Metter E J
Gerontology Research Center, National Institute on Aging, Baltimore, Maryland 21224.
Ann N Y Acad Sci. 1991;620:153-64. doi: 10.1111/j.1749-6632.1991.tb51581.x.
Positron emission tomography allows for the study of human brain physiology and chemistry including cerebral blood flow, oxygen or glucose metabolism. We applied PET to study glucose metabolism using aphasia as a model of neurobehavior. The most striking observation was that the extent of cerebral glucose metabolic changes in aphasic patients consistently involve brain regions that are not structurally damaged. The remote metabolic effects can be predicted depending on the location and extent of structural damage. Two observations were made: (1) In our experience, all right-handed aphasic patients with left hemisphere structural lesions have metabolic abnormalities in the left temporoparietal region, and (2) metabolic abnormalities are variably found in undamaged, left prefrontal lobe, basal ganglia, and thalamus. Variations in clinical aphasic syndromes were found to relate to these frontal metabolic changes, suggesting that aspects of the aphasia result from differences in prefrontal function rather than directly from structural damage to perisylvian or deep structures.
正电子发射断层扫描技术可用于研究人类大脑的生理和化学过程，包括脑血流量、氧气或葡萄糖代谢。我们应用正电子发射断层扫描技术，以失语症作为神经行为模型来研究葡萄糖代谢。最显著的观察结果是，失语症患者大脑葡萄糖代谢变化的程度始终涉及结构未受损的脑区。根据结构损伤的位置和程度，可以预测远程代谢效应。我们有两项观察结果：（1）根据我们的经验，所有左半球结构损伤的右利手失语症患者在左颞顶叶区域都有代谢异常，（2）在未受损的左前额叶、基底神经节和丘脑中也发现了不同程度的代谢异常。临床失语症综合征的差异与这些额叶代谢变化有关，这表明失语症的某些方面是由前额叶功能差异导致的，而非直接由颞周或深部结构的结构损伤引起。
