The Analysis Of Eeg Source Localization Under Magnetic Stimulation At Acupoint Neiguan

Magnetic stimulation, which is painless, non-invasive and has a good safety performance and many other advantages, has the unique effectiveness in the regulation of human neural function, disease treatment, rehabilitation therapy and other aspects. And it has similar effects with acupuncture. So it has important clinical value and research significance to research magnetic stimulation combined with acupuncture.This study used the Rapid2 produced by British company Magstim to get magnetic impulse sequence that stimulated Acu-point Neiguan (13 subjects) with the power of 80% threshold and different frequencies. At the same time, the EEG was recorded with the system produced by NeuroScan. We extracted the evoked potentials from EEG signals under all stimulated states, and then conducted the source localization analysis. We also analyzed the EEG signals under the 0.5Hz magnetic state with Gabor wavelet and Hilbert transform methods to explore the oscillation characteristics ofαwave. The purpose of this paper is to study the correspondence of magnetic stimulation at Neiguan and the brain functional region, and the effect of magnetic stimulation at Neiguan on the brainαwave distribution and energy.In this study, all the EEG was recorded from health undergraduate and graduate students in the school. We got the results such as:(1) The superimposed average method was used to extract the somatosensory evoked potentials from EEG signals under magnetic stimulation at Neiguan. Components N80 and P150 could be extracted in all different frequencies magnetic states. Among them, the 0.5Hz magnetic state had the maximum amplitude of components N80 and P150, while 3Hz had the minimum. There were significant individual differences in the amplitude of evoked potentials, but little effect on the latency of evoked potentials in different magnetic states.(2) The article used the equivalent dipole to conduct source localization analysis on components N80 and P150. The results showed that N80 and P150 were localized in the brain's frontal gyrus and anterior cingulated cortex. In other words, the brain's frontal gyrus and anterior cingulated cortex were activated by magnetic stimulation at Neiguan. This is consistent with the findings that the bilateral frontal and temporal were the main active brain's lobe, parietal lobe also active relatively under the acupuncture stimulation at Neiguan. Because of different incentives, there were still differences between magnetic stimulation and acupuncture stimulation at Neiguan, but compared with acupuncture points, magnetic stimulation can basically get the same effect.(3) Magnetic stimulation at Neiguan could cause the changes of distribution and energy ofαwave. Compared with the normal state, the distribution ofαwave was enhanced in the magnetic state. After magnetic stimulation, the energy ofαwave in the frontal and left occipital brain was significantly higher than that before stimulation. Alpha wave represented a passive state of the central nervous system, and its appearance or enhancement showed that people were sober and quiet. Acupuncture stimulation at Neiguan could play a sedative, refreshing effect. This also indicated that magnetic stimulation had similar effects with acupuncture and verified the effectiveness of magnetic stimulation from the microscopic view.The results of this study should be further proved because of the limitation of the method of data processing and the number of the subjects. It is only the preliminary exploration on the magnetic stimulation and provides some basis for the future study.This work is supported by the National Science Foundation of China (No. 50877023) and the Natural Science Foundation of Hebei Province (No.E2008000053 and No.E2009000049) and a grant by the Key Technology R&D Program of Hebei Province (Major program, No.09276103D-4).