早期血管性痴呆患者的效应连接研究
Effective Connectivity Analysis for Patients with Early Vascular Dementia

为探索早期血管性痴呆(VaD)患者与正常老年人脑区间效应连接(effective connectivity)的差异性,基于多导联脑电信号的相位信息,利用有向相位延迟指数(dPLI)算法,对两组受试者在执行oddball视觉探测任务过程中的脑电信号进行研究。结果表明:在θ频段,与正常老年人相比,早期VaD患者顶区到额区和顶区到中央区的连接强度均显著降低;正常老年人存在顶区脑活动相位超前、额区及中央区脑活动相位相对滞后的现象,而这种相位关系在早期VaD患者中被打破。因此,能够推测出远距离脑区间功能连接强度的下降,顶区核心地位的削弱,顶区相位超前、额区及中央区相位滞后现象的缺失可能是造成早期VaD患者认知功能下降的原因。该研究为VaD患者的发病机理研究、早期临床诊断研究提供了参考和依据。
To explore the difference of effective connectivity between normal elder and early vascular dementia (VaD) patients, the directed phase lag index (dPLI) based on phase information was applied to analyze the electroencepha？？logram (EEG) signals recorded during an oddball visual detection process. Firstly, in theta frequency, early VaD group showed obviously lower parietal？？to？？frontal and parietal？？to？？central connectivities compared with elderly group. Secondly, for elderly group, EEG phase lead occurred in parietal area and phase lag was in frontal and central areas; but the pattern of phase lead？？lag was destroyed in early VaD group. Thus, low effective connectivity between distant brain area, kernel position weakening for parietal lobe as a information hub, and the disturbed pattern of posterior to anterior phase gradients were possible main causes for cognition function decline in early VaD patients. Therefore, the study provides experience and approach for pathogenesis study and early diagnosis on VaD patients