Neuroimaging Studies of Acupuncture on Low Back Pain: A Systematic Review

Abstract

Objectives: This study was conducted in order to investigate the study design and main outcomes of acupuncture neuroimaging studies on low back pain (LBP).Methods: Neuroimaging studies of acupuncture on LBP were collected from three English databases such as PubMed and four Chinese databases such as China National Knowledge Infrastructure (CNKI) from inception to December 31, 2020. Study selection, data extraction, and assessment of risk of bias were performed independently by two investigators. The quality of studies was appraised with the Cochrane's risk of bias tools. Information on basic information, methodology, and brain imaging data were extracted.Results: The literature search returned 310 potentially eligible studies and 19 articles met inclusion criteria; 78.9% of studies chose manual acupuncture as the intervention, 89.5% of studies evaluated functional changes elicited by acupuncture, and 68.4% of studies used resting-state fMRI as imaging condition. The most frequently reported acupuncture-induced brain alterations of LBP patients were in the prefrontal cortex, insula, cerebellum, primary somatosensory cortex, and anterior cingulate cortex. There was a significant correlation between improved clinical outcomes and changes in the brain.Conclusions: The results suggested that improving abnormal structure and functional activities in the brain of the LBP patient is an important mechanism of acupuncture treatment for LBP. The brain regions involved in acupuncture analgesia for LBP were mainly located in the pain matrix, default mode network (DMN), salience network (SN), and descending pain modulatory system (DPMS). However, it was difficult to draw a generalized conclusion due to the heterogeneity of study designs. Further well-designed multimodal neuroimaging studies investigating the mechanism of acupuncture on LBP are warranted.

Acupuncture Modulates the Spontaneous Activity and Functional Connectivity of Calcarine in Patients With Chronic Stable Angina Pectoris

“…The improvements of symptoms in CSAP patients induced by acupuncture were associated with its multi-targeted modulations of the pain process. These similar results have also been observed in acupuncture treatment of other visceral pains and somatalgia ( Ma et al, 2020 , 2021 ; Wen et al, 2021 ).…”

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“…You et al (60) reported alterations in DMN hub configurations following acupuncture at ST36. A meta-analysis of acupuncture for low back pain revealed that the brain regions involved in acupuncture were located in the salience network, DMN, pain matrix, and descending pain modulatory system (61), demonstrating the analgesic effect of acupuncture. The DMN is associated with several advanced cognitive functions; the salience network mediates the switching between the DMN and the central executive network, and those three networks are theoretically the core "triple networks" in cognition.…”

Bibliometric Analysis of Functional Magnetic Resonance Imaging Studies on Acupuncture Analgesia Over the Past 20 Years

“… 24 A neuroimaging systematic review suggested that acupuncture improved the abnormal brain structure and functional activity in patients with low back pain (LBP) mainly through the pain matrix, default mode network (DMN), salience network (SN), and descending pain modulatory system (DPMS). 25 Tu et al found that neural markers of abnormal connectivity in the visual, default mode, sensorimotor, and frontal-parietal networks captured the unique features of migraine without aura (MwoA), and that changes in marker showed a significant correlation with changes in headache frequency during TA treatment. 26 Neuroimaging studies of acupuncture showed that true acupuncture activates the insula and thus increases the pain threshold significantly compared to controls.…”