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(Reference retrieved automatically from SciELO through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

Topographic abnormality of slow cortical potentials in schizophrenia

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Author(s):
L.F.H. Basile [1] ; J. Yacubian [2] ; B.L.C. Ferreira [3] ; A.C. Valim [4] ; W.F. Gattaz [5]
Total Authors: 5
Affiliation:
[1] Universidade de São Paulo. Faculdade de Medicina. Departamento de Psiquiatria - Brasil
[2] Universidade de São Paulo. Faculdade de Medicina. Departamento de Psiquiatria - Brasil
[3] Universidade de São Paulo. Faculdade de Medicina. Departamento de Psiquiatria - Brasil
[4] Universidade de São Paulo. Faculdade de Medicina. Departamento de Psiquiatria - Brasil
[5] Universidade de São Paulo. Faculdade de Medicina. Departamento de Psiquiatria - Brasil
Total Affiliations: 5
Document type: Journal article
Source: Brazilian Journal of Medical and Biological Research; v. 37, n. 1, p. 97-109, 2004-01-00.
Abstract

A recent study from our laboratory has provided evidence for the generation of slow potentials occurring in anticipation to task-performance feedback stimuli, in multiple association cortical areas, consistently including two prefrontal areas. In the present study, we intended to determine whether these slow potentials would indicate some abnormality (topographic) in schizophrenic patients, and thus serve as an indication of abnormal association cortex activity. We recorded slow potentials while subjects performed a paired-associates memory task. A 123-channel EEG montage and common average reference were used for 20 unmedicated schizophrenic (mean duration of illness: 11.3 ± 9.2 years; mean number of previous hospitalizations: 1.2 ± 1.9) and 22 healthy control subjects during a visual paired-associates matching task. For the topographic analysis, we used a simple index of individual topographic deviation from normality, corrected for absolute potential intensities. Slow potentials were observed in all subjects. Control subjects showed a simple spatial pattern of voltage extrema (left central positive and right prefrontal negative), whereas schizophrenic patients presented a more complex, fragmented pattern. Topographic deviation was significantly different between groups (P < 0.001). The increased topographic complexity in schizophrenics could be visualized in grand averages computed across subjects. Increased topographic complexity could also be seen when grand averages were computed for subgroups of patients assembled either according to task-performance (high versus low) or by their scores on psychopathological scales. There was no significant correlation between topographic deviation and psychopathology scores. We conclude that the slow potential topographic abnormalities of schizophrenia indicate an abnormality in the configuration of large-scale electrical activity in association cortices. (AU)

FAPESP's process: 97/11083-0 - Metabolism of phospholipids in schizophrenia and Alzheimer's disease
Grantee:Wagner Farid Gattaz
Support Opportunities: Research Projects - Thematic Grants
FAPESP's process: 98/07640-3 - Phospholipid metabolism in Alzheimer's disease and schizophrenia (4): electrophysiology of the frontal cortex in schizophrenia and in Alzheimer's disease
Grantee:Luis Fernando Hindi Basile
Support Opportunities: Scholarships in Brazil - Post-Doctoral