Effect of "needle sensation" and the real-time changes in autonomic nervous system activity during acupuncture analgesia

Introduction

Acupuncture analgesia (AA) is widely used in clinical practice. The autonomic nervous system (ANS) may be an important pathway for acupuncture signal transduction. However, real-time changes in autonomic function during AA and the effect of "needle sensation" remain unclear.

Methods

We established a human pain model in healthy adults and randomly assigned 128 participants to the model, sham acupuncture, and acupuncture groups in a 1:1:2 ratio. Heart rate variability (HRV), including total power (TP), low-frequency power (LF), high-frequency power (HF), ratio of LF to HF (LF/HF), standard deviation of the normal-normal intervals (SDNN), and root mean square of successive interval differences (RMSSD), were used to assess autonomic function. The visual analog scale (VAS) and efficiency were used to assess the analgesic effect of acupuncture. The Massachusetts General Hospital acupuncture sensation scale (MASS) was used to indicate the intensity of the needle sensation. Anxiety levels were also measured. Finally, the correlation of MASS with HRV, VAS, and anxiety levels was analyzed.

Results

VAS decreased after 10 min of needling and 5 min after needle withdrawal in the acupuncture group compared with those in the model group (p = 0.038, p = 0.020). The efficacy rates were 82.0, 50.0, and 61.3% in the acupuncture, model, and sham groups, respectively. These represent significant differences between the acupuncture group and the model and sham acupuncture groups (p < 0.001 in each case). No differences were observed between the model and sham acupuncture groups. HF, TP, SDNN, and RMSSD were all increased in the acupuncture group compared with those in the model group (p = 0.045, p = 0.041, p = 0.002, p = 0.006, respectively). No differences were observed in the sham acupuncture group compared to the model group (p = 0.632, p = 0.542, p = 0.093, p = 0.222, respectively). The LF and LF/HF did not differ among all three groups. A positive correlation was observed between MASS and RMSSD2, LF2, RMSSD4, TP4, VAS5, and anxiety levels.

Conclusion

AA was associated with enhanced vagal activity. The intensity of needle sensation was positively correlated with vagal and sympathetic nerve activities. Acupuncture is an effective means of regulating autonomic function, and needle sensation may be an important modulator.

Dry needling, trigger point electroacupuncture and motor point electroacupuncture for the treatment of myofascial pain syndrome involving the trapezius: a randomised clinical trial

OBJECTIVE

The objective of this study was to compare trigger point (TrP) dry needling, TrP electroacupuncture and motor point electroacupuncture of the trapezius muscle for the treatment of myofascial pain syndrome (MPS).

METHODS

This randomised clinical trial included 90 patients divided into three groups. Group 1 was treated with dry needling of TrPs, group 2 with intramuscular electrical stimulation of TrPs, and group 3 with electroacupuncture of motor points and/or the spinal accessory nerve. Each group received seven treatment sessions. The outcomes were the pain score measured by visual analogue scale (VAS) and quality of life evaluated by the 12-item short form (SF-12) health questionnaire. We compared the pain outcome over serial time points using growth curve analysis methods.

RESULTS

Participants in the three groups experienced significant improvements in pain scores over time. The average pain level of participants in group 3 across the repeated assessments was 0.98 units lower than in group 1 (mean difference (95% confidence interval (CI) = 1.74-0.23)), p = 0.012). There were no significant differences in pain scores between participants in groups 1 and 2, and there were no significant differences in quality of life across the three groups at the end of the treatment period.

CONCLUSION

Our results provide evidence that electrical stimulation of motor points and/or of the spinal accessory nerve may be superior in terms of pain relief (but not quality of life) to dry needling and possibly electrical stimulation of trigger points for the management of MPS involving the trapezius.

TRIAL REGISTRATION NUMBER

TRIAL-RBR-43R7RF (Brazilian Clinical Trials Registry).

Understanding of Spinal Wide Dynamic Range Neurons and Their Modulation on Pathological Pain

The spinal dorsal horn (SDH) transmits sensory information from the periphery to the brain. Wide dynamic range (WDR) neurons within this relay site play a critical role in modulating and integrating peripheral sensory inputs, as well as the process of central sensitization during pathological pain. This group of spinal multi-receptive neurons has attracted considerable attention in pain research due to their capabilities for encoding the location and intensity of nociception. Meanwhile, transmission, processing, and modulation of incoming afferent information in WDR neurons also establish the underlying basis for investigating the integration of acupuncture and pain signals. This review aims to provide a comprehensive examination of the distinctive features of WDR neurons and their involvement in pain. Specifically, we will examine the regulation of diverse supraspinal nuclei on these neurons and analyze their potential in elucidating the mechanisms of acupuncture analgesia.

Local analgesia of electroacupuncture is mediated by the recruitment of neutrophils and released β-endorphins

ABSTRACT

The efficacy of acupuncture in treating pain diseases has been recognized in clinical practice, and its mechanism of action has been a hot topic in academic acupuncture research. Previous basic research on acupuncture analgesia has focused mostly on the nervous system, with few studies addressing the immune system as a potential pathway of acupuncture analgesia. In this study, we investigated the effect of electroacupuncture (EA) on the β-endorphins (β-END) content, END-containing leukocyte type and number, sympathetic neurotransmitter norepinephrine (NE), and chemokine gene expression in inflamed tissues. To induce inflammatory pain, about 200 µL of complete Frester adjuvant (CFA) was injected into the unilateral medial femoral muscle of adult Wistar rats. Electroacupuncture treatment was performed for 3 days beginning on day 4 after CFA injection, with parameters of 2/100 Hz, 2 mA, and 30 minutes per treatment. The weight-bearing experiment and enzyme-linked immunosorbent assay showed that EA treatment significantly relieved spontaneous pain-like behaviors and increased the level of β-END in inflamed tissue. Injection of anti-END antibody in inflamed tissue blocked this analgesic effect. Flow cytometry and immunofluorescence staining revealed that the EA-induced increase in β-END was derived from opioid-containing ICAM-1 + /CD11b + immune cells in inflamed tissue. In addition, EA treatment increased the NE content and expression of β2 adrenergic receptor (ADR-β2) in inflammatory tissues and upregulated Cxcl1 and Cxcl6 gene expression levels. These findings provide new evidence for the peripheral analgesic effect of acupuncture treatment by recruiting β-END-containing ICAM-1 + /CD11b + immune cells and increasing the β-END content at the site of inflammation.

Efficacy of acupuncture on acute pharynx infections: A systematic review and meta-analysis

BACKGROUND

Several clinical reports have focused on acupuncture for the treatment of acute pharyngeal infections. However, the efficacy and safety of acupuncture for the treatment of acute pharyngeal infections are controversial. To systematically assess the efficacy and safety of acupuncture in treating acute pharynx infections, thus providing a reference for clinical decision-making.

METHODS

We searched PubMed, CENTRAL, Embase, Web of Science, China National Knowledge Infrastructure, China Biomedical, clinical research registration platforms, gray literature, and reference lists of the selected studies from inception to October 30, 2022. The risk of bias assessment was performed using RevMan. The meta-analysis was performed using STATA with the Hedges' g value. We also performed a subgroup analysis, meta-regression, and publication bias detection using Harbord's and Egger's tests.

RESULTS

We included 19 randomized controlled trials comprising 1701 patients, of which only one study had a high risk of bias. The primary outcome, i.e., the response rate, revealed that acupuncture was more effective than antibiotics. The secondary results revealed that the differences in the reduction of VAS scores, sore throat duration, and white blood cell counts were statistically significant in the acupuncture group compared with the antibiotic group. However, the difference in the modulation of the neutrophil percentage and C-reactive protein levels was insignificant. Moreover, the acupuncture treatment resulted in a lower incidence of adverse events than the antibiotic treatment.

CONCLUSIONS

Thus, acupuncture therapy for acute pharyngeal infections is safe and its response rate is superior to that of antibiotics. Acupuncture showed positive outcomes for alleviating the sore throat symptoms, shortening the sore throat duration, and improving the immune inflammation index. Nevertheless, owing to the limitations of this study, our conclusions should be interpreted with caution. More high-quality trials are warranted in the future for improving the methodology and reporting quality.

Efficacy of different acupuncture therapies on postherpetic neuralgia: A Bayesian network meta-analysis

Background

Postherpetic neuralgia (PHN) is a common, complex, and refractory type of neuropathic pain. Several systematic reviews support the efficacy of acupuncture and related treatments for PHN. Nevertheless, the efficacy of various acupuncture-related treatments for PHN remains debatable.

Objective

We aimed to assess the efficacy and safety of acupuncture-related treatments for PHN, identify the most effective acupuncture-related treatments, and expound on the current inadequacies and prospects in the applications of acupuncture-related therapies.

Methods

We searched PubMed, Cochrane Central Register of Controlled Trials, Embase, Web of Science, Google Scholar, four Chinese databases (China National Knowledge Infrastructure, China Biomedical, Chongqing VIP, and Wan Fang databases), clinical research registration platform (World Health Organization International Clinical Trial Registration platform, China Clinical Trial Registration Center) for relevant studies. We also examined previous meta-analyses; gray literature; and reference lists of the selected studies. We then evaluated the risk of bias in the included studies and performed a Bayesian multiple network meta-analysis.

Results

We included 29 randomized controlled trials comprising 1,973 patients, of which five studies showed a high risk of bias. The pairwise meta-analysis results revealed that the efficacy of all acupuncture-related treatments for pain relief related to PHN was significantly better than antiepileptics. The network meta-analysis results showed that pricking and cupping plus antiepileptics were the most effective treatment, followed by electroacupuncture (EA) plus antiepileptics for pain relief in patients with PHN. EA plus antiepileptics ranked the best regarding reduced Pittsburgh Sleep Quality Index (PSQI) and Self-Rating Depression Scale (SDS) scores in patients with PHN. No results were found regarding the total response rate or quality of life in this study. Acupuncture-related treatments showed a lower incidence of adverse events than that of antiepileptics.

Conclusion

Acupuncture-related therapies are potential treatment options for PHN and are safe. Pricking and cupping plus antiepileptics, are the most effective acupuncture-related techniques for pain relief, while EA plus antiepileptics is the best acupuncture-related technique for improving PHN-related insomnia and depression symptoms. However, owing to the limitations of this study, these conclusions should be cautiously interpreted, and future high-quality studies are needed.

Systematic review registration

https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42021226422, identifier CRD42021226422.

Mast Cell-Associated Serotonin in Acupoint Contributes to Acupuncture Analgesia in Arthritis Rats by Mediating ATP Release

BACKGROUND

The activation of subcutaneous mast cells (MCs) helps to trigger the analgesic effect induced by acupuncture (AP), a traditional oriental therapy, that has been gradually accepted worldwide. This work aimed to reveal whether the serotonin (5-hydroxytryptamine, 5-HT) released from MCs plays an important role in this process, which has a controversial effect in the mechanism of pain.

METHODS

In vivo tests, a 20-min session of AP was applied at Zusanli acupuncture point (acupoint) of acute ankle arthritis rats. Pain thresholds of the injured hindpaw were assessed to reflect the pain state, and the targeting substances in the interstitial space of the treated acupoint were sampled by microdialysis. In vitro experiments, exogenous 5-HT (exo-5-HT) was introduced to mediate adenosine triphosphate (ATP) release from cultured MCs.

RESULTS

Needling promoted 5-HT accumulation at the Zusanli acupoint, which was prevented by sodium cromolyn. AP's analgesic effect was suppressed by the inhibition of 5-HT receptors at the acupoint, especially 5-HT1A subtype. In vitro tests, mechanical perturbation mimicking needling stimulation induced MCs to release 5-HT. 1 μM and 10 μM of exo-5-HT facilitated ATP release, which was restrained by blocking of 5-HT1 receptors rather than 5-HT3 receptors. As 5-HT, ATP and adenosine were also transiently accumulated in the treated acupoint during needling. Promoting ATP hydrolysis or activation adenosine A1 receptors duplicated AP analgesic effect. Finally, the inhibition of ATP receptors by suramin or pyridoxal phosphate-6-azo tetrasodium salt hydrate (PPADS) prevented AP analgesic effect.

CONCLUSIONS

Our results suggest that MC-associated 5-HT release at acupoints contributes to AP analgesia, and the mediation of ATP secretion through 5-HT1A receptors might be the underlying mechanism at play. ATP could facilitate adenosine production or the propagation of needling signals.

Acupuncture Analgesia in Patients With Traumatic Rib Fractures: A Randomized-Controlled Trial

Pain management for traumatic rib fracture is important to prevent complications and reduce associated comorbidities. This trial investigated the analgesic efficacy of acupuncture on traumatic rib fracture. Patients with traumatic rib fracture were randomly assigned to traditional acupuncture (TA), laser acupuncture (LA) or sham laser acupuncture (SLA) groups in a 1:1:1 ratio. The intervention was performed on days 1 to 3 after treatment allocation. The acupoints included bilateral LI4 (Hegu), SJ6 (Zhigou), ST36 (Zusanli) and GB34 (Yanglingquan). The primary outcome was Numeric Rating Scale (NRS) scores for pain after the intervention. Secondary outcomes included sustained maximal inspiration (SMI) lung volume, stress responses, the use of analgesics, and associated complications. Data were analyzed via one-way analysis of variance (ANOVA) with Scheffé's post hoc testing or chi-squared testing. Of the 120 study participants, 109 completed all interventions and measurements. The primary outcomes, which indicated average pain intensity levels and pain while deep breathing, were both significantly lower in the TA and LA groups than in the SLA group after 2 treatments. No between-group differences were observed in SMI lung volume, stress response, analgesics use or associated complications. These findings suggest that TA and LA are safe and effective analgesic modalities for pain management for traumatic rib fracture.

Clinical Trial Registration

[ClinicalTrials.gov], identifier [NCT03822273].

Adiponectin regulates electroacupuncture-produced analgesic effects in association with a crosstalk between the peripheral circulation and the spinal cord

Neurotransmitter-mediated acupuncture analgesia has been widely studied in nervous systems. It remains largely unclear if peripheral substances are involved the acupuncture analgesia. Adiponectin (APN), a circulating adipokine, shows analgesic effects. The study aimed to examine whether APN regulates analgesic effects of electroacupuncture (EA) in the complete Freund's adjuvant (CFA)-induced mouse model. APN wild type (WT) and knockout (KO) mouse were employed in the study. We found that EA attenuates the CFA-induced pain as demonstrated by the Hargreaves thermal test and the von Frey filament test. The deletion of APN significantly reduced the acupuncture analgesia in the CFA-treated APN KO mice while the intrathecal administration of APN mimicked the analgesic effects of EA. We further revealed that EA produced analgesic effects mainly via APN/AdipoR2-mediated AMPK pathway by the siRNA inhibitions of APN receptors (adipoR1/2) in the spinal cord. The immunofluorescence staining analysis showed that EA increased the APN accumulation in spinal cord through the blood circulation. In conclusion, the study indicates a novel mechanism that acupuncture produces analgesic effects at least partially via APN/AdipoR2-AMPK pathway in the spinal cord.

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

Background

Researches on the central mechanisms of acupuncture analgesia have been widely conducted worldwide. However, there is no bibliometric analysis of functional magnetic resonance imaging (fMRI) studies on acupuncture analgesia. This study visualized the current status, hot spots and frontiers of fMRI studies on acupuncture analgesia in the past 20 years to provide a theoretical basis for its clinical application.

Methods

All publications were obtained from Science Citation Index-Expanded (SCI-E) of Web of Science (WOS). We used CiteSpace to analyze publications, journals, cited journals, authors, cited authors, institutions, countries, references, and keywords. We also analyzed collaborative network maps and co-occurrence network maps.

Results

We retrieved a total of 797 articles. Regarding the volume of publications, the total number of annual publications showed a fluctuating but overall increasing trend. Evidence-based Complementary and Alternative Medicine (21 articles) was the most productive journal, and Pain (225 articles) was the most cited journal. The most productive author was Qin W (16 articles), and the most co-cited author was Hui KKS (111). The most prolific institution and country were Massachusetts General Hospital (34 articles) and USA (212 articles). “Pain” was the top-ranked for keyword frequency and centrality. “Functional connectivity” was the frontier hotspot for 2018–2021.

Conclusion

First, fMRI researches on acupuncture analgesia involved several countries (regions) and institutions, mainly located in the USA, China and Korea, and most of them were universities. In addition, the USA was a major contributor in this field. Second, in terms of disciplinary distribution, the literatures were mainly from clinical neurology, neuroscience, and radiology nuclear medicine medical imaging. Third, the keyword co-occurrence analysis showed that the hot keywords included pain, fMRI, and lower back pain. Fourth, through keyword clustering analysis, the hot disease was found to be lower back pain, and the hot contents were acupuncture specificity and frequency specificity. Fifth, a timeline analysis of the references identified that chronic low back pain and specificity will remain a hot topic for future research.

Modulatory Effects of Actual and Imagined Acupuncture on the Functional Connectivity of the Periaqueductal Gray and Ventral Tegmental Area

OBJECTIVE

Both acupuncture and guided imagery hold promise for treating pain. The mechanisms underlying these alternative interventions remain unclear. The reported study aimed to comparatively investigate the modulation effect of actual and imagined acupuncture on the functional connectivity of descending pain modulation system and reward network.

METHODS

Twenty-four healthy participants (mean [standard error], 25.21 [0.77] years of age; 66.67% female) completed a crossover study that included five sessions, a training session and four intervention sessions administered in randomized order. We investigated the modulation effect of real acupuncture, sham acupuncture, video-guided acupuncture imagery treatment (VGAIT) and VGAIT control on the resting-state functional connectivity (rsFC) of periaqueductal gray (PAG) and ventral tegmental area (VTA). These are key regions of the descending pain modulatory system and dopaminergic reward system, respectively.

RESULTS

Compared with sham acupuncture, real acupuncture produced decreased PAG-precuneus (Pcu) rsFC and increased VTA-amygdala/hippocampus rsFC. Heat pain threshold changes applied on the contralateral forearm were significantly associated with the decreased PAG-Pcu (r = 0.49, p = .016) and increased VTA-hippocampus rsFC (r = -0.77, p < .001). Compared with VGAIT control, VGAIT produced decreased PAG-paracentral lobule/posterior cingulate cortex/Pcu, middle cingulate cortex (MCC), and medial prefrontal cortex rsFC, and decreased VTA-caudate and MCC rsFC. Direct comparison between real acupuncture and VGAIT showed that VGAIT decreased rsFC in PAG-paracentral lobule/MCC, VTA-caudate/anterior cingulate cortex/nucleus accumbens, and VTA-MCC.

CONCLUSIONS

Results suggest that both actual and imagined acupuncture can modulate key regions in the descending pain modulatory system and reward networks, but through different pathways. Identification of different pain relief mechanisms may facilitate the development of new pain management methods.

Mechanosensitive TRPV4 Channel-Induced Extracellular ATP Accumulation at the Acupoint Mediates Acupuncture Analgesia of Ankle Arthritis in Rats

(1) Background: Acupuncture (AP) is a safe and effective analgesic therapy. Understanding how fine needles trigger biological signals can help us optimize needling manipulation to improve its efficiency. Adenosine accumulation in treated acupoints is a vital related event. Here, we hypothesized that extracellular ATP (eATP) mobilization preceded adenosine accumulation, which involved local activation of mechanosensitive channels, especially TRPV4 protein. (2) Methods: AP was applied at the injured-side Zusanli acupoint (ST36) of acute ankle arthritis rats. Pain thresholds were assessed in injured-side hindpaws. eATP in microdialysate from the acupoints was determined by luminescence assay. (3) Results: AP analgesic effect was significantly suppressed by pre-injection of GdCl3 or ruthenium red in ST36, the wide-spectrum inhibitors of mechanosensitive channels, or by HC067047, a specific antagonist of TRPV4 channels. Microdialysate determination revealed a needling-induced transient eATP accumulation that was significantly decreased by pre-injection of HC067047. Additionally, preventing eATP hydrolysis by pre-injection of ARL67156, a non-specific inhibitor of ecto-ATPases, led to the increase in eATP levels and the abolishment of AP analgesic effect. (4) Conclusions: These observations indicate that needling-induced transient accumulation of eATP, due to the activation of mechanosensitive TRPV4 channels and the activities of ecto-ATPases, is involved in the trigger mechanism of AP analgesia.

[Research on community promotion and application of single acupoint electroacupuncture therapy for lumbar intervertebral disc herniation]

OBJECTIVE

To observe the clinical effect of single acupoint [Yaotu (extra)] electroacupuncture (EA) therapy on lumbar intervertebral disc herniation (LIDH) and its promotion and application in community medical institutions.

METHODS

This research adopted a three-level promotion model, and used multi-center collaboration topics as a platform. A total of 240 patients with LIDH were divided into a group A (top three hospital, 80 cases, 3 cases dropped off), a group B (secondary hospital, 80 cases, 8 cases dropped off), and a group C (community health center, 80 cases, 7 cases dropped off). All groups were treated with EA at a single acupoint [Yaotu (extra)] under the guidance of a unified experimental protocol. The EA was given 60 min each time and performed 3 times a week for a total of 2 weeks. The changes of visual analogue scale (VAS) scores of three groups before and after each treatment were compared, and the clinical efficacy was evaluated.

RESULTS

Compared with before each treatment, the VAS scores of three groups after each treatment decreased (P<0.05). Except for the second and fifth treatments, the immediate effect in the group A was higher than that in the group B and C (P<0.05). The total effective rate of group A, group B, and group C respectively was 90.9% (70/77), 93.1% (67/72), 86.3% (63/73), and there was no statistically significant difference among the three groups (P>0.05).

CONCLUSION

The single acupoint EA therapy has a significant effect in the treatment of LIDH, can quickly relieve the pain symptoms, and has the characteristics of simple operation and easy control, suitable for promotion and application in primary hospitals.

[Analgesic mechanism of acupuncture on neuropathic pain]

The research progress of acupuncture analgesia in recent years is analyzed to summarize the analgesic mechanism of acupuncture on neuropathic pain. The analgesic mechanism of acupuncture on neuropathic pain is discussed from peripheral level and central level, including peripheral sensitization and immune inflammatory response, changes of ion channel, central sensitization, regulation of cell signal pathway, activation of spinal glial cells, etc. It is suggested that the focus of future research should include conducting in-vitro studies with the help of multi-omics technology to detect the changes of metabolic substances and signal pathway molecules in patients with neuropathic pain before and after acupuncture to further clarify the mechanism of acupuncture analgesia.

Analgesic Effects Evoked by Real and Imagined Acupuncture: A Neuroimaging Study

Acupuncture can provide therapeutic analgesic benefits but is limited by its cost and scheduling difficulties. Guided imagery is a commonly used method for treating many disorders, such as chronic pain. The present study examined a novel intervention for pain relief that integrates acupuncture with imagery called video-guided acupuncture imagery treatment (VGAIT). A total of 27 healthy subjects were recruited for a crossover-design study that included 5 sessions administered in a randomized order (i.e., baseline and 4 different interventions). We investigated changes in pain threshold and fMRI signals modulated by: 1) VGAIT, watching a video of acupuncture previously administered on the participant's own body at baseline while imagining it being concurrently applied; 2) a VGAIT control condition, watching a video of a cotton swab touching the skin; 3) real acupuncture; and 4) sham acupuncture. Results demonstrated that real acupuncture and VGAIT significantly increased pain threshold compared with respective control groups. Imaging showed that real acupuncture produced greater activation of the insula compared with VGAIT. VGAIT produced greater deactivation at the rostral anterior cingulate cortex. Our findings demonstrate that VGAIT holds potential clinical value for pain management.

Augmented Mechanical Forces of the Surface-Modified Nanoporous Acupuncture Needles Elicit Enhanced Analgesic Effects

Over the past several decades, clinical studies have shown significant analgesic effects of acupuncture. The efficacy of acupuncture treatment has improved with the recent development of nanoporous needles (PN), which are produced by modifying the needle surface using nanotechnology. Herein, we showed that PN at acupoint ST36 produces prolonged analgesic effects in an inflammatory pain model; the analgesic effects of PN acupuncture were sustained over 2 h, while those using a conventional needle (CN) lasted only 30 min. In addition, the PN showed greater therapeutic effects than CN after 10 acupuncture treatments once per day for 10 days. We explored how the porous surface of the PN contributes to changes in local tissue, which may in turn result in enhanced analgesic effects. We showed that the PN has greater rotational torque and pulling force than the CN, particularly at acupoints ST36 and LI11, situated on thick muscle layers. Additionally, in ex vivo experiments, the PN showed greater winding of subcutaneous connective tissues and muscle layers. Our results suggest that local mechanical forces are augmented by the PN and its nanoporous surface, contributing to the enhanced and prolonged analgesic effects of PN acupuncture.

[Clinical effect of grain-moxibustion combined with acupuncture in treating cervical spondylosis with neck pain]

OBJECTIVE

To observe the differences in the clinical effects on cervical spondylosis with neck pain between the grain-moxibustion combined with acupuncture and simple acupuncture.

METHODS

Eighty-eight cervical spondylosis patients with neck pain who met the inclusion criteria were randomly divided into an observation group and a control group, 44 cases in each one. The patients in the control group were treated with conventional acupuncture, and grain-moxibustion was applied on the basis treatment of the control group in the observation group. The treatment was given 3 times a week, once every other day, 10 times as one course, and followed up after 6 months. Northwick Park neck pain inventory (NPQ) and the McGill pain questionnaire (MPQ) of the two groups before and after treatment and 6 months follow-up were observed. The clinical efficacy was compared.

RESULTS

After one course of treatment in both groups, the effective rate was 84.1% (37/44) in the control group and 86.4% (38/44) in the observation group; after 6 months follow-up, the effective rate was 79.5% (35/44) in the control group, and 81.8% (36/44) in the observation group. There was no significant difference in overall efficacy between the two groups (both P>0.05). Compared before treatment, the NPQ scores and MPQ scores were decreased at the end of one course of treatment and after 6 months follow-up in the two groups (all P<0.05). There was no significant difference in NPQ scores and MPQ scores between the two groups after one course of treatment (both P>0.05), but the NPQ scores and MPQ scores in the observation group were significantly lower than those in the control group after 6 months follow-up (both P<0.05).

CONCLUSION

The immediate efficacy of grain-moxibustion combined with acupuncture for cervical spondylosis with neck pain is similar to that of simple acupuncture, however, the long-term curative effect is better.

A Functional Neuroimaging Study of Expectancy Effects on Pain Response in Patients With Knee Osteoarthritis

Placebo treatments and healing rituals share much in common, such as the effects of expectancy, and have been used since the beginning of human history to treat pain. Previous mechanistic neuroimaging studies investigating the effects of expectancy on placebo analgesia have used young, healthy volunteers. Using functional magnetic resonance imaging (fMRI), we aimed to investigate the neural mechanisms by which expectancy evokes analgesia in older adults living with a chronic pain disorder and determine whether there are interactions with active treatment. In this fMRI study, we investigated the brain networks underlying expectancy in participants with chronic pain due to knee osteoarthritis (OA) after verum (genuine) and sham electroacupuncture treatment before and after experiencing calibrated experimental heat pain using a well tested expectancy manipulation model. We found that expectancy significantly and similarly modulates the pain experience in knee OA patients in both verum (n = 21, 11 female; mean ± SD age 57 ± 7 years) and sham (n = 22, 15 female; mean ± SD age 59 ± 7 years) acupuncture treatment groups. However, there were different patterns of changes in fMRI indices of brain activity associated with verum and sham treatment modalities specifically in the lateral prefrontal cortex. We also found that continuous electroacupuncture in knee OA patients can evoke significant regional coherence decreases in pain associated brain regions. Our results suggest that expectancy modulates the experience of pain in knee OA patients but may work through different pathways depending on the treatment modality and, we speculate, on pathophysiological states of the participants.

PERSPECTIVE

To investigate the neural mechanisms underlying pain modulation, we used an expectancy manipulation model and fMRI to study response to heat pain stimuli before and after verum or sham acupuncture treatment in chronic pain patients. Both relieve pain and each is each associated with a distinct pattern of brain activation.

[Acupuncture direction and analgesia]

The acupuncture direction is closely related with the efficacy of acupuncture analgesia. In this article, the relationship between efficacy of acupuncture analgesia and factors, such as whether the needle towards disease location, whether the needle towards meridian direction, whether the needle following spinal cord direction and whether the needle following muscle direction, were analyzed. The previous clinical and literature research indicated that the needle towards disease location was superior to reverse direction, however, the efficacy of analgesia between needle following and reversing meridian, needle towards and at disease location, needles following and reversing spinal cord direction, needles following and reversing muscle direction was controversial. Therefore, the solutions to these problems will benefit the optimized acupuncture treatment plan for pain disorders.

Reporting Characteristics and Quality of Systematic Reviews of Acupuncture Analgesia

BACKGROUND

Evaluating the clinical efficacy of acupuncture analgesia with systematic reviews (SRs) has attracted wide interest.

OBJECTIVE

To collect a sample of published SRs on acupuncture analgesia in PubMed and examine them in terms of reporting characteristics and quality.

METHODS

A search in PubMed was performed in January 2016. All SRs on acupuncture analgesia were included. To assess the quality of the SRs, AMSTAR tool and PRISMA Statements were used.

RESULTS

One hundred and nine SRs were included in our analysis, the yearly number of publications ranging from 1 in 1997 to 15 in 2015. Only 17% of these publications were Cochrane Systematic Reviews, and 94% were published in Science Citation Index journals. The United Kingdom was the country with the higher number of publications. Low back pain, headache, cancer pain, and labor pain were the most reported diseases or phenotypes. Nearly 73% of these SRs conducted a meta-analysis, 58% revealed positive results, 53% used RevMan software to analyze data, and 44% used the Cochrane Risk of Bias Tool for quality assessment. Only a few SRs assessed the likelihood of publication bias, reported details about the protocol and the registration information, and performed additional analyses.

CONCLUSIONS

The quantity and the quality of SRs regarding acupuncture analgesia have been promoted in recent years. More effort should be expended on the assessment of publication bias, the provision of detailed information about the protocol and the registration process, and the implementation of additional analyses to improve the validity of the SRs.

[Anti-inflammatory and analgesia effects of electroacupuncture device of point injection on rats of inflammatory pain]

OBJECTIVE

To explore the anti-inflammatory and analgesia mechanism of electroacupuncture (EA) device of point injection (PI) on rats of inflammatory pain.

METHODS

48 Sprague Dawley (SD) rats were randomly assigned into a control group, a model group, an EA+PI group, an EA device of PI (EAPI) group, an EA group and a PI group, eight rats in each one. The rats in the control group were subcutaneously injected with 50 μL of liquid paraffin oil solvent into the dorsum of left hindpaw, while rats in the remaining groups were treated with 50 μL of complete freund's adjuvant (CFA) at identical location to induce the model of inflammatory pain. After model establishment, the rats in the EA+PI group, EAPI group, EA group and PI group were treated with EA+PI,EA device of PI, EA and PI, respectively, once every other day (the 2nd day, 4th day and 6th day). Each treatment was given for 30 min. The mechanical withdrawal threshold, thermal withdrawal threshold and foot swelling before and 1 d to 6 d after model establishment were observed; the western blotting method was applied to measure IL-1β expression in inflammatory tissue of skin.

RESULTS

After model establishment, compared with the control group, the mechanical withdrawal threshold and thermal withdrawal threshold were reduced (all P<0.05) and the foot swelling was increased in the rest groups (all P<0.05). After treatment, the mechanical withdrawal threshold and thermal withdrawal threshold in the EAPI group were significantly increased compared with those in the EA+PI group, EA group and PI group (all P<0.05), but the foot swelling was reduced (all P<0.05). The IL-1β expression in the model group was higher than that in the control group (P<0.05); after treatment, the IL-1β expression in the EAPI group was lower than that in the model group, EA group and PI group (all P<0.05), but no significantly different from that in the EA+PI group (P>0.05).

CONCLUSIONS

The efficacy of EA device of PI on inflammatory pain is superior to EA combined with PI, EA alone and PI alone, which is suitable for further popularization and application.

Acupuncture-Induced Analgesia: A Neurobiological Basis in Purinergic Signaling

Chronic pain is a debilitating and rather common health problem. The present shortage in analgesic drugs with a favorable spectrum but without remarkable side effects furthered the search for alternative therapeutic manipulations. Increasing evidence from both basic and clinical research on acupuncture, a main alternative therapy of traditional Chinese medicine, suggests that chronic pain is sensitive to acupuncture procedures. Clarification of the underlying mechanisms is a challenge of great theoretical and practical significance. The seminal hypothesis of Geoffrey Burnstock and the astounding findings of Maiken Nedergaard on the involvement of purinergic signaling in the beneficial effects of acupuncture fertilized the field and led to an intensification of research on acupurines. In this review, we will summarize the state-of-the-art situation and try to forecast how the field is likely to develop in the future.

The cumulative analgesic effect of repeated electroacupuncture involves synaptic remodeling in the hippocampal CA3 region

In the present study, we examined the analgesic effect of repeated electroacupuncture at bilateral Zusanli (ST36) and Yanglingquan (GB34) once a day for 14 consecutive days in a rat model of chronic sciatic nerve constriction injury-induced neuropathic pain. In addition, concomitant changes in calcium/calmodulin-dependent protein kinase II expression and synaptic ultrastructure of neurons in the hippocampal CA3 region were examined. The thermal pain threshold (paw withdrawal latency) was increased significantly in both groups at 2 weeks after electroacupuncture intervention compared with 2 days of electroacupuncture. In ovariectomized rats with chronic constriction injury, the analgesic effect was significantly reduced. Electroacupuncture for 2 weeks significantly diminished the injury-induced increase in synaptic cleft width and thinning of the postsynaptic density, and it significantly suppressed the down-regulation of intracellular calcium/calmodulin-dependent protein kinase II expression in the hippocampal CA3 region. Repeated electroacupuncture intervention had a cumulative analgesic effect on injury-induced neuropathic pain reactions, and it led to synaptic remodeling of hippocampal neurons and upregulated calcium/calmodulin-dependent protein kinase II expression in the hippocampal CA3 region.

Correlation between the cumulative analgesic effect of electroacupuncture intervention and synaptic plasticity of hypothalamic paraventricular nucleus neurons in rats with sciatica

In the present study, a rat model of chronic neuropathic pain was established by ligation of the sciatic nerve and a model of learning and memory impairment was established by ovariectomy to investigate the analgesic effect of repeated electroacupuncture stimulation at bilateral Zusanli (ST36) and Yanglingquan (GB34). In addition, associated synaptic changes in neurons in the paraventricular nucleus of the hypothalamus were examined. Results indicate that the thermal pain threshold (paw withdrawal latency) was significantly increased in rats subjected to 2-week electroacupuncture intervention compared with 2-day electroacupuncture, but the analgesic effect was weakened remarkably in ovariectomized rats with chronic constrictive injury. 2-week electroacupuncture intervention substantially reversed the chronic constrictive injury-induced increase in the synaptic cleft width and thinning of the postsynaptic density. These findings indicate that repeated electroacupuncture at bilateral Zusanli and Yanglingquan has a cumulative analgesic effect and can effectively relieve chronic neuropathic pain by remodeling the synaptic structure of the hypothalamic paraventricular nucleus.

Cerebral blood flow-based evidence for mechanisms of low- versus high-frequency transcutaneous electric acupoint stimulation analgesia: a perfusion fMRI study in humans

Brain activities in response to acupuncture have been investigated in multiple studies; however, the neuromechanisms of low- and high-frequency transcutaneous electric acupoint stimulation (TEAS) analgesia are unclear. This work aimed to investigate how brain activity and the analgesic effect changed across 30-min low- versus high-frequency TEAS. Forty-six subjects received a 30-min 2, 100-Hz TEAS or mock TEAS (MTEAS) treatment on both behavior test and functional magnetic resonance imaging (fMRI) scan days. On the behavior test day, the pain thresholds and pain-related negative emotional feeling ratings were tested five times - at 4.5min before treatment, at 10, 20, and 30min during treatment and 4.5min after the treatment. On the fMRI scan day, to match the time-points in the behavioral testing session, the cerebral blood flow (CBF) signals were collected and incorporated with five independent runs before, during and after the treatment, each lasting 4.5min. The analgesic effect was observed in both the TEAS groups; the analgesic affect was not found in the MTEAS group. The effect started at 20min during the treatment and was maintained until the after-treatment states. In both TEAS groups, the regional CBF revealed a trend of early activation with later inhibition; also, a positive correlation between analgesia and the regional CBF change was observed in the anterior insula in the early stage, whereas a negative relationship was found in the parahippocampal gyrus in the later stage. The TEAS analgesia was specifically associated with the default mode network and other cortical regions in the 2-Hz TEAS group, ventral striatum and dorsal anterior cingulate cortex in the 100-Hz TEAS group, respectively. These findings suggest that the mechanisms of low- and high-frequency TEAS analgesia are distinct and partially overlapped, and they verify the treatment time as a notable factor for acupuncture studies.

Acupuncture in the management of acute dental pain

Acute dental pain is the main reason for seeking dental services to provide urgent dental care; there is consensus about the use of alternative therapies, such as acupuncture, to control dental pain in pre-dental care. This study aimed to evaluate the use of acupuncture in reducing the intensity of acute dental pain in pre-dental care in patients waiting for emergency dental care, and was conducted at the After-Hours Emergency Dental Clinic of Piracicaba Dental School, and at the Emergency Center Dental Specialties I in Piracicaba, São Paulo, Brazil. The sample consisted of 120 patients. The Visual Analog Scale (VAS) was used to measure pain intensity. All patients underwent one session of acupuncture; the points LI4, ST44 and CV23 were selected and were used alone or in combinations. Reduction in pain was observed in 120 patients (mean initial VAS=6.558±1.886, p<0; mean final VAS=0.962±2.163, p<0.00001). The results of this study indicate that acupuncture analgesia could be a technical adjunct to pain control in patients with acute dental pain, contributing to the restoration of health with social benefit.

Acupuncture anesthesia and analgesia for clinical acute pain in Japan

Acupuncture anesthesia has been practiced in China since about 1960. In Japan, Hyodo reported 30 cases of acupuncture anesthesia in 1972. However, from around 1980, the direction of acupuncture investigations turned from anesthesia to analgesia. Acupuncture analgesia is presently considered a way to activate the body's endogenous analgesic system. Recently, with the rise of acupuncture as one of the most well known CAM therapies, acupuncture or moxibustion treatment has been reported for both acute and chronic pain. Even so, few clinical reports and original articles have been reported in Japan. This review illustrates how acupuncture is being used in Japan for acute pain such as surgical operations, post- operative pain (POP), neuropathic pain, pain associated with teeth extractions and after the extraction of impacted wisdom teeth.