Tokunaga H, Nishikawa T, Ikejiri Y, Nakagawa Y, Yasuno F, Hashikawa K, Sugita Y, Takeda M
Medical Science for Health, 3rd Div., Faculty of Health & Sport Sciences, Osaka University, Toyonaka, Japan.
No To Shinkei. 1999 Feb;51(2):171-6.
We examined a drawing ability in a case with pure agraphia. The patient, having lesions in the left middle frontal gyrus and inferior parietal lobule, could not write in both dictation and spontaneous writing tasks, with the ability to copy letters being well spared. Correspondingly, he showed a deficit of spontaneous drawing, with the ability to copy complex figures being well spared. These findings suggest that he could have an impairment of retrieving visual image, not restricted to letter image. Although some previous cases with pure agraphia were attributed to an impairment of retrieving visual letter image, drawing ability which seemed to be related to retrieving visual image had not been investigated. In the present case, disability of both writing and drawing could be attributed to a common mechanism, that was an impairment of retrieving visual image. In addition, the patient did not show a significant difference between the performance on Kana writing and on Kanji writing. But it has been said that an impairment of retrieving visual letter image could be related to a deficit of Kanji writing more than of Kana writing. Then, it could be assumed that the mechanism of Kana writing involved not only the pathway depending on graphical motor pattern but one depending on visual image.
我们研究了一例纯失写症患者的绘图能力。该患者左额中回和顶下小叶有病变,在听写和自发书写任务中均无法书写,但字母抄写能力保存良好。相应地,他表现出自发绘图缺陷,复杂图形抄写能力保存良好。这些发现表明,他可能存在视觉图像提取障碍,而非仅限于字母图像。尽管之前一些纯失写症病例被归因于视觉字母图像提取障碍,但与视觉图像提取似乎相关的绘图能力尚未得到研究。在本病例中,书写和绘图障碍可能归因于共同机制,即视觉图像提取障碍。此外,该患者假名书写和汉字书写表现之间无显著差异。但据说视觉字母图像提取障碍与汉字书写缺陷的关联可能大于假名书写。那么,可以推测假名书写机制不仅涉及依赖图形运动模式的通路,还涉及依赖视觉图像的通路。