Neurospychological Studie of the Mechanism of Higher Brain Function Using Brain Damaged Patients with Pure Syndrome

我们调查了许多脑损伤患者，包括几种类型的纯文字综合征，并获得以下结果：1）一名60岁的右利手男性突然出现严重的纯文字哑巴和轻微的书写困难。在出现症状的第二天获得的CT显示右额叶有一个界限清楚的陈旧性梗死。MRI显示病变位于中央前回下部和第三额回隐带部，左侧额前回下部也有新发梗死。2）对4例面孔失认症患者（2例双侧，2例单侧）进行了熟悉面孔和陌生面孔的视知觉测试。结果表明：（1）面孔失认症可作为一种孤立的症状发生，而不伴有其他视知觉和视认知功能障碍;（2）面孔失认症可发生于一侧枕颞区（包括舌回和梭状回）病变后。作为面孔失认症的发病机制，有观点认为存储在颞叶视联合皮层中的熟悉面孔的记忆不能被视皮层充分处理的视觉输入激活，除此之外，我们还调查了另外几例患者，包括一名单纯失读者，他表现出选择性KANA阅读障碍，1例左手失能和1例左手异常抓握患者均在半卵圆中心沿着大脑纵裂出现长而窄的梗死，右侧单侧压后皮质梗死后地形记忆丧失2例等。

We investigated many brain damaged patients including several types of pure syndrome and obtained following results.1)A 60-year-old, right-handen man suddenly developed severe pure word dumbness and slight dysgraphia. CT obtained in the second day of symptom shows a well defined old infarcrtion in the right frontal lobe. MRI reveals the lesion localized in the lower part of the precentrasl gyrus and pars opacularis of the third frontal gyrus, and also new infarction in the lower part of the left prefrontal gyrus. It is obvious that the first infarction in the right frontal lobe did not show any symptom and the second infarction occured in the similar parts of the-left hemisphere ca used severe pure word dumbness.2)Four prosopagnosic patients, two were bilateral and two were unilateral infarction in the teritory of the posterior cerebrtal artery, were investigated with several visuo-perceptual tests including familiar and unfamiliar faces. The results indecated that(1)the prosopagnosia can be occured as a isolated symptom without any other visuo-perceptual and vvisuo-cognitive deficits, (2)the prosopagnosia can be occured after unilateral right occipitotemporal lesion including lingual and fusiform gyrie. As the mechanism of the prosopagnosia, it was suggested that the memories of the familiar faces stored in the temporal visual association cortex were not activated by the visual inputs processed adequately in the visual cortices.Besides those patients we investigated several other patients including a pure alexic showing selective impairment of KANA reading, a left-hand apraxic and a patient with left-hand abnormal grasping both had a long and narrow infarction in the centrume semiovale along the longitudinal cerebral fissure, two patients with topographical memory loss after right unilateral infarction in the retrosplenial cortex etc.