阿尔茨海默病及轻度认知损害转化患者的动态脑功能网络研究

Dynamic Functional Network Study of Alzheimer’s Disease Patients and Mild Cognitive Impairment Converters

目的基于静息态功能磁共振(rs-fMRI)技术,研究阿尔茨海默病(AD)患者及轻度认知损害(MCI)转化患者的动态脑功能网络及其与认知功能的关系。方法对AD组(27例)、MCI转化(MCI-C)组(25例)、MCI非转化(MCI-NC)组(45例)和健康对照组(41例)通过滑窗方法计算动态脑功能网络,计算比较4组被试者在不同脑网络状态的时间窗占比、平均停留时间及状态间切换次数,并与认知功能评分进行相关性分析。结果AD与MCI-C组在状态1(强模块化功能网络状态)占比及停留时间显著减少;状态2(整体弱连接网络状态)及状态3(中度正连接功能网络状态)的平均停留时间以及状态间切换次数与被试者认知功能评分显著相关。结论AD和MCI转化患者的脑动态功能网络配置出现异常,功能分离能力减弱,为AD进展过程的神经网络机制和MCI阶段转化预测研究提供了解释和基础。

Aim To study the dynamic brain function network in patients with Alzheimer’s disease(AD)and mild cognitive impairment(MCI)and its relationship with cognitive function,using resting state functional magnetic resonance(rs-fMRI).Methods The reoccurrence fraction and mean dwell time of different brain network states and number of transitions between them were calculated and compared in 27 AD,25 MCI converters(MCI-C),45 MCI non-converters(MCI-NC)and 41 healthy controls(HC),and their correlation with the cognitive score were evaluated.Results The AD and MCI-C groups presented a significant decrease in the reoccurrence fraction and dwell time of state 1(the brain states with strongly modularized functional network).The average dwell time in state 2(the brain network state with weak connections)and state 3(the brain network state with moderate positive connections)and number of transitions were correlated with the cognitive score.Conclusion In AD patients and MCI converters,the dynamic brain network was reconfigured into a weakened functional separation pattern,providing evidence for understanding of the pathophysiology and developing of novel biomarkers for MCI conversion.