Functional connectivity studies to detect neurophysiological correlates of amnestic mild cognitive impairment (aMCI), a prodromal stage of Alzheimer’s disease, have generated contradictory results in terms of compensation and deterioration, as most of the studies did not distinguish between the different aMCI subtypes: single-domain aMCI (sd-aMCI) and multiple-domain aMCI (md-aMCI). The present study aimed to characterize the neurophysiological correlates of aMCI subtypes by using resting-state functional magnetic resonance imaging. The study included sd-aMCI (n = 29), md-aMCI (n = 26), and control (n = 30) participants. The data were subjected to independent component analysis (ICA) to explore the default mode network (DMN) and the fronto-parietal control network (FPCN). Additionally, seed-based and moderation analyses were conducted to investigate the connectivity of the medial temporal lobe and functional networks. aMCI subtypes presented differences in functional connectivity relative to the control group: sd-aMCI participants displayed increased FPCN connectivity and reduced connectivity between the posterior parahippocampal gyrus (PHG) and medial structures; md-aMCI participants exhibited lower FPCN connectivity, higher anterior PHG connectivity with frontal structures and lower posterior PHG connectivity with central-parietal and temporo-occipital areas. Additionally, md-aMCI participants showed higher posterior PHG connectivity with structures of the DMN than both control and sd-aMCI participants, potentially indicating more severe cognitive deficits. The results showed gradual and qualitative neurofunctional differences between the aMCI subgroups, suggesting the existence of compensatory (sd-aMCI) and deterioration (md-aMCI) mechanisms in functional networks, mainly originated in the DMN. The findings support consideration of the subgroups as different stages of MCI within the Alzheimer disease continuum.

用于检测遗忘性轻度认知障碍 （aMCI） 的神经生理学相关性的功能连接研究是阿尔茨海默病的前驱阶段，在代偿和恶化方面产生了相互矛盾的结果，因为大多数研究没有区分不同的 aMCI 亚型：单域 aMCI （sd-aMCI） 和多域 aMCI （md-aMCI）。本研究旨在通过使用静息态功能磁共振成像来表征 aMCI 亚型的神经生理相关性。该研究包括 sd-aMCI （n = 29）、md-aMCI （n = 26） 和对照 （n = 30） 参与者。对数据进行独立成分分析 （ICA） 以探索默认模式网络 （DMN） 和额顶叶控制网络 （FPCN）。此外，还进行了基于种子和调节分析，以研究内侧颞叶和功能网络的连通性。aMCI 亚型相对于对照组表现出功能连接的差异： sd-aMCI 参与者表现出 FPCN 连接增加，后海马旁回 （PHG） 和内侧结构之间的连接减少;md-aMCI 参与者表现出较低的 FPCN 连接性，较高的前部 PHG 与额部结构的连接，以及较低的后部 PHG 与中央顶叶和颞枕区的连接。此外，md-aMCI 参与者表现出比对照组和 sd-aMCI 参与者更高的后部 PHG 与 DMN 结构的连接，这可能表明认知缺陷更严重。 结果显示 aMCI 亚组之间的逐渐和定性神经功能差异，表明功能网络中存在代偿 （sd-aMCI） 和恶化 （md-aMCI） 机制，主要起源于 DMN。这些发现支持将亚组视为阿尔茨海默病连续体中 MCI 的不同阶段。