The Role of Neuroglial Crosstalk and Synaptic Plasticity-Mediated Central Sensitization in Acupuncture Analgesia.

Although pain is regarded as a global public health priority, analgesic therapy remains a significant challenge. Pain is a hypersensitivity state caused by peripheral and central sensitization, with the latter considered the culprit for chronic pain. This study summarizes the pathogenesis of central sensitization from the perspective of neuroglial crosstalk and synaptic plasticity and underlines the related analgesic mechanisms of acupuncture. Central sensitization is modulated by the neurotransmitters and neuropeptides involved in the ascending excitatory pathway and the descending pain modulatory system. Acupuncture analgesia is associated with downregulating glutamate in the ascending excitatory pathway and upregulating opioids, 𝛾-aminobutyric acid, norepinephrine, and 5-hydroxytryptamine in the descending pain modulatory system. Furthermore, it is increasingly appreciated that neurotransmitters, cytokines, and chemokines are implicated in neuroglial crosstalk and associated plasticity, thus contributing to central sensitization. Acupuncture produces its analgesic action by inhibiting cytokines, such as interleukin-1ß, interleukin-6, and tumor necrosis factor-α, and upregulating interleukin-10, as well as modulating chemokines and their receptors such as CX3CL1/CX3CR1, CXCL12/CXCR4, CCL2/CCR2, and CXCL1/CXCR2. These factors are regulated by acupuncture through the activation of multiple signaling pathways, including mitogen-activated protein kinase signaling (e.g., the p38, extracellular signal-regulated kinases, and c-Jun-N-terminal kinase pathways), which contribute to the activation of nociceptive neurons. However, the responses of chemokines to acupuncture vary among the types of pain models, acupuncture methods, and stimulation parameters. Thus, the exact mechanisms require future clarification. Taken together, inhibition of central sensitization modulated by neuroglial plasticity is central in acupuncture analgesia, providing a novel insight for the clinical application of acupuncture analgesia.

Daily Caffeine Consumption Does Not Influence Acupuncture Analgesia in Healthy Individuals: A Preliminary Study.

Animal studies suggest that caffeine may interfere with acupuncture analgesia. This study investigated the modulation effect of daily caffeine intake on acupuncture analgesia in 27 healthy subjects using a crossover design. We found that real acupuncture increased pain thresholds compared to sham acupuncture. Further, there was no association between caffeine intake measurements of daily caffeine use, duration of caffeine consumption, or their interaction and preacupuncture and postacupuncture pain threshold changes. Our findings suggest that daily caffeine intake may not influence acupuncture analgesia in the cohort of healthy subjects who participated in study.

Research Advances on Acupuncture Analgesia.

Pain is a widespread and complex symptom which causes serious emotional and social burdens to individuals and society. Most patients with pain rely heavily on over the counter (OTC) and prescription pain killers. However, there would be a number of issues that arise from the use of pain killers, in which safety and addiction are the most critical issues. For traditional Chinese medicine (TCM), pain is a result of the meridians being blocked. This could occur as a symptom of or be caused by various diseases. In this case, the key to relieve pain depends on dredging the meridian or meridians. Acupuncture has been practiced in China for over 2000 years to lessen pain. It is based on the "meridian theory". Acupuncture is being used more widely and with a growing number of people in the treatment of pain because it is safer and has fewer side effects. Along with growing use and interest in acupuncture to treat pain, more attention has been paid to the mechanism underlying its analgesic effect, which is mainly associated with the changes of neurotransmitters. In this review, we summarize and analyze the range and mechanism of acupuncture analgesia treatment.

Unforgettable Ups and Downs of Acupuncture Anesthesia in China.

BACKGROUND: Acupuncture anesthesia originated from the pain relief and pain prevention theory in acupuncture and moxibustion. This technique is a new exploration of anesthesiology and an original achievement of China, representing a landmark combination of Traditional Chinese Medicine and Western medicine. OBJECTIVES: The aim of this historical vignette to introduce acupuncture anesthesia with its meaningful history, especially the use in neurosurgery to the public. DESIGN: This historical vignette introduced the development, mechanism research, awake craniotomy, in order to analyze the utility of acupuncture anesthesia, its global impact, the current situation and future of acupuncture anesthesia. CONCLUSION: Acupuncture anesthesia was initiated in 1958, and, reflecting the historical background of China after the 1960s, the use of this technique spread widely throughout the country. Reaching other countries after 1971, acupuncture anesthesia had a significant influence, drawing attention from medical academia worldwide. Thus, acupuncture anesthesia has made a special contribution to the medical science of modern China.

[Progresses of studies on acupuncture analgesia for postoperative reaction].

A large number of clinical trials and animal experiments have been carried out to focus on neurochemical mechanisms of acupuncture analgesia including postoperation pain relief, which may provide guidance for developing a novel clinical approach for postoperative analgesia. In the present paper, the authors review new progresses of researches on acupuncture analgesia for postoperative pain and side effects in the past few years from thyroidectomy, chest surgery, abdominal surgery, five sense organs (ear, nose, eye and throat) surgery, and others. Regarding the mechanism of acupuncture, central neurotransmitters (including the endop endorphin, 5-HT, gamma-aminobutyric acid, etc.), immune cytokines, cytokines from the spinal glia cells are complicated in the process of acupuncture analgesia. A lot of findings of researches demonstrated that acupuncture therapy is effective in reducing postoperative pain and adverse reactions as nausea, vomiting, etc. As a common technique widely used in the field of clinical medicine, the underlying mechanisms of acupuncture therapy for relieving post-surgery pain and side-effects should be studied profoundly in the future.

Acupuncture anesthesia for open heart surgery in contemporary China.

BACKGROUND: Although the use of acupuncture anesthesia for open heart surgery, which was introduced in China four decades ago, has declined in recent years, there is a renewed interest in it in contemporary China due to the escalating medical costs associated with open heart surgery. This study was aimed to determine whether a combined acupuncture-medicine anesthesia (CAMA) strategy reduces early postoperative morbidity and medical costs in patients undergoing open heart operation under cardiopulmonary bypass. METHODS: From July 2006 to October 2010, CAMA was applied in 100 patients undergoing open heart surgery in comparison with another 100 patients under the conventional general anesthesia (GA). For all the CAMA patients, an abdominal breathing training program was practiced for the 3 consecutive days prior to operation. About 15 to 20 min prior to surgical incision, acupuncture needles were inserted into the bilateral points ZhongFu, LieQue, and XiMen. During operation, patients were kept on spontaneous breathing. Endotracheal intubation was not employed but only prepared as a standby. The narcotic drugs, fentanyl and midazolam, were intravenously injected but in very low doses as compared to GA. Open heart procedures were performed routinely in both groups. RESULTS: Compared with the GA patients, the CAMA patients had a less usage of narcotic drugs (p<0.001), less postoperative pulmonary infection (p<0.05), shorter stay in intensive care unit (p<0.05), and a lower medical cost (P<0.05). CONCLUSIONS: A combined acupuncture-medicine anesthesia strategy reduces the postoperative morbidity and medical costs in patients undergoing open heart surgery under cardiopulmonary bypass.

Reduced analgesic effect of acupuncture-like TENS but not conventional TENS in opioid-treated patients.

UNLABELLED: Evidence from recent animal studies indicates that the analgesic effect of low-frequency transcutaneous electrical nerve stimulation (TENS) is reduced in opioid-tolerant animals. The aim of the present study was to compare the analgesic effect of conventional (high frequency) and acupuncture-like (low frequency) TENS between a group of opioid-treated patients and a group of opioid-naive patients in order to determine if this cross-tolerance effect is also present in humans. Twenty-three chronic pain patients (11 who took opioids and 12 who did not) participated in the study. Participants were assigned in a randomized crossover design to receive alternately conventional and acupuncture-like TENS. There was a significant reduction in pain during and after conventional TENS when compared to baseline for both the opioid and nonopioid group (P < .01). For acupuncture-like TENS however, the analgesic effect of TENS was only observed in the nonopioid group (P < .01), with opioid-treated patients showing no change in pain scores during and after TENS when compared to baseline (P > .09). The reduced analgesic effect of acupuncture-like TENS in opioid-treated patients is coherent with previous animal studies and suggests that conventional TENS should be preferred in patients taking opioids on a regular basis. PERSPECTIVE: This study shows that patients taking opioids on a regular basis are less susceptible to benefit from acupuncture-like TENS. This phenomenon is probably attributable to the fact that the analgesia induced by acupuncture-like TENS and opioids are mediated by the same receptors (ie, µ opioid receptors).

Bee venom acupuncture for musculoskeletal pain: a review.

UNLABELLED: Bee venom (BV) acupuncture (BVA) involves injecting diluted BV into acupoints and is used for arthritis, pain, and rheumatoid diseases. The objective of this systematic review was to evaluate the evidence for the effectiveness of BVA in the treatment of musculoskeletal pain. Seventeen electronic databases were systematically searched up to September 2007 with no language restrictions. All randomized clinical trials (RCTs) of BVA for patients with musculoskeletal pain were considered for inclusion if they included placebo controls or were controlled against a comparator intervention. Methodology quality was assessed and, where possible, statistical pooling of data was performed. A total of 626 possibly relevant articles were identified, of which 11 RCTs met our inclusion criteria. Four RCTs that tested the effects of BVA plus classic acupuncture compared with saline injection plus classic acupuncture were included in the main meta-analysis. Pain was significantly lower with BVA plus classic acupuncture than with saline injection plus classic acupuncture (weighted mean difference: 100-mm visual analog scale, 14.0 mm, 95% CI = 9.5-18.6, P < .001, n = 112; heterogeneity: tau(2) = 0, chi(2) = 1.92, P = .59, I(2) = 0%). Our results provide suggestive evidence for the effectiveness of BVA in treating musculoskeletal pain. However, the total number of RCTs included in the analysis and the total sample size were too small to draw definitive conclusions. Future RCTs should assess larger patient samples for longer treatment periods and include appropriate controls. PERSPECTIVE: Bee venom acupuncture involves injecting diluted BV into acupoints and is used for arthritis, pain, and rheumatoid diseases. A meta-analysis produced suggestive evidence for the effectiveness of BVA in musculoskeletal pain management. However, primary data were scarce. Future RCTs should assess larger patient samples for longer treatment periods and include appropriate controls.

Comparison of clinical and evoked pain measures in fibromyalgia.

UNLABELLED: Evoked pain measures such as tender point count and dolorimetry are often used to determine tenderness in studies of fibromyalgia (FM). However, these measures frequently do not improve in clinical trials and are known to be influenced by factors other than pain such as distress and expectancy. The purpose of this investigation was to determine whether evoked pain paradigms that present pressure stimuli in a random fashion (eg, Multiple Random Staircase [MRS]) would track with clinical pain improvement in patients with FM better than traditional measures. Sixty-five subjects enrolled in a randomized clinical trial of acupuncture were observed longitudinally. Clinical pain was measured on a 101-point numerical rating scale (NRS) and the Short Form McGill Pain Questionnaire (SF-MPQ), whereas evoked pressure sensitivity was assessed via manual tender point count, dolorimetry, and MRS methods. Improvements in clinical pain and evoked pain were assessed irrespective of group assignment. Improvement was seen in clinical pain during the course of the trial as measured by both NRS (P = .032) and SF-MPQ (P = .001). The MRS was the only evoked pain measure to improve correspondingly with treatment (MRS, P = .001; tender point count and dolorimeter, P > .05). MRS change scores were correlated with changes in NRS pain ratings (P = .003); however, this association was not stronger than tender point or dolorimetry correlations with clinical pain improvement (P > .05). Pain sensitivity as assessed by random paradigms was associated with improvements in clinical FM pain. Sophisticated pain testing paradigms might be responsive to change in clinical trials. PERSPECTIVE: Trials in fibromyalgia often use both clinical and experimental methods of pain assessment; however, these two outcomes are often poorly correlated. We explore the relationship between changes in clinical and experimental pain within FM patients. Pressure pain testing that applies stimuli in a random order is associated with improvements in clinical pain, but this association was not stronger than other experimental techniques.

Acupuncture use for the treatment of headache prior to neurological referral.

Acupuncture is a popular complementary treatment for various pain syndromes. Some studies claim efficacy in the treatment of primary headache syndromes. However, data on the frequency of acupuncture use by patients with headache prior to neurological referral have not been identified. In this study, 12% of patients with headache attending general neurology outpatient clinics had already received acupuncture; of the remainder, 73% said they would be willing to try it.

Acupuncture.

OBJECTIVE: The objective of this NIH Consensus Statement is to inform the biomedical research and clinical practice communities of the results of the NIH Consensus Development Conference on Acupuncture. The statement provides state-of-the-art information regarding the appropriate use of acupuncture, and presents the conclusions and recommendations of the consensus panel regarding these issues. In addition, the statement identifies those areas of study that deserve further investigation. Upon completion, the reader should possess a clear working clinical knowledge of the state-of-the-art regarding this topic. The target audience of physicians for this statement includes, but is not limited to, family practitioners, medical acupuncturists, psychiatrists, and specialists in pain medicine. PARTICIPANTS: A non-Federal, nonadvocate, 12-member panel representing the fields of acupuncture, pain, psychology, psychiatry, physical medicine and rehabilitation, drug abuse, family practice, internal medicine, health policy, epidemiology, statistics, physiology, biophysics, and the public. In addition, 25 experts from these same fields presented data to the panel and a conference audience of 1,200. EVIDENCE: The literature was searched through Medline, and an extensive bibliography of references was provided to the panel and the conference audience. Experts prepared abstracts with relevant citations from the literature. Scientific evidence was given precedence over clinical anecdotal experience. CONSENSUS PROCESS: The panel, answering predefined questions, developed their conclusions based on the scientific evidence presented in open forum and the scientific literature. The panel composed a draft statement, which was read in its entirety and circulated to the experts and the audience for comment. Thereafter, the panel resolved conflicting recommendations and released a revised statement at the end of the conference. The panel finalized the revisions within a few weeks after the conference. The draft statement was made available on the World Wide Web immediately following its release at the conference and was updated with the panel's final revisions. CONCLUSIONS: Acupuncture as a therapeutic intervention is widely practiced in the United States. While there have been many studies of its potential usefulness, many of these studies provide equivocal results because of design, sample size, and other factors. The issue is further complicated by inherent difficulties in the use of appropriate controls, such as placebos and sham acupuncture groups. However, promising results have emerged, for example, showing efficacy of acupuncture in adult postoperative and chemotherapy nausea and vomiting and in postoperative dental pain. There are other situations such as addiction, stroke rehabilitation, headache, menstrual cramps, tennis elbow, fibromyalgia, myofascial pain, osteoarthritis, low back pain, carpal tunnel syndrome, and asthma, in which acupuncture may be useful as an adjunct treatment or an acceptable alternative or be included in a comprehensive management program. Further research is likely to uncover additional areas where acupuncture interventions will be useful.