Spatio-temporal Dynamics Study Of EEG Feature In The Process Of Consciousness Recovery In Patients With Disorder Of Consciousness

At present,the clinical treatment of patients with disorder of consciousness is still a major problem,and research on the recovery of consciousness has become a major research hotspot in multidisciplinary fields,such as clinical and brain sciences.Brain plasticity is an intrinsic property of the nervous system,and this property becomes the basis for brain function recovery after brain injury.However,the relationship between brain function recovery caused by neural reconstruction and consciousness recovery is still not clear.Elucidating this relationship not only helps to further reveal the mechanism of consciousness recovery,but also provides some guiding significance for the clinical treatment of patients with disorder of consciousness.Electrophysiology and neuroimaging techniques can be used to statistically measure the correlation between neuron activities,and have become common tools for studying brain function recovery.Among them,EEG signals can directly reflect the neuroelectric activity of patients with disorder of consciousness at different levels of consciousness,and the signal recording has the advantages of non-invasiveness and painlessness,and low cost.Compared with other imaging methods,it is more suitable for tracking changes in brain function in patients’ consciousness recovery process.Currently,most related studies use comparison between groups to study consciousness recovery.In fact,the recovery of brain function is a continuous dynamic process,and it also involves the interaction of different brain regions,especially between the injured brain area and the uninjured brain area.The method of comparison between groups can not fully reveal the consciousness recovery mechanism.Therefore,it is necessary to analyze the changes in the brain function of patients in the process of consciousness recovery from both temporal dimension and spatial dimension.This study dynamically tracked the EEG signals of patients with disorder of consciousness(41 cases;18 vegetative state and 23 minimally conscious state;Average age: 53.95 ± 13.72 years),and used time-frequency analysis and nonlinear dynamic analysis methods to extract the features of EEG signals,including relative wavelet energy,approximate entropy,sample entropy and Lempel-Ziv complexity.The changes of EEG features in the process of patients’ consciousness recovery were analyzed in both temporal dimension and spatial dimension.The analysis results are as follows:(1)With the improvement of patient’s consciousness level,EEG features showed a nonmonotonic change trend,and when patients progressed from vegetative state to minimally conscious state,there was an inflection point in the EEG features;(2)As the patient’s consciousness recovered,the EEG features of the injured and uninjured brain regions also change non-monotonically(with inflection points),and the brain function recovery of the two brain areas showed a non-synchronous change pattern.Importantly,the level of this “nonsynchronization” tended to increase non-monotonically as the patient’s consciousness level increased.