Gau S S, Tseng W-L, Tseng W-Y I, Wu Y-H, Lo Y-C
Department of Psychiatry,National Taiwan University Hospital and College of Medicine,Taipei,Taiwan.
Institute of Child Development,University of Minnesota,Twin Cities, Minnesota, MN,USA.
Psychol Med. 2015 Feb;45(3):529-43. doi: 10.1017/S0033291714001664. Epub 2014 Jul 30.
Deficits in executive function (EF), impaired school functioning and altered white matter integrity in frontostriatal networks have been associated with attention-deficit/hyperactivity disorder (ADHD). However, relationships between impairments in these areas are unclear. Using a sample of youths with and without ADHD, this study examined the association between microstructural integrity of frontostriatal tracts and school dysfunction and the mediating roles of EF and ADHD symptoms in this association.
The sample included 32 Taiwanese youths with ADHD and 32 age-, sex-, handedness- and IQ-matched typically-developing (TD) youths. Participants were assessed using psychiatric interviews, parent reports on ADHD symptoms and school functioning, and EF measures from the Cambridge Neuropsychological Test Automated Battery (CANTAB). The frontostriatal tracts were reconstructed by diffusion spectrum imaging (DSI) tractography and were subdivided into four functionally distinct segments: caudate-dorsolateral, caudate-medial prefrontal, caudate-orbitofrontal and caudate-ventrolateral tracts.
Youths with ADHD, relative to TD youths, showed altered white matter integrity in all four bilateral pairs of frontostriatal tracts (decreased general fractional anisotropy, GFA), had poor attention, vigilance and response inhibition, and showed impaired school functioning. Altered microstructural integrity in frontostriatal tracts was significantly associated with school dysfunction, which was mediated by EF measures of attention/vigilance and response inhibition in addition to inattention and hyperactivity symptoms.
Our findings demonstrate an association between white matter integrity in the frontostriatal networks and school functioning and suggest that EF deficits and ADHD symptoms may be the mediating mechanisms for this association. Future research is needed to test the directionality and specificity of this finding.
执行功能（EF）缺陷、学校功能受损以及额纹状体网络中白质完整性改变与注意力缺陷多动障碍（ADHD）有关。然而，这些领域损伤之间的关系尚不清楚。本研究以有和没有ADHD的青少年为样本，考察额纹状体束的微观结构完整性与学校功能障碍之间的关联，以及EF和ADHD症状在这种关联中的中介作用。
样本包括32名患有ADHD的台湾青少年和32名年龄、性别、利手和智商相匹配的发育正常（TD）青少年。通过精神科访谈、家长对ADHD症状和学校功能的报告以及剑桥神经心理测试自动成套系统（CANTAB）的EF测量对参与者进行评估。通过扩散谱成像（DSI）纤维束成像重建额纹状体束，并将其细分为四个功能不同的节段：尾状核-背外侧束、尾状核-内侧前额叶束、尾状核-眶额束和尾状核-腹外侧束。
与TD青少年相比，患有ADHD的青少年在所有四对双侧额纹状体束中均表现出白质完整性改变（总体分数各向异性，GFA降低），注意力、警觉性和反应抑制能力较差，且学校功能受损。额纹状体束微观结构完整性的改变与学校功能障碍显著相关，除注意力不集中和多动症状外，还由注意力/警觉性和反应抑制的EF测量介导。
我们的研究结果表明额纹状体网络中的白质完整性与学校功能之间存在关联，并表明EF缺陷和ADHD症状可能是这种关联的中介机制。未来需要进一步研究来检验这一发现的方向性和特异性。
