Faculty of Dentistry, University of Toronto, Toronto, ON, Canada; Centre for the Study of Pain, University of Toronto, Toronto, ON, Canada.
Department of Neural and Pain Sciences, School of Dentistry, University of Maryland, Baltimore, MD, United States; Center to Advance Chronic Pain Research, University of Maryland Baltimore, Baltimore, MD, United States.
Neuroimage Clin. 2018;20:901-912. doi: 10.1016/j.nicl.2018.09.018. Epub 2018 Sep 25.
Chronic orofacial pain (COFP) disorders are prevalent and debilitating pain conditions affecting the head, neck and face areas. Neuroimaging studies have reported functional and grey matter abnormalities, but not all the studies have reported consistent findings. Identifying convergent abnormalities across COFPs provides a basis for future hypothesis-driven research aimed at elucidating common CNS mechanisms. Here, we perform three coordinate-based meta-analyses according to PRISMA guidelines to elucidate the central mechanisms of orofacial pain disorders. Specifically, we investigated consistent patterns of: (1) brain function to experimental orofacial pain in healthy subjects, (2) structural and (3) functional brain abnormalities in COFP. We computed our coordinate-based meta-analyses using GingerALE. The experimental pain meta-analysis revealed increased brain activity in bilateral thalami, posterior mid-cingulate cortices, and secondary somatosensory cortices, the right posterior parietal cortex extending to the orofacial region of the right primary somatosensory cortex and the right insula, and decreased activity in the right somatomotor regions. The structural COFP meta-analysis identified consistent higher grey matter volume/concentration in the right ventral thalamus and posterior putamen of COFP patients compared to healthy controls. The functional COFP meta-analysis identified a consistent increase in brain activity in the left medial and posterior thalamus and lesser activity in the left posterior insula in COFP, compared to healthy controls. Overall, these findings provide evidence of brain abnormalities in pain-related regions, namely the thalamus and insula, across different COFP disorders. The convergence of thalamic abnormalities in both structure and function suggest a key role for this region in COFP pathophysiology.
慢性头面痛（COFP）是一种常见的使人虚弱的疼痛疾病，影响头部、颈部和面部区域。神经影像学研究报告了功能和灰质异常，但并非所有研究都报告了一致的发现。在 COFP 中识别出趋同的异常可以为未来基于假说的研究提供基础，旨在阐明共同的中枢神经系统机制。在这里，我们根据 PRISMA 指南进行了三项基于坐标的荟萃分析，以阐明口腔疼痛障碍的中枢机制。具体来说，我们研究了以下方面的一致模式：（1）健康受试者中实验性口腔疼痛的大脑功能，（2）COFP 的结构和（3）功能大脑异常。我们使用 GingerALE 计算了我们的基于坐标的荟萃分析。实验性疼痛荟萃分析显示，双侧丘脑、后扣带皮层和次级体感皮层的大脑活动增加，右侧后顶叶皮层延伸至右侧初级体感皮层和右侧岛叶的口腔区域，右侧躯体运动区域的活动减少。结构 COFP 荟萃分析发现，与健康对照组相比，COFP 患者右侧腹侧丘脑和后壳核的灰质体积/浓度一致较高。功能 COFP 荟萃分析发现，与健康对照组相比，COFP 患者左侧内侧和后丘脑的大脑活动增加，左侧后岛叶的活动减少。总的来说，这些发现为不同 COFP 疾病中与疼痛相关的区域（即丘脑和岛叶）的大脑异常提供了证据。丘脑在结构和功能上的异常趋同表明该区域在 COFP 病理生理学中起着关键作用。
