静息态功能MRI评价轻度认知障碍背侧流视觉网络功能连接变化

Changes of Connectivity of Dorsal Stream in Patients with Mild Cognitive Impairment by Using Resting-state Functional Magnetic Resonance Imaging

目的阿尔茨海默病(AD)和轻度认知障碍(MCI)患者存在视觉功能异常,并可能与其他因素共同导致患者认知功能下降。本研究探讨MCI患者背侧流视觉网络功能连接的变化。资料与方法本研究中所有受试者数据均来自阿尔茨海默病神经影像计划(ADNI)公共数据库,包括87例MCI患者以及44例健康老年志愿者。首先采用激活似然估计法(ALE)定位背侧流视觉皮层坐标位置,而后根据获得的坐标定义皮层感兴趣区(ROI)。利用上述受试者的静息态功能磁共振成像计算并比较MCI患者每对ROI之间静息态功能连接(RSFC)的变化情况。结果与对照组相比,晚期MCI组患者背侧流视觉皮层存在RSFC异常升高的情况,包括右侧梭状回-右侧中央后回和右侧梭状回-左侧中央后回,差异均有统计学意义(P<0.001)。结论 MCI患者背侧流视觉皮层网络内部功能连接存在异常,从而为解释认知障碍状态下高级视觉功能方面的损害提供神经生理学依据。

Purpose Impairment of dorsal visual function and its functional connectivity play important role in the reduced cognitive function of Alzheimer＇s disease（AD） and mild cognitive impairment（MCI） patients. This study aims to explore the functional connectivity abnormalities of the dorsal stream in patients with MCI. Materials and Methods All the data used in this study were collected from the Alzheimer＇s Disease Neuroimaging Initiative（ADNI） database, including 87 MCI patients and 44 healthy controls.First, the cortical coordinates were located using activation likelihood estimation（ALE） analyses. Then, a series of cortical region of interest（ROI） were created based on the above coordinates. Thereafter, the pair-wise resting-state functional connectivity（RSFC） were calculated based on the resting-state functional magnetic resonance imaging data, and were compared among early MCI, late MCI and healthy controls. Results Compared with control group, late MCIs showed significantly increased RSFC of dorsal stream, including the RSFC between right fusiform and right postcentral gyrus, and between left right fusiform and postcentral gyrus（P〈0.001）. Conclusion The dorsal stream cortices exhibit abnormal functional connectivity in patients with MCI. This provides objective evidence to explain the high-level visual dysfunctions under MCI status.