Transcutaneous electrical nerve stimulation (TENS) for chronic pain - an overview of Cochrane Reviews

Abstract

BackgroundChronic pain, considered to be pain lasting more than three months, is a common and often difficult to treat condition that can significantly impact upon function and quality of life. Treatment typically includes pharmacological and non‐pharmacological approaches. Transcutaneous electrical nerve stimulation (TENS) is an adjunct non‐pharmacological treatment commonly recommended by clinicians and often used by people with pain.ObjectivesTo provide an overview of evidence from Cochrane Reviews of the effectiveness of TENS to reduce pain in adults with chronic pain (excluding headache or migraine).To provide an overview of evidence from Cochrane Reviews of the safety of TENS when used to reduce pain in adults with chronic pain (excluding headache or migraine).To identify possible sources of inconsistency in the approaches taken to evaluating the evidence related to TENS for chronic pain (excluding headache or migraine) in the Cochrane Library with a view to recommending strategies to improve consistency in methodology and reporting.To highlight areas of remaining uncertainty regarding the effectiveness of TENS for chronic pain (excluding headache or migraine) with a view to recommending strategies to reduce any uncertainty.MethodsSearch methodsWe searched the Cochrane Database of Systematic Reviews (CDSR), in the Cochrane Library, across all years up to Issue 11 of 12, 2018.Selection of reviewsTwo authors independently screened the results of the electronic search by title and abstract against inclusion/exclusion criteria. We included all Cochrane Reviews of randomised controlled trials (RCTs) assessing the effectiveness of TENS in people with chronic pain. We included reviews if they investigated the following: TENS versus sham; TENS versus usual care or no treatment/waiting list control; TENS plus active intervention versus active intervention alone; comparisons between different types of TENS; or TENS delivered using different stimulation parameters.Data extraction and analysisTwo authors independently extracted relevant data, assessed review quality using the AMSTAR checklist and applied GRADE judgements where required to individual reviews. Our primary outcomes included pain intensity and nature/incidence of adverse effects; our secondary outcomes included disability, health‐related quality of life, analgesic medication use and participant global impression of change.Main resultsWe included nine reviews investigating TENS use in people with defined chronic pain or in people with chronic conditions associated with ongoing pain. One review investigating TENS for phantom or stump‐associated pain in people following amputation did not have any included studies. We therefore extracted data from eight reviews which represented 51 TENS‐related RCTs representing 2895 TENS‐comparison participants entered into the studies.The included reviews followed consistent methods and achieved overall high scores on the AMSTAR checklist. The evidence reported within each review was consistently rated as very low quality. U...

Transcutaneous electrical nerve stimulation, acupuncture, and spinal cord stimulation on neuropathic, inflammatory and, non-inflammatory pain in rat models

“…This peripheral stimulation induces electrical activity which inhibits the brain's perception of pain. The 'gate control theory' of Wall and Melzack is based on the principle that there is a gateway in the dorsal horn of the spinal cord, which somehow controls or regulates the flow of pain messages that are then sent to (ascending) and from (descending) higher levels of the brain for central processing, thus reducing the perception of pain [30,31]. Other postulated mechanisms of the pain relief mediated by TENS include the promotion of endorphin release in the brain [32] and local dilatation of blood vessels in injured tissue [33].…”

Transcutaneous electrical nerve stimulation for advanced cancer pain inpatients in specialist palliative care—a blinded, randomized, sham-controlled pilot cross-over trial

“…For the sake of generalizability, we included patients with various types of cancer, sites of pain and types of pain, which enhanced heterogeneity of the sample. In contrast to trials assessing pain therapy in chronic non-cancer pain conditions [44], the primary outcome in palliative cancer pain trials is probably more influenced by progress and instability of the disease that may have further contributed to the heterogeneity and variance in the results.…”

<p>Remote Analgesic Effects Of Conventional Transcutaneous Electrical Nerve Stimulation: A Scientific And Clinical Review With A Focus On Chronic Pain</p>

“…Gibson et al recently described characteristics of studies necessary for inclusion in an evidenced-based Cochrane review of TENS for chronic pain. 142 The key features included randomized controlled trial (RCT), standard TENS method, TENS delivered at a clearly perceptible sensation, and one of the following randomized comparisons: TENS versus sham, TENS versus usual care/no treatment/waitinglist control, and TENS plus active intervention versus active intervention alone/comparisons between different types of TENS/TENS delivered using different stimulation parameters. Table 3 lists RCTs that have evaluated remote applications of conventional TENS and met these criteria.…”