Table_2_Acupuncture on mild cognitive impairment: A systematic review of neuroimaging studies.DOCX

Mild cognitive impairment (MCI) is a multifactorial and complex central neurodegenerative disease. Acupuncture appears to be an effective method for cognitive function improvement in MCI patients. Neural plasticity remaining in the MCI brain implies that acupuncture-associated benefits may not be limited to the cognitive function. Instead, neurological alternations in the brain play a vital role in corresponding to the cognitive improvement. However, previous studies have mainly focused on the effects of cognitive function, leaving neurological findings relatively unclear. This systematic review summarized existing studies that used various brain imaging techniques to explore the neurological effect regarding acupuncture use for MCI treatment. Potential neuroimaging trials were searched, collected, and identified independently by two researchers. Four Chinese databases, four English databases, and additional sources were searched to identify studies reporting the use of acupuncture for MCI from the inception of databases until 1 June 2022. Methodological quality was appraised using the Cochrane risk-of-bias tool. In addition, general, methodological, and brain neuroimaging information was extracted and summarized to investigate the potential neural mechanisms by which acupuncture affects patients with MCI. In total, 22 studies involving 647 participants were included. The methodological quality of the included studies was moderate to high. The methods used included functional magnetic resonance imaging, diffusion tensor imaging, functional near-infrared spectroscopy, and magnetic resonance spectroscopy. Acupuncture-induced brain alterations observed in those patients with MCI tended to be observable in the cingulate cortex, prefrontal cortex, and hippocampus. The effect of acupuncture on MCI may play a role in regulating the default mode network, central executive network, and salience network. Based on these studies, researchers could extend the recent research focus from the cognitive domain to the neurological level. Future researches should develop additional relevant, well-designed, high-quality, and multimodal neuroimaging researches to detect the effects of acupuncture on the brains of MCI patients.

轻度认知障碍（Mild cognitive impairment）是一种多因素参与的复杂中枢神经退行性疾病。针灸似乎是改善轻度认知障碍（MCI）患者认知功能的有效手段。轻度认知障碍患者大脑中尚存的神经可塑性（neural plasticity）提示，针灸带来的获益或不止于认知功能改善；相反，大脑的神经结构改变在认知功能改善中发挥着关键作用。然而，既往研究多聚焦于针灸对认知功能的影响，相关神经层面的研究结果仍相对模糊。本系统综述（systematic review）梳理了现有利用多种脑成像技术探究针灸治疗MCI神经效应的相关研究。由两名研究者独立完成潜在神经成像试验（neuroimaging trials）的检索、筛选与收录工作。本研究检索了4个中文数据库、4个英文数据库及其他补充数据源，检索时限自建库起至2022年6月1日，旨在筛选关于针灸治疗MCI的相关研究。采用Cochrane偏倚风险工具对研究的方法学质量进行评价。此外，本研究提取并总结了研究的一般信息、方法学信息及脑神经成像相关信息，以探究针灸改善MCI患者症状的潜在神经机制。最终共纳入22项研究，涉及647名受试者。纳入研究的方法学质量为中等至高等水平。所用成像方法包括功能磁共振成像（functional magnetic resonance imaging）、扩散张量成像（diffusion tensor imaging）、功能性近红外光谱技术（functional near-infrared spectroscopy）及磁共振波谱（magnetic resonance spectroscopy）。在MCI患者中观察到的针灸诱导大脑改变，多集中于扣带回皮层（cingulate cortex）、前额叶皮层（prefrontal cortex）及海马体（hippocampus）。针灸对MCI的干预作用或通过调节默认模式网络（default mode network）、中央执行网络（central executive network）及突显网络（salience network）实现。基于上述研究，未来可将研究重点从认知领域拓展至神经层面。未来应开展更多设计严谨、高质量的多模态神经成像相关研究，以进一步阐明针灸对MCI患者大脑的影响机制。