 |
Electrophysiological Study of Acupuncture Stimulation Synchronized with Patient’s Respiratory Rhythm
Tim Hideaki Tanaka, Ph.D., Kazushi Nishijo, Ph.D.
The Pacific Wellness Institute, Toronto, Ontario, Canada
(Paper presented at the 32nd Annual Meeting of Association for Applied Psychophysiology and Biofeedback, Raleigh-Durham, NC, March 29-April 1, 2001)
Introduction: Previous studies (Nishijo, Mori, Yoshida, Tsukayama, & Yamashita, 1994, Tanaka, 1996) suggest that superficial acupuncture stimulation (stimulating skin and subcutaneous tissue only) causes a significant autonomic reaction, which in turn induces various physiological reactions. However the degree of autonomic response significantly varied depending on the subject’s “biological state” (e.g., respiratory status) during acupuncture needling. This study further investigated and compared the effect of two types of superficial acupuncture stimulation (stimulation applied during patient’s expiratory phase only/ continuous stimulation) using various physiological parameters (EMG, Heart Rate, PPG, and SCL) and pain index.
Method
Subjects:
Ten chronic tension type headache sufferers who met the criteria made by the International Headache Society (IHS) (Headache Classification Committee of the International Headache Society, 1988) entered this study.
Type of acupuncture: There were 2 types of acupuncture procedures:
- Superficial needling and stimulation only during the subjects exhalation phase in a sitting position (referred to as SES stimulation)
- Superficial continuous needling stimulation during both exhalation and inhalation phases in a sitting position (referred to as CONT stimulation).
In both types of stimulation, an acupuncture needle was inserted approximately 2 mm. in depth at the TE 5 (an acupuncture point on the wrist) utilizing a guiding tube. Following the insertion, a gentle repetitive tapping stimulation was applied (approximately at the rate of 5 tappings per second) using the index finger on the top of the guiding tube.
Pain Measurements: At the beginning and end of the experiment session, subjects were asked to rate their headache intensity with a visual-analog scale (VAS) from 0 (equating no headache) to 10 (equating intolerable headache).
Procedure and Physiological Measurements: The subjects were asked to sit in a reclining chair and relax as much as possible with their eyes closed for 10 minutes. Following the stimulation (SES or CONT), the static EMG, heart rate, pulse height, and SCL were continuously monitored for 30 min.
The subjects were asked to return for a further experimental procedure within 2 to 7 days. The five subjects who had received SES stimulation at the first session received CONT stimulation on their return, and the remaining five subjects who had received CONT stimulation at the first session received SES stimulation.
Results:
1). Pain Scale:
Thirty minutes after SES stimulation, an averaged 59.1% pain score reduction was obtained (P=0.005, t-test). In contrast, CONT stimulation produced only an averaged 21.9 % pain score reduction, which was not statistically significant. The t-test revealed that after SES stimulation, pain score decreased significantly compared to the CONT stimulation. (P=0.009, t-test)
Interaction between stage (before and after stimulation) and type of stimulation: F(1,8)=10.14, P=0.013. The contrast for this effect indicates that the average reduction in pain over the course of SES is significantly greater than the average reduction in pain over the course of CONT.
All other main effects and interactions were strongly insignificant, indicating that the groups (order of administration) were irrelevant, and that average levels of pain were not significantly different between treatments.
2). Physiological Parameters
Responses to the EMG, heart rate, pulse height, SCL were analyzed by using ANOVA (Unique Sum of Squares Method) and no statistical significant interaction between time and type (SES, CONT) was found.
Frontalis EMG Activity:
There was a trend towards reduction of frontalis muscle activity immediately after SES stimulation.
Upper Trapezius (UT) EMG Activity:
There was a strong trend towards decreasing the UT EMG activity after SES.
Heart Rate:
Heart rate reduced after both types of stimulation.
Pulse Height: There was somewhat of a decreasing trend after both types of stimulation, however changes were not significant from the baseline.
Skin Conductance Level:
There was a constant increase in SCL observed after both types of stimulation.
3). Correlation of pain scale change and EMG change
The correlation between pain scale reduction and EMG reduction at 30 min. was analyzed by Spearman Correlation Coefficients (figure. 10, 11). There was a significant correlation between pain scale reduction and decreasing UT EMG activity (P=0.014). There was no significant correlation found between pain scale and frontalis EMG.
The baseline EMG means were also correlated with the baseline pain scale. It was discovered that there was no significant relationship between baseline EMG activity and pain scale.
Discussion:
Previous experiments (Nishijo, Mori, Yoshida, Tsukayama, & Yamashita, 1994, Tanaka, 1996) indicated that superficial needling during exhalation in a sitting position induced a consistent parasympathetic response while the same stimulation, applied during the inhalation phase, did not induce the response (Nishijo, Mori, Yoshida, Tsukayama & Yamashita 1994). Nishijo (1994) proposed the theory of the mechanism inducing parasympathetic activation response by SES application as follows: First, the stimulation site must be skin and subcutaneous tissue, because they have the receptors of stimulation using the parasympathetic nervous system as a centrifugal path. Second, the autonomic nervous system is directed towards activation in a sitting position. Third, during the expiratory phase, the parasympathetic nerve is activated in contrast to the suppression of the parasympathetic state during inhalation. Matching these three factors, the action of acupuncture can synchronize with a patient’s physiological state, which in turn, causes a consistent arousal of parasympathetic activity.
Many previously published articles covering clinical acupuncture, shifted towards a selection of the point/points according to the symptom or pattern of the patient and it now seems as if not enough emphasis was put on the issue of the patient’s somatic state during stimulation. There was little consideration. of “how to stimulate the point.” Our study indicated that acupuncture’s positive effect (whether superficial or deep) does not depend on the selection of acupuncture points alone but also of significant importance is the knowledge of a patient’s physiological state during needling.
For more information or to speak with the author, Dr. Tim Tanaka, contact him at the Pacific Wellness Institute in Toronto.
|
|
|
|
INFERTILITY
A case after three IUI failures. Natural infertility treatment using acupuncture.
BACK PAIN/SCIATICA
Successful recovery from sciatica due to disk herniation.
|
|
|
|
|
Contrary to popular belief, acupuncture provides more than pain relief. It is helpful in treating anxiety, insomnia, digestive problems, abdominal, menstrual cramps, skin conditions, infertility, weight control…
[MORE]
HOW TO CHOOSE AN ACUPUNCTURIST
Acupuncture Styles: difference between Chinese, Japanese, and Electroacupuncture
|
|
|
|
