基于复杂度分析阿尔茨海默病、轻度认知功能障碍患者的脑电特点

Complexity analysis of electroencephalogram in patients with Alzheimer＇ s disease and mild cognitive impairment

目的探讨阿尔茨海默病（Alzheimer’sdisease，AD）、轻度认知功能障碍（mildcognitiveimpairment，MCI）和健康老年人的脑电复杂度（Lemple—Ziecomplexity，LZC）特点，以及LZC值在鉴别AD、MCI以及健康老年人中的应用价值。方法对30例AD患者、30例MCI患者及20名健康老年对照者进行安静闭目状态下的脑电监测，用Matlab自编软件计算各组不同导联及脑区的LZC值。结果（1）AD组、MCI组、对照组全部导联平均值依次是0．396±0．036、0．470±0．051、0．523±0．055，AD组和MCI组与对照组相比均有所降低，差别有统计学意义（F=43．092，P=0．000）。（2）AD组的LZC值在各导联处[（0．373±0．042）～（0．430±0．083）]、全部导联均值、左右半球、双侧额颞区的均明显低于对照组[（0．498±0．067）～（0．566±0．059）]，差异有统计学意义（t=3．602—8．747，P=0．000～0．010）；且在双侧前中颞、双侧额区、左顶区具有较大降幅，均大于23％。（3）除导联T6外，AD组的LZC值在各导联处[（0．373±0．042）～（0．418±0．063）]、全部导联均值、左右半球及双侧额颞区均低于MCI组[（0．455±0．072）～（0．489±0．063）]，差异有统计学意义（在T5导联处，t=2．038、P=0．041，其余t=4．178～7．424，均P=0．000）。（4）MCI组的LZC值在全部导联均值、左右半球、双侧颞区、左额、双侧顶区较对照组降低，差异有统计学意义。结论随着认知功能的降低，脑电信号复杂度值可出现同向改变，说明LZC值可在一定程度上反映大脑认知功能的变化；出现额、颞区复杂度异常的MCI患者与AD的发生存在一定程度的联系。

Objective To investigate the Lemple-Zie complexity （LZC） characteristics in patients with Alzheimer＇ s disease（AD） , mild cognitive impairment（MCI） and normal elderly, and the possibility of differentiating AD, MCI and normal elderly by LZC. Methods Electroencephalogram （EEG） of 30 AD patients, 30 MCI patients and 20 normal elderly with eyes closed in rest state were recorded. In acquired EEG data, 2048 points（ 10. 14 s） of each channel were selected for LZC calculation by Matlab 7.0 software. Results （1） The average LZC values in AD, MCI and control groups were 0. 396 ± 0. 036, 0. 470 ± 0. 051,0. 523 ± 0. 055 respectively. As compared with control group, the values in AD and MCI groups were decreased （ F = 43. 092,P = 0. 000）. （ 2 ） LZC values of AD in all channels （ from 0. 373 ± 0. 042 to 0. 430 ± 0. 083 ）, whole brain, bilateral hemispheres, fi＇ontal and temporal areas were significantly lower than those in the normal group （ from 0. 498±0. 067 to 0. 566 - 0. 059 ; t = 3. 602--8. 747, P = 0. 000--0. 010）, and showed the significant decline（ 〉23% ）in bilateral anterior middle temporal, frontal areas, the left parietal area. （3） Except the T6 channel, LZC values of AD groups in the remaining channels（from 0. 373 ± 0. 042 to 0.418±0. 063）, the whole brain, bilateral hemispheres, frontal and temporal areas were significantly lower than those in the MCI group（from 0. 455 ± O. 072 to 0. 489 ± 0. 063 ; in T5 channel, t = 2. 038, P = 0. 041, the others t =4. 178--7. 424, all P =0. 000）. （4） LZC values of MCI groups in the whole brain, bilateral hemispheres, temporal areas, parietal areas, the left frontal area were notably lower than those in the control group. Conclusions With the decline of the cognitive function, the EEG complexity value shows the parallel change. It suggests that the EEG complexity value can reflect the change of brain function in theduration from normal age to dementia in some degree; The MCI patients with abnormal LZC values in temporal and frontal lobes have a certain degree relation with the occurrence of AD.