脑卒中后抑郁患者脑网络拓扑改变的研究

Study on changes of brain network topology in patients with post-stroke depression

目的探讨脑卒中后抑郁(PSD)患者脑网络拓扑属性的变化。方法对29例非PSD脑卒中患者(Non-PSD组)及19例PSD患者(PSD组)进行DTI检查。使用确定性纤维追踪方法基于部分各向异性值构建大脑白质结构网络。使用图论方法分析两组患者的脑网络拓扑属性,并对两组大脑网络聚类系数(Cp)、特征路径长度(Lp)、归一化的聚类系数(γ)、标准特征路径长度(λ)、小世界属性值(σ)、全局效率(Eglob)及局部效率(Eloc)进行比较。结果两组均有σ>1,Non-PSD组σ明显高于PSD组(P<0.05)。两组Eglob、Eloc、Lp、λ、Cp、γ比较差异均有统计学意义(均P<0.05)。Non-PSD组右嗅皮质Cp明显高于PSD组,左背外侧额上回、右背外侧额上回、右眶部额上回、额中回左、左岛盖部额下回、左三角部额下回、左内侧和旁扣带脑回、右海马、右角回、左尾状核、左豆状苍白球、左颞上回Cp均明显低于PSD组(均P<0.05)。NonPSD组左眶部额下回、右眶部额下回、左内侧额上回、左前扣带和旁扣带脑回、右前扣带和旁扣带脑回、左后扣带回、左海马、右海马、右丘脑、右颞中回节点效率均明显低于PSD组(均P<0.05)。结论 PSD患者大脑结构网络均具有小世界属性,部分脑区Cp发生改变,部分脑区节点效率也发生改变。

Objective To investigate the changes of brain network topology in patients with post-stroke depression（ PSD）. Methods DTI scan was performed in 29 stroke patients without PSD（ Non-PSD group） and 19 patients with PSD（ PSD group）. Basing on partial anisotropy,deterministic fiber tracking was used to construct white matter network. Graph theory was used to analyze the brain network topological properties of the two groups. And the clustering coefficient（ Cp）,characteristic path length（ Lp）,clustering coefficient normalized standard（ γ）,characteristic path length（ λ）,small world property value（ σ）,global efficiency（ Eglob） and local efficiency（ Eloc） of brain network between the two groups were compared. Results There was σ 1 in both two groups,andσ in Non-PSD group was significantly higher than that in PSD group（ P〈0. 05）. There were significant differences in Eglob,Eloc,Lp,λ,Cp,γ between the two groups（ all P〈0. 05）. The Cp of the right olfactory cortex of NonPSD group was significantly higher than that in PSD group,while the Cp of left dorsolateral frontal gyrus,right superior frontal gyrus,right dorsolateral orbital frontal gyrus,left middle frontal gyrus,left inferior frontal gyrus,left operculum triangular part of inferior frontal gyrus,left medial and cingulate gyrus,right next to the hippocampus,right angular gyrus,left caudate nucleus,left bean shaped globus pallidus and left superior temporal gyrus were significantly lower than those in PSD group（ all P〈0. 05）. The node efficiency of left orbital frontal gyrus,right inferior frontal gyrus,left medial orbital frontal gyrus,left anterior and adjacent cingulate gyrus,right anterior cingulate and adjacent cingulate gyrus,left posterior cingulate gyrus,left hippocampus,right hippocampus,right thalamus and right middle temporal gyrus of Non-PSD group were significantly lower than those in PSD group（ all P〈0. 05）. Conclusion The brain structure network of PSD patients have small-world attributes,and Cp of some brain regions is changed,and nodes efficiency of some brain regions is changed too.