fMRI study of effect on brain activity according to stimulation method at LI11, ST36: painful pressure and acupuncture stimulation of same acupoints.

Objectives: The objective of this study was to assess differences in brain responses between pressure and acupuncture stimulation at the same acupoint using functional magnetic resonance imaging (fMRI).
Subjects: A total of 10 healthy right-handed volunteers were studied.
Design: fMRI was performed with two different paradigms; namely, pressure and acupuncture stimulation at acupuncture points LI11 and ST36 on the left. fMRI data were analyzed using SPM2.
Results: In comparison with the left LI11 pressure stimulation, both sides of the parahippocampal gyrus, cerebellum, left side of thalamus, and right side of posterior cingulate regions were more activated by the left LI11 acupuncture stimulation. In comparison with the left ST36 pressure stimulation, the secondary motor cortex, limbic system (cingulate gyrus, posterior cingulate), primary visual cortex, pons, and medulla regions were more activated by left ST36 acupuncture stimulation. In comparison with the left ST36 pressure stimulation, both side of BA 4 and BA 6 were more activated by the LI11 pressure stimulation. In comparison with the left LI11 acupuncture stimulation, left BA 6, BA 8, and anterior cingulate cortex (ACC) were more activated by the left ST36 acupuncture stimulation.
Conclusions: In conclusion, brain signal activation patterns according to the stimulation methods and acupoints were observed to differ. Acupuncture stimulation activated more regions than pressure at the same acupoint. In particular, acupuncture stimulation activated the limbic system, such as the parahippocampal gyrus and ACC.