Connor Lisa Tabor, DeShazo Braby Tiffany, Snyder Abraham Z, Lewis Christopher, Blasi Valeria, Corbetta Maurizio
Department of Radiology, Box 8225, Washington University School of Medicine, 4525 Scott Avenue, St. Louis, MO 63110, USA, and Neuroradiology Institute, San Raffaele Hospital, Milan, Italy.
Neuropsychologia. 2006;44(2):171-7. doi: 10.1016/j.neuropsychologia.2005.05.019. Epub 2005 Jul 12.
The right postero-lateral cerebellum participates with the left frontal lobe in the selection and production of words. Using fMRI, we examined whether cerebellar activity switches hemispheres in parallel with recruitment of putative compensatory right homologous frontal regions in post-stroke aphasia. Re-examining the data of Blasi et al. [Blasi, V., Young, A. C., Tansy, A. P., Petersen, S. E., Snyder, A. Z., & Corbetta, M. (2002). Word retrieval learning modulates right frontal cortex in patients with left frontal damage. Neuron, 36(1), 159-170], we asked: (1) if activity in the right cerebellum was disrupted by a left frontal lesion, (2) if activity switched to the left cerebellum, and (3) if activity in the left cerebellum was modulated by learning, as was right frontal cortex. Fourteen age-matched controls and eight mildly aphasic stroke patients participated. Aphasic participants all had lesions due to unilateral left hemisphere stroke at or near Broca's area. Subjects silently performed a word stem completion task with either novel or repeated items. Activity in right cerebellum of aphasic individuals was minimal and was not modulated by learning, as for controls. However, we observed robust learning-related attenuation of the BOLD signal in the left postero-lateral cerebellum consistent with learning-related effects in right frontal cortex. These findings support the hypothesis that right frontal and left cerebellar circuits are likely to be functionally relevant to recovered/residual verbal function.
右侧后外侧小脑与左侧额叶共同参与单词的选择和生成。我们使用功能磁共振成像（fMRI）来研究在中风后失语症中，小脑活动是否会与假定的右侧同源额叶区域的代偿性激活同时发生半球切换。重新审视布拉西等人[布拉西，V.，杨，A. C.，坦西，A. P.，彼得森，S. E.，斯奈德，A. Z.，& 科尔贝塔，M.（2002年）。单词检索学习调节左侧额叶损伤患者的右侧额叶皮层。《神经元》，36(1)，159 - 170]的数据时，我们提出了以下问题：（1）左侧额叶病变是否会破坏右侧小脑的活动，（2）活动是否会切换到左侧小脑，以及（3）左侧小脑的活动是否会像右侧额叶皮层一样受到学习的调节。14名年龄匹配的对照组和8名轻度失语的中风患者参与了研究。失语症参与者均因单侧左半球中风累及或靠近布洛卡区而出现病变。受试者安静地完成了一个词干补全任务，任务内容包括新的或重复的项目。与对照组一样，失语症个体右侧小脑的活动极少，且不受学习调节。然而，我们观察到左侧后外侧小脑的血氧水平依赖（BOLD）信号出现了与学习相关的显著衰减，这与右侧额叶皮层的学习相关效应一致。这些发现支持了这样一种假设，即右侧额叶和左侧小脑回路可能在功能上与恢复的/残留的语言功能相关。
