ADHD儿童反应时和DTI部分各向异性值相关性研究

Correlated study between reaction time and fractional anisotropy for ADHD children

目的初步探讨注意缺陷多动障碍(ADHD)儿童反应时和大脑主要投射、联络和连合纤维的DTI部分各项异性(FA)值间相关性,以及这种相关性和正常对照组间有无不同,为揭示ADHD儿童反应时改变的可能神经基础提供帮助。方法以16名ADHD儿童和性别、年龄、利手及受教育程度方面相匹配的正常儿童为研究对象,采用分类n-Back工作记忆任务和DTI成像,对两组平均正确反应时和FA值进行统计学分析。结果与正常对照相比,ADHD组平均正确反应时[对照组为(626.92±41.28)ms;ADHD组为(700.45±66.98)ms]明显延长(P<0.01),其双侧扣带束(CB)(右侧CB:P<0.05;左侧CB:P<0.05)、右侧胼周额部深部白质(PCF)(P<0.01)的平均FA值显著减低。ADHD儿童右侧CB、双侧小脑中脚(MCP)的mFA和mRT间呈显著负相关;对照组右侧PCF、双侧内囊前肢(AIC)的mFA和mRT间亦呈显著负相关。结论在执行工作记忆任务时,ADHD儿童参与的神经网络可能与正常儿童不同。ADHD儿童的白质纤维束的结构异常可能介导着其行为学异常。

Objective To investigate whether there are correlations between reaction time （RT） performance and fractional anisotropy （FA） values of projection, communication and association white mater （WM） for attention-deficit/hyperactivity disorder （ADHD） children, and whether these correlations are different from those of normal controls, to explore the neural foundation for the changes of ADHD children＇s RT. Methods Sixteen ADHD children and 16 sex-, age-, handedness-, extent of education-matched normal controls underwent DTI scanning. Behavioral performance （mean correct reaction time, mRT） was recorded when they performaneed a Categorial N-Back Working Memory Task. Statistics analysis was done respectively for mRT and mFA between two groups. Results Compared with controls, ADHD children had much longer mRT （controls： [626.92±41.28] ms; ADHD group： [700. 45±66.98] ms; P〈0.01） and lower mFA in right perieallosal frontal WM （P〈0.01） and bilateral eingulum bundle WM （respectively P〈0.05）. The significantly negative correlations were shown between mRT and mFA in right eingulum bundle WM and bilateral middle eerebellar pendunele for ADHD children while in right perieallosal frontal WM and bilateral anterior limb of internal eapsual for controls. Conclusion When performing working memory task, there are different neural networks for ADHD children from controls, The changes of microstructures of WM might mediate the alterations of behavioral RT.