Mechanisms of acupuncture-electroacupuncture on persistent pain

This extremely detailed article on acupuncture-electroacupuncture for persisten pain from 2014 lays out all of the various physiological mechanisms involved in Acupuncture’s effect on pain.  I perused it for my writing project, Deep Resilience chapter on Pain.  It is SO detailed that I really can’t use it for my chapter.  But I’m happy to have it.  Some of the studies may be obsolete now since it’s an older study.

PDF here. mechanisms of acupunture electroacupuncture on persistent pain lao 2014

Zhang R, Lao L, Ren K, Berman BM. Mechanisms of acupuncture-electroacupuncture on persistent pain. Anesthesiology. 2014;120(2):482-503. doi:10.1097/ALN.0000000000000101

In the last decade, preclinical investigations of electroacupuncture mechanisms on persistent tissue-injury (inflammatory), nerve-injury (neuropathic), cancer, and visceral pain have increased. These studies show that electroacupuncture activates the nervous system differently in health than in pain conditions, alleviates both sensory and affective inflammatory pain, and inhibits inflammatory and neuropathic pain more effectively at 2–10 Hz than at 100 Hz. Electroacupuncture blocks pain by activating a variety of bioactive chemicals through peripheral, spinal, and supraspinal mechanisms. These include opioids, which desensitize peripheral nociceptors and reduce pro-inflammatory cytokines peripherally and in the spinal cord, and serotonin and norepinephrine, which decrease spinal n-methyl-d-aspartate receptor subunit GluN1 phosphorylation. Additional studies suggest that electroacupuncture, when combined with low dosages of conventional analgesics, provides effective pain management that can forestall the side effects of often-debilitating pharmaceuticals.

Pain, a major health problem with serious social and economic consequences, costs the
economy $560–635 billion annually in physician visits, analgesics, and loss of productivity.1
Conventional medical treatments are only moderately efficacious, and they often produce
problematic side effects. Acupuncture/electroacupuncture, used in China and other Asian
countries for the past 3,000 yr, represents a potentially valuable adjunct to existing pain
relief strategies.2 Approximately two million American adults used acupuncture in 2002;3
this increased to three million in 2007, with chronic pain being the most common reason for
seeking acupuncture treatment. Concomitant with increasing use of the modality, research
has been performed on acupuncture mechanisms, and data from these studies have
accumulated.
Based on etiology, pain may be classified into tissue damage-induced inflammatory/
nociception and nerve damage-induced neuropathy. The former is caused by a painful
stimulus on nociceptors, the latter by a primary lesion or dysfunction in the nervous system.
*Corresponding authors: Dr. Rui-Xin Zhang, Center for Integrative Medicine, 685 W. Baltimore St, MSTF Rm 8-22, Baltimore, MD
21201, Phone: 410-706-1582, Fax: 410-706-1583, rzhang@som.umaryland.edu.

Based on origin, pain may also be classified as somatic or visceral. Notably, some pain, for
example cancer-related pain, experienced by one-third of patients receiving treatment for
cancer and about two-thirds of those with advanced cancers, is not easily classifiable. A
variety of animal models have been used to study the effect and mechanisms of
electroacupuncture on persistent pain (fig. 1). This review synthesizes these studies to give
an overall picture of how electroacupuncture alleviates pain through peripheral and central
mechanisms of the body and to show that a number of bioactive chemicals are involved in
electroacupuncture inhibition of pain.
1. Inflammatory