Longitudinal magnetic resonance imaging study of schizophrenia and schizophreniform disorder / Avaliação longitudinal de pacientes portadores de esquizofrenia e transtorno esquizofreniforme utilizando ressonância magnética de crânio

AUTOR(ES)
DATA DE PUBLICAÇÃO

2008

RESUMO

Morphometric brain abnormalities have been extensively described in subjects with schizophrenia in many structural magnetic resonance imaging studies, the most consistent findings being ventricular enlargement and gray matter reductions in frontal and temporal neocortices, insula, thalamus and hippocampus/parahippocampal gyri. However, the nature and course of these abnormalities have not yet been clarified. Although the main hypothesis regarding the etiopathology of schizophrenia implies the presence of early and stable anatomical brains abnormalities, longitudinal magnetic resonance imaging studies have suggested that, despite being present at the first episode of psychosis, or even before its onset, some brain abnormalities may be progressive, especially at the first few years of the disorder. In the present study, gray matter volumes were compared, at baseline and longitudinally, between first-episode patients with schizophrenia or schizophreniform disorder and non-psychotic controls. Structural magnetic resonance images from 62 patients and 94 controls, recruited from the same catchment area for an epidemiological study in the city of São Paulo, were acquired using a 1.5 Tesla scanner. After a mean period of 16 months, 39 patients and 52 controls were rescanned. Images were analyzed by voxel-based morphometry with the Statistical Parametric Mapping software and statistical significance was set at p<0.05, corrected for multiple comparisons. The initial betweengroup comparison revealed gray matter reductions in patients, when compared to controls, in the right and left prefrontal cortices, left superior temporal cortex, bilateral insula and right hippocampus and parahipocampal gyrus. Longitudinally, patients exhibited significantly greater gray matter preservation in left superior temporal cortex and right hippocampus/ parahipocampal gyrus. There were no areas showing significantly greater gray matter loss in patients relative to controls in the longitudinal analysis. There were no gray matter differences between medicated and unmedicated patients, neither at baseline nor at follow-up. The findings of the baseline comparison are in accordance with previous studies that reported brain abnormalities in association with first episode psychosis. The longitudinal results are in accordance with some of the follow-up neuroimaging studies conducted to date and support the hypothesis that the described abnormalities could have been present before the onset of illness. Also, these findings suggest that, at least considering the follow-up interval of our study, such brain changes are not progressive. The volumetric differences between patients and controls observed in our study were not caused by antipsychotic medication effects

ASSUNTO(S)

córtex cerebral esquizofrenia magnetic resonance imaging imagem por ressonância magnética estudos longitudinais cerebral cortex longitudinal studies schizophrenia

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