基于静息态功能磁共振成像研究SCD患者脑功能损伤与空间导航障碍的相关性

Investigation of the Correlations between Brain Functional Impairment and Spatial Navigation Deficits in Patients with SCD Based on Resting-State Functional Magnetic Resonance Imaging

目的探索主观认知下降(SCD)患者的自发脑活动改变,并评估其与空间导航行为学的相关性。方法对21例SCD患者和年龄、性别、受教育程度相匹配的24名正常对照组(NC)行神经心理学量表测试及静息态功能磁共振成像(rs-fMRI)扫描,并对所有SCD患者行计算机版空间导航行为学测试。应用DPARSFA 2.3、SPM8软件比较分析SCD组和NC组的低频振幅(ALFF)、比例低频振幅(fALFF)、局部一致性(ReHo)及功能连接密度(FCD)值差异区域,评估有差异脑区的rs-fMRI指标与空间导航误差的相关性。结果与NC组相比,SCD组的右侧小脑前叶、小脑蚓部及右侧丘脑、壳核fALFF值减低;右侧小脑前叶及右侧丘脑、壳核、苍白球、尾状核ReHo值减低;右侧丘脑、壳核、苍白球、尾状核FCD值减低,左侧额下回、左侧岛叶FCD值增高;ALFF值未见显著差异。偏相关分析显示,SCD患者自我导航的平均误差距离与右侧丘脑、壳核、苍白球、尾状核ReHo值呈显著负相关(r=-0.53,P<0.01)。结论SCD患者局部脑功能异常,右侧丘脑等脑区活动减低与空间导航障碍相关。rs-fMRI有助于对SCD患者脑功能异常与空间导航行为相关性的深入理解。

Objective To explore the changes of spontaneous brain activity in patients with subjective cognitive decline(SCD),and to evaluate its correlations with spatial navigation behavior.Methods Neuropsychological tests and resting-state functional magnetic resonance imaging(rs-fMRI)data were collected in 21 SCD patients and 24 normal controls(NC)matched by age,sex and education level.All SCD patients performed the computerized spatial navigation test.DPARSFA 2.3 and SPM8 software were used to analyze and compare the amplitude of low frequency fluctuation(ALFF),fractional amplitude of low frequency fluctuation(fA LFF),regional homogeneity(ReH o)and functional connectivity density(FCD)values between the SCD and NC groups,and the correlations between the significantly altered rs-fMRI measures and spatial navigation errors were evaluated.Results Compared with NC group,the SCD group showed decreased fA LFF values in the right cerebellum anterior lobe,vermis and right thalamus/putamen.The SCD group also showed decreased ReHo values in the right cerebellum anterior lobe and right thalamus/putamen/globus pallidus/caudate nucleus.Moreover,SCD group showed decreased FCD in the right thalamus/putamen/globus pallidus/caudate nucleus and increased FCD in the left inferior frontal gyrus and left insular lobe.There was no significant difference in ALFF value between SCD and NC groups.Partial correlation analysis showed that the average error distances of egocentric navigation in SCD patients were negatively correlated with ReH o values in right thalamus/putamen/globus pallidus/caudate nucleus(r=-0.53,P<0.01).Conclusion SCD patients showed abnormal local brain function,and decreased activity in the right thalamus was associated with spatial navigation impairment.This study may benefit a better understanding of brain dysfunction and its correlation with spatial navigation behavior in SCD patients.