功能磁共振观察老年人大尺度脑功能网络选择性的退化模式  

Functional MRI observation of the aging selective degradation mode of large-scale brain functional networks

作　　者：吴晶涛[1] 陈文新[1] 张洪英[1] 田彤彤[1] 杨海山[2] 

机构地区：[1]江苏省苏北人民医院医学影像科,扬州225001 [2]吉林大学中日联谊医院放射科

出　　处：《中华老年医学杂志》2016年第4期347-351,共5页Chinese Journal of Geriatrics

基　　金：国家自然科学基金（81571652、81471642）

摘　　要：目的探讨功能磁共振大尺度脑网络在脑衰老进程中的变化特征和内在机制。方法招募健康青年人和老年人受试者，老年组20例，平均年龄（72．4±4．6）岁；青年人18例，平均年龄（23．9±1．8）岁。受试者接受血氧水平依赖的静息功能磁共振检查，采用种子区方法及双回归处理功能数据，提取默认网络、注意网络、执行控制网络、突显网络，视觉网络，进行统计学比较。结果相对于青年组，老年组的网络连接性损害呈现了明显不同的变化模式，执行控制网络受损最重，其次是注意网络，默认网络和突显网络轻度受影响，这些高级认知功能相关网络受损，而较低级的视觉感觉网络未见明显变化。结论健康人的脑衰老表现为在网络水平上呈现有组织性的变化；老年期大尺度的脑网络呈现选择性的损害，高级认知网络较低级脑功能网络退变更突出。Objective To investigate the degradation characteristics of the large-scale brain functional networks during aging by functional magnetic resonance imaging measurement and explore its intrinsic mechanism. Methods 40 healthy subjects including 20 elderly persons [mean aged（72.4 ±4.6）years] and 18 young persons [mean aged（23.9± 1.8）years] were enrolled in this study. All subjects underwent functional MRI scanning at blood oxygenation level-dependent contrast resting state. Four canonical resting state networks, including the default mode network （DMN）, dorsal attention network （ DAN）, executive control network （ ECN）, salience network, and visual network, were extracted by the seed zone and double regression methods. The functional connectivities in these canonical networks were compared between the young and elderly persons. Results Compared with young persons, the elderly showed the distinct and disruptive alterations in the large-scale aging-related resting brain networks. The impairment of ECN was the most serious, followed by the impairment of DAN. The salience networks and DMN showed relatively limited functional connectivity disruption. The networks associated to higher-order brain functions were impaired, while the visual network,which served as a network related to low-order brain functions,had no significant change. Conclusions The aged brain in healthy subjects is characterized by organized change in networks,and the selective impairments of large-scale brain networks were more significant in the networks associated to higher-order brain functions as compared with the networks related to low-order brain functions.

关 键 词：衰老 脑 神经网 磁共振成像 

分 类 号：R445.2[医药卫生—影像医学与核医学]