Nobuari Takakura

A placebo acupuncture needle with potential for double blinding – a validation study

Background The double blind, non-penetrating placebo needle is effective in masking patients who are not informed that they may receive a placebo needle. In this study, we aimed to examine whether such needles are effective in masking subjects who have been so informed. Methods One hundred and fourteen informed, consenting, healthy volunteers were recruited. An experienced acupuncturist applied one of the following needle pairs – penetrating/non-penetrating, non-penetrating/non-penetrating, penetrating/penetrating – randomly at bilateral TE5 points in subjects who were informed that they would receive either a non-penetrating or a penetrating needle. After the application of a pair of needles, the subjects reported for each arm on whether they identified the needle as non-penetrating or penetrating. The patients also rated skin penetration/penetration-like pain and the deep dull pain (de qi) associated with the needle application on a visual analogue scale (VAS). The chi squared goodness of fit test was used to determine the probability of the number of correctly and incorrectly identified needles. Statistical comparisons for VAS scores for skin penetration pain and de qi were made using Mann-Whitneys U test. Results Of the 114 non-penetrating needle applications, the subjects identified 64 incorrectly and 50 correctly, fitting a probability of 0.5 (χ2=1.72, P=0.19). Most interestingly, the subjects identified 36 (32%) of 114 penetrating needle applications incorrectly. Skin penetration/penetration-like pain and de qi scores did not differ significantly (P=0.87 and P=0.17, respectively) between the 114 non-penetrating and 114 penetrating needles. Conclusions The non-penetrating placebo needle was effective in masking fully informed subjects. When used together with the matched penetrating needle, it has potential for use in double blind (patient and practitioner blind) studies.

Double blinding with a new placebo needle: a validation study on participant blinding

Background A no-touch control needle in which the needle tip cannot reach the skin has been designed, and has been validated for practitioner blinding in a previous study but not for participant blinding. Objective To test whether the no-touch control needle can effectively blind subjects. Methods An acupuncturist applied, in turn, a no-touch control, skin-touch placebo and penetrating needle in one forearm of 80 healthy subjects. After removing each needle, the subjects were asked to judge the type of needle and rate the sensation of skin penetration/penetration-like or skin pressure/pressure-like pain on a 100 mm visual analogue scale. Results The subjects correctly identified 67% of needles overall. 17 of the 80 no-touch control needles were judged as skin-touch, and one as penetrating. In addition, six skin-touch placebo needles, and no penetrating needles, were judged as no-touch. Half of the 80 skin-touch placebo needles and 65 of the 80 penetrating needles and two no-touch control needles elicited pain. Of 240 needles, the practitioner identified 120 correctly that did not fit the probability of 1/3 (χ2=30.00, p<0.01). Conclusions The no-touch control needles may be used as a blind control for the acupuncture procedure, or to test the physiological effect of the skin-touch needles, but are not suitable for double-blind testing of the needle effect.

Double blinding with a new placebo needle: a further validation study

Background The masking properties of a new, non-penetrating, double-blind placebo acupuncture needle were demonstrated. Practitioners correctly identified some of the needles; if they were confident in this opinion, they would be unblinded. Objective To investigate the clues that led to correct identification, and the confidence in this decision. Methods Ten acupuncture practitioners, blindly and randomly, applied 10 each of three types of needle to the shoulder: blunt, non-penetrating needles that pressed the skin (‘skin-touch placebo needle’); new non-penetrating needles that penetrated soft material (stuffing) but did not reach the skin (‘non-touch control needle’); matching penetrating needles. Afterwards, practitioners were asked to judge the type of needle, their confidence in their decision and what clues led them to their judgements. Results Of the 30 judgements made by each practitioner, the mean number of correct, incorrect and unidentifiable answers were 10.4 (SD 3.7), 15.2 (SD 4.9) and 4.4 (SD 6.1), respectively. There was no significant difference in the confidence scores for 104 correct (mean, 54.0 (SD 20.2)%) and 152 incorrect (mean, 50.3 (SD 24.3)%) judgements. Twelve needles were identified with 100% confidence—three correct, and nine incorrect. For needles correctly identified, the proportions of non-touch (p = 0.14) and skin-touch (p = 0.17), needles were no greater than chance, but the proportion of penetrating needles correctly identified exceeded chance (p < 0.01). 53% of judgements were made from the “feeling of needle insertion”, but 57% of these were wrong. Conclusion Practitioners had a slight tendency to guess the penetrating needles correctly, but were uncertain about most of their judgments, posing only a very small risk to double blinding.

Can Acupuncture Treatment Be Double-Blinded? An Evaluation of Double-Blind Acupuncture Treatment of Postoperative Pain

Blinding protects against bias but the success of blinding is seldom assessed and reported in clinical trials including studies of acupuncture where blinding represents a major challenge. Recently, needles with the potential for double-blinding were developed, so we tested if acupuncture can be double-blinded in a randomized study of sixty-seven patients with acute pain ≥ 3 (0-10 scale following third molar removal) who received active acupuncture with a penetrating needle or placebo acupuncture with a non-penetrating needle. To test if acupuncture was administered double-blind, patients and acupuncturists were asked about perceived treatment allocation at the end of the study. To test if there were clues which led to identification of the treatment, deep dull pain associated with needle application and rotation (termed “de qi” in East Asian medicine), and patients’ pain levels were assessed. Perceived treatment allocation depended on actual group allocation (p < 0.015) for both patients and acupuncturists, indicating that the needles were not successful in double-blinding. Up to 68% of patients and 83% of acupuncturists correctly identified the treatment, but for patients the distribution was not far from 50/50. Also, there was a significant interaction between actual or perceived treatment and the experience of de qi (p = 0.027), suggesting that the experience of de qi and possible non-verbal clues contributed to correct identification of the treatment. Yet, of the patients who perceived the treatment as active or placebo, 50% and 23%, respectively, reported de qi. Patients’ acute pain levels did not influence the perceived treatment. In conclusion, acupuncture treatment was not fully double-blinded which is similar to observations in pharmacological studies. Still, the non-penetrating needle is the only needle that allows some degree of practitioner blinding. The study raises questions about alternatives to double-blind randomized clinical trials in the assessment of acupuncture treatment.

Changes in Blood Circulation of the Contralateral Achilles Tendon During and After Acupuncture and Heating

The purpose of this study was to investigate the effects of acupuncture and heating (application of hot pack) treatments on blood circulation in the contralateral Achilles tendon. During the treatments (10 min for acupuncture, 20 min for heating) and recovery period (40 min), the blood volume (THb) and oxygen saturation (StO2) of the treated and the non-treated tendons were measured using red laser lights. During both treatments, THb and StO2 of the treated tendon increased significantly from the resting level. The increased THb and StO2 of the treated tendon were maintained until the end of the recovery period after removal of the acupuncture needle, although these values decreased after removal of the hot pack. Although THb of the non-treated sides did not change during both acupuncture and heating treatments, it increased gradually after removal of the acupuncture needle or the hot pack. For both treatments, the amount of increase in THb of the non-treated tendon was significantly correlated to that of the treated tendon during the last phase of recovery period. These results obtained from the healthy subjects imply that blood circulation in the injured tendon in a plaster cast may be improved by applying acupuncture or heating treatments to the contralateral healthy limb.

Effect of acupuncture at the Hoku point on vibration-induced finger flexion reflex in man: comparison between press needle technique, electroacupuncture, and in-situ technique.

Effects of press needle technique (PN), electroacupuncture (EA), or in-situ technique (IS) on vibration-induced finger flexion reflex (VFR) were examined in 31 healthy adults. VFR, which is tonic finger flexion evoked by vibration applied to the finger tip, was induced by vibrating the volar side of the middle finger tip before and after acupuncture. Acupuncture was applied to the Hoku point on both sides. The three techniques, each studied on separate days, inhibited VFR and there was no significant difference in VFR inhibition among the three techniques (percentage of pre-acupuncture VFR was 71.5 +/- SE 2.2% after PN, 72.6 +/- SE 2.4% after EA, and 75.6 +/- SE 2.8% after IS). The results suggest that afferent signals from muscles contracting due to electrical stimulation had no significant effect on the reflex arcs of VFR; and that the intradermal stimulation by acupuncture played a significant role in VFR inhibition.

Vibration-induced finger flexion reflex and inhibitory effect of acupuncture on this reflex in cervical spinal cord injury patients

The vibration-induced finger flexion reflex (VFR) and the inhibitory effect of acupuncture on this reflex were studied in five cervical spinal cord injury patients (C-SCIs). VFR, which is a tonic finger flexion reflex induced by vibratory stimulation on the finger tip, was induced before and after acupuncture was carried out on the same hand. A stainless steel needle was inserted to the Hoku point. As in healthy subjects, VFR was performed and it was significantly inhibited by acupuncture in the C-SCIs; mean maximum VFR was 204.2 +/- S.E. 68.6 g before and 119.8 +/- S.E. 42.2 g after acupuncture. The present results suggest that at least part of the reflex center for VFR is located in the spinal cord and that part of VFR inhibition by acupuncture may be mediated via the spinal cord.

Double-Blind Acupuncture Needle: A Potential Tool to Investigate the Nature of Pain and Pleasure

Background. Most of our knowledge about similarities in the neural processing of painful and pleasant sensations in the brain derives from studying each phenomenon separately. Patients often feel pain induced by acupuncture, which is noxious stimulation having the symbolic message of the cure, as pleasant. Objectives. We investigated whether the double-blind acupuncture needles are a potential tool to investigate coinciding pain and pleasant events. Methods. Participants were 109 healthy acupuncture students. An acupuncturist applied the double-blind placebo and the matching penetrating needle at bilateral forearm of each subject, one needle on each side of the arm. We asked the subjects to rate the pain associated with needle application and its unpleasantness or pleasantness on a visual analogue scale. Results. Of 65 penetrating needle applications that elicited pain, 29 (45%) subjects did not describe the pain as being unpleasant, and interestingly, 18 (28%) subjects described the needle insertion as pleasant. There was no significant difference in reported pain intensity between penetrating needles elicited pain that elicited a pleasant sensation and those that elicited an unpleasant sensation (P = 0.34). Conclusions. The double-blind acupuncture needles can be a potential tool for investigating the concomitant hedonic (pleasure) experience of pain.

Tapping-in Method (Skin Penetration Technique) with a Placebo Needle for Double-Blind Acupuncture Trials

ObjectivesThis study investigated the effect of acupuncture needles developed for double-blind (practitioner — patient blinding) trials employing a tapping-in method that is commonly used to penetrate the skin in Japanesestyle acupuncture.Design, subjects, and interventionsAn acupuncturist applied a penetrating, a skin-touch placebo, and a notouch control needle designed to blind both practitioners and patients in the forearm in 80 healthy subjects (patients) by tapping-in method.SettingThe setting was a practice room of the Japan School of Acupuncture, Moxibustion and Physiotherapy, Tokyo, Japan.Outcome measuresThe outcome measures were the acupuncturist’s and subjects’ guesses at the type of needles and confidence of their guesses on a 100-mm visual analogue scale (VAS). The subjects were asked about pain with needle application.ResultsThe number of correct/incorrect guesses (the latter including unidentified) of the acupuncturist were 73/167 with a confidence of 55.2–16.9 (mean — standard deviation) on the VAS. The subjects identified 148 needles correctly and 92 needles incorrectly, the mean confidence being 71.0–28.4. There were a few penetrating and skin-touch placebo needles that the subjects guessed as “no-touch.” Whereas few of the 80 no-touch control needles were guessed as “penetrating,” 16 % of them were guessed as “skin-touch” and 11 % were reported as “unidentifiable” by the subjects. Forty percent (40 %) of the penetrating needles and 50 % of the skin-touch placebo needles did not elicit skin penetration pain.ConclusionsThe effect of practitioner blinding employing the needles for double blinding with the tapping-in method was satisfactory. It was difficult to blind the subjects when no-touch control needles together with penetrating and skin-touch placebo needles were used.

Effect of Acupuncture at the Right Hoku Point on Bilateral Vibration-induced Finger Flexion Reflex in Man: Comparison Between In-Situ and Sparrow Pecking Technique

The purpose of this study was to compare the effect of the Sparrow Pecking (SP) technique with that of the In-Situ (IS) technique of acupuncture on vibration-induced finger flexion reflex (VFR). Subjects were 30 healthy adults. VFR, flexion movement of the vibrated finger, was induced by vibrating the volar side of the middle finger tip. The acupuncture point was the right Hoku point. Both techniques of acupuncture inhibited VFR in the ipsilateral and contralateral sides, but inhibition with SP was significantly greater than that with IS (percentage control force of VFR, mean +/- SD: with SP right, 62.1 +/- 24.6%, left, 60.6 +/- 27.9%, with IS right, 74.9 +/- 26.6%, left, 78.1 +/- 29.5%, P < 0.0005). The results suggest that SP suppresses facilitation of VFR in the reflex arcs more than IS does.