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

Abstract

Background: Transcutaneous electrical nerve stimulation (TENS) is a safe, noninvasive treatment for chronic pain that can be self-administered. Conventional TENS involves stimulation of peripheral sensory nerves at a strong, non-painful level. Following the original gate-control theory of pain, stimulation is typically near the target pain. As another option, remote stimulation may also be effective and offers potential advantages. Objective: This narrative review examines mechanisms underlying the remote analgesic effects of conventional TENS and appraises the clinical evidence. Methods: A literature search for English-language articles was performed on PubMed. Keywords included terms related to the location of TENS. Citations from primary references and textbooks were examined for additional articles. Results: Over 30 studies reported remote analgesic effects of conventional TENS. The evidence included studies using animal models of pain, experimental pain in humans, and clinical studies in subjects with chronic pain. Three types of remote analgesia were identified: at the contralateral homologous site, at sites distant from stimulation but innervated by overlapping spinal segments, and at unrelated extrasegmental sites. Conclusion: There is scientific and clinical evidence that conventional TENS has remote analgesic effects. This may occur through modulation of pain processing at the level of the dorsal horn, in brainstem centers mediating descending inhibition, and within the pain matrix. A broadening of perspectives on how conventional TENS produces analgesia may encourage researchers, clinicians, and medical-device manufacturers to develop novel ways of using this safe, cost-effective neuromodulation technique for chronic pain.

Clinical Experience of High Frequency and Low Frequency TENS in Treatment of Diabetic Neuropathic Pain in Russia

“…The analgesic effect of HF TENS primarily addresses the sensory aspect of pain as a result of segmental gelatinous substance cell excitation, which has an inhibitory effect on nociceptive afferentation [ 27 , 28 ]. At the same time, long-term inhibition of nociceptive afferentation further enhances the segmental analgesic effect by reducing dorsal horn neuron sensitization [ 29 , 30 , 31 ]. Simultaneously there is a moderate secondary effect on the affective aspect of neuropathic pain as a consequence of decreased afferentation along nociceptive fibers.…”

Acute spinal cord injury: Pathophysiology and pharmacological intervention (Review)

“…Increasing evidence reveals that TENS is a safe treatment intervention with fewer side effects for most patients compared with other existing therapies ( 204 ). Several clinical investigations report that TENS has clear benefits in the management of SCI; however, there are controversies regarding treatment conditions and the appropriate parameters that should be adhered to during therapy using TENS ( 216 , 217 ). Some randomized controlled trials have explored the pain relief that can potentially be achieved using TENS and investigated its potential benefits in patients with SCI ( 218 , 219 ).…”

Effects of Wearable Transcutaneous Electrical Nerve Stimulation on Fibromyalgia: A Randomized Controlled Trial

“…17,18 Theses mechanisms align with pathological changes in pain processing that are thought to underlie fibromyalgia. TENS is usually applied to the site of pain, however its analgesic effects can be widespread, 19,20 potentially making it effective for multisite pain. 21,22 For these reasons, TENS has been suggested as a non-pharmacological option for patients with fibromyalgia.…”