脑电非线性分析评价缺氧缺血性脑损伤引起的意识障碍

EEG nonlinear dynamics analysis for unconsciousness in anoxia-ischemic patients

目的用脑电非线性分析方法中的多个参数定量评价缺血缺氧性脑损伤患者意识障碍的程度，从而探讨多种刺激状态下脑电非线性特性的变化规律，以及这些措施对意识障碍水平评估的作用。方法选取2008年-2010年宣武医院神经康复科患者60例，缺血缺氧性脑损伤后意识障碍的患者为病例组（30例），脑卒中后意识正常的患者为对照组（30例）。所有患者依次采集安静闭眼、听觉刺激（声音刺激和音乐刺激）、痛觉刺激（针刺患侧、健侧）状态下的脑电信号，并计算脑电信号的关联维数、复杂度及近似熵非线性指数。结果病例组所有脑区在不同刺激状态下关联维数、复杂度及近似熵指数均明显低于对照组（P〈0．05）；对照组在听觉刺激及痛觉刺激状态下非线性指数高于安静闭眼状态（P〈0．05）；病例组在听觉刺激和痛觉刺激下非线性指数与安静闭眼状态无明显差异。结论脑电非线性分析可以定量评价缺血缺氧性脑损伤意识障碍的严重程度，得出不同刺激状态下大脑功能活动的变化信息，可以为评估意识障碍患者的预后及促醒措施提供新的依据。

Objective To quantify the degree of unconsciousness with EEG nonlinear dynamics analysis and investigate the changes of EEG nonlinear properties under different statuses in unconscious anoxia-ischemic patients. Methods Thirty unconscious anoxia-ischemic cases were selected as the patient group. Thirty normal conscious patients with stroke were involved as the control group. EEG was recorded under three conditions, including eyes closed, auditory stimuli （verbal and music） and painful stimulio. Nonlinear indices such as correlation dimension, complexity and approximate entropy were calculated for all subjects. Result （1）EEG nonlinear indices of patient group were significantly lower than those of control group for all conditions and all brain regions. There was significant difference between the two groups （P 〈 0.05）. （2）Under the auditory stimulus and painful stimulus states, all EEG nonlinear indices in the control group were higher than those under eyes-closed condition. Nonlinear indices in the patient group had almost no change for different conditions. Conclusion EEG nonlinear analysis may quantify the degree of unconsciousness in anoxia-ischemic patients. The changes of brain function for unconscious subjects could be captured by EEG nonlinear analysis. EEG nonlinear analysis could provide information about the outcome of unconscious anoxia-ischemic patients.