The effect of acupuncture needle combination on central pain processing--an fMRI study

Hotspots and Trends in Research on Treating Pain with Electroacupuncture: A Bibliometric and Visualization Analysis from 1994 to 2022

Purpose

Electroacupuncture is widely used to pain management. A bibliometric analysis was conducted to identify the hotspots and trends in research on electroacupuncture for pain.

Methods

We retrieved studies published from 1994-2022 on the topic of pain relief by electroacupuncture from the Web of Science Core Collection database. We comprehensively analysed the data with VOSviewer, CiteSpace, and bibliometrix. Seven aspects of the data were analysed separately: annual publication outputs, countries, institutions, authors, journals, keywords and references.

Results

A total of 2030 papers were analysed, and the number of worldwide publications continuously increased over the period of interest. The most productive country and institution in this field were China and KyungHee University. Evidence-Based Complementary and Alternative Medicine was the most productive journal, and Pain was the most co-cited journal. Han Jisheng, Fang Jianqiao, and Lao Lixing were the most representative authors. Based on keywords and references, three active areas of research on EA for pain were mechanisms, randomized controlled trials, and perioperative applications. Three emerging trends were functional magnetic resonance imaging (fMRI), systematic reviews, and knee osteoarthritis.

Conclusion

This study comprehensively analysed the research published over the past 28 years on electroacupuncture for pain treatment, using bibliometrics and science mapping analysis. This work presents the current status and landscape of the field and may serve as a valuable resource for researchers. Chronic pain, fMRI-based mechanistic research, and the perioperative application of electroacupuncture are among the likely foci of future research in this area.

Current status of neuroimaging research on the effects of acupuncture: a bibliometric and visual analyses

OBJECTIVE

To conduct an inductive analysis of neuroimaging studies following the global popularity surrounding the effects of acupuncture.

METHODS

The relevant works of literature on acupuncture effects-related neuroimaging studies were retrieved from the web of science core collection database from the date of its establishment to 2022. Bibexcel software was used to extract information, such as article numbers, countries, journals, agencies, funding sources and keywords. The VOSviewer software's co-occurrence and clustering module was used for the co-occurrence and cluster analysis of collaborative networks and high frequency keywords, such as authors, institutions and countries.

RESULTS

Neuroimaging research on the effects of acupuncture began in the 1960 s and has since received the extensive attention of scholars. China, The United States and South Korea conduct more neuroimaging research on the effects of acupuncture than other countries. Academic journals such as Evidence-Based Complementary and Alternative Medicine, Journal of Alternative and Complementary Medicine, Neural Regeneration Research and Acupuncture in Medicine have published the highest number of acupuncture-related neuroimaging articles. Moreover, cluster analysis differentiates high-frequency keywords into six clusters. Furthermore, the use of the keyword 'density atlas' reveals that neuroimaging research on the effects of acupuncture surrounding pain and neurofunctional rehabilitation is currently the research focus.

CONCLUSIONS

This bibliometric study identifies six important research hot spots: Static brain functional connectivity analysis of acupuncture analgesic effects, key theories on the scientific problems of acupuncture, acupuncture analgesic effect of the placebo effect, the neuroimaging of acupoint ST-36, the value of acupuncture in regulating the autonomic nerves and acupuncture therapy as complementary medicine.

Effect of acupuncture on brain regions modulation of mild cognitive impairment: A meta-analysis of functional magnetic resonance imaging studies

Background

As a non-pharmacological therapy, acupuncture has significant efficacy in treating Mild Cognitive Impairment (MCI) compared to pharmacological therapies. In recent years, advances in neuroimaging techniques have provided new perspectives to elucidate the central mechanisms of acupuncture for MCI. Many acupuncture brain imaging studies have found significant improvements in brain function after acupuncture treatment of MCI, but the underlying mechanisms of brain regions modulation are unclear.

Objective

A meta-analysis of functional magnetic resonance imaging studies of MCI patients treated with acupuncture was conducted to summarize the effects of acupuncture on the modulation of MCI brain regions from a neuroimaging perspective.

Methods

Using acupuncture, neuroimaging, magnetic resonance, and Mild Cognitive Impairment as search terms, PubMed, EMBASE, Web of Science, Cochrane Library, Cochrane Database of Systematic Reviews, Cochrane Database of Abstracts of Reviews of Effects (DARE), Google Scholar, China National Knowledge Infrastructure (CNKI), China Biology Medicine disk (CBM disk), Wanfang and Chinese Scientific Journal Database (VIP) for brain imaging studies on acupuncture on MCI published up to April 2022. Voxel-based neuroimaging meta-analysis of fMRI data was performed using voxel-based d Mapping with Permutation of Subject Images (SDM-PSI), allowing for Family-Wise Error Rate (FWER) correction correction for correction multiple comparisons of results. Subgroup analysis was used to compare the differences in brain regions between the acupuncture treatment group and other control groups. Meta-regression was used to explore demographic information and altered cognitive function effects on brain imaging outcomes. Linear models were drawn using MATLAB 2017a, and visual graphs for quality evaluation were produced using R software and RStudio software.

Results

A total of seven studies met the inclusion criteria, with 94 patients in the treatment group and 112 patients in the control group. All studies were analyzed using the regional homogeneity (ReHo) method. The experimental design of fMRI included six task state studies and one resting-state study. The meta-analysis showed that MCI patients had enhanced activity in the right insula, left anterior cingulate/paracingulate gyri, right thalamus, right middle frontal gyrus, right median cingulate/paracingulate gyri, and right middle temporal gyrus brain regions after acupuncture treatment. Further analysis of RCT and longitudinal studies showed that Reho values were significantly elevated in two brain regions, the left anterior cingulate/paracingulate gyrus and the right insula, after acupuncture. The MCI group showed stronger activity in the right supramarginal gyrus after acupuncture treatment compared to healthy controls. Meta-regression analysis showed that the right anterior thalamic projection ReHo index was significantly correlated with the MMSE score after acupuncture treatment in all MCI patients.

Conclusions

Acupuncture therapy has a modulating effect on the brain regions of MCI patients. However, due to the inadequate experimental design of neuroimaging studies, multi-center neuroimaging studies with large samples are needed better to understand the potential neuroimaging mechanisms of acupuncture for MCI. In addition, machine learning algorithm-based predictive models for evaluating the efficacy of acupuncture for MCI may become a focus of future research.

Systematic review registration

https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42022287826, identifier: CRD 42022287826.

Neuroimaging in the Understanding of Acupuncture Analgesia: A Review of Acupuncture Neuroimaging Study Based on Experimental Pain Models

With the development of real-time and visualized neuroimaging techniques, the studies on the central mechanism of acupuncture analgesia gain increasing attention. The experimental pain models have been widely used in acupuncture-analgesia neuroimaging studies with quantitative and controlled advantages. This review aimed to analyze the study design and main findings of acupuncture neuroimaging studies to provide reference for future study. The original studies were collected and screened in English databases (PubMed, EMBASE, and Cochrane Library) and Chinese databases (Chinese Nation Knowledge Infrastructure, Chinese Biomedical Literature Database, the Chongqing VIP Database, and Wanfang Database). As a result, a total of 27 articles were included. Heat stimulation and electroacupuncture were the mostly used pain modeling method and acupuncture modality, respectively. The neuroimaging scanning process can be divided into two models and five subtypes. The anterior cingulate cortex and insula were the most commonly reported brain regions involved in acupuncture analgesia with experimental pain models.

Does the Acupoint Specificity Exist? Evidence from Functional Neuroimaging Studies

BACKGROUND

Using functional neuroimaging techniques to explore the central mechanism of acupoint specificity, the key of acupuncture theory and clinical practice, has attracted increasing attention worldwide. This review aimed to investigate the current status of functional neuroimaging studies on acupoint specificity and explore the potential influencing factors for the expression of acupoint specificity in neuroimaging studies.

METHODS

PubMed database was searched from January 1st, 1995 to December 31st, 2016 with the language restriction in English. Data including basic information, methodology and study results were extracted and analyzed from the eligible records.

RESULTS

Seventy-nine studies were finally enrolled. 65.8% of studies were performed in China, 73.4% of studies were conducted with healthy subjects, 77.2% of studies chose manual acupuncture as the intervention, 86.1% of studies focused on the instant efficacy and 89.9% of studies used functional magnetic resonance imaging as scanning technique. The average sample size was 16 per group. The comparison of verum acupoints and sham acupoints were the main body of acupoint specificity researches. 93.7% of studies obtained the positive results and favored the existence of acupoint specificity.

CONCLUSION

This review affirmed the existence of acupoint specificity and deemed that the acupoint specificity was relative. Multiple factors such as participants, sample size, acupoint combinations, treatment courses, and types of acupoint could influence the expression of acupoint specificity.

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

Chronic shoulder pain (CSP) is the third most common musculoskeletal problem. For maximum treatment effectiveness, most acupuncturists usually choose acupoint in the nonpainful side, to alleviate pain or improve shoulder function. This method is named opposite needling, which means acupuncture points on the right side are selected for diseases on the left side and vice versa. However, the underlying neural mechanisms related to treatment are currently unclear. The purpose of this study was to determine whether different mechanisms were observed with contralateral and ipsilateral acupuncture at Tiaokou (ST 38) in patients with unilateral CSP. Twenty-four patients were randomized to the contralateral acupuncture group (contra-group) and the ipsilateral acupuncture group (ipsi-group). The patients received one acupuncture treatment session at ST 38 on the nonpainful or painful sides, respectively. Before and after acupuncture treatment, they underwent functional magnetic resonance scanning. The treatment-related changes in degree centrality (DC) maps were compared between the two groups. We found alleviated pain and improved shoulder function in both groups, but better shoulder functional improvement was observed in the contra-group. Increased DC in the anterior/paracingulate cortex and decreased DC in bilateral postcentral gyri were found in the contra-group, while decreased DC in the bilateral cerebellum and right thalamus was observed in the ipsi-group. Furthermore, the DC value in the bilateral anterior/paracingulate cortex was positively correlated with the treatment-related change in the Constant–Murley score. The current study reveals different changes of DC patterns after acupuncture at contralateral or ipsilateral ST 38 in patients with CSP. Our findings support the hypothesis of acupoint specificity and provide the evidence for acupuncturists to select acupoints for CSP.

Evaluating the Effects of Acupuncture Using a Dental Pain Model in Healthy Subjects - A Randomized, Cross-Over Trial

Acupuncture is a complementary and nonpharmacological intervention that can be effective for the management of chronic pain in addition to or instead of medication. Various animal models for neuropathic pain, inflammatory pain, cancer-related pain, and visceral pain already exist in acupuncture research. We used a newly validated human pain model and examined whether acupuncture can influence experimentally induced dental pain. For this study, we compared the impact of manual acupuncture (real acupuncture), manual stimulation of a needle inserted at nonacupuncture points (sham acupuncture) and no acupuncture on experimentally induced dental pain in 35 healthy men who were randomized to different sequences of all 3 interventions in a within-subject design. BORG CR10 pain ratings and autonomic responses (electrodermal activity and heart rate variability) were investigated. An initial mixed model with repeated measures included preintervention pain ratings and the trial sequence as covariates. The results showed that acupuncture was effective in reducing pain intensity when compared to no acupuncture (β = -.708, P = .002), corresponding to a medium Cohen's d effect size of .56. The comparison to the sham acupuncture revealed no statistically significant difference. No differences in autonomic responses between real and sham acupuncture were found during the intervention procedures. PERSPECTIVE: This study established a dental pain model for acupuncture research and provided evidence that experimentally induced dental pain can be influenced by either real acupuncture or manual stimulation of needles at nonacupuncture points. The data do not support that acupoint specificity is a significant factor in reducing experimental pain.

Interaction of energetic points, tendinomuscular meridian and 5 elements in the treatment of osteoarthritis of the knee in patients over 45 years old: a randomized controlled trial

INTRODUCTION

Acupuncture had a different approaches since its beginnings. Using traditional energetic points with an interaction of 5 elements and meridian theories with manual diagnosis of tender points has been proposed. This procedure can be an effective treatment in musculoskeletal disease but its development is short.

OBJECTIVES

To evaluate the efficacy of energetic points of tendinomuscular meridian in the treatment of pain, quality of life and function of the knee.

DESIGN

Randomized controlled trial, non standardized and double blind. Inclusions criteria were: being over 45 years, having had pain for more than 3 months, level II o greater in Kellgren-Lawrence and suffering morning stiffness. Exclusion criteria were artoplasty, corticosteroids and rehabilitation, arthropaties, autoinmune diseases and neuropathic pain.

RESULTS

Intervention group had significant improvement in average pain in the last 15 days at end of treatment (p<0.04) and quality of life at the end of follow-up (p<0.015). Other measurements no show significant differences between groups.

CONCLUSIONS

Energetic points of tendinomuscular meridian and the 5 elements related are equal or better than local acupuncture in the treatment of pain, quality of life and function in osteoarthritis of the knee. However, it is necessary to have more research with more tracing and poblation to improve the quality of the results.

Pain-related white matter tract abnormalities in mild traumatic brain injury patients with persistent headache

Background

The occurrence of debilitating chronic persistent (24/7) headache after mild traumatic brain injury represents a central neuropathic pain state. Previous studies suggest that this chronic headache state can be attributed to altered supraspinal modulatory functional connectivity in both resting and evoked pain states. Abnormalities in the myelin sheaths along the supraspinal superior longitudinal fasciculus and anterior thalamic radiation are frequently associated with alteration in pain modulation related to functional connectivity deficit with the prefrontal cortex. This study assessed the correlated axonal injury-related white matter tract abnormality underlying these previously observed prefrontal functional connectivity deficits by comparing the fractional anisotropy, axial diffusivity, and radial diffusivity of brain white matter in patients with mild traumatic brain injury-related headache to healthy controls.

Result

Diffusion tensor imaging data from patients (N = 12, average age ± SD = 35.0 ± 8.0 years old, 10 male) with mild traumatic brain injury-headache were compared with images acquired from healthy controls. The mild traumatic brain injury cohort demonstrated two areas of significant (P < 0.01, F value >16, cluster size >50 voxels) white matter tract abnormalities closely related to pain affective and modulatory functions in (1) the left superior longitudinal fasciculus which connects the prefrontal cortices with the parietal cortices and (2) the right anterior thalamic radiation connecting the prefrontal cortices with the anterior cingulate cortex. In addition, a significant (P < 0.01) decrease in axial diffusivity and increase in radial diffusivity at the superior longitudinal fasciculus cluster were noted in the mild traumatic brain injury cohort.

Conclusion

The identified white matter tract abnormalities may represent a state of Wallerian degeneration which correlates with the functional connectivity deficit in pain modulation and can contribute to the development of the chronic persistent headache in the patients with mild traumatic brain injury.

Different mechanisms of contralateral- or ipsilateral-acupuncture to modulate the brain activity in patients with unilateral chronic shoulder pain: a pilot fMRI study

Background

Chronic shoulder pain (CSP) is a common disease causing pain and functional limitation, which is highly prevalent and has substantial negative effects on the quality of life. Acupuncture has gained popularity and has been accepted gradually by many countries because it can successfully treat patients with chronic pain, but the specific brain mechanisms under acupuncture treatment for CSP remain unclear. Therefore, in this study, we aimed to 1) compare the clinical effects between acupuncture at the contralateral and ipsilateral Tiaokou (ST 38) point in patients with unilateral shoulder pain and 2) explore how contralateral- and ipsilateral-acupuncture modulates the regional homogeneity (ReHo) of patients with CSP.

Patients and methods

This was a pilot functional magnetic resonance imaging (fMRI) trial. Twenty-four patients with CSP were recruited and randomized to the contralateral acupuncture group (contra-group) and the ipsilateral acupuncture group (ipsi-group). All patients completed resting-state functional magnetic resonance imaging (fMRI) scans before and after acupuncture treatment. Shoulder pain intensity (visual analog scale [VAS]) and shoulder joint function (Constant–Murley score [CMS]) were used to evaluate clinical efficiency of treatment. ReHo was used to assess resting-state brain activity.

Results

We found clinical improvement in decreasing pain intensity and increasing shoulder function in both groups, and the mean objective shoulder functional improvement in contra-group was better than that in ipsi-group (p = 0.010). Interestingly, the brain mechanism of contra-acupuncture at ST 38 was distinguishable from ipsi-acupuncture regarding ReHo values.

Conclusion

Anterior cingulate cortex (ACC) may play a direct role in the regulation of brain by the contralateral acupuncture at ST 38 in patients with shoulder pain. On the contrary, the pathway of brainstem-thalamus-cortex may be likely to work in mechanism of acupuncture at ipsilateral ST 38.

Significance

Our results indicate that the clinical effects and brain mechanisms are different between the stimulation given at contralateral and ipsilateral acupoints in patients with CSP and imply that the selection of either contralateral or ipsilateral acupuncture therapy to treat some chronic pain conditions is necessary.

Nonpainful wide-area compression inhibits experimental pain

Compression therapy, a well-recognized treatment for lymphoedema and venous disorders, pressurizes limbs and generates massive non-noxious afferent sensory barrages. The aim of this study was to study whether such afferent activity has an analgesic effect when applied on the lower limbs, hypothesizing that larger compression areas will induce stronger analgesic effects, and whether this effect correlates with conditioned pain modulation (CPM). Thirty young healthy subjects received painful heat and pressure stimuli (47°C for 30 seconds, forearm; 300 kPa for 15 seconds, wrist) before and during 3 compression protocols of either SMALL (up to ankles), MEDIUM (up to knees), or LARGE (up to hips) compression areas. Conditioned pain modulation (heat pain conditioned by noxious cold water) was tested before and after each compression protocol. The LARGE protocol induced more analgesia for heat than the SMALL protocol (P < 0.001). The analgesic effect interacted with gender (P = 0.015). The LARGE protocol was more efficient for females, whereas the MEDIUM protocol was more efficient for males. Pressure pain was reduced by all protocols (P < 0.001) with no differences between protocols and no gender effect. Conditioned pain modulation was more efficient than the compression-induced analgesia. For the LARGE protocol, precompression CPM efficiency positively correlated with compression-induced analgesia. Large body area compression exerts an area-dependent analgesic effect on experimental pain stimuli. The observed correlation with pain inhibition in response to robust non-noxious sensory stimulation may suggest that compression therapy shares similar mechanisms with inhibitory pain modulation assessed through CPM.

Pain and motor processing in the human cerebellum

Pain-related adaptations in movement require a network architecture that allows for integration across pain and motor circuits. Previous studies addressing this issue have focused on cortical areas such as the midcingulate cortex. Here, we focus on pain and motor processing in the human cerebellum. The goal of this study was to identify areas of activation in the cerebellum, which are common to pain and motor processing, and to determine whether the activation is limited to the superior and inferior cerebellar motor maps or extends into multimodal areas of the posterior cerebellum. Our observations identified overlapping activity in left and right lobules VI and VIIb during pain and motor processing. Activation in these multimodal regions persisted when pain and motor processes were combined within the same trial, and activation in contralateral left lobule VIIb persisted when stimulation was controlled for. Functional connectivity analyses revealed significant correlations in the BOLD time series between multimodal cerebellar regions and sensorimotor regions in the cerebrum including anterior midcingulate cortex, supplementary motor area, and thalamus. The current findings are the first to show multimodal processing in lobules VI and VIIb for motor control and pain processing and suggest that the posterior cerebellum may be important in understanding pain-related adaptations in motor control.

Evidence of a Synergistic Effect of Acupoint Combination: A Resting-State Functional Magnetic Resonance Imaging Study

Objective: This study aimed to find evidence of a synergistic effect of acupoint combinations by analyzing different brain regions activated after acupuncture at different acupoint combinations.

Methods: A total of 57 healthy subjects were randomly distributed into three groups: LR3 plus KI3 acupoints, LR3 plus sham acupoint, or LR3 alone. They underwent a magnetic resonance imaging scan before and after acupuncture. The amplitude of low-frequency fluctuation (ALFF) and regional homogeneity (ReHo) values of different brain regions were analyzed to observe changes in brain function.

Results: ALFF and ReHo produced an activated area in the cerebellum posterior lobe after acupuncture at LR3 plus KI3 acupoints versus LR3 alone. ALFF and ReHo revealed altered activity in Brodmann area 10 (BA10), BA18, and brainstem pons after acupuncture at LR3 plus sham acupoint compared with at LR3 alone. A comparison of acupuncture at LR3 plus KI3 acupoints with LR3 plus sham acupoint demonstrated an increase in BA6 of ALFF and a downregulation of ReHo.

Conclusions: The increased number of brain regions with altered brain activity after acupuncture at acupoint combinations versus a single acupoint are evidence of the synergistic effect of acupoint combinations. BA6 was significantly activated after acupuncture at LR3 plus KI3 acupoints compared with at LR3 plus sham acupoint, suggesting that BA6 is the specific region of synergistic effect of acupoint combinations of LR3 plus KI3 acupoints. Affected brain regions were different between acupuncture at LR3 plus sham acupoint and LR3 alone, which indicates that the sham acupoint may have some psychological effect. However, the specific mechanism of acupoint combinations requires further research.

Diminished supraspinal pain modulation in patients with mild traumatic brain injury

Background

Chronic pain conditions are highly prevalent in patients with mild traumatic brain injury. Supraspinal diffuse axonal injury is known to dissociate brain functional connectivity in these patients. The effect of this dissociated state on supraspinal pain network is largely unknown. A functional magnetic resonance imaging study was conducted to compare the supraspinal pain network in patients with mild traumatic brain injury to the gender and age-matched healthy controls with the hypothesis that the functional connectivities of the medial prefrontal cortices, a supraspinal pain modulatory region to other pain-related sensory discriminatory and affective regions in the mild traumatic brain injury subjects are significantly reduced in comparison to healthy controls.

Results

The mild traumatic brain injury group (N = 15) demonstrated significantly (P < 0.01, cluster threshold > 150 voxels) less activities in the thalamus, pons, anterior cingulate cortex, insula, dorsolateral prefrontal cortex, and medial prefrontal cortices than the healthy control group (N = 15). Granger Causality Analyses (GCA) indicated while the left medial prefrontal cortices of the healthy control group cast a noticeable degree of outward (to affect) causality inference to multiple pain processing related regions, this outward inference pattern was not observed in the mild traumatic brain injury group. On the other hand, only patients’ bilateral anterior cingulate cortex received multiple inward (to be affected) causality inferences from regions including the primary and secondary somatosensory cortices and the inferior parietal lobe. Resting state functional connectivity analyses indicated that the medial prefrontal cortices of the mild traumatic brain injury group demonstrated a significantly (P < 0.01, F = 3.6, cluster size > 150 voxels) higher degree of functional connectivity to the inferior parietal lobe, premotor and secondary somatosensory cortex than the controls. Conversely, the anterior cingulate cortex of the healthy group demonstrated significantly (P < 0.01, F = 3.84, cluster size > 150 voxels) less degree of functional connectivities to the inferior parietal lobe and secondary somatosensory cortex than their mild traumatic brain injury counterparts.

Conclusions

In short, the current study demonstrates that patients with mild traumatic brain injury and headaches appear to have an altered state of supraspinal modulatory and affective functions related to pain perception.

Gender differences in the neural response to acupuncture: clinical implications

OBJECTIVE

To examine gender differences and similarities in the psychophysical and brain responses to acupuncture at GB34, a point that is frequently used to treat motor function issues in Traditional Chinese Medicine.

METHODS

Functional MRI (fMRI) was used to measure brain activation in response to acupuncture at GB34 (on the right) in 19 healthy participants (9 male, 10 female). De qi sensations were rated to measure their psychophysical responses.

RESULTS

Overall de qi scores did not differ by gender, although females reported greater intensity of aching (p=0.04). Acupuncture activated the hippocampus, thalamus, globus pallidus, caudate body, claustrum, cingulate gyrus, and culmen in males, and the middle and inferior frontal gyrus, precuneus, postcentral gyrus, inferior parietal lobule, superior temporal gyrus, caudate body, insula, fusiform gyrus, cingulate gyrus, amygdala, and parahippocampal gyrus in females. The middle/medial frontal gyrus, middle temporal gyrus, thalamus, globus pallidus, caudate body, uvula, and cerebellar tonsil were activated when data from all subjects were combined. Relative to males, females exhibited greater brain activation in the right-sided postcentral gyrus, precentral gyrus, precuneus, postcentral gyrus, inferior parietal lobule, declive, middle occipital gyrus and parahippocampal gyrus.

CONCLUSIONS

The neural effects of GB34 acupuncture might differ between males and females because different brain structures were modulated in response to acupuncture. This potential gender effect should be taken into account in future clinical research. We also revealed that the caudate body was activated by GB34 acupuncture in both males and females and may represent a major target of GB34 acupuncture.

TRIAL REGISTRATION NUMBER

KMC IRB 0861-06.

Manual acupuncture at the SJ5 (Waiguan) acupoint shows neuroprotective effects by regulating expression of the anti-apoptotic gene Bcl-2

Acupuncture at the SJ5 (Waiguan) acupoint has neuroprotective effects in cerebral infarction, but the underlying mechanism remains poorly understood. Here, we analyzed gene expression in healthy rat cerebellum using a pathway-focused DNA microarray to screen 113 genes associated with 18 signal transduction pathways. After 20 minutes of acupuncture at SJ5, the expression of Bcl-2 and Birc1b mRNA was markedly increased. This was confirmed by real-time reverse transcription PCR. Furthermore, western blot analysis showed that Bcl-2 protein expression remained high in the cerebellum until at least 2 hours after cessation of acupuncture. These findings indicate that acupuncture at SJ5 exerts neuroprotective effects by regulating the expression of anti-apoptotic gene Bcl-2.

The modulation effect of longitudinal acupuncture on resting state functional connectivity in knee osteoarthritis patients

Recent advances in brain imaging have contributed to our understanding of the neural activity associated with acupuncture treatment. In this study, we investigated functional connectivity across longitudinal acupuncture treatments in older patients with knee osteoarthritis (OA). Over a period of 4 weeks (six treatments), we collected resting state functional magnetic resonance imaging (fMRI) scans from 30 patients before and after their first, third and sixth treatments. Clinical outcome showed a significantly greater pain subscore on the Knee Injury and Osteoarthritis Outcome Score (KOOS) (indicative of improvement) with verum acupuncture than with sham acupuncture. Independent component analysis (ICA) of the resting state fMRI data showed that the right frontoparietal network (rFPN) and the executive control network (ECN) showed enhanced functional connectivity (FC) with the rostral anterior cingulate cortex/medial prefrontal cortex, a key region in the descending pain modulatory system, in the verum groups as compared to the sham group after treatments. We also found that the rFPN connectivity with the left insula is (1) significantly associated with changes in KOOS pain score after treatments, and (2) significantly enhanced after verum acupuncture treatments as compared to sham treatment. Analysis of the acupuncture needle stimulation scan showed that compared with sham treatment, verum acupuncture activated the left operculum/insula, which also overlaps with findings observed in resting state analysis. Our results suggest that acupuncture may achieve its therapeutic effect on knee OA pain by modulating functional connectivity between the rFPN, ECN and the descending pain modulatory pathway.

Clinical trial number: NCT01079390

Acupuncture modulates cortical thickness and functional connectivity in knee osteoarthritis patients

In this study, we investigated cortical thickness and functional connectivity across longitudinal acupuncture treatments in patients with knee osteoarthritis (OA). Over a period of four weeks (six treatments), we collected resting state functional magnetic resonance imaging (fMRI) scans from 30 patients before their first, third and sixth treatments. Clinical outcome showed a significantly greater Knee Injury and Osteoarthritis Outcome Score (KOOS) pain score (improvement) with verum acupuncture compared to the sham acupuncture. Longitudinal cortical thickness analysis showed that the cortical thickness at left posterior medial prefrontal cortex (pMPFC) decreased significantly in the sham group across treatment sessions as compared with verum group. Resting state functional connectivity (rsFC) analysis using the left pMPFC as a seed showed that after longitudinal treatments, the rsFC between the left pMPFC and the rostral anterior cingulate cortex (rACC), medial frontal pole (mFP) and periaquiduct grey (PAG) are significantly greater in the verum acupuncture group as compared with the sham group. Our results suggest that acupuncture may achieve its therapeutic effect on knee OA pain by preventing cortical thinning and decreases in functional connectivity in major pain related areas, therefore modulating pain in the descending pain modulatory pathway.