自闭症儿童脑结构的MRI研究

Magnetic resonance imaging study of brain structure in autistic children

目的通过MRI研究自闭症儿童的脑结构异常。方法对26例自闭症儿童和16例正常儿童进行脑部磁共振扫描,比较两组全脑各向异性分散(FA)的差异,分析自闭症儿童各被检测部位的FA值与儿童行为评估量表(CBQ-R)得分的相关性。结果 (1)自闭症组右侧额下回、左侧额中回、右侧颞下回邻近白质的FA值(0.32±0.12、0.28±0.03、0.17±0.09)低于对照组(0.76±0.08、0.57±0.01、0.61±0.36),P<0.05;自闭症组左顶小叶邻近白质的FA值(0.75±0.47)高于对照组(0.42±0.90),P<0.05。(2)自闭症组右侧胼胝体压部FA值与CBQ-R的语言评分值呈负相关(r=-0.419,P<0.05)。(3)自闭症组内囊后肢、胼胝体膝部FA值高于对照组,差异有统计学意义(P<0.05)。结论自闭症儿童的多个脑部位的白质纤维的完整性遭到破坏,胼胝体神经纤维连接存在异常。

Objective To study the abnormality of the brain structure in autistic children by Magnetic Resonance Imaging. Methods Diffusion tensor images were obtained in 26 children with autism and 16 aged-matched normal controls. Voxel-based analysis was applied to asses the fractional anisotropy（FA） in cerebral tissues. The correlation coefficients between FA and the CBQ-R score in autistic children were calculated. Results （1）Compared with the controls, the FA values in autistic children were significantly decreased in the white matter of right inferior frontal gyrus, left middle frontal gyrus and right inferior temporal gyrus, and increased in the white matter of left super parietal lobule （P〈0.05）. （2）FA values in right side of splenium of corpus callosum was negatively related to CBQ-R communication scores in autistic children（r=-0.419, P〈0.05）. （3）The FA values of posterior limb of the internal capsule and genu of corpus callosum in autistic children were significantly higher than the normal controls（P〈0.05）. Conclusion The white matter integrity is probably disconnected in many brain regions and aberrant callosal connectivity maybe occur in autistic children.