Xuan Bu, PhD*; Chuang Yang, MD*; Kaili Liang, BM; Qingxia Lin, MM; Lu Lu, PhD; Lianqing Zhang, PhD; Hailong Li, PhD; Yingxue Gao, PhD; Shi Tang, MM; Xiaoxiao Hu, MM; Yanlin Wang, PhD; Xinyu Hu, PhD; Meihao Wang, MD; Xiaoqi Huang, PhD, MD
Background: The specific role of the corticospinal tract with respect to inattention and impulsive symptoms in children with attention-deficit/hyperactivity disorder (ADHD) has been explored in the past. However, to our knowledge, no study has identified the exact regions of the corticospinal tract that are affected in ADHD. We aimed to determine comprehensive alterations in the white matter microstructure of the corticospinal tract and underlying neuropsychological substrates in ADHD.
Methods: We recruited 38 drug-naïve children with ADHD and 34 typically developing controls. We employed a tract-based quantitative approach to measure diffusion parameters along the trajectory of the corticospinal tract, and we further correlated alterations with attention and response inhibition measures.
Results: Compared with controls, children with ADHD demonstrated significantly lower fractional anisotropy and higher radial diffusivity at the level of cerebral peduncle, and higher fractional anisotropy at the level of the posterior limb of the internal capsule in the right corticospinal tract only. As well, increased fractional anisotropy in the posterior limb of the internal capsule was negatively correlated with continuous performance test attention quotients and positively correlated with reaction time on the Stroop Colour–Word Test; increased radial diffusivity in the right peduncle region was positively correlated with omissions in the Stroop test.
Limitations: The sample size was relatively small. Moreover, we did not consider the different subtypes of ADHD and lacked sufficient power to analyze subgroup differences. Higher-order diffusion modelling is needed in future white matter studies.
Conclusion: We demonstrated specific changes in the right corticospinal tract in children with ADHD. Correlations with measures of attention and response inhibition underscored the functional importance of corticospinal tract disturbance in ADHD.
*These authors contributed equally to this work.
Submitted Jan. 29, 2019; Revised May 25, 2019; Accepted Jul. 11, 2019; Published online Nov. 25, 2019
Acknowledgments: This study was supported by the National Natural Science Foundation (Grant No. 81671669) and Science and Technology Project of Sichuan Province (Grant No. 2017JQ0001).
Affiliations: From the Huaxi MR Research Center (HMRRC), Department of Radiology, Sichuan University West China Hospital, 37 Guo Xue Xiang, Chengdu, Sichuan 610041, China (Bu, Liang, Lu, Zhang, Li, Gao, Tang, Hu, Wang, Hu, Huang); the Department of Psychiatry, Wenzhou Medical University First Affiliated Hospital, Nan Bai Xiang, Wenzhou, Zhejiang 325003, China (Yang, Lin); and the Department of Radiology, Wenzhou Medical University First Affiliated Hospital, Nan Bai Xiang, Wenzhou, Zhejiang 325003, China (Wang).
Competing interests: None declared.
Contributors: X. Bu, C. Yang, and X. Huang designed the study. Q. Lin and C. Yang acquired the data, which all authors analyzed. X. Bu, C. Yang, and X. Huang, which all authors reviewed. All authors approved the final version to be published and can certify that no other individuals not listed as authors have made substantial contributions to the paper.
Correspondence to: X. Huang, Huaxi MR Research Center (HMRRC), Department of Radiology, Sichuan University West China Hospital, 37 Guo Xue Xiang, Chengdu, Sichuan Province 610041, China; email@example.com