Takada T, Sakurai Y, Takeuchil S, Sakuta M
Department of Neurology, Japanese Red Cross Medical Center.
Rinsho Shinkeigaku. 1998 Feb;38(2):154-6.
We present a patient with pure alexia following a hemorrhagic infarction in the left fusiform gyrus. The symptom began with alexia preferentially disturbed for kana, but during the course of recovery slight agraphia for kanji became pronounced. In the earlier phase, alexia was more severe than agraphia and he could write kanji that he could not read. Furthermore, kinesthetic reading was effective. These findings are consistent with the symptoms of pure alexia, although the fact that a writing disturbance for kanji persisted resembles the profile of alexia with agraphia for kanji due to a posterior inferior temporal lesion. Based on the fact that the posterior inferior temporal lesion showed more severe agraphic symptom and more frequent nonresponse writing errors of kanji, and that our patient's lesion was mainly located in the fusiform gyrus that is medial to the inferior temporal gyrus, we believe that alexia occurred when the inferior temporal gyrus was disconnected from the fusiform gyrus, as a result, visual information could not reach the inferior temporal gyrus in which the visual images of individual kanji are stored.
我们报告一例在左侧梭状回发生出血性梗死之后出现纯失读症的患者。症状始于对假名的失读优先受到干扰,但在恢复过程中,对汉字的轻度失写变得明显。在早期阶段,失读比失写更严重,他能写出自己读不出的汉字。此外,动觉阅读是有效的。这些发现与纯失读症的症状相符,尽管对汉字的书写障碍持续存在这一事实类似于因颞叶后下部病变导致的伴有汉字失写的失读症表现。基于颞叶后下部病变表现出更严重的失写症状以及更频繁的汉字无反应书写错误,且我们患者的病变主要位于颞下回内侧的梭状回这一事实,我们认为当颞下回与梭状回断开连接时发生了失读,结果视觉信息无法到达存储单个汉字视觉图像的颞下回。