Abstract:
Aberrant anatomical brain connections in attention-deficit/hyperactivity disorder (ADHD) are reported inconsistently across diffusion weighted imaging (DWI) studies. Based on a pre-registered protocol (Prospero: CRD42021259192), we searched PubMed, Ovid, and Web of Knowledge until 26/03/2022 to conduct a systematic review of DWI studies. We performed a quality assessment based on imaging acquisition, preprocessing, and analysis. Using signed differential mapping, we meta-analyzed a subset of the retrieved studies amenable to quantitative evidence synthesis, i.e., tract-based spatial statistics (TBSS) studies, in individuals of any age and, separately, in children, adults, and high-quality datasets. Finally, we conducted meta-regressions to test the effect of age, sex, and medication-naïvety. We included 129 studies (6739 ADHD participants and 6476 controls), of which 25 TBSS studies provided peak coordinates for case-control differences in fractional anisotropy (FA)(32 datasets) and 18 in mean diffusivity (MD)(23 datasets). The systematic review highlighted white matter alterations (especially reduced FA) in projection, commissural and association pathways of individuals with ADHD, which were associated with symptom severity and cognitive deficits. The meta-analysis showed a consistent reduced FA in the splenium and body of the corpus callosum, extending to the cingulum. Lower FA was related to older age, and case-control differences did not survive in the pediatric meta-analysis. About 68% of studies were of low quality, mainly due to acquisitions with non-isotropic voxels or lack of motion correction; and the sensitivity analysis in high-quality datasets yielded no significant results. Findings suggest prominent alterations in posterior interhemispheric connections subserving cognitive and motor functions affected in ADHD, although these might be influenced by non-optimal acquisition parameters/preprocessing. Absence of findings in children may be related to the late development of callosal fibers, which may enhance case-control differences in adulthood. Clinicodemographic and methodological differences were major barriers to consistency and comparability among studies, and should be addressed in future investigations.
摘要:
在弥散加权成像(DWI)研究中,注意力缺陷/多动障碍(ADHD)的解剖脑连接异常的报道不一致。基于预先注册的协议(Prospero:CRD42021259192),我们搜索了PubMed,奥维德,和WebofKnowledge,直到26/03/2022对DWI研究进行系统审查。我们基于成像采集进行了质量评估,预处理,和分析。使用有符号差分映射,我们对检索到的适合定量证据综合的研究的子集进行了荟萃分析,即,基于道的空间统计(TBSS)研究,任何年龄的人,分开,在儿童中,成年人,和高质量的数据集。最后,我们进行了元回归来检验年龄的影响,性别,和药物-天真的。我们纳入了129项研究(6739名ADHD参与者和6476名对照),其中25个TBSS研究提供了病例对照的分数各向异性(FA)(32个数据集)和18个平均扩散率(MD)(23个数据集)差异的峰值坐标。系统评价强调了投影中的白质改变(尤其是FA降低),多动症患者的连带和关联途径,与症状严重程度和认知障碍有关。荟萃分析显示,call体和体的FA一致降低,延伸到扣带。较低的FA与年龄较大有关,在儿科荟萃分析中,病例-对照差异无法生存.大约68%的研究质量低,主要是由于非各向同性体素的采集或缺乏运动校正;并且在高质量数据集中的灵敏度分析没有产生显著的结果。研究结果表明,在ADHD中受影响的认知和运动功能方面,后半球间连接的显着改变,尽管这些可能会受到非最佳采集参数/预处理的影响。儿童缺乏发现可能与call骨纤维的晚期发育有关,这可能会增强成年期的病例控制差异。临床人口统计学和方法学差异是研究之间一致性和可比性的主要障碍,并应在今后的调查中加以解决。