躯体形式障碍患者脑葡萄糖代谢功能网络研究

目的探讨躯体形式障碍(SFD)患者大脑葡萄糖代谢网络的拓扑变化。方法用2011年10月至2012年12月期间复旦大学附属华山医院的18例SFD患者男10例、女8例,年龄(39.5±12.0)岁,病程(3.67±3.20)年;SFD组]、21名健康体格检查者男13名、女8名,年龄(43.9±8.4)岁;对照组]的18F-脱氧葡萄糖(FDG)PET图像,建立静息状态下2组的大脑葡萄糖代谢网络。使用图论的方法计算脑网络的全局参数(标准化聚类系数、标准化最短路径长度、小世界属性和全局效率)和节点参数(聚类系数和介数中心度)。2组脑网络参数间的差异采用重复1000次的置换检验进行统计学分析。根据聚类系数和介数中心度定义前20%(18/90)的节点为脑网络的关键(Hub)节点,分析SFD患者Hub节点的改变。结果SFD组患者的脑网络和对照组一样具有小世界属性(σ>1),但标准化聚类系数、小世界属性和全局效率有降低趋势,标准化最短路径长度有增加趋势(P>0.05)。与对照组相比,SFD患者左侧苍白球、左侧杏仁核、左侧楔前叶和右侧角回的介数中心度明显升高(置换检验,P<0.05),左侧颞中回和右侧枕上回的介数中心度明显降低(置换检验,P<0.05);双侧苍白球、双侧丘脑和左侧杏仁核的聚类系数明显降低(置换检验,P<0.05)。SFD组发生改变的Hub节点多数(16/24)位于边缘系统。结论SFD患者的葡萄糖代谢脑网络拓扑性质发生改变,小世界属性和全局效率呈降低的趋势及Hub节点的改变,导致网络信息传递效率有所降低,功能整合和功能分离的平衡被打破,这为躯体化症状的脑功能异常提供了有效的影像学证据。

Brain glucose metabolism network and connectivity in patients with somatoform disorders

Objective To observe the alteration of brain glucose metabolic network in patients with somatoform disorders(SFD).Methods 18F-fluorodeoxyglucose(FDG)PET images of 18 SFD patients(10 males,8 females;age:(39.5±12.0)years;illness duration:(3.67±3.20)years)and 21 matched healthy controls(13 males,8 females;age:(43.9±8.4)years)in Huashan Hospital of Fudan University from October 2011 to December 2012 were enrolled to construct the brain glucose metabolic networks for 2 groups(SFD group,control group)respectively.Then the global network properties(normalized clustering coefficient,normalized shortest path length,small-worldness and global efficiency)and local parameters(clustering coefficient and betweenness centrality of the node)were calculated using the graph theory.Differences between 2 groups were compared by permutation test with 1000 permutations.The top 20%(18/90)were classified as Hub nodes based on the results of clustering coefficient and betweenness centrality of the node.Results Small-worldness of SFD patients was similar to that of healthy controls(σ>1).There were decreased tendency in normalized clustering coefficient and global efficiency,and increased tendency in normalized shortest path length in SFD patients,but without significant differences(P>0.05).Compared to healthy controls,the betweenness centrality of left pallidum,left amygdala,left precuneus and right angular gyrus increased(permutation test,P<0.05);the betweenness centrality of left middle temporal gyrus,right superior occipital gyrus decreased(permutation test,P<0.05);the clustering coefficients of bilateral pallidum,bilateral thalamus,and left amygdala decreased(permutation test,P<0.05).Most changed Hub nodes(16/24)belonged to limbic system.Conclusion The changes of topological properties of brain glucose metabolic network in SFD patients including the decreased tendency of small-worldness and global efficiency,as well as the altered Hub nodes,may provide valid imaging evidences for brain dysfunction of somatization symptoms.