儿童注意缺陷多动障碍的功能磁共振成像研究

目的使用功能磁共振成像(functional magnetic resonance imaging，fMRI)方法研究正常儿童及注意缺陷多动障碍儿童在执行高级抑制功能执行-不执行(Go-NoGo)操作任务时脑功能状态及激活模式。方法注意缺陷多动障碍患儿10例与年龄、性别、利手匹配的正常儿童11例执行组块设计的Go-NoGo任务，采集全脑血氧水平依赖对比的fMRI扫描数据，用SPM99软件包进行￡检验统计分析，以获取执行不同任务与静息状态对比的脑功能图像。结果(1)在执行刺激匹配的Go任务时，正常儿童脑激活区主要在左侧丘脑及右侧扣带回，右侧额中回(BA9／10)有小范围激活。注意缺陷多动障碍儿童左侧丘脑激活范围显著减小，右侧基底节区及中脑出现了激活。(2)在执行反应匹配的Go任务时，正常儿童右侧岛叶、扣带回及左侧额叶可见激活。多动症儿童在右侧额中回(BA6／9)可见少量激活。(3)在执行NoGo任务时正常儿童右侧额中回(BA46)为主要激活区，左侧前扣带回、左侧额中回及右侧丘脑可见激活。多动症儿童右侧额叶激活区增多，但主要在BA8区，而前额叶(BA9、10)的激活并不显著，丘脑激活范围及强度较正常儿童均有增加。结论注意缺陷多动障碍儿童存在以前额叶及扣带回前部为主的功能低下脑区，同时有丘脑功能的异常。

Functional MRI studies in children with attention deficit hyperactivity disorder

Objective To investigate the brain activation map during Go-NoGo tasks in children with attention deficit hyperactivity disorder (ADHD) and matched controls using functional MRI.Methods Block designed BOLD functional MRI scan covering the whole brain was performed on 10 boys having ADHD and 11 healthy boys.The 2 groups were matched by age,sex,and handedness.Executing advanced inhibitory Go-NoGo tasks served as stimuli for all subjects.The fMRI data was analyzed by SPM99 (Statistical Parametric Mapping) software with statistic t-test to generate the activation map.Results (1) The normal children showed significant activations in left thalamus and right cingulate gyrus and fewer activations in right middle frontal gyrus during stimulate controlled Go task,but the children with ADHD showed less activations in left thalamus.(2) In response controlled Go task,the normal children showed activations in right insula,cingulate gyrus and left frontal gyrus,while the ADHD children showed lower power of response in the right middle frontal gyrus.(3) In NoGo task,right middle frontal gyrus was the dominant activated regions,and left anterior cingulate,left middle frontal gyrus and right thalamus also had some activations in normal children,while the activations of right prefrontal decreased and the thalamus increased in ADHD boys.Conclusion In children with ADHD,some dysfunctional brain areas,mainly the prefrontal lobe and anterior cingulate gyrus were found.Thalamus was also involved according to the brain activation map.