Source Localization And Cortical Brain Network Research Based On Electroencephalogram Signals Of Magnetic Stimulation At Acupionts

The imaging study of acupoint stimulation mechanism is still in its infancy.There are some limitations in research models and methods,and the consistency of relevant research conclusions is low.Brain network provides a new way to reveal the dynamic response pattern of central nervous system during acupoint stimulation.Magnetic stimulation is similar to acupuncture.And magnetic stimulation is noninvasive and easy to quantify.It is expected to form a standardized technical system with broad application prospects.In this paper,the traditional acupoint theory,magnetic stimulation technology and complex network were combined.Through the source localization of electroencephalogram(EEG)data and constructing cerebral cortex functional networks,the network characterization of the interaction of EEG signals induced by acupoint stimulation and the corresponding relationship between the functional connection mode of cerebral cortex and the effect of acupoints were studied.It provides a new method for revealing the mechanism of acupoint stimulation and new evidence for the theory of acupoint function relative specificity.The main research work of this paper is as follows:(1)Neiguan(PC6)and Daling(PC7)acupoints along the pericardium meridian of Shoujueyin,Guangming(GB37)acupoint along the gall bladder meridian of Zushaoyang,and Non-acupiont point were taken as the magnetic stimulation targets to carry out acupoint magnetic stimulation experiment for 14 healthy subjects and synchronously record EEG signals.The EEG data source localization of the resting state,the magnetic stimulation at acupoints and Non-acupoint point was obtained by group independent component analysis(Group ICA)and standardized low-resolution brain electromagnetic tomography(s LORETA).The current density distribution of cerebral cortex corresponding to EEG data reconstructed by component related to brain activity in different states was estimated.(2)After source localization of EEG data reconstructed from components related to brain activity,the position of maximum current density in cortex was taken as a node.Based on the correlation of ?-wave power spectrum,the cerebral cortex functional networks of the resting state,the magnetic stimulation at acupoints and non-acupoint were constructed.Combining the measurement method of complex network with the specific function of acupoints,the similarities and differences in the topological structure changes of cortical brain network based on the correlation of alpha-wave power spectrum during magnetic stimulation at different acupoints by were studied.The results showed that during the magnetic stimulation at PC6 and PC7,the functional connections of the nodes in brain areas related to movement reduced,and the functional connections of the nodes in the brain areas associated with advanced cognitive function increased.During the magnetic stimulation at GB37,the functional connections of the nodes in brain areas associated with movement and vision both increased.The topological structure changes of cortical brain network caused by magnetic stimulation at acupoints basically coincide with the therapeutic effects of each acupoint.(3)The centroids of Bradmann Areas in the cerebral cortex were taken as the nodes.Based on the correlation of current density,the cerebral cortex function networks of the resting state,the magnetic stimulation at PC6 and Non-acupoint point were constructed.The characteristic parameters in common use of cortical brain network based on current density correlation and the changes of functional connections in each brain areas were analyzed in detail.The results showed that the average degree,the average clustering coefficient,and the global efficiency of the brain networks both increased,and the characteristic path length decreased when the stimulating PC6.The functional connections of the nodes in frontal lobe,temporal lobe,limbic lobel,and insula both increased.It was indicated that the neuronal activity of the brain areas related to the functions such as emotion,memory and executive control,could be promoted during the magnetic stimulation at PC6.It also provided some theoretical supports for PC6 in the treatment of mental illness.