Effects of auricular transcutaneous electrical nerve stimulation on experimental pain threshold.

This study was conducted to examine the effects of high intensity transcutaneous electrical nerve stimulation at auricular acupuncture points on experimental pain threshold. Forty-five healthy adult male and female subjects were assigned randomly to one of two treatment groups or to a control group. Subjects in the two treatment groups received high intensity TENS to either appropriate or inappropriate (placebo) acupuncture points on one ear. Experimental pain threshold at the ipsilateral wrist was determined with a painful electrical stimulus before and after ear stimulation. Only the group receiving stimulation of appropriate ear acupuncture points exhibited a significant increase (p less than .01) in experimental pain threshold after ear stimulation. The comparable placebo and control groups, again, did not exhibit significant pretest-posttest differences in experimental pain threshold. The results suggest that, if applied accurately, auricular TENS can increase pain threshold. Further research is needed to assess the effects of this technique on patient groups.