Pillon B, Signoret J L, Lhermitte F
Rev Neurol (Paris). 1981;137(12):831-42.
Visual agnosia following ischaemic accidents of the left posterior cerebral artery is often associated with intellectual deficiencies, memory disorders, elementary perceptive disturbances and elements of visuoverbal disconnection, with the result that some authors reject the notion of visual agnosia. By using a relatively simple examination procedure it is, however, possible to clearly differentiate the various disturbances, as shown by the case of a right-handed 66-year-old man in whom this type of vascular accident occurred. Neither the reduced intellectual capacities nor the memory disorders can explain the differences observed in the treatment of visual stimuli, which was very disturbed, and the normal treatment of other types of stimulus. Elementary difficulties are not sufficient to prevent correct discrimination, as all tests of matching object, images, colours, and graphic signs were successfully accomplished. Identification was disturbed however: the patient could not show the use of objects presented visually, and this disorder is related to the visual characteristics of the stimuli, which excludes a simple visuogestural disconnection; results of tests of classifying types of object images, colours, and graphic signs were markedly abnormal. Naming of these stimuli was also affected, even when they were correctly identified; this results from the visuoverbal disconnection associated with the agnosia, but it is insufficient to account for it, as the patient could correctly use objects that had been wrongly named, but could not use those that had been poorly identified. This case, therefore, has enabled a visual identification disorder to be isolated independently from a discrimination problem, and visuoverbal or visuogestural disconnections. It is the significance of ths stimulus that is disturbed. In contrast, functional or categorical classification is respected in right temporo-occipital lesions. It is the individuality of a stimulus within a physical category which is disturbed.
左大脑后动脉缺血性病变后出现的视觉失认症常伴有智力缺陷、记忆障碍、基本感知障碍以及视言语分离的表现，因此一些作者反对视觉失认症这一概念。然而，通过使用一种相对简单的检查程序，可以清楚地区分各种障碍，一名66岁右利手男性发生此类血管病变的病例就说明了这一点。智力能力下降和记忆障碍都无法解释在视觉刺激处理方面观察到的差异，视觉刺激处理受到严重干扰，而对其他类型刺激的处理则正常。基本困难不足以妨碍正确辨别，因为所有关于匹配物体、图像、颜色和图形符号的测试都成功完成了。然而，识别受到了干扰：患者无法展示对视觉呈现物体的使用，这种障碍与刺激的视觉特征有关，这排除了单纯的视手势分离；对物体图像、颜色和图形符号类型进行分类的测试结果明显异常。对这些刺激的命名也受到了影响，即使它们被正确识别；这是由与失认症相关的视言语分离导致的，但这不足以解释全部情况，因为患者能够正确使用被错误命名的物体，但不能使用那些识别不佳的物体。因此，这个病例使得能够将视觉识别障碍与辨别问题、视言语或视手势分离独立开来。受到干扰的是刺激的意义。相比之下，右侧颞枕叶病变时功能或类别分类是正常的。受到干扰的是物理类别内刺激的个体性。
