Greicius Michael D
Department of Neurology and Neurological Sciences, Stanford University School of Medicine, 401 Quarry Road, Stanford, CA 94305-5719, USA.
Curr Opin Neurol. 2003 Apr;16(2):143-6. doi: 10.1097/01.wco.0000063763.15877.d2.
This review considers the role of neuroimaging in developmental disorders by highlighting recent studies in two distinct, but overlapping, developmental disorders: autism and fragile X syndrome.
After a decade of conflicting results in neuroimaging studies of autism, recent studies have provided some convergent data. One well-replicated finding is that autistic subjects have larger brains. Further, this enlargement, present as early as 3 years of age, appears to represent accelerated growth in infancy and may be followed by slowed growth in late childhood. Other findings are discussed but considered preliminary in the absence of converging evidence or replication studies. Recent work in fragile X syndrome suggests aberrant fronto-striatal and fronto-parietal networks and relates these abnormalities "forward" to behavior and "backward" to decreased protein expression.
As the field of neuroimaging has matured, it has revealed its promise as a safe, reliable, in-vivo tool in the study of developmental disorders. By insisting on larger, more homogeneous patient groups and longitudinal rather than cross-sectional studies, the field is poised to fulfill its ultimate role of linking defects in molecular biology to aberrant behavior.
本综述通过重点介绍在两种不同但有重叠的发育障碍——自闭症和脆性X综合征——方面的近期研究，探讨神经影像学在发育障碍中的作用。
在自闭症神经影像学研究历经十年相互矛盾的结果之后，近期研究提供了一些趋同的数据。一个得到充分重复验证的发现是，自闭症患者的大脑更大。此外，这种增大在3岁时就已出现，似乎代表婴儿期的加速生长，随后在儿童晚期生长减缓。其他发现也有讨论，但在缺乏趋同证据或重复研究的情况下被视为初步结果。脆性X综合征的近期研究表明存在异常的额纹状体和额顶网络，并将这些异常“向前”与行为、“向后”与蛋白质表达降低联系起来。
随着神经影像学领域的成熟，它已展现出作为研究发育障碍的一种安全、可靠的体内工具的前景。通过坚持纳入更大、更同质的患者群体并开展纵向而非横断面研究，该领域有望实现其将分子生物学缺陷与异常行为相联系的最终作用。
