The Research Of Pain Mechanism And Acupuncture Anesthesia Based On EEG And FMRI

Pain is one of the most important sensations in daily life, it is necessary to get theessence and mechanism of pain in pain treatment and control. The TraditionalChinese Medicine (TCM) such as acupuncture has shown great potential in pain relief.The research of principle and objective assessment criterion of acupuncture anesthesiaare the key point of the modernization of TCM. In this article the EEG(Electroencephalogrpah) and fMRI (Functional Magnetic Resonance Imaging)techniques were used to study the brain nerve activity and functional metabolismwhich was modulated by pain. Furthermore, the brain nerve activity was studiedduring the acupuncture in pain relief to get the mechanism and assessment criterion ofacupuncture anesthesia.Firstly the pain stimulation experiment was designed. The pain was inducedthrough injection angelica on the left shoulder, as placebo-control stimulation, theisotonic saline was injection. Then the EEG feature, the power percentile ofδ,θ,α,βand the peak and volume of bicoherence, were extracted during the experiment.At the same time, the activated brain function areas were analyzed.The research demonstrated that theδband energy ratio increased and theθ,α,βband energy ratio decreased after pain stimulation, though the activated areas werenot strictly same, they mainly located on left frontal cortex, left temporal cortex, leftparietal cortex, occipital cortex. It indicated that these areas were modulatedsignificantly by pain stimulation.Bicoherence is the High Order Statistic, the peak of the bicoherence was a directindicator of the degree of Quadratic Phase Coupling (QPC) and the volume of thebicoherence indicates the deviation from Gaussian distribution. They were sensitiveand positive related to the pain stimulation, the main activated areas were occipitalcortex, right frontal cortex. It indicated the pain stimulation could increase thenon-Gaussianity of EEG.The fMRI research indicated the pain stimulation could activate wide brain functional areas, they mainly located on anterior lobe, occipital lobe, pons andmidbrain. It showed these areas had tightly connection with pain perception.In the end, the principle and assessment criterion of acupuncture in pain relief werestudied. The changes of EEG and the activated brain functional area were studied atdifferent acupuncture mode, transcutaneous electrical acupoint stimulation (TEAS)and manual needle on Hegu acupoint.The research indicated the TEAS and manual needled acupuncture on Heguacupoint had good effect on pain relief. And the spectral edge frequency (SEF90) hadpositive relationship with pain extent. It had shown the potential to be used asassessment criterion of acupuncture anesthesia.The different activated brain area between TEAS and manual needle on Heguacupoint were studied. The effect of pain relief of manual needle and TEAS wererealized through active brain functional area with pain perception, but the manualneedle active wider area than TEAS.