首发精神分裂症患者威斯康星卡片分类测验中的脑功能障碍研究

摘要

目的：探讨首发未服药精神分裂症患者进行威斯康星卡片分类测验（WCST）操作时的脑功能状态特点。方法：20名健康受试者（对照组）和20名首发未服药精神分裂症患者（患者组）操作 WCST 和颜色卡片分类测验（CCST）时进行脑功能磁共振成像（fMRI），比较2组激活脑区的激活体积。结果：对照组 WCST 和CCST 功能图像相减获得的脑活动功能图像显示，激活主要分布在双侧前额叶，尤其是背外侧部以及顶叶后下部皮质和前扣带回。患者组 WCST 操作成绩较对照组差，有显著性差异（<0.01）。与对照组相比，患者组的左侧前额叶背外侧部、左前扣带回皮质激活低下，左顶叶后下部皮质激活增加（<0.01或0.05）。结论：双侧前额叶，尤其是背外侧部，以及顶叶后下部皮质和前扣带回皮质参与 WCST 操作的高级认知过程。精神分裂症患者在未治疗前就存在执行功能缺陷，其前额叶和扣带回功能低下，可能与患者执行功能障碍相关；后顶叶皮质功能亢进，可能对前额叶功能低下有补偿作用。%ObjectiveTo explore the characteristics of cerebral activation during the performance of Wisconsin card sorting test (WCST) in newly-developed schizophrenic patients without drug therapy. Methods: Twenty healthy subjects (control group) and twenty schizophrenic patients (patients group) underwent functional MRI (fMRI) during the performance of WCST and Color card sorting test (CCST). The active volume of the interested brain areas were compared between the 2 groups. Results: The images subtracted the functional images of CCST from those of WCST in the control group suggested that activations were mainly localized in the bilateral frontal lobes, especially in the dorsolateral prefrontal cortices, posterior parietal cortices and anterior cingulate gyry. The performance of WCST in the schizophrenic group were significantly lower than that in the healthy group ( <0.01). The patients showed less activations in the left dorsolateral prefrontal cortex, and left anterior cingulated, but more activations in the left posterior parietal cortex, relative to the controls ( <0.01 or 0.05). Conclusion: The bilateral frontal lobes, especially the dorsolateral prefrontal cortices, anterior cingulate gyri and posterior parietal cortices are involved in higher cognitive components of performance of WCST. Schizophrenic patients have executive function disorder at the initial stage of the disease. Evidences from fMRI indicate that the brain areas of patients including the left dorsolateral prefrontal cortex and left anterior cingulate are hypoactivative and hypofunctional whereas the posterior parietal cortices are hyperactive. The dysfunction of the prefrontal cortices and anterior cingulate cortices may be associated with the executive function disorder in schizophrenia. The hyperactivity of the posterior parietal cortices may compensate the hypofrontality to certain degree.