海洛因成瘾患者眶额叶皮层功能连接异常与决策能力缺失的关系

摘要

Objective To investigate the changes in orbitofrontal cortex (OFC) functional connectivity and its association with decision-making deficits in chronic heroin-dependent individuals (HDIs) and explore the neural mechanisms of heroin addiction and relapse.Methods Fourteen male chronic HDIs and 14 healthy subjects matched for age,education,and nicotine consumption participated in this study.Resting state functional magnetic resonance imaging (fMRI) was performed using a 1.5 T MR scanner.Functional connectivity of the OFC and the rest of the brain were calculated using REST software.Voxel-based analysis of the functional connectivity maps between the control and HDI groups was performed with two-sample t test.The Iowa gambling task (IGT) was used to assess the participants' decision making during uncertainty.Results Compared with the control group,the HDIs showed significantly decreased functional connectivity of the OFC and the right inferior parietal lobule (rIPL) (t=3.5,P＜0.05).A significant negative correlation was noted between the functional connectivity of the OFC-rIPL and performance level at the IGT.Conclusion The OFC-rIPL functional connectivity is significantly disrupted in HDIs,which may be the neural basis for decision-making deficits.%目的 探讨慢性海洛因成瘾者眶额叶皮层(OFC)功能连接的变化及其与慢性海洛因成瘾者冲动性决策行为的关系.方法 慢性海洛因成瘾男性患者14例,与之年龄、受教育程度和尼古丁依赖水平匹配的健康被试14例参加本研究.采用1.5 T磁共振扫描仪,16通道神经血管线圈,对被试分别进行头颅结构和静息态功能磁共振扫描,后利用SPM8软件以双侧眶额叶皮层为感兴趣区,分别进行组内和组间眶额叶皮层静息态功能网络分析.采用爱荷华赌博任务(IGT)对两组被试进行决策能力评估.结果 与对照组比较,慢性海洛因成瘾组眶额叶皮层与右侧顶下小叶(rIPL)之间功能连接显著下降(t=3.5,P＜0.05,多重比较校正).IGT的行为学结果发现,随决策次数递增,两组被试的净分数均逐渐提高(P＜0.001),但正常对照组的净分数明显高于海洛因成瘾组(P＜0.001).海洛因成瘾患者OFC-rIPL功能连接与IGT评分呈明显负相关性(r=-0.550,P=0.041).结论 慢性海洛因成瘾者OFC-rIPL脑网络存在异常,而这种异常可能是其在行为学上存在冲动性决策障碍的神经基础,也可能是其成瘾行为的产生、维持和复吸的原因之一.