as evaluated by regional homogeneity (ReHo) and functional connectivity (FC), respectively, in prodromal Alzheimer’s disease (AD). Moreover, the intra- and interregional intrinsic brain connectivities have been demonstrated to have a significant relationship with each other. Objective: To explore FCs from brain regions which display a difference in ReHo between an amnestic mild cognitive impairment (aMCI) group and healthy controls (HC) and to examine the relationship of intra- and interregional intrinsic brain connectivity to cognitive function in both groups. Methods: Thirty-four subjects with aMCI and 38 HC underwent 3T MRI scanning and a battery of neuropsychological tests. Results: The aMCI group exhibited significantly higher ReHo in the left putamen and lower ReHo in the left inferior temporal gyrus than the HC. Furthermore, both groups showed a distinctive functional connectivity pattern seeded from 2 regions of interest which exhibited significant ReHo differences between the groups. In the HC group, only ReHo exhibited significant associations with memory performance, but in the aMCI group, only FC seeded from the left inferior temporal gyrus showed significant correlations with memory performance. Conclusions: By approaching both intra- and interregional intrinsic brain activities in the early stages of AD, the findings of this research provide insights into the early pathogenesis of AD as related to memory performance.

背景：既往针对阿尔茨海默病（AD）前驱期的研究分别采用局部一致性（ReHo）与功能连接（FC）评估脑区内与脑区间固有连接的空间模式，且已有研究证实脑区内、脑区间的固有连接之间存在显著关联。
研究目的：探究遗忘型轻度认知障碍（aMCI）组与健康对照（HC）组间局部一致性存在差异的脑区的功能连接，并探讨两组人群中脑区内、脑区间固有连接与认知功能的关联。
研究方法：本研究纳入34名遗忘型轻度认知障碍受试者与38名健康对照者，所有受试者均接受3T磁共振成像（MRI）扫描与一套神经心理学测验。
研究结果：与健康对照组相比，遗忘型轻度认知障碍组左侧壳核的局部一致性显著升高，而左侧颞下回的局部一致性显著降低。此外，两组均呈现出以两组间局部一致性存在显著差异的2个感兴趣区为种子点的独特功能连接模式。在健康对照组中，仅局部一致性与记忆表现存在显著关联；而在遗忘型轻度认知障碍组中，仅以左侧颞下回为种子点的功能连接与记忆表现存在显著相关。
研究结论：本研究同时关注阿尔茨海默病早期阶段的脑区内与脑区间固有神经活动，其研究结果为阐释阿尔茨海默病早期发病机制与记忆表现的关联提供了新的视角。