Functional MRI in healthy subjects during acupuncture: different effects of needle rotation in real and false acupoints

The cerebral activation pattern due to acupuncture is not completely understood. Although the effect of acupuncture on cerebral haemodynamics has been studied, no previous report has focused on different puncture and stimulation methods. We used functional MRI (fMRI) in 15 healthy subjects to investigate cortical activation during stimulation of two real acupoints (Liv3 and G40) and one sham point, needled in a random and, for the subjects, blinded order employing rotating and non-rotating methods, using a blocked paradigm on a 1.5 tesla imager. Compared to the non-rotating stimulation method, during rotating stimulation of the real acupoints, we observed an increase in activation in both secondary somatosensory cortical areas, frontal areas, the right side of the thalamus and the left side of the cerebellum; no such effects of the needling technique were seen while stimulating the sham point. The observation that rotating the needle strengthened the effects of acupuncture only at real acupoints suggests that, as claimed in Chinese traditional medicine, stimulation of these acupoints has a specific effect on cortical neuronal activity, absent with sham acupoints. These specific cerebral activation patterns might explain the therapeutic effects of acupuncture in certain subjects.