抑郁症患者脑结构网络效率属性及与疾病严重程度的相关分析

The efficiency of the brain structural networks and its relationship with the severity of disease in depression

目的 探讨抑郁症患者与健康对照者脑结构的网络效率及节点效率属性的异同,分析抑郁症患者大脑全局信息处理模式和脑区间信息整合效率的改变,及其与疾病严重程度的关系.方法 对27例抑郁症患者（抑郁症组）和36名健康对照者（对照组）进行弥散张量成像扫描,利用解剖学自动标记模板将整个大脑划分为90个区域,同时对全脑进行确定性纤维追踪,构建脑结构二值化网络.并对所得抑郁症组与对照组脑结构网络的效率属性值进行双样本t检验.结果 （1）2组脑网络分别与相匹配的随机网络比较：网络全局效率均与随机网络相似;网络局部效率均大于随机网络.（2）抑郁症组网络全局效率（0.86±0.01）较对照组（0.87±0.01）下降（t=-2.31;P =0.02）.（3）抑郁症组节点全局效率属性值较对照组（右侧额上回眶部：0.41±0.04与0.44±0.02;左侧颞中回颞极：0.31 ±0.02与0.33±0.03）下降（t=-3.52、-3.84;P=0.0008、0.0003;通过多重校正）.（4）抑郁症组右侧额上回眶部全局效率属性值与HAMD17总分呈负相关（r=-0.46,P=0.02）.结论 抑郁症患者与健康人大脑都具有高效经济的“小世界”式的信息处理模式.抑郁症患者脑区间信息整合的能力已受损,且与疾病严重程度呈负相关.

Objective To explore the differences of the efficiency of the networks and the nodes between the depression and the healthy,the changes of the model of information processing across the whole brain and the efficiency of information integrating across brain regions of the depression and the relationship between the global efficiency of the nodes and the severity of the disease.Methods The diffusion tensor imaging data were obtained from 27 depressive patients and 36 healthy controls.The whole cerebral cortex was divided into 90 regions by the anatomical tabel map.Fiber tracking was performed in the whole cerebral cortex of each subject to reconstruct white matter tracts of the brain using the fiber assignment by continuous tracking algorithm.And then the brain structural binary networks were constructed using the complex network theory.The efficiency of the brain structural networks of the depression and healthy were examined by two sample t-tests.Results The brain structural networks of both the depression and the healthy exhibited a higher local efficiency and a similar global efficiency when compared with the matched random networks.But the global efficiency of the brain structural networks of the depression （0.86 ± 0.01） decreased significantly when compared with the healthy （0.87 ± 0.01 ; t =-2.31 ; P =0.02）.And the global efficiency of the nodes in the networks of depression （the right superior frontal gyrus （orbital part）：0.41 ± 0.04 ; the left middle temporal gyrus （temporal pole）：0.31 ± 0.02） decreased significantly when compared with the healthy （0.44 ± 0.02,0.33 ± 0.03 ; t =-3.52,-3.84 ; P =0.0008,0.0003,survived critical false discorery rate threshold for multiple comparisons）.Significant negative correlation was found between the global efficiency of the right superior frontal gyrus （orbital part） and the total scores of HAMD-17 （r =-0.46,P =0.02）.Conclusion Efficient small-world properties when processing information across the whole brain could exhibit in both the depressive patients and the healthy persons.But the efficiency of information integrating across brain regions may be decreased in the depressive patients and be negatively related with the severity of depression.