[The correlation of functional connectivity and structural connectivity between hippocampus and thalamus in Alzheimer's disease and amnestic mild cognitive impairment].

Objective: To investigate the correlation of functional connectivity (FC) and the integrity of connective fibres between hippocampus and thalamus in Alzheimer's disease(AD) and amnestic mild cognitive impairment (aMCI). Methods: Both resting-state functional magnetic resonance imaging (rs-fMRI) and diffusion tensor imaging (DTI) data of 40 AD patients, 37 aMCI patients and 41 normal control subjects matching with age and educational level were collected. These subjects were all recruited from outpatient Department of Neurology in the Second Medical Center of Chinese PLA General Hospital, as well as poster, from May 2016 to January 2018. The FC strength between bilateral hippocampus and thalamus, as well as the parameters representing integrity of connective fibres, including fractional anisotropy (FA) and mean diffusivity(MD),were analyzed. Also, the correlations between FC strength and FA or MD strength were analyzed in the study. Results: Compared to that of normal control subjects, the FC strength between billateral hippocampus and thalamus in patients with AD, aMCI were not significantly different(P>0.05). The integrity of bilateral connective fibres between hippocampus and thalamus were damaged in AD patients when compared to normal control subjects(P<0.01). A positive correlation of connective fibres integrity with FC strength between hippocampus and thalamus was found in the left side(r=0.25,P<0.05) but rather in the right side. Conclusion: In AD and aMCI patients, structural connectivity between left hippocampus and thalamus affects the functional connectivity between them.目的： 探讨阿尔茨海默病（AD）及遗忘型轻度认知功能损害（aMCI）的海马-丘脑功能连接（FC）强度与连接纤维完整性的相关性。 方法： 对2016年5月至2018年1月解放军总医院第二医学中心神经内科门诊及海报招募纳入的40例AD、37例aMCI和41例年龄和受教育程度相匹配的正常对照者，分别采集静息态功能磁共振（rs-fMRI）及弥散张量成像（DTI）数据，分析双侧海马-丘脑FC值，代表其连接纤维完整性的DTI参数即各向异性分数（FA）、衡量水分子速度的平均扩散率（MD），以及FC值与FA、MD值的相关性。 结果： AD、aMCI和正常对照相比，双侧海马-丘脑FC值的组间差异均无统计学意义（P>0.05）。AD患者双侧海马-丘脑连接纤维的完整性均较正常对照者受损（P<0.01），左侧连接纤维完整性的受损程度与海马-丘脑的FC值呈正相关（r=0.25，P<0.05），而右侧的受损程度与FC值不相关。 结论： 在AD及aMCI中，左侧海马-丘脑间的结构连接可影响两者的功能连接。.