海洛因成瘾患者静息状态下脑默认网络功能及结构连接的改变

Aberrant Default-mode Functional and Structural Connectivity in Heroin-dependent Individuals

【目的】探讨海洛因成瘾患者在静息状态下脑默认网络功能连接及结构连接的变化,同时探讨海洛因成瘾患者脑默认网络的改变与成瘾患者临床决策能力的关系。【方法】本研究纳入了14名海洛因成瘾患者和14名健康对照。观察海洛因成瘾患者脑默认网络结构连接(DTI三维白质纤维束追踪获取的路径长度,FA(分数各向异性),MD(平均扩散系数),AD(轴向弥散率)和RD(纵向弥散率))和功能连接(f-MRI获取的时间相关系数)改变,应用皮尔森相关分析调查海洛因患者的默认网络结构/功能连接指数与海洛因成瘾时间及临床决策能力(爱荷华赌博任务(IGT))间的关系。【结果】与正常对照组相比,海洛因成瘾患者PCC/PCUN和PHG及内侧前额叶(MPFC)之间的功能连接显著减低,同时,海洛因成瘾患者PCC/PCUN和MPFC间白质纤维平均FA值显著减低,而MD显著增高。PCC/PCUN至MPFC之间功能连接与海洛因成瘾患者临床决策能力有显著相关性。【结论】海洛因成瘾患者脑默认网络的结构连接和功能连接均存在不同程度破坏。海洛因成瘾患者脑默认网络连接的破坏随着海洛因成瘾时间的延长而持续进展,并与其临床决策能力缺失相关。

【Objective】 To investigate the structural and functional connectivity within the default mode network（DMN） in HDI,and to explore the correlation between aberrant default-mode function and clinical decision making of heroin-dependent individuals（HDI）. 【Methods】 Fourteen HDI and 14 controls participated in the study. Structural（path length, tracts count,（fractional anisotropy） FA and（mean diffusivity） MD derived from DTI tractography and functional（temporal correlation coefficient derived from rs-f MRI） DMN connectivity changes were examined in HDI. Pearson correlation analysis was performed to compare the structural /functional indices and duration of heroin use / Iowa gambling task（IGT） performance in HDI. 【Results】 HDI had lower FA and higher MD in the tract connecting the posterior cingulate cortex / precuneus（PCC / PCUN） to right parahippocampal-gyrus（PHG）, compared to the controls. HDI also had decreased FA and track count in the tract connecting the PCC / PCUN and medial prefrontal cortex（MPFC）, as well as decreased functional connectivity between the PCC / PCUN and bilateral PHG and MPFC, compared to controls.FA values for the tract connecting PCC / PCUN to the right PHG and connecting PCC / PCUN to the MPFC were negatively correlated to the duration of heroin use. The temporal correlation coefficients between the PCC / PCUN and the MPFC, and the FA values for the tract connecting the PCC / PCUN to the MPFC were positively correlated to IGT performance in HDI. 【Conclusions】 Structural and functional connectivity within the DMN are both disturbed in HDI. This disturbance progresses as duration of heroin use increases and is related to deficits in decision making in HDI.