The Effect of Acupuncture Needle Combination on Central Pain Processing-An fMRI Study

Abstract

BackgroundEmpirical acupuncture treatment paradigm for acute pain utilizing Tendinomuscular Meridians (TMM) calls for the stimulation of Ting Points (TPs) and Gathering point(GP). This study aims to compare the supraspinal neuronal mechanisms associated with both TPs and GP needling (EA3), and TPs needling alone (EA2) with fMRI.ResultsA significant (P < 0.01) difference between pre-scan (heat Pain) HP, and post-EA HP VAS scores in both paradigms was noted (n = 11). The post-EA HP VAS score was significantly (P < 0.05) lower with EA3 comparing to EA2 Within-group random effect analysis indicated that EA3+HP>EA3 (condition EA3+HP subtracted by condition EA3) appeared to exert a significant degree of activity suppression in the affective supraspinal regions including the IPL, anterior cingulate cortex (ACC) and the insular cortex (IN). This level of suppression was not observed in the EA2+HP>EA2 (condition EA2+HP subtracted by condition EA2) within-group random effect analysis Between-group random effect analysis indicated that EA3 induced a significantly (P < 0.01, cluster size threshold 150) higher degree of deactivation than EA2 in several pain related supraspinal regions including the right prefrontal cortex, rostral anterior cingulate (rACC), medial cingulate cortex, left inferior frontal lobe and posterior cerebellum. The 2-factor ANOVA in those regions indicated both rACC and posterior cerebellum had a significant (P < 0.01) needle effect, and the right prefrontal area showed a significant (P < 0.01) HP effect. However, a significant interaction between the two factors was only found in the right prefrontal lobe. Granger causality analysis showed EA3 induced a much higher degree of inference among HP related supraspinal somatosensory, affective and modulatory components than EA2. Deactivation pattern at the medullary-pontine area casted a direct inference on the deactivation pattern of secondary somatosensory cortices which also affected the deactivation of the IN.ConclusionsWhile both EA2 and EA3 induced a significant degree of deactivation in the human brain regions related to pain processing, the addition of GP stimulation further exerts an inhibitory effect on the ascending spinoreticular pain pathway. Therefore, different needling position as mandated in different empirical acupuncture treatment paradigms may play a different role in modulating pain related neuronal functions.

Different Degree Centrality Changes in the Brain after Acupuncture on Contralateral or Ipsilateral Acupoint in Patients with Chronic Shoulder Pain: A Resting-State fMRI Study

“…Interestingly, in the present study, the brain region, demonstrating a decreased DC after acupuncture at the ipsilateral acupoint, was in the cerebellum bilaterally overlapped with the vermal lobules IV/V. Similarly, Leung et al demonstrated that changes in pain perception after acupuncture are associated with reduced functional activity in the cerebellum [45]. Our findings extended these observations obtained from measuring regional activity by calculating the full range of functional connectivity of the cerebellum to the whole brain, thereby illustrating a hublike role of the cerebellum in pain relief using ipsilateral acupuncture for the first time.…”

Pain and motor processing in the human cerebellum

“…33 Cerebellar structure and function are also integral to models that detect and predict experimental pain 79 and clinical pain, 78 and changes in pain perception after acupuncture have been associated with reduced functional activity in the posterior cerebellum. 38 Other evidence shows that transcranial direct current stimulation over the cerebellum influences the perception of both pain-eliciting and non-pain-eliciting stimuli, with current flow models suggesting that these effects are driven by focal stimulation over lobules VI and VIIb. 9 In our study, activity in posterior cerebellum was found during separate trials of pain and force production, when pain processing and force production were combined and also when the FP and FW conditions were directly compared.…”

Acupuncture modulates cortical thickness and functional connectivity in knee osteoarthritis patients

“…Brain imaging studies have also shown that acupuncture needle stimulation1718192021 can evoke widespread brain activity changes and modulate the functional connectivity (FC) of the pain processing network2223242526272829, which opens a new window to understand the central mechanism of acupuncture treatment.…”