Objective To investigate the pathogenesis of Broca-like and Wernicke-like conduction aphasia. Methods 7 cases with Broca-like aphasia (Group A), 7 cases with Wernicke-like aphasia (Group B) and 10 healthy volunteers (Group C) participated in the study. Broca's area, Wernicke's area,and the arcuate fasciculus were analyzed by diffusion tensor imaging, and their fractional anisotropy (FA) were measured and compared; The fiber construction of Broca's and Wernicke's areas were also compared by diffusion tensor imaging-fibre tractography. Results In Group C, All of the FA was higher in the left hemisphere than in the right hemisphere (P＜0.05); In Group A, the FA of the Broca's area and anterior segment of the arcuate fasciculus were less in the left than in the right hemisphere (P＜0.05); In Group B, the FA of the Wernicke's area and posterior segment of the arcuate fasciculus were less in the left than in the right (P＜0.05). Conclusion Conduction aphasia results not only from arcuate fasciculus destruction, but also from disruption of the associated cortical area. A lesion involving Broca's area and the anterior segments of the arcuate fasciculus would lead to Broca-like conduction aphasia, whereas a lesion involved Wernicke's area and posterior segments of the arcuate fasciculus would lead to Wernicke-like conduction aphasia.%目的 探讨临床上类似运动性和感觉性的传导性失语发病机制.方法 分别选择7例类似运动性失语和7例感觉性失语症的传导性失语患者以及10例健康志愿者,采用扩散张量成像分析研究Broca区、Wernicke区及弓状纤维束,并测量三者的各向异性(FA)值,分别比较健康志愿者与传导性失语患者双侧大脑半球的FA值;采用扩散张量成像纤维追踪的方式,比较Broca区、Wemicke区的纤维结构.结果 在健康志愿者中,左侧大脑半球各项FA值大于右侧(P<0.05);在类似运动性失语症的传导性失语患者中,左侧Broca区以及弓状纤维束前部的FA值小于右侧镜像区(P<0.05);在类似感觉性失语的传导性失语患者中,左侧Wemicke区以及弓状纤维后部的FA值小于右侧镜像区(P<0.05),Broca区的FA值与正常健康志愿者相似.结论 除弓状纤维束受损外,皮层的病变同样可以引起传导性失语.如果病变部位靠近Broca区且弓状纤维束的前部受损,则临床症状类似于运动性失语症;靠近Wernicke区且弓状纤维束的后部受损,则类似于感觉性失语症.
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