Basile Luis F H, Yacubian Juliana, de Castro Claudio C, Gattaz Wagner F
University of São Paulo, Department of Psychiatry, Laboratory of Neurosciences (LIM-27), Faculty of Medicine, Av. Dr Ovidio Pires de Campos s/n, P.O. Box 3671, São Paulo, SP 05403-010, Brazil.
Schizophr Res. 2004 Aug 1;69(2-3):255-66. doi: 10.1016/j.schres.2003.09.018.
The purpose of this study was to compare slow cortical electrical activity between healthy and schizophrenic individuals using 123-channel EEG and current density reconstruction (CDR). Twenty-nine healthy subjects and 14 drug-free patients performed three visual paired-associate tasks (verbal, pictorial and spatial). We modeled the generators of the slow potentials (SPs) at their peak amplitude by Lp-norm minimization using individual MRIs to model the volume conductor and source. Activity in each architectonic area of Brodmann was scored with respect to individual maximum current by a percentile method. Resulting scores by cortical area were analyzed by multivariate analysis of variance (MANOVA) with planned comparisons, to search for differences among levels. Results showed a multifocal pattern of current density foci comprising the SP generators, including frontal and posterior cortices in all subjects. A few cortical areas, not exclusively frontal, were observed to significantly differ between groups. Moreover, changes in patients' frontal activity were not exclusively to lower scores or 'hipofrontality': overall effects (all tasks collapsed) included increased electrical activity in right area 10, left 38 and 47 bilaterally, and decreased activity in right area 6 and left areas 39, 21 and 19. A few additional areas showed significantly altered activity only in particular tasks. We conclude that the present method, by preserving individual anatomical and functional information, indicates bidirectional patterns of altered electrical activity in specific cortical association areas in schizophrenia, which are not compatible with the exclusive 'hipofrontality' hypothesis. Our results agree with the hypothesis of schizophrenia as a syndrome resulting from abnormalities in multiple encephalic foci.
本研究的目的是使用123通道脑电图和电流密度重建（CDR）比较健康个体和精神分裂症患者之间的慢皮层电活动。29名健康受试者和14名未服用药物的患者进行了三项视觉配对联想任务（言语、图像和空间）。我们使用个体磁共振成像（MRI）对容积导体和源进行建模，通过Lp范数最小化在慢电位（SP）峰值幅度处对其发生器进行建模。根据个体最大电流，采用百分位数法对Brodmann每个构筑区域的活动进行评分。通过多变量方差分析（MANOVA）和计划比较对各皮层区域的得分结果进行分析，以寻找不同水平之间的差异。结果显示，电流密度焦点呈现多灶性模式，包括所有受试者的额叶和后皮质中的SP发生器。观察到几组之间在一些并非仅为额叶的皮层区域存在显著差异。此外，患者额叶活动的变化并非仅表现为得分降低或“额叶功能低下”：总体效应（所有任务汇总）包括右侧10区、双侧左侧38区和47区的电活动增加，以及右侧6区和左侧39区、21区和19区的活动减少。一些其他区域仅在特定任务中显示出显著改变的活动。我们得出结论，本方法通过保留个体解剖和功能信息，表明精神分裂症患者特定皮层联合区域存在电活动改变的双向模式，这与排他性的“额叶功能低下”假说不相符。我们的结果与精神分裂症是由多个脑区异常导致的综合征这一假说一致。
