You may need a nerve to treat pain: the neurobiological rationale for vagal nerve activation in pain management.
OBJECTIVE
Pain is a complex common health problem, with important implications for quality of life and with huge economic consequences. Pain can be elicited due to tissue damage, as well as other multiple factors such as inflammation and oxidative stress. Can there be 1 therapeutic pathway that may target multiple etiologic factors in pain?


METHODS
In the present article, we review evidence for the relationships between vagal nerve activity and pain, and between vagal nerve activity and 5 factors that are etiologic to or protective in pain.


RESULTS
Vagal nerve activity inhibits inflammation, oxidative stress, and sympathetic activity, activates brain regions that can oppose the brain "pain matrix," and finally it might influence the analgesic effects of opioids. Together, these can explain the antinociceptive effects of vagal nerve activation or of acetylcholine, the principal vagal nerve neurotransmitter. These findings form an evidence-based neurobiological rationale for testing and possibly implementing different vagal nerve-activating treatments in pain conditions.


CONCLUSIONS
In this article, we show evidence for the relationships between vagal nerve activity and pain, and between vagal nerve activity and 5 factors that are etiologic to pain. Given the evidence and effects of the vagus nerve activation in pain, people involved in pain therapy may need to seriously consider activation of this nerve.
*Center for Neuroscience, Faculty of Pharmacy and Medicine †Pain in Motion Research Group, Departments of Human Physiology and Rehabilitation Sciences, Faculty of Physical Education and Physiotherapy, Vrije Universiteit Brussels, Brussels, Belgium.
Marijke
M
De Couck
Jo
J
Nijs
Yori
Y
Gidron
D000818:Animals; D018679:Cholinergic Agonists / Q000627:therapeutic use; D006801:Humans; D009446:Neurobiology; D010146:Pain / Q000188:drug therapy; D059408:Pain Management; D055536:Vagus Nerve Stimulation / Q000379:methods*
D018679:Cholinergic Agonists