Mills Kathryn L, Bathula Deepti, Dias Taciana G Costa, Iyer Swathi P, Fenesy Michelle C, Musser Erica D, Stevens Corinne A, Thurlow Bria L, Carpenter Samuel D, Nagel Bonnie J, Nigg Joel T, Fair Damien A
Department of Behavioral Neuroscience, Oregon Health and Science University Portland, OR, USA.
Front Psychiatry. 2012 Jan 25;3:2. doi: 10.3389/fpsyt.2012.00002. eCollection 2012.
Attention deficit hyperactivity disorder (ADHD) captures a heterogeneous group of children, who are characterized by a range of cognitive and behavioral symptoms. Previous resting-state functional connectivity MRI (rs-fcMRI) studies have sought to understand the neural correlates of ADHD by comparing connectivity measurements between those with and without the disorder, focusing primarily on cortical-striatal circuits mediated by the thalamus. To integrate the multiple phenotypic features associated with ADHD and help resolve its heterogeneity, it is helpful to determine how specific circuits relate to unique cognitive domains of the ADHD syndrome. Spatial working memory has been proposed as a key mechanism in the pathophysiology of ADHD.
We correlated the rs-fcMRI of five thalamic regions of interest (ROIs) with spatial span working memory scores in a sample of 67 children aged 7-11 years [ADHD and typically developing children (TDC)]. In an independent dataset, we then examined group differences in thalamo-striatal functional connectivity between 70 ADHD and 89 TDC (7-11 years) from the ADHD-200 dataset. Thalamic ROIs were created based on previous methods that utilize known thalamo-cortical loops and rs-fcMRI to identify functional boundaries in the thalamus.
RESULTS/CONCLUSION: Using these thalamic regions, we found atypical rs-fcMRI between specific thalamic groupings with the basal ganglia. To identify the thalamic connections that relate to spatial working memory in ADHD, only connections identified in both the correlational and comparative analyses were considered. Multiple connections between the thalamus and basal ganglia, particularly between medial and anterior dorsal thalamus and the putamen, were related to spatial working memory and also altered in ADHD. These thalamo-striatal disruptions may be one of multiple atypical neural and cognitive mechanisms that relate to the ADHD clinical phenotype.
注意缺陷多动障碍（ADHD）涵盖了一组异质性儿童，其特征是一系列认知和行为症状。以往的静息态功能连接磁共振成像（rs-fcMRI）研究试图通过比较患ADHD儿童与未患该疾病儿童之间的连接测量值来了解ADHD的神经相关性，主要关注由丘脑介导的皮质-纹状体回路。为了整合与ADHD相关的多种表型特征并帮助解决其异质性问题，确定特定回路与ADHD综合征的独特认知领域之间的关系是很有帮助的。空间工作记忆已被认为是ADHD病理生理学中的关键机制。
我们在一个由67名7至11岁儿童（ADHD儿童和发育正常儿童[TDC]）组成的样本中，将五个丘脑感兴趣区域（ROI）的rs-fcMRI与空间跨度工作记忆分数进行了关联。然后，在一个独立的数据集中，我们检查了来自ADHD-200数据集的70名ADHD儿童和89名TDC儿童（7至11岁）之间丘脑-纹状体功能连接的组间差异。丘脑ROI是基于先前利用已知丘脑-皮质环路和rs-fcMRI来识别丘脑中功能边界的方法创建的。
结果/结论：利用这些丘脑区域，我们发现特定丘脑分组与基底神经节之间存在非典型的rs-fcMRI。为了确定与ADHD中空间工作记忆相关的丘脑连接，仅考虑在相关性分析和比较分析中都识别出的连接。丘脑与基底神经节之间的多个连接，特别是内侧和背侧前丘脑与壳核之间的连接，与空间工作记忆相关，并且在ADHD中也发生了改变。这些丘脑-纹状体功能紊乱可能是与ADHD临床表型相关的多种非典型神经和认知机制之一。
