摘要： 阿尔茨海默病是以进行性智能减退为特征的中枢神经系统变性疾病，目前对其病理生理学机制尚不十分清楚。近年来，利用功能磁共振成像技术结合基于图论的复杂脑网络理论，发现阿尔茨海默病患者大脑功能网络存在局部和全局拓扑性质异常改变，这不仅为了解其病理生理学机制提供了新视角，也可能为早期诊断寻找到新的影像学标志。本文主要介绍复杂脑网络理论的基本概念，回顾近年来人脑功能网络在阿尔茨海默病中的研究进展，尤其是“小世界”网络模型的研究，并提出存在的问题及未来研究方向。

关键词: 阿尔茨海默病, 磁共振成像, 小世界网络（非MeSH 词）, 综述

Abstract: Alzheimer's disease (AD), a progressive neurodegenerative disease, is clinically characterized by impaired memory and many other cognitive functions. However, the pathophysiological mechanisms underlying the disease are not thoroughly understood. In recent years, using functional magnetic resonance imaging (fMRI) as well as advanced graph theory based network analysis approach, several studies of patients with AD suggested abnormal topological organization in both global and regional properties of functional brain networks, specifically, as demonstrated by a loss of small-world network characteristics. These studies provide novel insights into the pathophysiological mechanisms of AD and could be helpful in developing imaging biomarkers for disease diagnosis. In this paper we introduce the essential concepts of complex brain networks theory, and review recent advances of the study on human functional brain networks in AD, especially focusing on the graph theoretical analysis of small-world network based on fMRI. We also propound the existent problems and research orientation.

Key words: Alzheimer disease, Magnetic resonance imaging, Small-work network (not in MeSH), Review