Yuan Qianqian, Qi Wenzhang, Xue Chen, Ge Honglin, Hu Guanjie, Chen Shanshan, Xu Wenwen, Song Yu, Zhang XuLian, Xiao Chaoyong, Chen Jiu
Department of Radiology, The Affiliated Brain Hospital of Nanjing Medical University, Nanjing, China.
Department of Neurosurgery, Nanjing Brain Hospital Affiliated to Nanjing Medical University, Nanjing, China.
Front Aging Neurosci. 2021 Oct 5;13:708687. doi: 10.3389/fnagi.2021.708687. eCollection 2021.
Mild cognitive impairment (MCI) represents a transitional state between normal aging and dementia disorders, especially Alzheimer's disease (AD). The disruption of the default mode network (DMN) is often considered to be a potential biomarker for the progression from MCI to AD. The purpose of this study was to assess MRI-specific changes of DMN in MCI patients by elucidating the convergence of brain regions with abnormal DMN function. We systematically searched PubMed, Ovid, and Web of science for relevant articles. We identified neuroimaging studies by using amplitude of low frequency fluctuation /fractional amplitude of low frequency fluctuation (ALFF/fALFF), regional homogeneity (ReHo), and functional connectivity (FC) in MCI patients. Based on the activation likelihood estimation (ALE) algorithm, we carried out connectivity modeling of coordination-based meta-analysis and functional meta-analysis. In total, this meta-analysis includes 39 articles on functional neuroimaging studies. Using computer software analysis, we discovered that DMN changes in patients with MCI mainly occur in bilateral inferior frontal lobe, right medial frontal lobe, left inferior parietal lobe, bilateral precuneus, bilateral temporal lobe, and parahippocampal gyrus (PHG). Herein, we confirmed the presence of DMN-specific damage in MCI, which is helpful in revealing pathology of MCI and further explore mechanisms of conversion from MCI to AD. Therefore, we provide a new specific target and direction for delaying conversion from MCI to AD.
轻度认知障碍（MCI）是正常衰老与痴呆症（尤其是阿尔茨海默病，AD）之间的一种过渡状态。默认模式网络（DMN）的破坏常被认为是MCI进展为AD的潜在生物标志物。本研究的目的是通过阐明DMN功能异常的脑区的汇聚情况，评估MCI患者DMN的MRI特异性变化。我们系统地在PubMed、Ovid和Web of science上搜索相关文章。我们通过使用MCI患者低频振幅/低频振幅分数（ALFF/fALFF）、局部一致性（ReHo）和功能连接（FC）来识别神经影像学研究。基于激活可能性估计（ALE）算法，我们进行了基于协调的荟萃分析和功能荟萃分析的连接性建模。总共，这项荟萃分析包括39篇关于功能神经影像学研究的文章。通过计算机软件分析，我们发现MCI患者的DMN变化主要发生在双侧额下回、右侧额内侧回、左侧顶下小叶、双侧楔前叶、双侧颞叶和海马旁回（PHG）。在此，我们证实了MCI中存在DMN特异性损伤，这有助于揭示MCI的病理情况，并进一步探索MCI向AD转化的机制。因此，我们为延缓MCI向AD的转化提供了一个新的特异性靶点和方向。
