Ohnaka K, Sakurai Y, Fuse S, Shimpo T, Kaga K
Department of Neurology, International Medical Center of Japan.
Rinsho Shinkeigaku. 1995 Mar;35(3):290-5.
We report a patient with pure word deafness after subcortical hemorrhage in the left temporal lobe. Repetition and auditory comprehension were severely impaired, while reading and visual comprehension of the same material were almost normal. He did not show hearing loss, but speech discrimination and melody recognition was poor. On the speech discrimination test, his score was low especially in the right ear. The threshold on the directional hearing test was mildly elevated. There was no temporal summation by click sounds. CT and MRI disclosed a subcortical hematoma in the left superior temporal gyrus. PET demonstrated hypoperfusion in the surrounding area, which was not activated by hearing a story. It was considered that pure word deafness in this case was due to the interruption of auditory inputs to Wernicke's area from both hemisphere by the hematoma. After 5 months, auditory comprehension recovered so that he did not have difficulty in conversation. Speech discrimination improved in both ears, probably due to the recovery of two auditory pathways; the ipsilateral pathway through the left auditory radiation and the contralateral pathway through the right auditory radiation and the corpus callosum. This case suggests that in pure word deafness due to a unilateral lesion, the improvement in speech discrimination during follow-up period may provide a clue as to the site of the responsible lesion and its recovery.
我们报告了一例左颞叶皮质下出血后出现纯词聋的患者。复述和听觉理解严重受损，而对相同材料的阅读和视觉理解几乎正常。他没有听力损失，但言语辨别和旋律识别能力较差。在言语辨别测试中，他的得分很低，尤其是右耳。定向听力测试的阈值轻度升高。点击声未出现时间总和现象。CT和MRI显示左颞上回皮质下血肿。PET显示周围区域灌注不足，听故事时该区域未被激活。认为该病例中的纯词聋是由于血肿阻断了来自双侧半球的听觉输入至韦尼克区。5个月后，听觉理解恢复，他在对话中没有困难。双耳的言语辨别能力均有所改善，这可能是由于两条听觉通路的恢复：通过左听辐射的同侧通路以及通过右听辐射和胼胝体的对侧通路。该病例表明，在单侧病变导致的纯词聋中，随访期间言语辨别能力的改善可能为责任病变的部位及其恢复情况提供线索。
