Ohyama M, Senda M, Kitamura S, Ishii K, Mishina M, Terashi A
Positron Medical Center, Tokyo Metropolitan Institute of Gerontology, Japan.
Stroke. 1996 May;27(5):897-903. doi: 10.1161/01.str.27.5.897.
Although the resting regional cerebral blood flow (rCBF) in aphasic patients has been thoroughly investigated with positron emission tomography (PET) and single-photon emission CT, and PET studies in normal subjects have elucidated the functional localization of language processing, little is known about the activation pattern of language processing in aphasic patients.
We measured the changes in rCBF during a repetition task (hearing a single word and repeating it aloud) and the resting state using the H2(15)O PET activation technique in 6 normal subjects (mean +/- SD age, 58.3 +/- 8.1 years) and 16 aphasic patients: 10 fluent aphasics (age, 60.3 +/- 12.5 years) and 6 nonfluent aphasics (age, 50.5 +/- 8.3 years).
In normal subjects, the posteroinferofrontal area (PIF) including Broca's area, the posterosuperotemporal area (PST) including Wernicke's area, the rolandic areas, and a few other areas were activated with left side dominance by the repetition task. In the resting state, the rCBF in the left PIF and the left posterotemporal area was reduced in both fluent and nonfluent aphasics. In aphasic patients, the magnitude of activation in the right PIF and PST by the repetition task was greater than in normal subjects. The increase in rCBF during the repetition task in the left PIF correlated with the Western Aphasia Battery score of spontaneous speech in the nonfluent aphasics with a left inferofrontal lesion.
This study shows the importance in aphasic patients of the mirror regions of the left PIF and PST in the nondominant (right) hemisphere for performing the word repetition task. The results also show the importance for nonfluent aphasic patients of the recruitment of the undamaged PIF for spontaneous speech.
尽管已通过正电子发射断层扫描（PET）和单光子发射计算机断层扫描对失语症患者的静息局部脑血流量（rCBF）进行了全面研究，且PET对正常受试者的研究已阐明了语言处理的功能定位，但对于失语症患者语言处理的激活模式却知之甚少。
我们使用H2(15)O PET激活技术，在6名正常受试者（平均年龄±标准差为58.3±8.1岁）和16名失语症患者中测量了重复任务（听到一个单词并大声重复）和静息状态期间rCBF的变化：10名流利性失语症患者（年龄为60.3±12.5岁）和6名非流利性失语症患者（年龄为50.5±8.3岁）。
在正常受试者中，包括布洛卡区的后下额叶区（PIF）、包括韦尼克区的后上颞叶区（PST）、中央沟周围区域以及其他一些区域在重复任务时以左侧优势被激活。在静息状态下，流利性和非流利性失语症患者左侧PIF和左侧颞后区的rCBF均降低。在失语症患者中，重复任务时右侧PIF和PST中的激活程度大于正常受试者。在左侧额叶下部有病变的非流利性失语症患者中，左侧PIF在重复任务期间rCBF的增加与西方失语症成套测验的自发言语得分相关。
本研究表明，在非优势（右侧）半球中，左侧PIF和PST的镜像区域对于失语症患者执行单词重复任务具有重要性。结果还表明，对于非流利性失语症患者，募集未受损的PIF进行自发言语具有重要意义。
