Dissociation of letter and picture naming resulting from callosal disconnection
Dissociation of letter and picture naming resulting from callosal disconnection
复制标题
胼胝体断开导致字母和图片命名分离
作者：
Kyoko Suzuki;A. Yamadori;K. Endo;T. Fujii;M. Ezura;A. Takahashi
背景：人类胼胝体功能分离的详细定位仍然不完整。目的：研究胼胝体纤维（尤其是压部）对视觉信息的可分离的半球间传递。研究方法：我们检查了一个14岁男孩的胼胝体分离的迹象，病变局限于压部的后部，并回顾了胼胝体病变的报告病例。结果与结论：该患者以左侧失读症为唯一的胼胝体分离综合征表现。唯一的困难表现在阅读或抄写字母时，这些字母是用他的右手通过速示镜呈现给左视野的。然而，他可以用左手复制呈现在他左视野中的字母。因此，左侧失读症不是由于偏侧弱视或偏侧弱视。左侧视野无图像和颜色的命名障碍。MRI显示病变仅限于压部的腹后端。回顾40例胼胝体病变的报告表明，压部的前部到中部参与了从语言非优势半球到语言优势半球的图片信息的传输，腹后部参与了字母信息的传输。
Background: Detailed mapping of the corpus callosum for functional fractionation in humans remains incomplete. Objective: To examine separable interhemispheric transfer of visual information by callosal fibers, especially in the splenium. Methods: We examined callosal disconnection signs in a 14-year-old boy with a lesion confined to the posterior part of the splenium and reviewed reported cases with callosal lesions. Results and Conclusion: The patient presented with left hemialexia as the only manifestation of callosal disconnection syndrome. The only difficulty demonstrated was in reading aloud or copying letters, which were presented tachistoscopically to the left visual field, with his right hand. He could copy letters presented to his left visual field with his left hand, however. Therefore, left hemialexia was not due to hemiamblyopia or hemineglect. There was no anomia for pictures and colors in the left visual field. MRI revealed that the lesion was limited to the ventroposterior end of the splenium. Review of 40 reported patients with callosal lesions suggests that the anterior to middle part of the splenium is involved in transferring picture information from the language-nondominant hemisphere to the language-dominant hemisphere and that the ventroposterior part is involved in transferring letter information.