Search

It is well known that acupuncture has pain-relieving effects, but the contribution of specific and especially non-specific factors to acupuncture analgesia is less clear. One hundred and one patients who developed pain ≥ 3 on a visual analog scale (VAS, 0-10) following third molar surgery were randomized to receive active acupuncture, placebo acupuncture, or no treatment for 30 min with acupuncture needles with potential for double-blinding. Patients’ perception of the treatment (active or placebo), and expected pain levels (VAS) were assessed prior to and halfway through the treatment. Looking at actual treatment allocation, there was no specific effect of active acupuncture (P = 0.240), but a large and significant non-specific effect of placebo acupuncture (P < 0.001), which increased over time. Interestingly, however, looking at perceived treatment allocation, there was a significant effect of acupuncture (P < 0.001) indicating that patients who believed they received active acupuncture had significantly lower pain levels than those who believed they received placebo acupuncture. Expected pain levels accounted for significant and progressively larger amounts of the variance in pain ratings following both active and placebo acupuncture (up to 69.8%), This is the first study to show that under optimized blinding conditions non-specific factors such as patients’ perception of and expectations toward treatment are central to the efficacy of acupuncture analgesia and that these factors may contribute to self-reinforcing effects in acupuncture treatment To obtain an effect of acupuncture in clinical practice it may, therefore, be important to incorporate and optimize these factors.

Acupuncture is frequently used to treat pain, although data supporting the analgesic efficacy from placebo-controlled studies is sparse. In order to get evidence for acupuncture analgesia we performed a study with 2 well-recognized experimental human pain models - the cold-pressor (CP) test and intradermal capsaicin injection. Fifty healthy men were included. Our study compared Traditional Chinese Medicine-based acupuncture to sham acupuncture with Streitberger placebo needles in a randomized, controlled, double-blinded trial. The primary endpoint was the reduction of mean pain intensity during 3minutes of CP test or of mean pain intensity within 10minutes after capsaicin injection. Secondary parameters were defined to substantiate the findings. To ensure comparability, somatosensory (measured by quantitative sensory testing) and psychological parameters were investigated and found to be the same in both groups. Analyses (repeated-measures analyses of variance) showed a significant (P=0.009) but clinically questionable pain reduction in the verum group for capsaicin-induced pain, which was mainly driven by an effect of Traditional Chinese Medicine acupuncture on small pain ratings (max. reduction from 7/100 rating at baseline to 2.5/100 at intervention). Neither pin-prick hyperalgesia, nor allodynia, nor neurogenic flare associated with capsaicin injection, nor pain ratings during the CP test, were significantly different between groups. In addition, there was no placebo response. Attitude towards acupuncture and partial unblinding did not affect the results. We conclude that acupuncture on predefined points has a minor effect on experimental pain in healthy subjects.

Our aim was to distinguish between spinal and supraspinal mechanisms in the intact nervous system by comparing homosegmental and heterosegmental effects of electroacupuncture (EA) and manual acupuncture (MA) on sensory perception in healthy volunteers by means of quantitative sensory testing. Seventy-two healthy volunteers were randomly assigned to receive either MA or EA at SP 6, SP 9, GB 39, and ST 36 at the left leg or relaxed for 30 minutes (control group [CG]). Blinded examiners assessed 13 sensory modalities (thermal and mechanical detection and pain thresholds) at the upper arms and lower legs before and after intervention by means of a standardized quantitative sensory testing battery. Change scores of all 13 sensory thresholds were compared between groups. The main outcome measure was the change score of the pressure pain threshold (PPT). There were no baseline differences between groups. Pressure pain threshold change scores at the lower left leg, in the same segment as the needling site, differed significantly (P = 0.008) between the EA (median: 103.01 kPa) and CG groups (median: 0.00 kPa) but not between the MA (median: 0.00 kPa) and CG groups. No further significant change score differences were found between one of the acupuncture groups and the CG. The PPT can be changed by EA. The PPT increase was confined to the segment of needling, which indicates that it is mainly mediated by segmental inhibition in the spinal cord. This underscores the importance of segmental needling and electrical stimulation in clinical practice.

Chronic neck pain is highly prevalent. To determine the efficacy and safety of acupuncture, in comparison with transcutaneous nerve stimulation-placebo (TENS-placebo) in the treatment of chronic uncomplicated neck pain, a single blind prospective study was designed, to be carried out at a Primary Healthcare Centre, with random assignment to two parallel groups and with evaluation and analysis by independent evaluators. A random assignment was made from 123 patients of the 149 initially recruited. These patients had been diagnosed with uncomplicated neck pain and experienced neck motion-related pain intensity equal to or exceeding 30 on a visual analogue scale (VAS) from 0 to 100 mm. The treatment with acupuncture was compared with TENS-placebo, applied over 5 sessions in three weeks. The primary endpoint was the change in maximum pain intensity related to motion of the neck, one week after the final treatment. Sensitivity was analysed per protocol (PP) and variant analyses were by intention to treat (ITT). Adjustment was made for confounders by multiple linear regression, including baseline values and rescue therapy. By ITT analysis, the change in the pain-VAS variable was greater among the experimental group (28.1 (95% CI 21.4-34.7)). The improvements in quality of life (physical aspect), active neck mobility and reduced rescue medication were clinically and statistically significant. In the treatment of the intensity of chronic neck pain, acupuncture is more effective than the placebo treatment and presents a safety profile making it suitable for routine use in clinical practice.

The aim of this systematic review is to assess the effectiveness of acupuncture as an adjunctive analgesic method to standard anaesthetic procedures for surgery and to determine whether acupuncture has any analgesic-sparing effect. Electronic literature searches for randomised clinical trials (RCTs) of acupuncture during surgery were performed in seven electronic databases. No language restrictions were imposed. All included studies were rated according to their methodological quality and validity. As the studies were clinically heterogeneous, no meta-analyses were performed. The evidence was classified according to four levels: strong, moderate, limited, or inconclusive. Nineteen RCTs were identified. Seven of them suggested that acupuncture is efficacious. Of nine high-quality RCTs, two studies had positive outcomes. There was no significant association between study quality and direction of outcome. One of eight high-validity trials reported a positive outcome and there was a significant relationship between validity and direction of outcome. The evidence that acupuncture is more effective than no acupuncture as an adjunct to standard anaesthetic procedures is therefore inconclusive. Strong evidence exists that real acupuncture is not significantly different from placebo acupuncture. For an analgesic-sparing effect of acupuncture, evidence remains inconclusive. In conclusion, this review does not support the use of acupuncture as an adjunct to standard anaesthetic procedures during surgery.

The study was carried out to examine whether acupuncture treatment can reduce chronic pain in the neck and shoulders and related headache, and also to examine whether possible effects are long-lasting. Therefore, 24 female office workers (47+/-9 years old, mean+/-SD) who had had neck and shoulder pain for 12+/-9 years were randomly assigned to a test group (TG) or a control group (CG). Acupuncture was applied 10 times during 3-4 weeks either at presumed anti-pain acupoints (TG) or at placebo-points (CG). A physician measured the pain threshold (PPT) in the neck and shoulder regions with algometry before the first treatment, and after the last one and six months after the treatments. Questionnaires on muscle pain and headache were answered at the same occasions and again 3 years after the last treatment. The intensity and frequency of pain fell more for TG than for CG (Pbor = 0.04) during the treatment period. Three years after the treatments TG still reported less pain than before the treatments (Pw0.001) contrary to what CG did (Pb0.04) The degree of headache fell during the treatment period for both groups, but more for TG than for CG (Pb=0.02) Three years after the treatments the effect still lasted for TG (Pw0.01) while the degree of headache for CG was back to the pre-treatment level (Pb0.001) PPT of some muscles rose during the treatments for TG and remained higher 6 months after the treatments (Pw0.05) which contrasts the situation for CG. Adequate acupuncture treatment may reduce chronic pain in the neck and shoulders and related headache. The effect lasted for 3 years.

In the present study, we examined the effects of preoperative electroacupuncture (EA) at classical bilateral acupuncture points (Zusanli, also known as ST-36) on postoperative pain and opioid-related side effects. One hundred healthy consenting women undergoing lower abdominal surgery were randomly assigned to four treatment regimens: Group I (n=25), control; Group II (n=25), sham-EA (needle insertion without electrical stimulation); Group III (n=25), low-EA (2 Hz of electrical stimulation); and Group IV (n=25), high-EA (100 Hz of electrical stimulation). EA groups received needle insertion with or without electrical stimulation 20 min prior to anesthesia. All patients received patient-controlled analgesia (PCA) of morphine postoperation. Postoperative pain was evaluated by recording (1). the time of the first required analgesic, (2). the number of PCA demands, (3). the total amount of morphine required by PCA, and (4) patients' VAS pain score. We found that the time of first analgesic requested was 10, 18, 28, and 28 min in the control, sham-, low-, and high-EA groups, respectively. During the first 24h, the total amount of morphine required was decreased by 21, 43 and 61% in the sham-, low- and high-EA groups, respectively. The incidence of nausea and dizziness during the first 24h after surgery was significantly reduced in both the low-EA and high-EA groups compared with the control and sham-EA groups. We also found that sham-EA exerts a beneficial effect with respect to its pain relieving quality but not the side effect profiles. Our findings demonstrates that preoperative treatment with low-EA and high-EA can reduce postoperative analgesic requirements and associated side effects in patients undergoing lower abdominal surgery.

To evaluate immediate effects of two different modes of acupuncture on motion-related pain and cervical spine mobility in chronic neck pain patients compared to a sham procedure. Thirty-six patients with chronic neck pain and limited cervical spine mobility participated in a prospective, randomized, double-blind, sham-controlled crossover trial. Every patient was treated once with needle acupuncture at distant points, dry needling (DN) of local myofascial trigger points and sham laser acupuncture (Sham). Outcome measures were motion-related pain intensity (visual analogue scale, 0-100 mm) and range of motion (ROM). In addition, patients scored changes of general complaints using an 11-point verbal rating scale. Patients were assessed immediately before and after each treatment by an independent (blinded) investigator. Multivariate analysis was used to assess the effects of true acupuncture and needle site independently. For motion-related pain, use of acupuncture at non-local points reduced pain scores by about a third (11.2 mm; 95% CI 5.7, 16.7; P = 0.00006) compared to DN and sham. DN led to an estimated reduction in pain of 1.0 mm (95% CI -4.5, 6.5; P = 0.7). Use of DN slightly improved ROM by 1.7 degrees (95% CI 0.2, 3.2; P = 0.032) with use of non-local points improving ROM by an additional 1.9 degrees (95% CI 0.3, 3.4; P = 0.016). For patient assessment of change, non-local acupuncture was significantly superior both to Sham (1.7 points; 95% CI 1.0, 2.5; P = 0.0001) and DN (1.5 points; 95% CI 0.4, 2.6; P = 0.008) but there was no difference between DN and Sham (0.1 point; 95% CI -1.0, 1.2; P = 0.8). Acupuncture is superior to Sham in improving motion-related pain and ROM following a single session of treatment in chronic neck pain patients. Acupuncture at distant points improves ROM more than DN; DN was ineffective for motion-related pain.

Immunocytochemical localization of the c-fos primary gene protein, Fos, was used to identify spinal cord and brain-stem sites activated by either 4-Hz or 100-Hz electroacupuncture (EA) applied to the Zusanli acupuncture points of both hind limbs in lightly anesthetized Sprague-Dawley rats. The number and distribution of Fos-immunoreactive neurons in the brain stem and spinal cord of 4-Hz and 100-Hz EA-treated rats were compared with these in anesthesia and room control rats. Compared to non-stimulated control rats or rats in which EA was applied to a non-acupuncture point, both 4-Hz and 100-Hz EA-treated groups exhibited a significantly greater number of Fos-labeled neurons in the dorsal horn of the L2 spinal cord segment, lateral parabrachial nucleus, substantia nigra, nucleus raphe pallidus, dorsal raphe, locus coeruleus, posterior pretectal nucleus, and the lateroventral periaqueductal gray. In the 4-Hz-treated group, significant increases in Fos labeling were also observed in the cuneiform nucleus, dorsal and laterodorsal subdivisions of the periaqueductal gray, habenular nucleus, arcuate hypothalamic nucleus, and the lateroventral and lateral hypothalamic nuclei as compared to non-stimulated controls. The only brain-stem nucleus that exhibited significantly increased Fos-immunoreactive neurons in 100-Hz but not 4-Hz EA was the rostolateroventral nucleus of the medulla. These results indicate that many brain-stem regions are activated by both 4-Hz and 100-Hz EA but additional brain-stem regions are selectively activated by 4-Hz EA which may relate to the opiate sensitivity of 4-Hz EA. In sum, these data identify several distinct brain-stem nuclei that may play a role in acupuncture-mediated analgesia.

Hypnosis and acupuncture can alleviate experimentally induced pain but the mechanism of analgesia remains unclear for both techniques. Experimental pain was induced by cold pressor test (CPT) in 8 male volunteers. Analgesic effect of hypnosis (HA) and acupuncture (AA) was assessed before and after double-blind administration of placebo or naloxone, in a prospective, cross-over study. We found that pain intensity was significantly lower with HA as compared with AA, both with naloxone (P less than 0.001) and placebo (P less than 0.001). Within HA or AA groups, pain scores did not differ significantly when naloxone or placebo was administered. During AA, however, pain scores were similar to control values when naloxone was given (P = 0.05) but decreased significantly with placebo (P less than 0.002). Analog scales for pain intensity and pain relief showed a good correlation (r = 0.94). Plasma levels of beta-endorphins did not change significantly in any combination. Heart rate, peripheral arterial blood pressure and skin conductance were very insensitive indices to assess pain intensity or relief, as well as intensity of acupuncture stimulation or depth of hypnotic trance. We conclude: (1) HA and AA can significantly reduce pain from CPT, and HA is more effective than AA: (2) HA and AA are not primarily mediated by the opiate endorphin system; and (3) plasmatic levels of beta-endorphins are not significantly affected by either HA or AA nor by naloxone or placebo administration.

There is some evidence for the efficacy of acupuncture in chronic low-back pain (LBP), but it remains unclear whether acupuncture is superior to placebo. In a randomized, blinded, placebo-controlled trial, we evaluated the effect of traditional acupuncture in chronic LBP. A total of 131 consecutive out-patients of the Department of Orthopaedics, University Goettingen, Germany, (age=48.1 years, 58.5% female, duration of pain: 9.6 years) with non-radiating LBP for at least 6 months and a normal neurological examination were randomized to one of three groups over 12 weeks. Each group received active physiotherapy over 12 weeks. The control group (n=46) received no further treatment, the acupuncture group (n=40) received 20 sessions of traditional acupuncture and the sham-acupuncture group (n=45) 20 sessions of minimal acupuncture. Changes from baseline to the end of treatment and to 9-month follow-up were assessed in pain intensity and in pain disability, and secondary in psychological distress and in spine flexion, compared by intervention groups. Acupuncture was superior to the control condition (physiotherapy) regarding pain intensity (P=0.000), pain disability (P=0.000), and psychological distress (P=0.020) at the end of treatment. Compared to sham-acupuncture, acupuncture reduced psychological distress (P=0.040) only. At 9-month follow-up, the superiority of acupuncture compared to the control condition became less and acupuncture was not different to sham-acupuncture. We found a significant improvement by traditional acupuncture in chronic LBP compared to routine care (physiotherapy) but not compared to sham-acupuncture. The trial demonstrated a placebo effect of traditional acupuncture in chronic LBP.

Individual differences in sensitivity to pain and analgesia are well appreciated, and increasing evidence has pointed towards a role of inherited genetic factors in explaining some proportion of such variability. It has long been known by practitioners of acupuncture, an ancient modality of analgesia, that some patients are 'responders' and others 'non-responders.' The present research was aimed at defining the inherited genetic influence on acupuncture analgesia in the mouse, using 10 common inbred strains. Two pairs of metallic needles were inserted into acupoints ST 36 and SP 6, fixed in situ and then connected to the output channel of an electric pulse generator. Electroacupuncture (EA) parameters were set as constant current output (intensity: 1.0-1.5-2.0 mA, 10 min each; frequency: 2 or 100 Hz) with alteration of a positive and negative square wave, 0.3 ms in pulse width. Tail-flick latencies evoked by radiant heat were measured before, during and after EA stimulation. Narrow-sense heritability estimates of 2 and 100 Hz EA were 0.37 and 0.16, respectively. We found that the C57BL/10 strain was the most sensitive, and the SM strain was the least sensitive to both 2 and 100 Hz EA. However, the relative sensitivities of other strains to these two EA frequencies suggested some genetic dissociation between them as well. These results demonstrate a role of inherited genetic factors in EA sensitivity in the mouse, although the low-to-moderate heritability estimates suggest that environmental factors may be of greater importance in predicting who will benefit from this analgesic modality.

Acupuncture has gained increasing attention in the treatment of chronic pain. The lack of a satisfying placebo method has made it impossible to show whether needling is an important part of the method or whether the improvement felt by the patient is due to the therapeutic setting and psychological phenomena. Also, the effectiveness of acupuncture has not been demonstrated sufficiently. We treated 52 sportsmen with rotator cuff tendinitis in a randomised single-blind clinical trial using a new placebo-needle as control. Patients were treated for 4 weeks. The primary endpoint of the trial was the change in the modified Constant-Murley-score from the baseline. Assessment of the treatment outcome was made by experienced orthopaedists not informed of the treatment allocation. Acupuncture with penetration of the skin was shown to be more effective than a similar therapeutic setting with placebo needling in the treatment of pain. The acupuncture-group improved 19.2 Constant-Murley-score points (SD 16.1, range from −13 to 50), the control-group improved 8.37 points (SD 14.56, range from −20 to 41), (P=0.014; C.I. 2.3;19.4). This study showed that needling is an important part of the acupuncture effect in the treatment of chronic shoulder pain in athletes. No conclusions can be derived from this study concerning the importance of choosing points and the rules of Traditional Chinese Medicine. Using the new placebo method as control for other ailments could improve the evidence of specific acupuncture effects beyond pain treatment.

The analgesic effects of the rat in response to electroacupuncture (EA) or low-dose morphine (3 mg/kg) show marked individual variations. In the midbrain periaqueductal gray (PAG) of the rat, the content of the neuropeptide cholecystokinin octapeptide (CCK-8) was found to be significantly higher in the low responder (LR) rats as compared to that in the high responders (HR). Since PAG has been shown to be a strategic site for CCK-8 to exert an anti-opioid action, a high CCK content in PAG may account for the low analgesic responsiveness to EA and morphine. In order to block the expression of the gene encoding preproCCK in the brain, antisense CCK expression vector pSV2-CCKAS was microinjected into the lateral cerebral ventricle of the rat, leading to a decrease of the CCK-mRNA as well as the CCK-8 content in rat brain. This effect started 4 days after the intracerebroventricular (i.c.v.) injection of the antisense expression vector, and lasted no more than 1 week. This procedure was shown to be very effective in converting LR rats into HR for EA analgesia and morphine analgesia, and also delayed the development of tolerance elicited by prolonged EA stimulation or repeated morphine administration. The time course of the augmentation of opioid analgesia (4-6 days after the i.c.v. injection of the expression vector) paralleled the decrease of the brain CCK-8 content. The results argue that blocking the CCK gene expression in the brain may tilt the balance between opioid and anti-opioid peptides in favor of the former, thus strengthening the EA analgesia and morphine analgesia, and delaying the development of opioid tolerance.

On July 4, 1980 a small group of neurosurgeons visited the Shanghai Institute of Physiology. They met primarily with neurophysiologists who are actively investigating the neural mechanism of acupuncture analgesia. These studies are being done at the levels of the peripheral nerve, spinal cord, basal ganglia, thalamus and cortex. These studies are briefly summarized and a bibliography of acupuncture related publications is appended.

Considerable evidence implicates sympathetic neural activity in acupuncture analgesia. However, the exact nature of these effects has not been specified in detail, and many experimental findings are contradictory. This study evaluated in normal conditions the specific sympathetic effects of both manual and electrical acupuncture applied to the same hand (Hoku) point. Thermographic measures of superficial skin temperature were used to assess sympathetic vasomotor tone in the face, hand and foot of 19 normal subjects. Baseline assessment, manual acupuncture and electrical acupuncture were performed in 3 separate sessions in a well controlled, 23 degrees C environment. Superficial skin temperature decreased slowly in the control condition. Both manual and electrical acupuncture produced a generalized long-lasting warming effect, indicating reduced sympathetic activity (sympatholytic effect). In addition, electrical acupuncture induced a localized short-term cooling effect, indicating a transient segmental increase in sympathetic activity (sympathomimetic effect).

The 26 chronic pain patients were tested in a baseline plus cross-over design. Half of the subjects were first treated with high intensity acupuncture; then they were treated with low intensity acupuncture. For the other 13 subjects the treatment order was reversed. In the first treatment sequence subjects reported lower pain estimates and engaging in more activities of daily living during treatment with high intensity acupuncture — but not with low intensity acupuncture. In addition, under high intensity acupuncture (i.e. with low pain levels), subjects had higher levels of platelet serotonin; this last finding is consistent with recent research which implicates central serotonin in pain control. The results of the second treatment sequence were ambiguous.

The aim of this study was to verify the validity and reliability of analgesia elicited by acupuncture stimulation in rabbits. Ninety-five experiments were performed using 21 adult animals. The reaction time of the avoidance response elicited by noxious heat stimulation on the snout, and the presence or absence of the start response elicited by pin-prick and clamping of the skin were studied. Bilateral electric acupuncture stimulation in the area of Tsu-san-li and Shang-chu-hsu points in the hind legs was used. The animals were either held in a soft bag, loosely attached by cords, or suspended in a hammock; the eyes were either free of blindfolded. On the basis of operational behavioral measurements, it was found that acupuncture stimulation did not produce analgesia in undisturbed, placid animals. However, during agitated or fighting periods and the immobility reflex-like state, sometimes associated with acupuncture maneuvers, long reaction times were observed. Pin-pricking and clamping stimulation of the skin were not reliable methods of noxious stimulation in the rabbit.

On a no treatment trial, a group of 24 oriental subjects rated cold pressor pain as significantly more painful and distressing than did a group of 24 occidental subjects. For half of the Orientals and half of the Occidentals, a second trial was conducted after acupuncture analgesia had been induced. The remaining 12 Orientals and 12 Occidentals served as no treatment controls on trial 2. Regardless of racial group, there was no difference between the pain of those experimental subjects who received acupuncture and the pain of those controls who did not. As they had on trial 1, Orientals reported significantly more pain and distress in response to ice water on trial 2. It is concluded that: 1. (1) if acupuncture does work better for the Chinese than for other racial groups, the likely cause is a more refined patient selection procedure rather than an -inherent difference in response to acupuncture; 2. (2) evidence does not support the stereotyped view of Orientals as stoical in the face of physical pain.