Wang Jing, Sun Tingting, Zhang Ying, Yu Xin, Wang Huali
Peking University Institute of Mental Health (Sixth Hospital), Beijing, China.
National Clinical Research Center for Mental Disorders, NHC Key Laboratory of Mental Health, Peking University, Beijing, China.
Front Aging Neurosci. 2022 May 26;14:830149. doi: 10.3389/fnagi.2022.830149. eCollection 2022.
Abnormal electroencephalography (EEG) activity has been demonstrated in mild cognitive impairment (MCI), and theta rhythm might be inversely related to memory. The apolipoprotein E (ApoE) epsilon 4 (ε4) allele, as a genetic vulnerability factor for pathologic and normal age-related cognitive decline, may influence different patterns of cognitive dysfunction. Therefore, the present study primarily aimed to verify the role of resting theta rhythm in delayed recall deficits, and further explore the effects of the ApoE genotype on the associations between the resting theta power and delayed recall performance in the elderly individuals without dementia.
A total of 47 individuals without dementia, including 23 MCI and 24 healthy subjects (HCs), participated in the study. All subjects were administered the Hopkins Verbal Learning Test-Revised (HVLT-R) to measure delayed recall performance. Power spectra based on resting-state EEG data were used to examine brain oscillations. Linear regression was used to examine the relationships between EEG power and delayed recall performance in each subgroup.
The increased theta power in the bilateral central and temporal areas ( = 0.02-0.044, uncorrected) was found in the patients with MCI, and were negatively correlated with delayed recall performance (r = -0.358 to -0.306, = 0.014-0.036, FDR corrected) in the elderly individuals without dementia. The worse delayed recall performance was associated with higher theta power in the left central and temporal areas, especially in ApoE ε4 non-carriers and not in carriers ( = -0.404 to -0.369, = 0.02-0.035, uncorrected).
Our study suggests that theta disturbances might contribute to delayed recall memory decline. The ApoE genotype may have distinct effects on EEG-based neural correlates of episodic memory performance.
轻度认知障碍（MCI）患者已被证实存在异常脑电图（EEG）活动，且θ节律可能与记忆呈负相关。载脂蛋白E（ApoE）ε4（ε4）等位基因作为病理性和正常年龄相关性认知衰退的遗传易感性因素，可能影响不同模式的认知功能障碍。因此，本研究主要旨在验证静息θ节律在延迟回忆缺陷中的作用，并进一步探讨ApoE基因型对无痴呆老年人静息θ功率与延迟回忆表现之间关联的影响。
共有47名无痴呆个体参与研究，其中包括23名MCI患者和24名健康受试者（HCs）。所有受试者均接受霍普金斯词语学习测验修订版（HVLT-R）以测量延迟回忆表现。基于静息态EEG数据的功率谱用于检测脑电活动。采用线性回归分析各亚组中EEG功率与延迟回忆表现之间的关系。
在MCI患者中发现双侧中央和颞区的θ功率增加（P = 0.02 - 0.044，未校正），且与无痴呆老年人的延迟回忆表现呈负相关（r = -0.358至-0.306，P = 0.014 - 0.036，经FDR校正）。延迟回忆表现越差与左侧中央和颞区较高的θ功率相关，尤其是在ApoE ε4非携带者中，而在携带者中并非如此（P = -0.404至-0.369，P = 0.02 - 0.035，未校正）。
我们的研究表明，θ紊乱可能导致延迟回忆记忆衰退。ApoE基因型可能对基于EEG的情景记忆表现的神经相关性有不同影响。
