Zilbovicius M, Boddaert N, Belin P, Poline J B, Remy P, Mangin J F, Thivard L, Barthélémy C, Samson Y
Service Hospitalier Frédéric Joliot, Direction des Sciences du Vívant, Département de Recherche, Commisariat à l'Energie Atomique, Tours, France.
Am J Psychiatry. 2000 Dec;157(12):1988-93. doi: 10.1176/appi.ajp.157.12.1988.
The nature of the underlying brain dysfunction of childhood autism, a life-long severe developmental disorder, is not well understood. Although researchers using functional brain imaging have attempted to contribute to this debate, previous studies have failed to report consistent localized neocortical brain dysfunction. The authors reasoned that early methods may have been insensitive to such dysfunction, which may now be detectable with improved technology.
To test this hypothesis, regional cerebral blood flow was measured with positron emission tomography (PET) in 21 children with primary autism and in 10 nonautistic children with idiopathic mental retardation. Autistic and comparison groups were similar in average age and developmental quotients. The authors first searched for focal brain dysfunction in the autistic group by using a voxel-based whole brain analysis and then assessed the sensitivity of the method to detect the abnormality in individual children. An extension study was then performed in an additional group of 12 autistic children.
The first autistic group had a highly significant hypoperfusion in both temporal lobes centered in associative auditory and adjacent multimodal cortex, which was detected in 76% of autistic children. Virtually identical results were found in the second autistic group in the extension study.
PET and voxel-based image analysis revealed a localized dysfunction of the temporal lobes in school-aged children with idiopathic autism. Further studies will clarify the relationships between these temporal abnormalities and the perceptive, cognitive, and emotional developmental abnormalities characteristic of this disorder.
儿童自闭症是一种终身性的严重发育障碍，其潜在的大脑功能障碍的本质尚未得到充分理解。尽管使用功能性脑成像的研究人员试图为这场辩论做出贡献，但先前的研究未能报告一致的局限性新皮质脑功能障碍。作者推断，早期方法可能对这种功能障碍不敏感，而现在借助改进的技术可能可以检测到。
为了验证这一假设，使用正电子发射断层扫描（PET）对21名原发性自闭症儿童和10名患有特发性智力迟钝的非自闭症儿童进行了局部脑血流量测量。自闭症组和对照组在平均年龄和发育商方面相似。作者首先通过基于体素的全脑分析在自闭症组中寻找局灶性脑功能障碍，然后评估该方法检测个体儿童异常的敏感性。随后对另外一组12名自闭症儿童进行了扩展研究。
第一个自闭症组在以联合听觉和相邻多模式皮质为中心的双侧颞叶存在高度显著的灌注不足，在76%的自闭症儿童中检测到。在扩展研究的第二个自闭症组中发现了几乎相同的结果。
PET和基于体素的图像分析揭示了患有特发性自闭症的学龄儿童颞叶存在局限性功能障碍。进一步的研究将阐明这些颞叶异常与该疾病特有的感知、认知和情感发育异常之间的关系。
