失语症病人皮层语言活动的功能MRI初步研究

Cortical language activation in aphasia: a functional MRI study

目的 用功能磁共振成像 (fMRI)技术研究失语症患者皮层语言功能状态 ,并探讨该技术临床应用的可行性。方法 在 6位健康志愿者和 3位处于恢复阶段的失语症患者完成词汇联想任务的同时 ,用fMRI技术测量局部神经元活动引起的脑区信号改变 ,分析处理成代表语言功能区的统计激活图。结果 6例正常志愿者的语言加工活动激活了 1个由额叶、顶叶、颞叶和枕叶等许多脑区组成的神经网络。而失语症患者无论左侧额叶有无病变 ,均无左侧额叶下部的激活。此外 ,2位患者显示了右侧大脑半球某些区域的激活 ,而这些区域没有参与正常志愿者的语言加工。结论 失语症患者皮层语言功能存在脑内局部病灶的远隔效应和皮层语言功能区的重新分布或重组现象。

Objective To investigate the differences of the underlying neural basis of language processing between normal subjects and aphasics, and to study the feasibility for functional magnetic resonance imaging (fMRI) in examining the cortical language activation in clinical aphasics. Methods(fMRI was) used to map language network in 6 normal subjects and 3 patients with aphasia who were in the stage of recovery from acute stroke. The participants performed word generation task during fMRI scanning, which measured the signal changes associated with regional neural activity induced by the task. These signal changes were processed to statistically generate the activation map that represented the language area. Results In normal subjects, a distributed language network was activated. Activations were present in the frontal, temporal, parietal and occipital regions in normal group. In the patient group, however, no activation was showed in the left inferior frontal gyrus whether or not the patient had lesion in the left frontal lobe. Two patients showed activations in some right hemisphere regions where no activation appeared in normal subjects. Conclusion The remote effect of focal lesion and functional redistribution or reorganization was found in aphasic patients. fMRI was useful in evaluating the language function in aphasic patients.