Zhang Yanan, Huang Yiran, Liu Ni, Wang Zhenjia, Wu Junchen, Li Wenxun, Xia Jing, Liu Zhidan, Li Yingqiu, Hao Ying, Huo Jianwei
Department of Radiology, Beijing Hospital of Traditional Chinese Medicine, Capital Medical University, Beijing, China.
School of Acupuncture Moxibustion & Tuina, Beijing University of Chinese Medicine, Beijing, China.
Quant Imaging Med Surg. 2022 Mar;12(3):1958-1967. doi: 10.21037/qims-21-731.
Neuroimaging studies have confirmed that functional connectivity (FC) disruption of pain-related brain networks may contribute to the cerebral pathophysiology of primary dysmenorrhea (PDM). However, it remains unclear whether FC of symmetrical regions of bilateral hemispheres associated with PDM is abnormal. This functional MRI study aimed to explore the changes of voxel-mirrored homotopic connectivity (VMHC) and seed-based FC in patients with PDM.
A cohort comprising patients with PDM (n=35) and healthy controls (HCs) (n=41) underwent resting-state functional MRI scans during their menstrual phase. Interhemispheric FC was compared between the two groups using VMHC analysis. Brain areas with significant group differences in VMHC were selected as seed regions for FC analysis. Correlation analysis was also conducted to examine the relationship between abnormal connectivity of brain regions and clinical measures of pain and anxiety.
Compared with healthy individuals, patients with PDM showed significantly enhanced VMHC in the bilateral orbital part of the superior frontal gyrus and the bilateral middle frontal gyrus. Subsequent seed-based FC analysis showed enhanced connectivity between the aforementioned areas and pain-related brain structures. Hyperconnectivity between the left middle frontal gyrus and the right cingulate gyrus in patients was negatively correlated with an increase in the visual analogue score (VAS) for pain (r=-0.341, P<0.05).
Our findings indicate that ongoing dysmenorrhea is accompanied by abnormal interhemispheric functional coordination and enhanced connectivity in pain-related regions, attention networks, and the reward system. These findings may provide a novel perspective on the central mechanism of pain caused by PDM.
神经影像学研究已证实，疼痛相关脑网络的功能连接（FC）破坏可能导致原发性痛经（PDM）的大脑病理生理学改变。然而，与PDM相关的双侧半球对称区域的FC是否异常仍不清楚。这项功能磁共振成像研究旨在探讨PDM患者体素镜像同伦连接（VMHC）和基于种子点的FC的变化。
一个由PDM患者（n = 35）和健康对照者（HCs，n = 41）组成的队列在月经期间接受静息态功能磁共振成像扫描。使用VMHC分析比较两组之间的半球间FC。将VMHC存在显著组间差异的脑区选为FC分析的种子区域。还进行了相关性分析，以检验脑区异常连接与疼痛和焦虑临床指标之间的关系。
与健康个体相比，PDM患者在双侧额上回眶部和双侧额中回显示出显著增强的VMHC。随后基于种子点的FC分析显示，上述区域与疼痛相关脑结构之间的连接增强。患者左侧额中回与右侧扣带回之间的高连接性与疼痛视觉模拟评分（VAS）的增加呈负相关（r = -0.341，P < 0.05）。
我们的数据表明，持续性痛经伴随着半球间功能协调异常以及疼痛相关区域、注意力网络和奖赏系统的连接增强。这些发现可能为PDM所致疼痛的中枢机制提供一个新的视角。
