Neuronal fiber pathway abnormalities in autism: an initial MRI diffusion tensor tracking study of hippocampo-fusiform and amygdalo-fusiform pathways.
Neuronal fiber pathway abnormalities in autism: an initial MRI diffusion tensor tracking study of hippocampo-fusiform and amygdalo-fusiform pathways.
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DOI：
10.1017/s1355617708081381
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发表时间：
2008-11
期刊：
影响因子：
--
通讯作者：
Minshew NJ
中科院分区：
文献类型：
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作者：
Conturo TE;Williams DL;Smith CD;Gultepe E;Akbudak E;Minshew NJ
MRI弥散张量跟踪（DTT）进行了17个高功能的青少年/成人自闭症和17个配对匹配的控制。由于面部知觉与自闭症社会症状的相关性，以及已知的自闭症行为和功能成像结果，研究了涉及面部处理的白色物质通路。孤独症组海马-梭状（HF）和杏仁-梭状（AF）通路大小和形状正常，但微结构异常。与对照组相比，右侧HF的跨纤维扩散率（D-min）降低，与全脑效应的D-min增加相反。相反，左侧HF、右侧AF和左侧AF的D-min增加，沿纤维扩散率（D-max）增加，与全脑效应更一致。与对照组相比，一侧化普遍丧失。与低Benton对照组和高Benton自闭症组相比，Benton面部识别评分较低的自闭症组的右HF D-min明显较低。类似的行为关系被发现的性能智商。这些结果表明，在右侧HF中的早期功能显著的病理过程与小直径轴突（具有相应较慢的神经传递）和/或较高的堆积密度一致。在左侧AF和HF中，变化被解释为继发性的，可能反映了轴突丢失和/或髓鞘形成减少。
MRI diffusion-tensor tracking (DTT) was performed in 17 high-functioning adolescents/adults with autism and 17 pairwise-matched controls. White matter pathways involved in face processing were examined due to the relevance of face perception to the social symptoms of autism, and due to known behavioral and functional imaging findings in autism. The hippocampo-fusiform (HF) and amygdalo-fusiform (AF) pathways had normal size and shape but abnormal microstructure in the autism group. The right HF had reduced across-fiber diffusivity (D-min) compared with controls, opposite to the whole-brain effect of increased D-min. In contrast, left HF, right AF, and left AF had increased D-min and increased along-fiber diffusivity (D-max), more consistent with the whole-brain effect. There was a general loss of lateralization compared with controls. The right HF D-min was markedly low in the autism subgroup with lower Benton face recognition scores, compared with the lower-Benton control subgroup, and compared with the higher-Benton autism subgroup. Similar behavioral relationships were found for performance IQ. Such results suggest an early functionally-significant pathological process in right HF consistent with small-diameter axons (with correspondingly slower neural transmission) and/or higher packing density. In left AF and HF, changes were interpreted as secondary, possibly reflecting axonal loss and/or decreased myelination.