Jiang Zheng-Yan, Zheng Lei-Lei, Yu En-Yan
Department of Psychiatry, Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China.
Med Sci Monit. 2008 Oct;14(10):CR515-23.
The aim was to examine and compare the characteristics of intra- and inter-hemispheric EEG coherence in patients with mild cognitive impairment (MCI) and healthy controls at rest and during a working memory (WM) task having three levels.
MATERIAL/METHODS: The subjects included 35 patients with MCI according to the DSM-IV criteria (mean age: 62.3+/-6.5 years) and 34 healthy controls (mean age: 57.4+/-4.0) selected from the community. All the subjects performed a simple calculation and recall task of WM with three levels of (WM1-3) while their EEG signal was recording. Inter- and intra-hemispheric EEG coherence was analyzed during the WM loads.
Intra- and inter-hemispheric coherence during the WM task showed a "drop-to-rise" tendency compared with that at-rest condition. There was significantly higher coherence in MCI patients than in controls during the WM task. Intra-hemispheric ortical connectivity diminished while inter-hemispheric connectivity dominated in the MCI patients during WM with increasing task difficulty.
MCI patients and normal controls may have differences in cortical connection and MCI patients have a cortical connection disturbance during WM tasks. With increasing task difficulty the MCI patients mobilized more inter-hemispheric than intra-hemispheric cognitive resources.
目的是检查和比较轻度认知障碍（MCI）患者与健康对照者在静息状态下以及在具有三个水平的工作记忆（WM）任务期间半球内和半球间脑电图相干性的特征。
材料/方法：根据DSM-IV标准，受试者包括35例MCI患者（平均年龄：62.3±6.5岁）和34名健康对照者（平均年龄：57.4±4.0），均从社区中选取。所有受试者在记录脑电图信号时执行具有三个水平（WM1-3）的WM简单计算和回忆任务。在WM负荷期间分析半球内和半球间脑电图相干性。
与静息状态相比，WM任务期间半球内和半球间相干性呈现“下降-上升”趋势。在WM任务期间，MCI患者的相干性显著高于对照组。在WM任务中，随着任务难度增加，MCI患者半球内皮质连接减少，而半球间连接占主导地位。
MCI患者和正常对照者在皮质连接方面可能存在差异，并且MCI患者在WM任务期间存在皮质连接障碍。随着任务难度增加，MCI患者动员的半球间认知资源多于半球内认知资源。
