Objective: The aim of this study was to compare the results of healthy volunteers with patients in chronic pain, in terms of acupuncture needle sensation. The search for a credible mechanism that underpins the effect of acupuncture in pain has recently involved the use of brain imaging techniques in an attempt to identify the neural correlates involved in pain control. Such studies have usually enrolled healthy participants rather than patients. This practice might be inappropriate as we are unsure if we can generalize from healthy volunteers to patients in chronic pain.
Method: This paper describes a comparison of data obtained from 2 small randomized controlled studies, 1 involving patients with chronic pain and the other which recruited healthy volunteers. Both studies used real acupuncture and a nonpenetrating "placebo" needle in a crossover design. The outcome studied in this paper was a comprehensive needling sensation questionnaire.
Results: There was a difference in the sensations experienced by patients as compared with healthy volunteers. Patients tended to feel much stronger sensation. Neither group differed in distinguishing between real and placebo needling. However, patients were more likely to state that both needles were real, whereas healthy participants were more likely to suggest that neither were real.
Discussion: It is concluded that if the nature of the sensation felt is of importance, then it might be inappropriate to recruit healthy volunteers in lieu of patients and a larger study is required to clarify this.