Research Of Music Stimulation Response Of Patients With Severe Disorders Of Consciousness Based On Brain Effect Network

Severe disorders of consciousness can be divided into the minimally conscious state(MCS)and vegetative state(VS)in the level of consciousness.Such patients need long-term treatment and escort,which brings a heavy economic and psychological burden to the families of patients.The increasing number of severe disturbance of consciousness patients,due to the frequent occurrence of traffic accidents,the increased incidence of stroke and other diseases and the improvement of emergency medical technology,has become the social problem to be solved urgently at the present stage of our country.How to evaluate the state of consciousness and to implement effective awakening has become an urgent problem in the medical field.Currently,behavioral scale is usually used to evaluate patients' conscious state,but its dependency on doctors' experience leads to a strong subjectivity.Therefore,it is important to explore effective methods to evaluate the state of consciousness and awakening.Electroencephalogram(EEG)has many advantages,such as noninvasiveness and painlessness,high time resolution,low cost,bedside detection,and facilitating access signals.It can objectively reflect the patient's brain information,and gradually be used as an auxiliary method of clinical examination.At present,EEG signals are often combined with nonlinear dynamics,brain effect network and other methods to study the working mechanism of the brain.Brain effect network is a directional network,which reflects the causal relationship and information flow between brain network nodes.Additionally,literatures show that music stimulation is conducive to the rehabilitation of patients with severe disorders of consciousness.Therefore,this paper used the popular folk song "Jasmine" as a stimulus,cooperating with EEG technology,to study the properties of brain network under the stimulation(include pre-stimulating resting state,stimulating state and pro-stimulating resting state),and thus to evaluate the effectiveness of music stimulus on awaking patients.Main works are as follows:(1)Data selection and feature extraction: This part mainly includes subjects selected standard,data acquisition,data preprocessing,brain network building and feature extraction.(2)Analysis of mean Granger Causality(meanGC): This feature was used to explore the connection strength of brain effective network.In this paper,we analyzed the meanGC responses of the MCS and VS in each of 10 acquisitions during music stimulation.The results are as follows: The meanGC of MCS and VS were significantly responsive to music stimulation;There was no significant difference between the two groups in stimulating state,but obvious difference in pro-stimulating resting state;The meanGC of MCS was smaller than that of VS;Music stimulation had effect on patients with severe disorders of consciousness,and VS showed a stronger response.(3)Analysis of Global efficiency(glb): This feature was used to measure the communication efficiency and information integration ability of brain network.In this paper,we focused on two aspects: fixed threshold and multi-threshold.The results are as follows: In fixed threshold,the glb of MCS was bigger than that of VS,and the response of glb in pre-stimulating resting state was smaller than that in stimulating state or in pro-stimulating resting state;In Alpha band of pro-stimulating resting state,there was significant difference between MCS and VS;In multi-threshold,the glb of MCS was similar to that of VS,and there was a tendency that the response of glb in pre-stimulating resting state was smaller than that in stimulating state or in pro-stimulating resting state;In Alpha band of stimulating state and pro-stimulating resting state,there was significant difference between MCS and VS.The results showed that the information transmission and integration ability of MCS and VS were improved,and with the increase of the threshold,the glb response increased at first and then stabilized.The effect was the best when the threshold equaled 0.30.(4)Causal Flow and Causal Density: The features were used to measure the interaction between nodes in brain network and interaction of brain regions.In this paper,we used brain electrical activity mapping to compare the causal flow and density of MCS with those of VS.The results are as follows: In terms of causal flow,MCS responded strongly to the prefrontal and temporal lobes in stimulating state,while VS responded strongly to the frontal lobe and the left center area between central region and parietal lobe in stimulating state;In terms of causal density,MCS responded strongly to frontal and temporal lobes in stimulating state,while VS responded strongly to frontal lobes and parietal lobe middle area in stimulating state.The results showed that the music stimulus had a certain effect on the patients with severe disturbance of consciousness.It can be used as a guide to assess the effectiveness and diversification of clinical urge.