Acupuncture-related modulation of pain-associated brain networks during electrical pain stimulation: a functional magnetic resonance imaging study.
OBJECTIVE
Findings of existing functional MRI (fMRI) studies on the neural mechanisms that mediate effects of acupuncture analgesia are inconsistent. This study analyzes the effects of manual acupuncture on pain ratings and brain activation in response to experimental, electrical pain stimuli.


METHODS
Fourteen healthy volunteers were examined by using a 1.5-T MRI scanner. The intensity of pain stimuli was adjusted to individual pain ratings on a numeric rating scale. Baseline fMRI was performed during electrical pain stimulation in a blocked design. For the second session, manual acupuncture with repeated stimulation was performed on contralateral acupoints-large intestine 4, liver 3, and stomach 36-before imaging. After imaging, subjective pain ratings and ratings of the de qi sensation were assessed.


RESULTS
Compared with baseline, volunteers showed modulated brain activity under pain conditions in the cingulate gyrus, insula, primary somatosensory cortex, and prefrontal areas after the acupuncture session. In accordance with the literature, anterior insular and prefrontal activity seemed to be correlated with acupuncture treatment.


CONCLUSIONS
This study supports the existence of analgesic acupuncture effects that outlast the needling period. Pain-associated brain areas were modulated in direct response to a preceding acupuncture treatment.
1 Department of Diagnostic and Interventional Radiology and Neuroradiology, University Hospital Essen , Essen, Germany .
Nina
N
Theysohn
Kyung-Eun
KE
Choi
Elke R
ER
Gizewski
Ming
M
Wen
Thomas
T
Rampp
Thomas
T
Gasser
Gustav J
GJ
Dobos
Michael
M
Forsting
Frauke
F
Musial
D015667:Acupuncture Analgesia; D015669:Acupuncture Points; D015670:Acupuncture Therapy; D000293:Adolescent; D000328:Adult; D000368:Aged; D001921:Brain / Q000503:physiopathology*; D001931:Brain Mapping; D004558:Electric Stimulation; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D010146:Pain / Q000209:etiology / Q000503:physiopathology*; D017288:Pain Threshold / Q000502:physiology; D019413:Qi; D055815:Young Adult