缺血性脑白质损害患者视觉空间工作记忆的事件相关电位特征

Characterization of event-related potential of visual-spatial working memory in patients with ischemic white matter lesions

目的:已有研究认为血管性认知损害以执行功能损害为突出特点,其病理基础是皮质下缺血;文中拟考察以缺血性脑白质损害为病理基础的视觉空间工作记忆的事件相关电位(ERP)特征,为血管性认知损害的评估提供电生理证据。方法:招募12名头颅磁共振扫描未见异常老年人为对照组,13名经头颅磁共振证实为轻度缺血性白质损害者,11名中重度缺血性白质损害者,完成视觉空间工作记忆的ERP试验。结果:在记忆延迟阶段,识别出3个波:N330、P420和晚期负成分。2球记忆负荷下,中额叶、右额叶、枕叶的N330波幅,对照组>轻度缺血性脑白质损害组(均为P<0.01)和中重度缺血性脑白质损害组(均为P<0.05),差异有统计学意义。左额叶(P<0.05)、中央区(P<0.05)、顶叶(P<0.01)、左颞叶(P<0.05)N330波幅,对照组>轻度缺血性脑白质损害组,差异有统计学意义。其他各项指标中,均未发现对于缺血性脑白质损害组与对照组有甄别意义的ERP。结论:2球记忆负荷下,中额叶、右额叶和枕叶N330波幅的显著降低是缺血性脑白质损害患者视觉空间工作记忆的ERP特征。

Objective： Executive dysfunction is a typical characteristic of vascular cognitive impairment （VCI） , with subcortical ischemia as its pathological basis. The aim of this study was to investigate the characteristics of event-related potential of visual-spatial working memory based on ischemic white matter lesions, and offer more electrophysiological evidence for the evaluation of VCI. Methods ： We included in this study 24 patients with ischemic white matter lesions （13 mild and 11 severe cases） and 12 elderly healthy controls, and induced event-related potentials （ERP） of visual-spatial working memory from the delayed matching-to-sample task in all the participants. Results： Three waves were identified： N330, P420 and late negative component. On the two-ball-load, the N330 amplitude in the middle frontal, right frontal and occipital lobe was significantly smaller in the mild and severe lesion groups （P 〈 0. 01 and P 〈 0.05 ） than in the normal control, with no difference between the two groups of patients. The N330 amplitude in the left frontal lobe, central region, left temporal lobe （P 〈 0.05 ） and parietal lobe （P 〈 0.01 ） was significantly smaller in the mild lesion group than in the control. On the left targets of ERP,there were no differential markers of ERP between the patients and the controls. Conclusion ： On the two-ball-load, in the middle frontal, right frontal and occipital lobe, ERP of visual-spatial working memory is characterized by a significant decrease of the N330 amplitude,-which is based on ischemic white matter lesions.