Transcutaneous Electrical Nerve Stimulation in Relieving Neuropathic Pain: Basic Mechanisms and Clinical Applications

Transcutaneous electrical nerve stimulation (TENS) is widely used as a non-pharmacological approach for pain relief in a variety of clinical conditions. This manuscript aimed to review the basic mechanisms and clinical applications regarding the use of TENS for alleviating the peripheral (PNP) and central neuropathic pain (CNP).

Basic studies on animal models showed that TENS could alleviate pain by modulating neurotransmitters and receptors in the stimulation site and its upper levels, including the spinal cord, brainstem, and brain. Besides, many clinical studies have investigated the efficacy of TENS in patients with CNP (caused by spinal cord injury, stroke, or multiple sclerosis) and PNP (induced by diabetes, cancer, or herpes zoster). Most clinical trials have demonstrated the efficacy of TENS in attenuating neuropathic pain and suggested that appropriate stimulation parameters (e.g., stimulation frequency and intensity) were critical to improving the analgesic effects of TENS. However, there are some conflicting findings related to the efficacy of TENS in relieving neuropathic pain. With optimized stimulation parameters, TENS would be effective in attenuating neuropathic pain. To obtain sufficient evidence to support the use of TENS in the clinic, researchers recommended performing multicenter clinical trials with optimized TENS protocols for the treatment of various CNP and PNP.