The Cerebral Laterality Investigation Of Acupuncture At Left And Right Hegu (LI4): A FMRI Study

ObjectiveTo investigate whether the acupuncture has the cerebral laterality feature, for offering the theory basis for clinical acupoint selection of left and right Hegu(LI4). MethodWe recruited eighty right-handed healthy volunteers underwent the same fMRI scans. The healthy volunteers were divided into left group and right group, they were acupunctured at left and right LI4respectively during the fMRI scans. We collected their gender and age messages as the covariate to compute for eliminating the possible impact to the results. And recorded the feelings after acupunctured. Through the use of AFNI program, we analyzed all the fMRI data and then analyzed the group data. For investigating whether the acupuncture has the cerebral laterality effects, we flipped the right group data compared with the left group. All results Satisfied with the MonteCarlo method (p=0.005, a<0.05)Results(1)The results of the acupuncture sensations comparison between left and right groupThe MASS index statistics showed that there were no statistical differences of acupuncture sensations and degree between the two groups (p>0.5)(2) The results of fMRI scanning of the left and right group①The left group results show that the signal increased regions included right insula, paracentral lobule, Lentiform nucleus, middle temporal gyrus, postcentral gyrus, thalamus, uncus, cingulate gyrus, parahippocampal gyrus, left inferior parietal lobule, insula, precentral gyrus, superior occipital gyrus superior frontral gyrus and middle temporal gyrus.The right group results show that the signal increased regions included left precentral gyrus, insula, postcentral gyrus, superior frontal gyrus, cingulate gyrus, inferior parietal lobule, uncus and inferior temporal gyrus, right middle temporal gyrus, middle occipital gyrus, postcentral gyrus, inferior temporal gyrus, superior temporal gyrus, inferior parietal lobule, inferior frontal gyrus, inferior temporal gyrus, inferior parietal lobule, precentral gyrus, superior temporal gyrus, claustrum and superior temporal gyrus, signal increased regions included right anterior cingulate and leftsuperior occipital gyrus.②The results of fMRI comparison between the left and right groupThe comparison group analysis between the left group to flipped right group show that the the two groups were different, the different brain areas between the groups were right precentral gyrus, superior frontal gyrus, postcentral gyrus, middle temporal gyrus, parahippocampal gyrus, parahippocampal gyrus and left middle temporal gyrus, inferior temporal gyrus, inferior temporal gyrus and inferior occipital gyrus.Conclusion(1) Acupunctured at left and right LI4might existed the brain laterality on right hemisphere. And there were no specific connection between the feature and the acupuncture sensations.(2) The right insula and cingulate may be the key regions in function of acupuncture at Hegu.(3) The somatotopic area of both hand and face in primary motor cortex were activated by acupuncture at left and right Hegu (LI4), which directly illustrated the link of Hegu (LI4) with the face and mouth at the levels of central nervous system. And it also offered the future neurophysiological evidence to the traditional Chinese medical theory-"fall and hand controlled by Hegu (LI4)".