阿尔茨海默病及轻度认知功能损害在不同状态下的脑电相对功率比研究

The study on relative power ratio of EEG in patients with Alzheimer's disease and mild cognitive impairment

目的研究不同程度记忆障碍患者在不同脑功能状态下脑电相对功率比的变化,探讨阿尔茨海默病(AD)发病进程中的脑功能变化特点。方法分别记录AD患者12例(AD组)、轻度认知功能损害(MCI)患者11例(MCI组)和健康体检者11例(对照组)在安静状态和认知负载状态下的16导脑电信号,经预处理分别计算δ、θ、α1、α2、β1、β2、γ频带的相对功率比。结果在安静状态下,AD组低频带δ、θ相对功率比高于其他两组,高频带β1、β2相对功率比低于其他两组,MCI组在γ频带(双前额、右颞)相对功率比明显高于其他两组(P<0.05,P<0.01)。在认知负载状态下,对照组γ频带相对功率比较安静状态明显增高(P<0.05);MCI组和AD组无明显变化。结论支持AD发病机制的胆碱能损伤学说,进一步证实记忆功能与高频脑电(γ频带)相关。MCI阶段进展到AD阶段在双前额、右颞区可以出现功能性代偿向功能失代偿的变换。

Objective To study the changes in the relative power ratio of EEG in patients with different levels of memory decline in rest and cognitive states in order to explore the characteristics of changes in brain function in AD during different disease processes. Methods Twelve AD, 11 mild cognitive impairment（MCI） and 11 healthy control subjects were involved. All the subjects went through EEG examination both in rest and cognitive states. The EEG data were analyzed by spectral estimate based on FFT transform at each band： δ,θ, α1, α2, β1 ,β2 and γ. Results In the rest condition,the relative power ratio of lower band 3,0 in AD group was higher than that in the others, the relative power ratio of higher band β1, β2 in AD group was lower than that in the others and relative power ratio of Y band at both sides of forehead and right temporal in MCI group was higher than that in the others （P〈0.05 ,P〈0.01）. In the cognitive condition,relative power ratio of γ band at right temporal in AD group was lower than that in control group （P G0.05）. The changes between two conditions showed that relative power ratio of γ band could increase from rest to cognitive state in control group （P〈0.05） ,but no changes in MCI group and AD group. Conclusions There was a functional compensation both in forehead and right temporal areas at the stage of MCI,while at the stage of AD,the right temporal area lost compensation.