【作者】 王丹；

【导师】 郝伟；

【作者基本信息】 中南大学 ， 临床医学， 2013， 博士

【摘要】 目的：了解甲基苯丙胺(methamphetamine, MA)依赖者的临床特征,包括神经认知功能和人格特征等,探讨MA依赖者临床特征的脑结构和脑功能活动基础。方法：本课题以35名处于恢复期的MA依赖者和34名匹配的正常对照者为研究对象,采用数字符号测验、连线测验A和Stoop色词测验评估受试者的神经认知功能,采用巴瑞特冲动量表评估冲动性,采用磁共振三维成像技术和基于体素的形态学分析方法测量脑灰质体积,采用血氧水平依赖的功能磁共振成像技术和首次采用局部一致性方法测量静息状态下MA依赖者的脑功能活动。结果：与正常对照者相比,MA依赖者在数字符号测验中正确填写数字符号的个数更少,在连线测验A中的错误数和抬笔次数更多,完成Stroop色词测验甲的时间更长；MA依赖者巴瑞特冲动量表总分及各因子分均明显高于对照组,并且MA依赖者的运动冲动因子分与首次使用MA的年龄呈负相关；MA依赖者右侧额极、右侧额中回、右侧眶额皮质、双侧前扣带回、左侧后扣带回、双侧颞中回和双侧枕叶的灰质体积减少,并且MA依赖者左侧后扣带回的灰质体积与戒断天数呈正相关；在静息状态下MA依赖者左侧眶额皮质、右侧额叶中央前回和双侧枕中回的局部一致性降低,并且MA依赖者左侧眶额皮质的局部一致性与使用MA的时间呈负相关。结论：本研究结果表明MA依赖者主要存在注意能力、执行功能和冲动控制能力下降这三个方面的神经认知功能损害,他们具有冲动性增加的人格特征,这种人格特征可能是MA依赖的一个易感性标志,可能影响个体对滥用物质的感受及随后发展为物质使用障碍者的风险；本研究从脑影像学方面提示前额叶脑区的结构和功能异常可能与MA依赖者冲动抑制受损、冲动性增加有关。本研究为进一步阐明MA依赖的神经生物学机制、发现MA成瘾的易感性标志提供了一定的科学依据,为MA成瘾的临床治疗和早期预防提供了方向。更多还原

【Abstract】 Objective:The aim of this study is to explore the clinical features, including cognitive function and personality traits, and neuroimaging alterations of abstinent methamphetamine (MA) dependent individuals.Methods:We used Digit Symbol Test, Trail Making Test and the Stroop Color-Word Test to measure cognitive function in35MA-dependent individuals and34controls. We compared self-report impulsivity using Barratt Impulsiveness Scale between these two groups. We examined local differences in brain structure in MA-dependent individuals and controls with voxel-based morphometry and three dimensional magnetic resonance imaging technology. We also examined local difference in brain function in these two groups with blood oxygen level-dependent functional magnetic resonance imaging technology and regional homogeneity (ReHo) approach.Results:Compared with healthy controls, MA users correctly filled in significantly less symbols in Digit Symbol Test, had significantly more errors and more times of pen’s lifting from paper in Trail Making Test and they spent significantly more time completing the Stroop Color-Word Test. Impulsivity was higher in the MA group and motor impulsivity was negatively correlated with age of first MA use. The MA group had a decrease in gray matter volume relative to controls in right frontal pole, right middle frontal gyrus, right orbitofrontal cortex, bilateral anterior cingulate cortex, left posterior cingulate cortex, bilateral middle temporal gyrus and bilateral occipital cortex. And gray matter volume in left posterior cingulate cortex was positively correlated with length of abstinence from MA. Compared with controls, decreased ReHo was found in MA users in left orbitofrontal cortex, right precentral gyrus and bilateral middle occipital gyrus. And the duration of MA use was negatively correlated with ReHo in left orbitofrontal cortex.Conclusions:Our data suggested that MA abusers have cognitive deficits and personality traits of increased impulsivity. Impulsivity might be a vulnerability marker for addiction which could affect the subjective reponses to stimulants and the risk for subsequent substance abuse. Our findings indicated that the structural abnormalities and dysfunction of the prefrontal regions in MA abusers might be associated with increased impulsivity. Our results contribute to further elucidate the neurobiological mechanisms of MA dependence and find out vulnerability markers for addiction, and also provide a direction for clinical treatment and early intervention of MA dependence.更多还原