额叶癫痫工作记忆的theta振荡特征研究

摘要

目的 通过对额叶癫痫(FLE)患者静息态和工作记忆延迟期的多通道脑电(EEGs)分析,研究FLE工作记忆的theta振荡特征.方法 实验分组为FLE组19例及对照组17例,采集受试者执行视觉工作记忆任务时的34通道脑电信号,分析2组工作记忆行为学差异;应用傅里叶变换计算各频段及34通道的能量密度,分析2组静息态和工作记忆延迟期theta振荡的变化.结果 与对照组相比,FLE组工作记忆行为学表现为反应时间显著延长(P<0.01),正确率显著降低(P<0.05);FLE组静息态在Fz通道及额区的theta频段能量密度均较对照组显著增加(P<0.01);与对照组相比,FLE组工作记忆延迟期额区theta振荡能量密度显著降低.结论 FLE存在明显工作记忆障碍,工作记忆延迟期额区theta振荡缺失是其可能的神经机制之一.%Objective To investigate the characteristic of theta oscillation in patients with frontal lobe epilepsy (FLE) by the analysis of multi-channel electroencephalographs (EEGs) during rest state and working memory(WM) maintenance. Methods The 19 FLE patients and 17 healthy subjects underwent EEG recording with 34-channel EEG machine during visual working memory task performance. The differences of behavioral results were analyzed between FLE group and controls. Short-time Fourier transform was used to calculate the power spectral density of different frequency bands in 34 channels. The theta power values during the retention period of working memory and rest state were compared between two groups. Results Compared with controls, reaction time of FLE increased significantly (P<0.01) and accuracy decreased (P<0.05). The power spectral density of theta band for FLE increased both in Fz and frontal region during rest state (P<0.01). Compared with controls, the power spectral density of theta oscillation decreased significantly in the frontal region for FLE during WM maintenance. Conclusion Our results suggest that working memory in patients with FLE was impaired. The absence of theta oscillation during the WM delayde period may provide a possible neural mechanism for the working memory dysfunction in FLE.