注意缺陷多动障碍儿童的脑网络特点

Characteristics of brain networks in children with attention deficit hyperactivity disorder

脑网络异常被认为是注意缺陷/多动障碍(attention deficit hyperactivity disorder,ADHD)的潜在神经生物学机制。目前,借助功能性核磁共振技术、功能性近红外光谱技术等无创脑功能神经影像技术,ADHD儿童脑功能特点和脑功能网络机制的研究已取得显著进展。本研究综述了ADHD儿童脑功能网络多模态研究的最新成果。在脑网络的结构特征上,ADHD儿童在默认网络、突显网络、中央控制网络的核心节点以及皮质下核团上存在脑灰质特征异常(例如额叶、扣带回皮层更薄,杏仁核、尾状核灰质体积更小),也存在白质纤维束连接发育异常。在静息态下的脑功能网络特征上,ADHD儿童表现出各网络间功能整合的非典型发展,并且与不良的ADHD症状表现有关联。在突显网络和默认网络相关区域,与正常发育儿童相比,ADHD儿童脑结构与静息态下脑功能耦合更强。在执行控制任务中,无论功能性核磁共振技术还是近红外技术,均发现ADHD儿童右侧额叶激活不足的情况稳定存在。ADHD儿童在需要执行功能参与的任务中出现默认网络与中央控制网络相关脑区活动异常,并且不同临床行为表现分型的ADHD儿童在脑网络组织模式上表现出稳定可辨识的特征。

Functional abnormalities in brain networks are considered as potential neurobiological mechanisms underlying attention deficit hyperactivity disorder(ADHD).Currently,significant progress has been made in the exploration of the brain functional characteristics and network mechanisms of ADHD children using non-invasive neuroimaging technologies such as functional magnetic resonance imaging(fMRI)and functional near-infrared spectroscopy(fNIRS).This study summarized the latest results of multimodal research on functional brain network of children with ADHD,and took into account the latest progress of structural brain network.In terms of the structural characteristics of brain networks,abnormal gray matter features exist in core nodes of the default network,salience network,and central executive network,as well as in subcortical structures(thinner prefrontal and cingulate cortices,smaller amygdala and caudate nucleus volumes)in children with ADHD.Additionally,there are anomalies in the development of white matter fiber tract connections.Regarding the functional characteristics of brain networks during resting state,children with ADHD demonstrate atypical development in the functional integration across networks,which is also correlated with the manifestation of ADHD symptoms.In regions associated with the salience network and default network,children with ADHD show stronger coupling between brain structure and resting-state functional connectivity compared to typically developing children.During executive control tasks,both fMRI and fNIRS consistently reveal insufficient activation in the right frontal lobe of children with ADHD.fNIRS further detects abnormal brain activity related to the default network and central executive network in children with ADHD during tasks requiring functional engagement.Different clinical subtypes of children with ADHD exhibit stable and identifiable characteristics in the organizational patterns of brain functional networks.