Department of Psychiatry, National Taiwan University Hospital and College of Medicine, Taipei, Taiwan.
Graduate Institute of Clinical Medicine, College of Medicine, National Taiwan University, Taipei, Taiwan.
Hum Brain Mapp. 2017 Dec;38(12):6053-6067. doi: 10.1002/hbm.23810. Epub 2017 Sep 20.
Despite the evidence of altered white-matter tract property in individuals with autism spectrum disorder (ASD), little is known about their unaffected siblings. This study aimed to investigate white-matter integrity in unaffected siblings of ASD probands. Thirty-nine unaffected siblings (mean age 15.6 ± 6.0 years; 27 males, 69.2%) and 39 typically developing controls (TDC) (14.2 ± 5.6 years; 26 males, 66.7%) were assessed with diffusion spectrum images and neuropsychological tests. Using the tract-based automatic analysis and the threshold-free cluster weighted (TFCW) scores, we searched for the segments among 76 tracts with the largest difference over the entire brain compared to TDC. Tract integrity was quantified by calculating the mean generalized fractional anisotropy (mGFA) values of the segments with the largest difference in TFCW scores. Unaffected siblings showed reduced mGFA in the bilateral frontal aslant tracts, the right superior longitudinal fasciculus 2 (SLF2), the frontostriatal tracts from the right dorsolateral and left ventrolateral prefrontal cortices, the thalamic radiations of the left ventral and the right dorsal thalamus, the callosal fibers of the splenium, and the increased mGFA of the callosal fibers of the precuneus and the left inferior longitudinal fasciculus. Among these, reduced right SLF2 mGFA was associated with social awareness deficits; impaired frontostriatal tract was associated with internalizing problems, while right frontal aslant tract integrity was associated with visual memory deficits. In conclusion, unaffected siblings showed the aberrant integrity of several white-matter tracts, which were correlated with clinical symptoms and neurocognitive dysfunction. The altered tract integrity could be further examined in the probands with ASD. Hum Brain Mapp 38:6053-6067, 2017. © 2017 Wiley Periodicals, Inc.
尽管自闭症谱系障碍（ASD）个体的白质束性质发生了改变，但对于其未受影响的兄弟姐妹知之甚少。本研究旨在探讨 ASD 先证者未受影响的兄弟姐妹的白质完整性。39 名未受影响的兄弟姐妹（平均年龄 15.6±6.0 岁；27 名男性，69.2%）和 39 名正常发育对照者（TDC）（14.2±5.6 岁；26 名男性，66.7%）接受了弥散张量成像和神经心理学测试。我们使用基于束的自动分析和无阈值聚类加权（TFCW）分数，在整个大脑中搜索与 TDC 相比差异最大的 76 个束中的段。通过计算 TFCW 分数差异最大的段的平均广义各向异性分数（mGFA）值来量化束的完整性。未受影响的兄弟姐妹在双侧额斜束、右侧上纵束 2（SLF2）、右侧背外侧和左侧腹侧前额叶皮质的额纹状体束、左侧腹侧和右侧背侧丘脑的丘脑辐射、胼胝体压部的胼胝体纤维以及扣带回纤维的 mGFA 值降低，而扣带回纤维的 mGFA 值增加。其中，右侧 SLF2 mGFA 值降低与社会意识缺陷有关；额纹状体束受损与内化问题有关，而右侧额斜束完整性与视觉记忆缺陷有关。总之，未受影响的兄弟姐妹表现出几个白质束的异常完整性，这与临床症状和神经认知功能障碍有关。ASD 患者中可以进一步检查改变的束完整性。人类大脑映射 38:6053-6067,2017. © 2017 威利父子公司
