Abstract: Objective  To evaluate the features of EEG spectrum and its clinical significance for patients with non-occupational chronic mercury poisoning.  Methods  Eighteen patients with chronic mercury poisoning were collected continuously as poisoning group at Affiliated Hospital of Academy of Military Medical Sciences from March 2012 to September 2013. At the same time, 12 age- and sex-matched healthy people were selected as control group. All patients underwent video EEG, and EEGLAB in Matlab 2013 software was used to analyze their EEG data. Relevant spectrum data of the 2 groups were compared and analyzed.  Results  The frequency-energy curves of 12 normal subjects were similar to sine curve, with obvious energy peak at α band. The frequency-energy curves of 18 patients showed as follows: 5 cases had the peak at slow δ wave, and the energy curve decreased since δ band appeared, with α band peak disappearing. The curve of 10 cases had 2 peaks respectively at α and δ band, and δ peak was higher than α peak. The spectrum in other 3 cases was normal. The quantitative analysis of EEG revealed the proportion of δ band for the total energy. The proportion of δ band for total energy of the poisoning group in right middle temporal (P = 0.018) and left posterior temporal (P = 0.039) channel was significantly higher than that of the normal group, while the proportion of δ band in middle frontal (P = 0.003), right frontal (P = 0.016) and right anterior temporal (P = 0.024), left middle temporal (P = 0.036) and right posterior temporal (P = 0.031) was lower than that of the normal group. Conclusions  EEG examination plays an important role in assessing the severity of brain injury for patients with non-occupational chronic mercury poisoning. Spectrum analysis is an intuitive and simple method, and can provide some help for clinical diagnosis and treatment.

Key words: Mercury poisoning, nervous system, Electroencephalography

摘要： 目的 评价非职业性慢性汞中毒患者脑电图特征及其临床意义。方法 分别以18 例汞中毒患者，以及性别和年龄相匹配的12 例健康志愿者为观察对象，利用Matlab 2013 软件中EEGLAB 工具箱对受试者脑电图数据进行二次分析，生成个体频谱分析图并进行统计分析。结果 12 例正常对照者频率能量曲线似正弦曲线，在α波存在明显能量峰值。18 例汞中毒患者中5 例频率能量曲线α波能量峰值消失，波峰出现于慢波δ波，自δ波起能量曲线呈进行性下降趋势；10 例能量曲线分别在α波和δ波出现双峰值，且δ波能量大于α波；3 例频谱无异常。汞中毒组患者右中颞区（P = 0.018）、左后颞区（P = 0.039）δ波所占总能量百分比高于正常对照组；而中线额区（P = 0.003）、右额区（P = 0.016）、右前颞区（P = 0.024）、左中颞区（P = 0.036）、右后颞区（P = 0.031）δ波所占总能量百分比低于正常对照组。结论 脑电图对于评价汞中毒患者脑损伤程度具有重要意义，频谱分析是一种直观、简便的分析方法，可为临床诊断与治疗提供一定帮助。

关键词: 汞中毒, 神经系统, 脑电描记术