Müller Ralph-Axel, Kleinhans Natalia, Kemmotsu Nobuko, Pierce Karen, Courchesne Eric
Department of Psychology, San Diego State University, Childrens Hospital Reserch Children, La Jolla, California 92120, USA.
Am J Psychiatry. 2003 Oct;160(10):1847-62. doi: 10.1176/appi.ajp.160.10.1847.
Autism is a neurally based psychiatric disorder, but there is no consensus regarding the underlying neurofunctional abnormalities. Previous functional magnetic resonance imaging (fMRI) studies of simple movement suggested individually variable and scattered functional brain organization in autism. The authors examined whether such abnormalities generalize to multimodal processing (visually driven motor sequence learning).
Eight male autistic patients and eight comparison subjects matched with the patients on age, gender, and handedness were examined by using fMRI while they performed finger press movements prompted by visually presented repeating six-digit sequences. Hemodynamic responses to the six-digit sequences were statistically compared to responses to single-digit stimuli in one experiment and to regular six-digit sequences in another experiment.
Both groups showed activations in bilateral premotor, superior parietal, and occipital cortices in both experiments. Task-by-group interactions showed that superior parietal activations were less pronounced in the autism group, whereas prefrontal cortex and more posterior parietal loci showed greater activation in the autism group than in the comparison group. The distances between Individual subjects' activation peaks and the groupwise peak were greater in the autism group than in the comparison group.
The results support earlier findings of abnormal variability and scatter of functional maps in autism. They are consistent with evidence from other studies suggesting early-onset disturbances in the development of cerebello-thalamo-cortical pathways in autism.
自闭症是一种基于神经的精神障碍，但对于其潜在的神经功能异常尚无共识。先前关于简单运动的功能磁共振成像（fMRI）研究表明，自闭症患者的大脑功能组织存在个体差异且分布分散。作者研究了这种异常是否会扩展到多模态加工（视觉驱动的运动序列学习）。
八名男性自闭症患者和八名在年龄、性别和利手方面与患者匹配的对照受试者在进行由视觉呈现的重复六位数序列提示的手指按压运动时接受了fMRI检查。在一个实验中，将对六位数序列的血流动力学反应与对个位数刺激的反应进行统计学比较，在另一个实验中，将其与规则的六位数序列的反应进行比较。
在两个实验中，两组在双侧运动前区、顶上叶和枕叶皮质均显示激活。任务×组交互作用表明，自闭症组顶上叶的激活不太明显，而前额叶皮质和更靠后的顶叶位点在自闭症组中的激活比对照组更大。自闭症组个体受试者激活峰值与组平均峰值之间的距离比对照组更大。
结果支持了先前关于自闭症功能图谱异常变异性和分散性的研究发现。它们与其他研究的证据一致，这些证据表明自闭症患者小脑-丘脑-皮质通路发育存在早期干扰。
