Transcutaneous electrical acupoint stimulation for people with chronic musculoskeletal pain: an exploratory review

Background Transcutaneous electrical acupoint stimulation (TEAS) is a form of stimulation-induced analgesia with potential as a non-invasive alternative to acupuncture, suitable for self-application. The clinical evidence for TEAS for people with chronic musculoskeletal pain is limited. Objectives This exploratory review aimed to evaluate the potential of TEAS as a pain relief option for people with chronic musculoskeletal pain and explore the evidence relating to dose parameters. Methods A literature search was conducted using Medline, EMBASE, CINAHL, AMED and the Cochrane Database for studies that used TEAS or specified the use of Transcutaneous electrical nerve stimulation (TENS) over acupuncture points for people with chronic pain. Data relating to the treatment dose parameters was extracted including frequency, intensity, treatment duration and stimulation location, to identify themes and trends with a narrative analysis and review. Results The review included 20 studies consisting of 13 randomised controlled trials, four comparative trials and three cross-over studies. Most RCTs indicated some beneficial effect on pain scores, but the overall quality of evidence was low. Most studies applied a TENS device for 20–40 minutes, several times a week similar to an acupuncture treatment protocol. There was no clear evidence that the electrical parameters of frequency and intensity or the choice of acupuncture points had an effect on the outcomes. Conclusions People with chronic musculoskeletal pain may achieve pain relief using TEAS but the existing evidence is limited and high quality clinical evidence is required to establish efficacy. Effects appear to be achieved with short applications, several times a week in a protocol similar to those used with acupuncture. It is not clear whether the choice of acupuncture point, stimulation frequency or intensity has an impact on the results. Further investigation of the effect of stimulation duration for both TEAS and TENS is recommended