Shanghai Mental Health Center, Shanghai Jiaotong University School of Medicine, Shanghai 200030, China.
Int J Psychophysiol. 2010 Mar;75(3):249-57. doi: 10.1016/j.ijpsycho.2009.12.005. Epub 2009 Dec 24.
Decreased P300 amplitude has been reported in schizophrenics during their first episode. The brain sources that contribute to this abnormality have not yet been well documented, and were investigated in the present study using high density EEG recordings. Nineteen drug-naive first episode schizophrenics were compared to 25 normal controls. Auditory P300 was elicited using an oddball paradigm. The brain sources of P300 ERP were reconstructed by performing low resolution of electromagnetic tomography (LORETA) analysis. No group difference in P300 latency was found. P300 amplitude was smaller for schizophrenics than for controls. Topographical analysis revealed that P300 amplitude reduction in schizophrenics was significant over left and medial regions of interest (ROIs). LORETA analysis of the P300 peak revealed that, the brain sources of P300 were symmetrically distributed over left and right hemispheres among the normal controls, but were asymmetrically distributed among the patients, with a reduction predominantly over the left temporal area. Statistical non-Parametric Mapping analysis identified 29 voxels of a significant group difference, which focused on left insula, left superior temporal gyrus (STG) and left postcentral gyrus (PCG). In addition, the mean P300 current source density over left insula, left STG and left PCG correlated inversely with the patients' Positive and Negative Syndrome Scale scores. The neural substrates that contributed to the decreased P300 amplitude in drug-naive first episode schizophrenia relatively focused on left STG and its nearby areas. These areas are probably involved in the pathogenesis of schizophrenia, and possible mechanisms for pathology need to be further clarified.
首次发病的精神分裂症患者的 P300 波幅降低已有报道。导致这种异常的大脑源尚未得到很好的记录，并在本研究中使用高密度 EEG 记录进行了研究。将 19 名未经药物治疗的首发精神分裂症患者与 25 名正常对照进行比较。使用Oddball 范式诱发听觉 P300。通过进行低分辨率电磁断层成像（LORETA）分析来重建 P300 ERP 的大脑源。未发现潜伏期的组间差异。与对照组相比，精神分裂症患者的 P300 波幅较小。拓扑分析显示，精神分裂症患者的 P300 波幅减少在左和内侧感兴趣区域（ROI）显著。P300 峰值的 LORETA 分析表明，正常对照组的 P300 大脑源在左右半球对称分布，但患者的 P300 大脑源不对称分布，主要集中在左颞区。统计非参数映射分析确定了 29 个具有显著组间差异的体素，这些体素主要集中在左侧岛叶、左侧颞上回（STG）和左侧后中央回（PCG）。此外，左侧岛叶、左侧 STG 和左侧 PCG 上的平均 P300 电流源密度与患者的阳性和阴性症状量表评分呈负相关。导致药物初发精神分裂症患者 P300 波幅降低的神经基础相对集中于左侧 STG 及其附近区域。这些区域可能与精神分裂症的发病机制有关，需要进一步阐明其病理机制。
