Neurobiological mechanisms of TENS-induced analgesia.

Author: Peng WW1, Tang ZY2, Zhang FR3, Li H1, Kong YZ2, Iannetti GD4, Hu L5
Affiliation:
1College of Psychology and Sociology, Shenzhen University, Shenzhen, China.
2CAS Key Laboratory of Mental Health, Institute of Psychology, Beijing, China; Department of Psychology, University of Chinese Academy of Sciences, Beijing, China.
3Research Center of Brain Cognitive Neuroscience, Liaoning Normal University, Dalian, China.
4Neuroscience and Behaviour Laboratory, Istituto Italiano di Tecnologia, Rome, Italy; Department of Neuroscience, Physiology and Pharmacology, University College London, London, UK.
5CAS Key Laboratory of Mental Health, Institute of Psychology, Beijing, China; Department of Psychology, University of Chinese Academy of Sciences, Beijing, China; Department of Neuroscience, Physiology and Pharmacology, University College London, London, UK; Department of Pain Management, The State Key Clinical Specialty in Pain Medicine, The Second Affiliated Hospital of Guangzhou Medical University, Guangzhou, China. Electronic address: huli@psych.ac.cn.
Conference/Journal: Neuroimage.
Date published: 2019 Apr 1
Other: Pages: S1053-8119(19)30284-8 , Special Notes: doi: 10.1016/j.neuroimage.2019.03.077. [Epub ahead of print] , Word Count: 247


Pain inhibition by additional somatosensory input is the rationale for the widespread use of Transcutaneous Electrical Nerve Stimulation (TENS) to relieve pain. Two main types of TENS produce analgesia in animal models: high-frequency (∼50-100 Hz) and low-intensity 'conventional' TENS, and low-frequency (∼2-4 Hz) and high-intensity 'acupuncture-like' TENS. However, TENS efficacy in human participants is debated, raising the question of whether the analgesic mechanisms identified in animal models are valid in humans. Here, we used a sham-controlled experimental design to clarify the efficacy and the neurobiological effects of 'conventional' and 'acupuncture-like' TENS in 80 human volunteers. To test the analgesic effect of TENS we recorded the perceptual and brain responses elicited by radiant heat laser pulses that activate selectively Aδ and C cutaneous nociceptors. To test whether TENS has a long-lasting effect on brain state we recorded spontaneous electrocortical oscillations. The analgesic effect of 'conventional' TENS was maximal when nociceptive stimuli were delivered homotopically, to the same hand that received the TENS. In contrast, 'acupuncture-like' TENS produced a spatially-diffuse analgesic effect, coupled with long-lasting changes both in the state of the primary sensorimotor cortex (S1/M1) and in the functional connectivity between S1/M1 and the medial prefrontal cortex, a core region in the descending pain inhibitory system. These results demonstrate that 'conventional' and 'acupuncture-like' TENS have different analgesic effects, which are mediated by different neurobiological mechanisms.

Copyright © 2019. Published by Elsevier Inc.

KEYWORDS: Analgesia; Electroencephalography (EEG); Human; Pain; Resting state; Transcutaneous electrical nerve stimulation (TENS)

PMID: 30946953 DOI: 10.1016/j.neuroimage.2019.03.077

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