Mechanism of memory impairment in patients with schizophrenia.

本研究的第一个目的是开发和检验精神分裂症患者记忆组织的评分系统。其次，我们进行了包括记忆功能在内的神经心理测试，研究了记忆功能与其他神经心理功能的关系。第三，利用磁共振成像（MRI）研究记忆表现与脑形态特征的关系，探讨记忆组织和语义记忆障碍的神经基础。对精神分裂症患者和健康正常人进行神经心理学测试，包括韦氏记忆量表、韦氏成人智力量表、语言学习测试、语言流畅性测试和卡片分类测试。对可能的受试者进行核磁共振扫描。采用韦氏记忆量表（修订版）的逻辑记忆故事或言语学习测验对记忆的组织结构进行评价。作为故事记忆的结果，精神分裂症患者在记忆组织，特别是语义序列方面的得分低于正常对照组。在言语学习测试中，精神分裂症患者无论回忆次数多少，其语义聚类表现都低于正常人，但序列聚类表现不明显。神经心理功能因子分析表明，正常被试的逻辑记忆与语言流畅性相关。另一方面，精神分裂症患者的语言流畅性与逻辑记忆和语言学习指数无关。这些结果表明，精神分裂症患者的记忆结构与正常人不同。此外，精神分裂症患者的额叶体积与记忆组织得分存在显著相关。这表明精神分裂症患者的记忆组织缺陷可能与额叶区功能障碍有关。

The first purpose of this study was to develop and examine the scoring system of memory organization for patients with schizophrenia. Second, we administered neuropsychological tests battery including memory function, and investigated the relationship between memory function and other neuropsychological functions. Third, we examined the relationship between memory performance and brain morphological feature by the Magnetic Resonance Imaging(MRI) in order to study neural basis of impairment of memory organization and semantic memory. The patients with schizophrenia and healthy normal subjects were administered a neuropsychological battery including the Wechsler Memory Scale-Revised, the Wechsler Adult Intelligence Scale-Revised, the verbal learning test, the verbal fluency test, and the card sorting test. MRI scans were obtained in the possible subjects. The organization structure of memory was evaluated with the Logical Memory stories of the Wechsler Memory Scale-Revised or the verbal learning test. As a result of story memory, schizophrenic patients showed lower scores of memory organization, particularly, semantic sequence than normal controls. In the verbal leaning test, patients with schizophrenia showed less semantic clustering than normal people irrespective of the number of recall, but not serial clustering. Factor analysis of neuropsychological functions indicated the logical memory was related to the verbal fluency in normal subjects. On the other hand, the verbal fluency was not related to the logical memory and the verbal learning index in patient with schizophrenia. These results suggest memory structure is different between patients with schizophrenia and normal people. Moreover, there was a significant relationship between frontal lobe volume and score of memory organization in patients with schizophrenia. This indicates that memory organization deficits in schizophrenia may be related to dysfunction in the frontal region.