Liang Xuhong, Yuan Qianqian, Xue Chen, Qi Wenzhang, Ge Honglin, Yan Zheng, Chen Shanshan, Song Yu, Wu Huimin, Xiao Chaoyong, Chen Jiu
Department of Radiology, The Affiliated Brain Hospital of Nanjing Medical University, Nanjing, China.
Institute of Brain Functional Imaging, Nanjing Medical University, Nanjing, China.
Front Aging Neurosci. 2022 Jul 15;14:919859. doi: 10.3389/fnagi.2022.919859. eCollection 2022.
Mild cognitive impairment (MCI) is considered to be an intermediate stage between normal aging and Alzheimer's disease (AD). The earliest and most common symptom of MCI is impaired episodic memory. When episodic memory is impaired in MCI patients, specific functional changes occur in related brain areas. However, there is currently a lack of a unified conclusion on this change. Therefore, the purpose of this meta-analysis is to find MRI-specific functional changes in episodic memory in MCI patients.
Based on three commonly used indicators of brain function: functional connectivity (FC), the amplitude of low-frequency fluctuation /fractional amplitude of low-frequency fluctuation (ALFF/fALFF), and regional homogeneity (ReHo), we systematically searched PubMed, Web of Science and Ovid related literature and conducted the strict screening. Then we use the activation likelihood estimation (ALE) algorithm to perform the coordinate-based meta-analysis.
Through strict screening, this meta-analysis finally included 21 related functional neuroimaging research articles. The final result displays that functional changes of episodic memory in MCI patients are mainly located in the parahippocampal gyrus, precuneus, posterior cingulate gyrus, cuneus, middle temporal gyrus, middle frontal gyrus, lingual gyrus, and thalamus.
There are specific functional changes in episodic memory brain regions in MCI patients, and the brain functional network can regulate episodic memory through these brain regions. And these specific changes can assist in the early diagnosis of MCI, providing new ideas and directions for early identification and intervention in the process of MCI.
轻度认知障碍（MCI）被认为是正常衰老与阿尔茨海默病（AD）之间的中间阶段。MCI最早且最常见的症状是情景记忆受损。当MCI患者的情景记忆受损时，相关脑区会发生特定的功能变化。然而，目前关于这种变化尚无统一结论。因此，本荟萃分析的目的是找出MCI患者情景记忆中磁共振成像（MRI）特定的功能变化。
基于脑功能的三个常用指标：功能连接性（FC）、低频波动幅度/低频波动分数幅度（ALFF/fALFF）和局部一致性（ReHo），我们系统检索了PubMed、科学网和Ovid的相关文献并进行严格筛选。然后使用激活可能性估计（ALE）算法进行基于坐标的荟萃分析。
通过严格筛选，本荟萃分析最终纳入21篇相关的功能神经影像学研究文章。最终结果显示，MCI患者情景记忆的功能变化主要位于海马旁回、楔前叶、后扣带回、楔叶、颞中回、额中回、舌回和丘脑。
MCI患者情景记忆脑区存在特定的功能变化，脑功能网络可通过这些脑区调节情景记忆。并且这些特定变化有助于MCI的早期诊断，为MCI过程中的早期识别和干预提供新的思路和方向。
