An examination of the analgesic effects of microcurrent electrical stimulation (MES) on cold-induced pain in healthy subjects

Abstract

Microcurrent electrical stimulation (MES) is an electrotherapeutic approach proposed by manufacturers for the management of acute and chronic pain. Evidence for analgesic efficacy is anecdotal and few controlled studies have been performed to date. This single-blind, placebo-controlled study examined the analgesic effects of MES on experimentally induced pain threshold and pain intensity rating in 36 healthy non-paid university student volunteers. Pain threshold and pain intensity recordings to cold-induced pain were made before, during and after a 20 min treatment session. Subjects received either active MES (DC biphasic pulses, 600 μA, 103 pulses per second) or placebo MES (no current output). The results showed no significant differences between active MES and placebo MES for the change in ice pain threshold or pain intensity rating during treatment. However, a significant increase in pain threshold was found in both active MES and placebo MES during the treatment cycles when compared to pre-treatment baseline. This change in pain threshold during active and placebo MES was similar in magnitude to placebo transcutaneous electrical nerve stimulation (TENS) and lower than active TENS as previously reported by ourselves. We conclude that the analgesic effects of active MES on cold-induced pain in healthy subjects were no greater than placebo. It is important to extend these laboratory findings by investigating the clinical efficacy of MES in patients with pain.