Neurophysiology of Placebo Analgesia: A Literature Review

Abstract

Goal: Explain the neurophysiology of placebo analgesia and its clinical implications in improving the prognosis of patients with chronic pain. Method: Bibliographic review carried out in October and November 2022, through research using the keywords "placebo analgesia", "mechanisms", "pain" and "placebo effect", in the PubMed Central (PMC) database. 1448 articles were found, of which 13 were considered eligible, after being selected according to the inclusion criteria, to compose this work. Review: Several neurophysiological mechanisms of placebo analgesia were found, and despite the different effects, several brain areas are related to these mechanisms such as somatomotor networks, thalamus, insula, limbic associations and thalamic nuclei, which are mediated by important neurotransmitters. Final considerations:The influence of pain modulation by the subjective pain mechanism is explained, showing placebo analgesia as an important component in the prognosis of patients with chronic pain.