脊髓小脑共济失调3型患者神经影像功能网络的MRI研究

Research on the neuroimaging functional network of patients with spinocerebellar ataxia type 3

目的采用MRI探讨脊髓小脑共济失调(SCA)3型患者脑功能网络的异常及其与行为学量表评分的关系。方法该研究为横断面研究。前瞻性分析2017年5月至2023年5月在陆军军医大学第一附属医院就诊的SCA 3型患者52例(SCA 3型组)和正常对照组55名的临床及影像资料。所有受试者均接受结构和静息态功能MRI。基于图论方法分析脑网络连接的全局属性和节点属性, 包括聚类系数(Cp)、特征路径长度(Lp)、标准化的聚类系数(γ)、标准化的特征路径长度(λ)、小世界指数(σ)、全局效率(Eglob)、局部效率(Eloc)、同配性和节点效率。计算全局属性参数曲线下面积(AUC)并采用双样本t检验对2组全局属性相关参数AUC值进行比较, 以错误发现率校正(FDR)校正。采用双样本t检验对2组节点效率进行比较, 以基于网络的统计(NBS)方法校正, 选取2组节点效率显著差异脑区为兴趣脑区, 采用双样本t检验比较SCA 3型组与正常对照组兴趣脑区与其他脑区静息态脑功能连接(rsFC)值的差异, 以NBS校正。采用Spearman检验对2组显著差异的rsFC值(P<0.01)与其临床行为学评分进行相关性分析。结果与正常对照组比较, SCA 3型组脑网络连接的Cp的AUC值明显增加(Z=2.05、P=0.043), 而γ、λ、σ、Eglob、Eloc、Lp和同配性在2组间差异均无统计学意义(P>0.05)。SCA 3型组在左侧楔前叶(t=-2.16, NBS校正P=0.033)、左侧颞下回(t=-2.25, NBS校正P=0.027)较正常对照组节点效率显著降低, 在右侧豆状壳核(t=2.05, NBS校正P=0.043)、左侧颞中回(t=2.25, NBS校正P=0.027)较正常对照组节点效率明显增高。SCA 3型患者多个脑区间的rsFC值存在显著改变, 且与临床资料和行为学量表评分相关。结论 SCA 3型患者脑功能网络发生特异性改变, 包括聚类系数和节点效率, 且脑区间rsFC值与行为学异常存在相关性。

Objective To explore the abnormalities of functional brain networks and their relationship with behavioral scale scores in patients with spinal cerebellar ataxia(SCA)type 3 using MRI.Methods The study was a cross-sectional study.Clinical and imaging data of 52 patients with SCA type 3(SCA type 3 group)and 55 normal control group admitted to the First Affiliated Hospital of Army Medical University from May 2017 to May 2023 were prospectively analyzed.All participants underwent structural and resting-state functional MRI.Graph theory analysis assessed global and nodal properties of brain network connectivity,including clustering coefficient(Cp),characteristic path length(Lp),normalized clustering coefficient(γ),normalized characteristic path length(λ),small-world index(σ),global efficiency(Eglob),local efficiency(Eloc),assortativity,and nodal efficiency.The area under the curve(AUC)for global attribute parameters was calculated and a two-sample t-test was used to compare the AUC values of the global attribute parameters between the 2 groups,and corrected for false discovery rate correction(FDR).A two-sample t-test was used to compare the node efficiencies of the 2 groups,corrected for network-based statistics(NBS),and the brain regions with significant differences in node efficiencies between the 2 groups were selected as the brain regions of interest,and a two-sample t-test was used to compare the differences in resting state functional connectivity(rsFC)values between the brain regions of interest and other brain regions in the SCA type 3 group and the normal control group,corrected for NBS.Spearman test was used to correlate significantly different rsFC values(P<0.01)between the 2 groups and their clinical behavioral scores.Results Compared with the normal control group,the AUC value of Cp for brain network connectivity was significantly increased in the SCA type 3 group(Z=2.05,P=0.043),whereas the differences inγ,λ,σ,Eglob,Eloc,Lp,and homozygosity were not statistically significant between the 2 groups(all P>0.05).The SCA type 3 group had significantly lower nodal efficiency in the left precuneus(t=-2.16,NBS corrected P=0.033)and left inferotemporal gyrus(t=-2.25,NBS corrected P=0.027),and significantly higher nodal efficiency in the right lentiform nucleus(t=2.05,NBS corrected P=0.043)and left middle temporal gyrus(t=2.25,NBS corrected P=0.027)compared to normal control group.Significant alterations in rsFC values were found between multiple brain regions in SCA type 3 patients,correlating with clinical data and behavioral assessment scores.Conclusions SCA type 3 patients exhibit specific alterations in brain functional networks,including changes in clustering coefficient and nodal efficiency.Furthermore,rsFC between brain regions correlates with behavioral abnormalities.