Recent work in healthy adults suggests that white matter organization within the superior longitudinal fasciculus (SLF) may, at least partly, explain individual differences in fine motor skills. The SLF is also often implicated in the neurobiology underlying attention deficit hyperactivity disorder (ADHD) as part of the attention network connecting frontal and parietal regions. While ADHD is primarily characterized by inattention, impulsivity and/or hyperactivity, atypical fine motor control is a common comorbid feature. This study aimed to investigate the association between reduced fine motor skills in ADHD and microstructural properties within the SLF. Participants were 55 right-handed children with ADHD and 61 controls aged 9-11 years. Fine motor control was assessed using the Grooved Pegboard task. Children underwent high angular resolution diffusion MRI. Following pre-processing, constrained spherical deconvolution tractography was performed to delineate the three SLF branches bilaterally. Children with ADHD showed significantly poorer fine motor performance relative to controls in the non-dominant hand, indicated by significantly slower left handed Grooved Pegboard task performance. This slower response time for the non-dominant (left) hand was significantly associated with reduced apparent fibre density within the right SLF I, and reduced right SLF I, II and III volume. This finding was independent of spatial attention performance. These data support previous reports indicating that children with ADHD have poorer fine motor performance than controls in their non-dominant hand, and indicates that the neurobiological basis for impaired fine motor control may involve white matter properties within the contralateral SLF. This suggests that white matter properties in fronto-parietal areas may have broader implications than attention.

中文翻译：

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多动症儿童的精细运动能力降低与上纵筋膜内的非典型显微组织有关。

健康成年人的最新研究表明，上纵筋膜（SLF）内的白质组织至少可以部分解释精细运动技能的个体差异。SLF通常还作为连接额叶和顶叶区域的注意力网络的一部分，牵涉到作为注意力缺陷多动障碍（ADHD）的神经生物学。尽管注意力缺陷多动症的主要特征是注意力不集中，冲动和/或活动亢进，但非典型的精细运动控制是一种常见的共病特征。这项研究旨在调查多动症减少精细运动技能和SLF内的微结构属性之间的关联。参加者为55名右撇子多动症儿童和61名9-11岁的对照组。使用Grooved Pegboard任务评估了精细运动控制。儿童接受高角度分辨率弥散核磁共振成像。经过预处理后，进行了约束球面反卷积术，以画出两侧的三个SLF分支。相对于非优势手的对照组，患有多动症的儿童表现出的精细运动能力明显较差，这表明左手Grooved Pegboard任务的表现明显较慢。非显性（左）手较慢的响应时间与右SLF I内表观纤维密度降低以及右SLF I，II和III体积减少明显相关。这一发现与空间注意力表现无关。这些数据支持了以前的报告，表明多动症儿童的非运动性手掌运动能力较对照组弱，并表明精细运动控制受损的神经生物学基础可能涉及对侧SLF内的白质特性。这表明额顶区域的白质特性可能具有比关注更广泛的含义。