Joint effects of gray matter atrophy and altered functional connectivity on cognitive deficits in amnestic mild cognitive impairment patients
Joint effects of gray matter atrophy and altered functional connectivity on cognitive deficits in amnestic mild cognitive impairment patients
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DOI：
10.1017/s0033291714002876
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发表时间：
2014-12
影响因子：
6.9
通讯作者：
C. Xie;F. Bai;B. Yuan;H. Yu;Yong-mei Shi;Yonggui Yuan;Di Wu;Zhengsheng Zhang;Zhijun Zhang
中科院分区：
文献类型：
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作者：
C. Xie;F. Bai;B. Yuan;H. Yu;Yong-mei Shi;Yonggui Yuan;Di Wu;Zhengsheng Zhang;Zhijun Zhang
背景遗忘型轻度认知功能障碍（aMCI）患者常伴有灰质（GM）萎缩和内在功能连接（IFC）中断，是发展为阿尔茨海默病的高危因素。然而，关于GM萎缩和IFC改变之间的关系，以及它们是否与认知能力下降有关，我们知之甚少。方法选取30例aMCI患者和26例认知功能正常（CN）患者作为研究对象。优化的基于体素的形态测量和静息态功能连接磁共振成像方法分别测量GM体积（GMV）和萎缩相关IFC。在控制了年龄、教育程度、性别和组别的影响后，采用多变量线性回归分析来研究GM萎缩和IFC对受试者认知表现的影响。结果与正常对照组相比，aMCI组额叶-顶叶和内侧颞叶系统的GMV和IFC均显著降低。多元回归分析进一步表明，GMV和IFC降低同时影响认知功能。具体而言，GMV与认知表现（包括整体认知和情景记忆）呈正相关，并且在GMV与非情景记忆之间显示出强烈的相关性趋势，而IFC与上述三种认知指标呈正相关。此外，在所有受试者中，GMV和IFC强度改变之间存在显著相关性。结论我们的研究结果表明，GMV和IFC共同有助于认知性能，并结合定量信息的GMV和功能连接的强度可以作为一个指标的认知功能障碍的非痴呆老年人。
Background Gray matter (GM) atrophy and disrupted intrinsic functional connectivity (IFC) are often present in patients with amnestic mild cognitive impairment (aMCI), which shows high risk of developing into Alzheimer's disease. Little is known, however, about the relationship between GM atrophy and altered IFC, and whether they are related to cognitive decline. Method A total of 30 aMCI and 26 cognitively normal (CN) subjects were recruited for this study. Optimized voxel-based morphometric and resting-state functional connectivity magnetic resonance imaging approaches were performed to measure the GM volumes (GMVs) and atrophy-related IFC, respectively. Multivariate linear regression analysis was used to examine the effects of GM atrophy and IFC on cognitive performance across subjects, after controlling for the effects of age, education, gender and group. Results Compared with CN subjects, aMCI subjects showed significantly reduced GMVs and decreased IFC in the frontal-parietal and medial temporal lobe systems. Multivariate regression analysis further demonstrated that the GMVs and decreased IFC simultaneously affected the cognitive function. Specifically, GMVs were positively correlated with cognitive performances, including global cognition and episodic memory, and showed a strong trend in correlation between GMVs and non-episodic memory, whilst IFC was positively correlated with the above three cognitive measures, across all subjects. In addition, significant correlation was found between GMVs and altered IFC strength across all subjects. Conclusions Our findings demonstrated that GMVs and IFC jointly contribute to cognitive performance, and combining quantitative information about GMVs and the strength of functional connectivity may serve as an indicator of cognitive deficits in non-demented elderly.