Nickel K, Tebartz van Elst L, Perlov E, Endres D, Müller G T, Riedel A, Fangmeier T, Maier S
Section for Experimental Neuropsychiatry, Department for Psychiatry & Psychotherapy, Medical Center - University of Freiburg, Freiburg, Germany.
Luzerner Psychiatrie, Hospital St. Urban, St. Urban, Switzerland.
Acta Psychiatr Scand. 2017 Jun;135(6):573-583. doi: 10.1111/acps.12731. Epub 2017 Apr 13.
White matter (WM) alterations have been reported in children and adults with autism spectrum disorder (ASD). In particular, impaired connectivity of limbic structures may be related to social deficits. Heterogeneous findings could be explained in terms of differences in sample characteristics and methodology. In this context, non-syndromic forms might differ substantially in WM structure from secondary ASD forms.
In an attempt to recruit a homogeneous study sample, we included adults with high-functioning ASD and an IQ > 100 to decrease the influence of syndromic forms being often associated with cognitive deficits. Diffusion tensor imaging (DTI) was performed in 30 participants with ASD and 30 pairwise-matched controls. Fractional anisotropy (FA) and mean diffusivity (MD) as surrogate imaging markers for WM integrity were calculated.
We found a significant FA decrease in the ASD group in the genu and body of the corpus callosum (CC). Increased MD was detected in the subgenual anterior cingulate cortex (sACC).
The finding of decreased WM integrity in the genu of the CC is in line with earlier studies reporting a decreased number of interhemispheric fibers in the frontal lobe of ASD. Alterations in the sACC might be associated with 'Theory of mind' deficits.
已有报道称，患有自闭症谱系障碍（ASD）的儿童和成人存在白质（WM）改变。特别是，边缘结构的连接受损可能与社交缺陷有关。研究结果的异质性可以用样本特征和方法的差异来解释。在这种情况下，非综合征形式的WM结构可能与继发性ASD形式有很大不同。
为了招募一个同质化的研究样本，我们纳入了高功能ASD且智商>100的成年人，以减少通常与认知缺陷相关的综合征形式的影响。对30名ASD参与者和30名配对对照进行了扩散张量成像（DTI）。计算了分数各向异性（FA）和平均扩散率（MD）作为WM完整性的替代成像标志物。
我们发现ASD组胼胝体（CC）膝部和体部的FA显著降低。在膝下前扣带回皮质（sACC）检测到MD增加。
CC膝部WM完整性降低的发现与早期研究一致，早期研究报告ASD额叶半球间纤维数量减少。sACC的改变可能与“心理理论”缺陷有关。
