Moxibustion for primary dysmenorrhea: A resting-state functional magnetic resonance imaging study exploring the alteration of functional connectivity strength and functional connectivity

Han Yang; Xiang Li; Xiao-Li Guo; Jun Zhou; Zhi-Fu Shen; Li-Ying Liu; Wei Wei; Lu Yang; Zheng Yu; Jiao Chen; Fan-Rong Liang; Si-Yi Yu; Jie Yang

doi:10.3389/fnins.2022.969064

Moxibustion for primary dysmenorrhea: A resting-state functional magnetic resonance imaging study exploring the alteration of functional connectivity strength and functional connectivity

Front Neurosci. 2022 Aug 30:16:969064. doi: 10.3389/fnins.2022.969064. eCollection 2022.

Authors

Han Yang¹, Xiang Li¹, Xiao-Li Guo², Jun Zhou¹, Zhi-Fu Shen³, Li-Ying Liu¹, Wei Wei², Lu Yang¹, Zheng Yu⁴, Jiao Chen¹, Fan-Rong Liang¹, Si-Yi Yu^{1

5}, Jie Yang^{2

1}

Affiliations

¹ Acupuncture and Tuina School, Chengdu University of Traditional Chinese Medicine, Chengdu, China.
² Chengdu Xi'nan Gynecological Hospital, Chengdu, China.
³ Department of Traditional Chinese and Western Medicine, North Sichuan Medical College, Nanchong, China.
⁴ College of Medical Information and Engineering, Chengdu University of Traditional Chinese Medicine, Chengdu, China.
⁵ Acupuncture & Brain Research Center, Chengdu University of Traditional Chinese Medicine, Chengdu, China.

Abstract

Introduction: Primary dysmenorrhea (PDM) is a common gynecological disease and chronic pain disorder. Moxibustion, a form of traditional Chinese medicine therapy, has proven to be effective for PDM. However, the central mechanisms of PDM and moxibustion for PDM are still unclear. This study aims to explore the potential central mechanism of PDM and clarify the possible mechanism of moxibustion for relieving pain.

Materials and methods: A total of 23 PDM patients and 23 matched healthy controls (HCs) were enrolled. For PDM patients, resting-state functional magnetic resonance imaging (rs-fMRI) data were collected pre- and post-moxibustion treatment of 3 consecutive menstrual cycles, respectively. For HCs, rs-fMRI data were collected in the baseline. The resting-state functional connectivity strength (rs-FCS) analysis and the resting-state functional connectivity (rs-FC) analysis based on the region of interest (ROI) were combined to be conducted.

Results: Compared to HCs, PDM patients showed weaker rs-FCS in the left inferior frontal gyrus (IFG). After the moxibustion treatment, rs-FCS in the left IFG was increased with clinical improvement. Then, the left IFG was chosen as ROI, and the rs-FC analysis was conducted. It showed that the left IFG rs-FC in the bilateral anterior cingulate cortex (ACC)/middle cingulate cortex (MCC), the left posterior cingulate cortex (PCC)/precuneus (PCU), and the left parahippocampal gyrus (PHG) decreased after moxibustion treatment, most of which belong to the default mode network (DMN).

Conclusion: Our results highlight the role of the left IFG and the DMN in PDM. Specifically, the central mechanism of moxibustion for analgesia may be related to modulating the disorders of the reappraisal and processing of pain stimuli through influencing the cognition of pain.

Keywords: default mode network; functional connectivity; functional connectivity strength; left inferior frontal gyrus; moxibustion; primary dysmenorrhea.