Mode of Anisotropy Reveals Global Diffusion Alterations in Attention-Deficit/Hyperactivity Disorder.
Mode of Anisotropy Reveals Global Diffusion Alterations in Attention-Deficit/Hyperactivity Disorder.
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DOI：
10.1016/j.jaac.2015.11.011
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发表时间：
2016-02
影响因子：
13.3
通讯作者：
Castellanos FX
中科院分区：
文献类型：
--
作者：
Yoncheva YN;Somandepalli K;Reiss PT;Kelly C;Di Martino A;Lazar M;Zhou J;Milham MP;Castellanos FX
扩散张量成像（DTI）能够识别注意缺陷/多动障碍（ADHD）中的结构连接改变。大多数ADHD的DTI研究都集中在分数各向异性（FA）的区域差异上，尽管它对复杂的白质结构敏感性有限，且越来越多的证据表明ADHD存在全脑差异。在此，我们在患有和未患有ADHD的儿童和成人的独立样本中检测多种DTI指标，主要关注组间的整体差异。
两个样本：患有ADHD的成人（n = 42）和未患ADHD的成人（n = 65），以及患有ADHD的儿童（n = 82）和未患ADHD的儿童（n = 80），分别在年龄、性别和头部运动方面进行了组匹配。通过基于纤维束的空间统计分析了五种DTI指标（FA、轴向扩散率、径向扩散率、平均扩散率和各向异性模式）。组分析测试了每种指标在整体（整个白质骨架的平均值）和区域水平上的诊断差异。
在成人中发现了扩散指数的显著整体组间差异，其中各向异性模式（MA；科恩d值 = 1.45）的效应量最大。在儿科样本中，组间的整体MA也存在显著差异（d = 0.68）。在两个样本中，与仅使用临床康纳斯ADHD评分的模型相比，整体MA提高了分类准确性。区域诊断差异在多重比较的家族错误率校正后不显著。
整体DTI指标，特别是对交叉纤维敏感的各向异性模式，在儿科和成人样本中都捕捉到了ADHD的连接异常。这些发现凸显了ADHD中潜在的弥漫性白质微观结构差异。
Diffusion tensor imaging (DTI) can identify structural connectivity alterations in attention-deficit/hyperactivity disorder (ADHD). Most ADHD DTI studies have concentrated on regional differences in fractional anisotropy (FA) despite its limited sensitivity to complex white matter architecture and increasing evidence of global brain differences in ADHD. Here, we examine multiple DTI metrics in separate samples of children and adults with and without ADHD with a principal focus on global between-group differences. Two samples: adults with ADHD (n = 42) and without (n = 65) and children with ADHD (n = 82) and without (n = 80) were separately group matched for age, sex, and head motion. Five DTI metrics (FA, axial diffusivity, radial diffusivity, mean diffusivity, and mode of anisotropy) were analyzed via tract-based spatial statistics. Group analyses tested for diagnostic differences at the global (averaged across the entire white matter skeleton) and regional level for each metric. Robust global group differences in diffusion indices were found in adults, with the largest effect size for mode of anisotropy (MA; Cohen’s d = 1.45). Global MA also differed significantly between groups in the pediatric sample (d = 0.68). In both samples, global MA increased classification accuracy compared to the model with clinical Conners’ ADHD ratings alone. Regional diagnostic differences did not survive familywise correction for multiple comparisons. Global DTI metrics, particularly the mode of anisotropy, which is sensitive to crossing fibers, capture connectivity abnormalities in ADHD across both pediatric and adult samples. These findings highlight potential diffuse white matter microarchitecture differences in ADHD.