Department of Child and Adolescent Psychiatry, NYU Langone Medical Center, New York, NY, USA.
Academic Unit of Psychology and Clinical and Experimental Sciences (CNS and Psychiatry), University of Southampton, Southampton.
J Child Psychol Psychiatry. 2018 Mar;59(3):193-202. doi: 10.1111/jcpp.12778. Epub 2017 Jul 3.
Diffusion tensor imaging studies have shown atypical fractional anisotropy (FA) in individuals with attention-deficit/hyperactivity disorder (ADHD), albeit with conflicting results. We performed meta-analyses of whole-brain voxel-based analyses (WBVBA) and tract-based spatial statistics (TBSS) studies in ADHD, along with a qualitative review of TBSS studies addressing the issue of head motion, which may bias results.
We conducted a systematic literature search (last search on April 1st, 2016) to identify studies comparing FA values between individuals with ADHD and typically developing (TD) participants. Signed differential mapping was used to compute effect sizes and integrate WBVBA and TBSS studies, respectively. TBSS datasets reporting no between-group motion differences were identified.
We identified 14 WBVBA (ADHDn = 314, TDn = 278) and 13 TBSS datasets (ADHDn = 557, TDn = 568). WBVBA meta-analysis showed both significantly lower and higher FA values in individuals with ADHD; TBSS meta-analysis showed significantly lower FA in ADHD compared with TD in four clusters: two in the corpus callosum (isthmus and posterior midbody), one in right inferior fronto-occipital fasciculus, and one in left inferior longitudinal fasciculus. However, four of six datasets confirming no group-differences in motion showed no significant between-group FA differences.
A growing diffusion tensor imaging (DTI) literature (total N = 1,717) and a plethora of apparent findings suggest atypical interhemispheric connection in ADHD. However, FA results in ADHD should be considered with caution, since many studies did not examine potential group differences in head motion, and most of the studies reporting no difference in motion showed no significant results. Future studies should address head motion as a priority and assure that groups do not differ in head motion.
尽管存在相互矛盾的结果，但扩散张量成像研究表明，注意力缺陷/多动障碍（ADHD）患者的各向异性分数（FA）存在异常。我们对 ADHD 的全脑体素基于分析（WBVBA）和基于束流的空间统计学（TBSS）研究进行了荟萃分析，并对涉及头部运动可能导致结果偏倚问题的 TBSS 研究进行了定性综述。
我们进行了系统的文献检索（最后一次检索时间为 2016 年 4 月 1 日），以确定比较 ADHD 患者和正常发育（TD）参与者之间 FA 值的研究。使用符号差分映射来计算效应大小，并分别整合 WBVBA 和 TBSS 研究。确定了报告无组间运动差异的 TBSS 数据集。
我们确定了 14 项 WBVBA（ADHDn=314，TDn=278）和 13 项 TBSS 数据集（ADHDn=557，TDn=568）。WBVBA 荟萃分析显示，ADHD 患者的 FA 值较低和较高；TBSS 荟萃分析显示，与 TD 相比，ADHD 患者的 FA 值在四个簇中显著降低：两个在胼胝体（峡部和后体），一个在右侧下额枕束，一个在左侧下额纵束。然而，六个确认运动无组间差异的数据集中有四个没有显示出组间 FA 差异的显著差异。
越来越多的扩散张量成像（DTI）文献（总 N=1717）和大量明显的发现表明，ADHD 存在异常的半球间连接。然而，ADHD 的 FA 结果应谨慎考虑，因为许多研究没有检查头部运动的潜在组间差异，而且大多数报告运动无差异的研究没有显示出显著的结果。未来的研究应优先解决头部运动问题，并确保两组在头部运动方面没有差异。
