Central Nervous Pathway for Acupuncture Stimulation: Localization of Processing with Functional MR Imaging of the Brain—Preliminary Experience

Abstract

Functional MR imaging can demonstrate the CNS pathway for acupuncture stimulation. Acupuncture at ST.36 and LI.4 activates structures of descending antinociceptive pathway and deactivates multiple limbic areas subserving pain association. These findings may shed light on the CNS mechanism of acupuncture analgesia and form a basis for future investigations of endogenous pain modulation circuits in the human brain.

A combined [11C]diprenorphine PET study and fMRI study of acupuncture analgesia

“…Recently, functional magnetic resonance imaging (fMRI) has been used to investigate the neurobiological mechanisms underlying acupuncture needle manipulation [11,20,22,24,25,29,[42][43][44][45]. It is commonly reported that manual acupuncture needle manipulation induces fMRI signal change in widespread neuronal networks.…”

“…Functional magnetic resonance imaging (fMRI) and Positron Emission Tomography (PET) studies of acupuncture needle manipulation [3,11,[20][21][22]24,25,29,31,[42][43][44] and acupuncture analgesia [5,45,46] demonstrate involvement of these neuronal networks during acupuncture. Additionally, there is strong evidence that acupuncture analgesia is mediated at least in part by opioid systems [4,6,26,32].…”

An fMRI study of acupuncture using independent component analysis

“…Zhang et al [31] demonstrated that electroacupuncture stimulation (EAS) at two pairs of acupoints in the same spinal segment evokes specific responses in brain images obtained with fMRI. The studies of Hui et al and Wu et al [20,28,29] on acupoint ST 36 showed significant modulatory effects on the limbic system, paralimbic and subcortical gray structures, while control stimulation showed strong activation mainly at the somatosensory cortex. Kong et al [21] studied activa-tion patterns evoked by manual and electroacupuncture, showing that electroacupuncture mainly produced fMRI signal increases in the precentral and postcentral gyri, inferior parietal lobule (IPL), and putamen/insula.…”

“…These previous acupuncture studies [7,31,20,28,29,21,30] were mainly based on multiple-block design, and fMRI data were analyzed using the whole block paradigm. However, from our analysis, we found that the 'on-state,' during which needle manipulation was performed, consisted of three main components: mechanical stimulation due to needle manipulation, subject expectation of what they would experience and the actual acupuncture effects.…”

“…In this study we only analyzed the fMRI data from run 1. Because sham is the control, which is predominantly activated in the somatosensory cortex [20,28,29,30], thus it is not possible for it to replicate the specific brain activity seen in acupoint stimulation.…”