Acupuncture for Japanese Katakori (Chronic Neck Pain): A Randomized Placebo-Controlled Double-Blind Study.

Background and Objectives: Although acupuncture is listed as a beneficial treatment for neck/shoulder stiffness, which has increased with the spread of information technology, to date, evidence of its efficacy under double-blind conditions has not been shown. This study aimed to assess whether acupuncture treatment with superficial skin piercing is superior to placebo treatment. Materials and Methods: A randomized, double-blind (practitioner-patient) placebo-controlled trial was performed at a single center with four arms (ISRCTN76896018). Four hundred patients with essential neck/shoulder stiffness were randomly assigned to penetrating needle treatment (acupuncture ritual and skin penetration), skin-touch needle treatment (acupuncture ritual and skin touch), no-touch needle treatment (acupuncture ritual alone), and no-treatment control. Each of the six acupuncturists applied a needle to each of the four acupoints in the neck/shoulder of 50 patients. Results: Each of the three treatments significantly (p = 0.01) improved neck/shoulder stiffness compared with the no-treatment control immediately and 24 h after treatment. There was a significant improvement in penetrating needle treatment over no-touch needle treatment 24 h later. However, there was no significant difference between the penetrating and skin-touch and skin-touch vs. no-touch. Conclusions: All treatments that received the ritual of acupuncture were better than the no-treatment control. Only genuine acupuncture involves the specific effects of needle insertion into the body. The acupuncture ritual had a significant impact on the subjective improvement of neck/shoulder stiffness; however, improvement with ritual alone versions of placebo acupuncture was not maintained as with superficial skin piercing. Our study provides important evidence of acupuncture efficacy and information regarding inert no-touch placebo control in acupuncture research.

Evaluation of Sedation Levels Using SedLine During Intravenous Sedation for Dental Procedures: A Case-Series Study.

The Patient State Index (PSI) is the numerical value of anesthesia depth as measured using a SedLine Sedation Monitor (Masimo Corporation). In this pilot study, we evaluated PSI values captured during intravenous (IV) moderate sedation for dental treatment. During the dental treatment, a dental anesthesiologist maintained the Modified Observer's Assessment of Alertness/Sedation (MOAA/S) score at 3 to 4 by adjusting the administration of midazolam and propofol while PSI values were recorded. The mean (SD) and median (25th percentile, 75th percentile) PSI values during dental treatment under IV moderate sedation were 72.7 (13.6) and 75 (65, 85), respectively.

Effects on Acupuncturist Blinding: Different Diameters of Double-blind Acupuncture Needles.

CONTEXT: It's difficult to conduct experiments using a double-blind design in controlled clinical trials of acupuncture. To resolve this problem with blinding, we designed double-blind needles (DBNs) with stuffing to mimic the resistance felt during insertion of a regular acupuncture needle. Results of the past studies using 0.16 mm diameter DBNs found that the resistance felt by the acupuncturists during insertion successfully blinded them. OBJECTIVE: The study intended to compare the effects on an acupuncturist's blinding when the practitioner used penetrating DBNs with 0.14, 0.16, 0.18, and 0.20 mm diameters. DESIGN: We conducted a double-blind randomized trial. SETTING: The study took place at the Japan School of Acupuncture, Moxibustion. and Physiotherapy in Tokyo, Japan. PARTICIPANTS: The participant was one licensed acupuncturist who performed 320 needle insertions during acupuncture for 20 healthy students, who were familiar with acupuncture and who attended the Japan School of Acupuncture, Moxibustion, and Physiotherapy. METHODS: The acupuncturist was informed she would administer a penetrating or non-penetrating needle; however, only penetrating needles were used. She inserted the four sizes of needles in both of each student's dorsal forearms using an alternating twirling technique. This procedure was repeated once more on another day, with at least one day between sessions. PRIMARY OUTCOME MEASURES: After the acupuncturist removed each needle, we asked her to guess: (1) the type of needle inserted, (2) her level of confidence in the guess, and (3) the clues that contributed to her guess. A chi-squared test was used to determine whether the ratio of correctly or incorrectly identified needles met an expected probability of 0.5 for each needle diameter. RESULTS: Of the 320 needle insertions, the acupuncturist correctly identified 54% of 0.14 mm, 45% of 0.16 mm, 46% of 0.18 mm, and 50% of 0.20 mm needle insertions. The correct and incorrect ratios of identified needles were fitted with a probability of 0.5, with no significant differences in the acupuncturist's confidence (P = .16). In 99% of the tests, the cue that contributed to the acupuncturist's guess was the feeling of the needle insertion. CONCLUSION: These findings indicate that the differences in the diameters of DBNs from 0.14 to 0.20 mm didn't significantly affect the acupuncturist's blinding.

Dexmedetomidine inhibits LPS-induced inflammatory responses through peroxisome proliferator-activated receptor gamma (PPARγ) activation following binding to α2 adrenoceptors.

Over the past decade, dexmedetomidine (DEX) has been found to possess an anti-inflammatory effect. However, the local anti-inflammatory mechanism of DEX has not been fully clarified. Some intracellular inflammatory pathways lead to negative feedback during the inflammatory process. The cyclooxygenase (COX) cascade synthesizes prostaglandins (PGs) and plays a key role in inflammation, but is known to also have anti-inflammatory properties through an alternative route of a PGD2 metabolite, 15-deoxy-delta-12,14-prostaglandin J2 (15d-PGJ2), and its receptor, peroxisome proliferator-activated receptor gamma (PPARγ). Therefore, we hypothesized that DEX inhibits LPS-induced inflammatory responses through 15d-PGJ2 and/or PPARγ activation, and evaluated the effects of DEX on these responses. The RAW264.7 mouse macrophage-like cells were pre-incubated with DEX, followed by the addition of LPS to induce inflammatory responses. Concentrations of TNFα, IL-6, PGE2, and 15d-PGJ2 in the supernatants of the cells were measured, and gene expressions of PPARγ and COX-2 were evaluated in the cells. Furthermore, we evaluated whether a selective α2 adrenoceptor antagonist, yohimbine or a selective PPARγ antagonist, T0070907, reversed the effects of DEX on the LPS-induced inflammatory responses. DEX inhibited LPS-induced TNFα, IL-6, and PGE2 productions and COX-2 mRNA expression, and the effects of DEX were reversed by yohimbine. On the other hand, DEX significantly increased 15d-PGJ2 production and PPARγ mRNA expression, and yohimbine reversed these DEX's effects. Furthermore, T0070907 reversed the anti-inflammatory effects of DEX on TNFα and IL-6 productions in the cells. These results suggest that DEX inhibits LPS-induced inflammatory responses through PPARγ activation following binding to α2 adrenoceptors.

In vitro changes in the proportion of protein-unbound-free propofol induced by valproate.

PURPOSE: It has been reported that oral valproate (VPA) reduces the dose of propofol required for sedation. As  a potential reason for this, it is considered that VPA displaces serum protein-bound propofol and increases the proportion of protein-unbound-free propofol. To examine this hypothesis, the present in vitro study investigated the influence of VPA on the proportion of protein-unbound-free propofol in human serum samples. METHODS: Serum samples were collected from 10 healthy volunteers, who were not taking any medication. VPA (final concentration: 0.05, 0.1 or 1 mg/mL) and propofol (final concentration: 1 or 5 µg/mL) were mixed with serum samples with normal (4.0 g/dL) or low (2.5 g/dL) albumin concentrations. Then, protein-unbound-free propofol was extracted from the samples, and its concentration was measured using high-performance liquid chromatography. We compared the proportion of protein-unbound-free propofol in each of the VPA-containing samples with that in serum samples without VPA (control). RESULTS: In the serum samples with normal albumin concentrations, 1 mg/mL VPA significantly increased the proportion of protein-unbound-free propofol at 1 and 5 µg/mL propofol. Furthermore, in the serum samples with low albumin concentrations, the proportion of protein-unbound-free propofol was significantly increased by both 0.1 and 1 mg/mL VPA at propofol concentrations of 1 and 5 µg/mL. CONCLUSION: VPA might increase the proportion of protein-unbound-free propofol in human serum via displacement reactions.

Patient blinding with blunt tip placebo acupuncture needles: comparison between 1 mm and 2 mm skin press.

OBJECTIVE: To investigate the influence of the depth of skin press in blunt tip placebo acupuncture needles on patient blinding and its relationship to needle diameter. METHODS: Forty healthy volunteers were enrolled as subjects for patient blinding. Four acupuncturists applied the following needles randomly at three points in each forearm: 0.18 mm and 0.25 mm diameter penetrating needles inserted to a depth of 5 mm, and 0.18 mm and 0.25 mm diameter skin-touch needles depressing the skin at the acupoint to a depth of 1 mm and 2 mm from the skin surface. The subjects reported their guesses at the nature of needles they received, and rated needle pain and de qi. A blinding index was calculated to define the success of blinding for subjects. RESULTS: The blinding status of subjects for 1 mm press needles of 0.18 mm diameter was "random guess", but "unblinded" for 1 mm press needles of 0.25 mm diameter. For 2 mm press needles of both diameters, the blinding status was "opposite guess" and the blinding status for penetrating needles of both diameters was "unblinded." The percentages of "felt pain" with 2 mm press needles of both diameters were similar to that with penetrating needles, but those were not similar for 1 mm press needles. The frequency of de qi occurrence with 2 mm press needles of 0.18 mm diameter was similar to that of penetrating needles of both diameters. CONCLUSION: Placebo needles of 2 mm press made more subjects guess that the needles penetrated the skin than 1 mm press needles. The use of small diameter needles increased patient blinding.

Effect of a low dose of midazolam on high blood pressure in dental patients: a randomised, double-blind, placebo-controlled, two-centre study.

Some patients have transient hypertension before dental treatment as a result of anxiety and stress. Midazolam is an anxiolytic, and thought to be effective for the management of this sort of transient hypertension. We have evaluated in a randomised, controlled trial whether a low dose of midazolam can lower blood pressure in dental patients to an acceptable level without excessive sedation. Suitable patients were randomised to be given midazolam (trial group) or physiological saline (control group) intravenously. Blood pressure, heart rate, degree of anxiety, and amount of sedation were measured before and after injection. After injection, blood pressure in the trial group significantly decreased to clinically acceptable levels compared with controls. The degree of anxiety in the trial group was also significantly less than that in the control group, but there were no significant differences in sedation. These results suggest that injection of a low dose of midazolam stabilises the blood pressure of dental patients with transient hypertension.

The inhibitory effect of locally injected dexmedetomidine on carrageenan-induced nociception in rats.

Recent studies showed that the administration of dexmedetomidine relieved hyperalgesia in the presence of neuropathic pain. These findings have led to the hypothesis that the local administration of dexmedetomidine is useful for relieving acute inflammatory nociception, such as postoperative pain. Thus, we evaluated the inhibitory effect of locally injected dexmedetomidine on acute inflammatory nociception. Acute inflammatory nociception was induced by an intraplantar injection of 1% carrageenan into the hindpaws of rats, and dexmedetomidine was also injected combined with carrageenan. The paw withdrawal threshold based on von Frey filament stimulation was measured until 12 h after injection. We compared the area under the time-curve (AUC) between carrageenan and carrageenan with dexmedetomidine. To clarify that the action of dexmedetomidine was via α2-adrenoceptors, we evaluated the effect of yohimbine, a selective antagonist of α2-adrenoceptors, on the anti-nociception of dexmedetomidine. As the results, the intraplantar injection of carrageenan with over 10 µM dexmedetomidine significantly increased AUC, compared to that with only carrageenan injection. This effect of dexmedetomidine was reversed by the addition of yohimbine to carrageenan and dexmedetomidine. These results demonstrated that the locally injected dexmedetomidine was effective against carrageenan-induced inflammatory nociception via α2-adrenoceptors. The findings suggest that the local injection of dexmedetomidine is useful for relieving local acute inflammatory nociception.

Is Skin-Touch Sham Needle Not Placebo? A Double-Blind Crossover Study on Pain Alleviation.

It remains an open question whether placebo/sham acupuncture, in which the needle tip presses the skin, can be used as a placebo device for research on pain. We compare the analgesic effect of the skin-touch placebo needle with that of the no-touch placebo needle, in which the needle tip does not touch the skin, in a double-blind crossover manner including no-treatment control in 23 healthy volunteers. The subjects received painful electrical stimulation in the forearm before and during needle retention to the LI 4 acupoint and after the removal of the needle and rated pain intensity using a visual analogue scale. We found no significant difference in analgesic effects among the skin-touch placebo needle, no-touch placebo needle, and no-treatment control at every point before, during, and after the treatments (p > 0.05). The results indicate that the skin-touch placebo needle can be used as a placebo device in clinical studies on pain.

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.

Design of a randomised acupuncture trial on functional neck/shoulder stiffness with two placebo controls.

BACKGROUND: Functional neck/shoulder stiffness is one of the most well-known indications for acupuncture treatment in Japan. There is little evidence for the effectiveness of acupuncture treatment for functional neck/shoulder stiffness. Research using two different placebos may allow an efficient method to tease apart the components of real acupuncture from various kinds of 'non-specific' effects such as ritual with touch or ritual alone. Herein, we describe a protocol of an ongoing, single-centre, randomised, placebo-controlled trial which aims to assess whether, in functional neck/shoulder stiffness, acupuncture treatment with skin piercing has a specific effect over two types of placebo: skin-touching plus ritual or ritual alone. METHODS: Six acupuncturists and 400 patients with functional neck/shoulder stiffness are randomly assigned to four treatment groups: genuine acupuncture penetrating the skin, skin-touch placebo or no-touch placebo needles in a double-blind manner (practitioner-patient blinding) or no-treatment control group. Each acupuncturist applies a needle to each of four acupoints (Bladder10, Small Intestine14, Gallbladder21 and Bladder42) in the neck/shoulder to 50 patients. Before, immediately after and 24 hours after the treatment, patients are asked about the intensity of their neck/shoulder stiffness. After the treatment, practitioners and patients are asked to guess whether the treatment is "penetrating", "skin-touch" or "no-touch" or to record "cannot identify the treatment". DISCUSSION: In addition to intention-to-treat analysis, we will conduct subgroup analysis based on practitioners' or patients' guesses to discuss the efficacy and effectiveness of treatments with skin piercing and various placebo controls. The results of practitioner and patient blinding will be discussed. We believe this study will further distinguish the role of different components of acupuncture. TRIAL REGISTRATION: Current Controlled Trial ISRCTN76896018.

The Potential of Double Blinding with Two Placebo Acupuncture Needles: A Randomized Controlled Pilot-Trial.

BACKGROUND: Whether acupuncture treatment employing multiple penetrating, skin-touch placebo, or no-touch placebo needles designed for double blinding actually do blind practitioners and patients has not been investigated. We aimed to investigate this question. SUBJECTS: 120 patients with functional neck/shoulder stiffness but in otherwise healthy condition were randomly assigned to a treatment using four penetrating, four skin-touch placebo, or four no-touch placebo needles. Each of six acupuncturists applied four needles to four acupoints in the neck/shoulder of 20 patients. Acupuncturists and patients were asked to guess the treatment mode and their confidence in their guesses on 100 mm visual analog scales. RESULTS: The kappa coefficients between practitioner guesses and treatment type and between patient guesses and treatment type were 0.15 and 0.44, respectively. The median score of practitioner confidence was 46.8, and no significant difference in confidence between correct and incorrect guesses was revealed for any treatment. The median score of patient confidence for correct guesses was 77.6. The kappa coefficient between practitioner and patient guesses was 0.06. CONCLUSIONS: The practitioners were blinded to the nature of treatment using the same multiple needles, but patient blinding was insufficient. Further improvement is necessary to achieve satisfactory patient blinding with these acupuncture needles.

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 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.

Analgesia Is Enhanced by Providing Information regarding Good Outcomes Associated with an Odor: Placebo Effects in Aromatherapy?

No previous report has described whether information regarding an odor used in aromatherapy has placebo effects. We investigated whether placebo analgesia was engendered by verbal information regarding the analgesic effects of an odor. Twelve of 24 subjects were provided with the information that a lavender odor would reduce pain (informed), whereas the other 12 subjects were not (not-informed). Concurrent with respiration recording, the subjects were administered a lavender-odor or no-odor treatment during application of painful stimulation to the forefinger. The subjects reported their experience of pain and its unpleasantness on a visual analogue scale after the painful stimulation. The lavender-odor treatment significantly alleviated pain and unpleasantness compared with the no-odor treatment in the informed (P < 0.01) and not-informed groups (P < 0.05). The no-odor treatment in the informed group significantly alleviated pain and unpleasantness compared with both the no-odor and lavender-odor treatments in the not-informed group (P < 0.05). Rapid and shallow breathing induced by the painful stimulation became slow and deep during the lavender-odor and no-odor treatments in both groups. Information regarding a lavender odor, the lavender odor itself, and slower breathing contributed to reduced perceptions of pain and unpleasantness during painful stimulation, suggesting that placebo effects significantly contribute to analgesia in aromatherapy.

Tapping-in method (skin penetration technique) with a placebo needle for double-blind acupuncture trials.

OBJECTIVES: This 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 Japanese-style acupuncture. DESIGN, SUBJECTS, AND INTERVENTIONS: An acupuncturist applied a penetrating, a skin-touch placebo, and a no-touch control needle designed to blind both practitioners and patients in the forearm in 80 healthy subjects (patients) by tapping-in method. SETTING: The setting was a practice room of the Japan School of Acupuncture, Moxibustion and Physiotherapy, Tokyo, Japan. OUTCOME MEASURES: The 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. RESULTS: The 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. CONCLUSIONS: The 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.

Inhibitory Effect of Acupuncture on Vibration-Induced Finger Flexion Reflex in Humans: Comparisons Among Radial, Median, and Ulnar Nerve Stimulation.

BACKGROUND: Vibration-induced finger flexion reflex (VFR) is inhibited with acupuncture to TE 5 or LI 4 at the skin innervated by the radial nerve. OBJECTIVE: The aim of this study was to determine if acupoints in regions innervated by the radial nerve are specific to inhibit VFR. MATERIALS AND METHODS: This experiment was performed using a crossover design with 3 acupuncture groups (needle insertion to the right LU 11, PC 9, or SI 1) and a control group (no needle treatment). Each acupoint was randomly needled on separate days. Ten healthy volunteers were recruited for this study. VFR was induced by applying vibration on the volar side of the right middle fingertip. An acupuncture needle was inserted in the acupoint and retained for 5 minutes. For the main outcome measure, maximum finger flexion force (MFFF) was measured during vibration and was compared among four groups. RESULTS: MFFFs in the acupuncture groups were significantly lower (p<0.05) than that in the control group. However, no significant difference was observed in MFFFs in the three intervention groups after acupuncture to LU 11, PC 9, and SI 1. CONCLUSIONS: Acupuncture to the right LU 11, PC 9, or SI 1 point inhibited the ipsilateral VFR, which suggests that afferent inputs from the radial nerve with needle insertion were not specific, compared with those from the median and ulnar nerves to suppress neuronal activities in the VFR reflex circuits.

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 (χ(2)=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.

Inhibitory effect of needle penetration on vibration-induced finger flexion reflex in humans.

BACKGROUND: Vibration-induced finger flexion reflex (VFR) in the upper extremity is inhibited by needle insertion acupuncture to the large intestine 4 (LI4) at the hand. This claim has a limitation because the inhibitory effect is deduced only from reduction in the maximum finger flexion (FF) force during the tonic flexion reflex by vibratory stimulation after acupuncture. METHODS: The study was a crossover design with two conditions-acupuncture and control-to which 16 healthy volunteers were subjected. VFR in the upper extremity was induced by applying vibratory stimulation on the volar side of the middle fingertip of the right hand, before and after acupuncture at the right LI4 in 16 healthy volunteers. We measured the area under the curve (AUC) of finger flexion force and surface electromyogram (EMG) in the flexor muscles, in addition to the maximum FF force during vibratory stimulation. We compared AUC, surface EMG and maximum FF force in the acupuncture condition with those in the control condition. We also estimated the correlation between AUC, surface EMG and maximum FF force. RESULTS: AUC, surface EMG and maximum FF force were significantly reduced (p <0.01) after acupuncture compared with those of the control group. A strong correlation was observed in maximum FF force versus AUC (r=0.98, p <0.01) and surface EMG (r=0.77, p <0.01). CONCLUSIONS: Acupuncture at ipsilateral LI4 inhibited tonic activities in the finger flexor muscles during VFR, which suggests that afferent input with needle penetration has inhibitory effect on the motor neuronal activities in the reflex circuits of VFR.

Typical dipole locations can be estimated using averaged somatosensory-evoked potentials and a standard brain model.

It is reasonable to hypothesize that dipoles estimated from grand averaged event-related potentials based on summed-up data obtained from multiple subjects and standard head models could correspond to typical brain regions associated to a particular event. Six healthy subjects were enrolled in a study to test this hypothesis. We estimated dipoles from somatosensory-evoked potentials (SEP) elicited by electrical stimulation to the left median nerve. We also created individual three-layered (scalp, skull, and brain) head models from each subject's magnetic resonance imaging scan, and dipoles were estimated from the individual averaged SEP with each individual head model. We then estimated dipoles using grand averaged SEP across all subjects on the standard head model created from the Montreal Neurological Institute (MNI) standard coordinate system brain template to compare the estimated dipoles located on our own head model and those on the MNI. The dipoles in the post-central gyrus were estimated from negative potentials at 20 ms from the grand averaged data incorporated with the MNI head model, corresponding to a typical location related to SEP stimulation. The results suggest the validity of estimating the dipole location from the grand averaged potential of all subjects with the MNI model if we focus on typical regions related to the task.