Institute for Social Medicine, Epidemiology and Health Economics, Charité University Medical Center, Berlin, Germany.
PLoS One. 2012;7(4):e32960. doi: 10.1371/journal.pone.0032960. Epub 2012 Apr 9.
The mechanisms of action underlying acupuncture, including acupuncture point specificity, are not well understood. In the previous decade, an increasing number of studies have applied fMRI to investigate brain response to acupuncture stimulation. Our aim was to provide a systematic overview of acupuncture fMRI research considering the following aspects: 1) differences between verum and sham acupuncture, 2) differences due to various methods of acupuncture manipulation, 3) differences between patients and healthy volunteers, 4) differences between different acupuncture points.
METHODOLOGY/PRINCIPAL FINDINGS: We systematically searched English, Chinese, Korean and Japanese databases for literature published from the earliest available up until September 2009, without any language restrictions. We included all studies using fMRI to investigate the effect of acupuncture on the human brain (at least one group that received needle-based acupuncture). 779 papers were identified, 149 met the inclusion criteria for the descriptive analysis, and 34 were eligible for the meta-analyses. From a descriptive perspective, multiple studies reported that acupuncture modulates activity within specific brain areas, including somatosensory cortices, limbic system, basal ganglia, brain stem, and cerebellum. Meta-analyses for verum acupuncture stimuli confirmed brain activity within many of the regions mentioned above. Differences between verum and sham acupuncture were noted in brain response in middle cingulate, while some heterogeneity was noted for other regions depending on how such meta-analyses were performed, such as sensorimotor cortices, limbic regions, and cerebellum.
Brain response to acupuncture stimuli encompasses a broad network of regions consistent with not just somatosensory, but also affective and cognitive processing. While the results were heterogeneous, from a descriptive perspective most studies suggest that acupuncture can modulate the activity within specific brain areas, and the evidence based on meta-analyses confirmed some of these results. More high quality studies with more transparent methodology are needed to improve the consistency amongst different studies.
针刺作用的机制，包括穴位特异性，尚不清楚。在过去的十年中，越来越多的研究应用 fMRI 来研究针刺刺激的大脑反应。我们的目的是提供一个系统的概述针刺 fMRI 研究考虑以下几个方面：1）针刺和假针刺之间的差异，2）不同针刺手法的差异，3）患者与健康志愿者之间的差异，4）不同穴位之间的差异。
方法/主要发现：我们系统地检索了英文、中文、韩文和日文数据库，检索时间从最早到 2009 年 9 月，没有任何语言限制。我们包括了所有使用 fMRI 研究针刺对人脑影响的研究（至少有一组接受基于针的针刺）。共检索到 779 篇论文，149 篇符合描述性分析的纳入标准，34 篇符合荟萃分析的纳入标准。从描述性的角度来看，多项研究报告针刺调节特定脑区的活动，包括躯体感觉皮层、边缘系统、基底节、脑干和小脑。对真针刺刺激的荟萃分析证实了上述许多区域的大脑活动。在中扣带脑区，真针刺和假针刺的脑反应存在差异，而在其他区域，由于如何进行荟萃分析等因素，存在一定的异质性，如感觉运动皮层、边缘区域和小脑。
针刺刺激的大脑反应包括一个广泛的区域网络，不仅与躯体感觉有关，而且与情感和认知处理有关。虽然结果存在异质性，但从描述性的角度来看，大多数研究表明针刺可以调节特定脑区的活动，基于荟萃分析的证据证实了其中的一些结果。需要更多高质量、方法更透明的研究来提高不同研究之间的一致性。
