PET study of dopamine D1 and D2 receptors in epilepsy and epileptic psychosis.

自世纪以来，精神病学家一直对癫痫患者的精神病状态感兴趣。在先前的临床描述中报告了癫痫精神分裂症样精神病（SLPE）的特征;（a）癫痫患者发生精神分裂症样精神病的可能性是一般人群的6-12倍，（B）癫痫发作后约10-15年发生精神病，（c）颞叶癫痫患者发生精神病的风险最高。为了研究精神分裂症和SLPE之间的关系，结构和功能神经影像学技术越来越不可或缺。关于癫痫精神病患者的神经化学异常，与无精神病的患者相比，已证明精神病患者中碘-123 IBZM（多巴胺D2受体拮抗剂）与多巴胺D2受体的特异性结合减少。这一结果支持精神分裂症的“多巴胺假说”。那里 ...更多信息 越来越多的证据表明，纹状体外D2受体，尽管其密度低，有病理生理意义的精神分裂症。我们使用CBA（计算机脑图谱），探索纹状体外分布的D2受体在13名健康受试者使用[11 C]FLB 457，取代苯甲酰胺具有非常高的亲和力D2和D3受体。大脑皮层显示出较低的水平，具有显着的区域差异。结合率最高的是颞叶皮层和海马，其次是前扣带回，顶叶和额叶皮层，但最低的是枕叶皮层。使用CBA分析[11 C]FLB 457结合，使得有可能在活体人脑中建立纹状体外D2受体的正常数据库。此外，我们的目的是检查精神分裂症患者的纹状体外D2受体。使用[11 C]FLB 457对11例首次用药的男性精神分裂症患者进行了正电子发射断层扫描检查。并与18名健康对照组进行比较。使用参考组织方法进行感兴趣区域分析，并将结合电位（BP）用于多巴胺D2受体结合的指数。首次用药的精神分裂症患者前扣带回BP值较正常对照组显著降低约12%。纹状体外区D2受体功能的改变可能是精神分裂症阳性症状的基础。最后，我们检查了一组SLPE患者，并将其与一组无精神病的癫痫患者和正常数据库进行比较。目前，我们已经完成了对[11 C] FLB 457 PET图像的检查评估，未发现多巴胺D2受体分布的显著差异。进一步的分析，使用复杂的方法，如逐像素分析是必要的。少

Since the nineteenth century, psychiatrists have been interested in psychotic states in epileptic patients. The characteristics of schizophrenia-like psychosis of epilepsy(SLPE)were reported in the previous clinical description ; (a)schizophrenia-like psychosis is 6-12 times more likely to occur in epileptic patients than in the general population, (b)the onset of psychosis follows some 10-15 years after the onset of the epilepsy, and(c)the risk to occur the psychosis is highest for patients with temporal lobe epilepsy. To study the association between schizophrenia and SLPE, structural and functional neuroimaging techniques are increasingly indispensable. As regards neurochemical abnormalities of psychotic patients with epilepsy, reduced specific binding of Iodine-123 IBZM(dopamine D2 receptor antagonist)to strial D2 receptors have been demonstrated in the psychotic patients compared to those without psychosis. This result support to the "dopamine hypothesis" for schizophrenia. There … More is growing evidence that extrastriatal D2 receptors, in spite of their low density, have pathophysiological significance for schizophrenia. We used the CBA(computerized brain atlas)to explore the extrastriatal distribution of D2 receptors in 13 healthy subjects using[11C]FLB 457, a substituted benzamide with very high affinity for D2 and D3 receptors. The cerebral cortices showed lower levels with significant regional differences. Binding was highest in the temporal cortex and hippocampus followed by the anterior cingulate gyrus, and the parietal and frontal cortices, but was lowest in the occipital cortex. The use of CBA for analysis of[11C]FLB 457 binding makes it possible to build a normal database for the extrastriatal D2 receptors in the living human brain. Further, we aimed to examine the extrastriatal D2 receptors of patients with schizophrenia. Eleven drug-naive male patients with schizophrenia were examined with positron emission tomography using[11C]FLB 457. Comparison was made with 18 healthy controls. Region of interest analysis was performed using the reference tissue method and binding potential(BP)was used for the index of dopamine D2 receptor binding. The BP value was significantly lower in the anterior cingulate cortex about 12% in drug naive patients with schizophrenia than in normal controls. Alteration in D2 receptor function in the extrastriatal region may underlie the positive symptoms of schizophrenia. Finally, we examined a group of SLPE patients and compared them with a group of epileptic patients without psychosis and a normal data base. At the present, we have completed inspective evaluation of[11C]FLB457 PET images and have found no remarkable difference in the distribution of dopamine D2 receptors. Further analysis using sophisticated method such as pixel-by-pixel analysis is need to conclude. Less