VOLUMETRIC EVALUATION OF THE THALAMUS IN SCHIZOPHRENIC MALE-PATIENTS USING MAGNETIC-RESONANCE-IMAGING

Background: The thalamus, an important subcortical brain region connec ting limbic and prefrontal cortices, has a significant role in sensory and cortical processing. Although inconsistently, previous studies ha ve demonstrated neuroanatomical abnormalities in the thalamus of schiz ophrenic patients. Methods: This structural magnetic resonance imaging study, based on segmentation of contiguous coronal 1.5-mm images, com pared thalamic brain volumes of 15 chronic, male schizophrenic patient s with 15 normal controls matched on age, sex, handedness, and parenta l socioeconomic status. Results: There were no significant differences between patients and controls in thalamic volumes, right or left, adj usted for total brain volume; however there were significantly differe nt correlations of thalamic volumes with prefrontal white matter and l ateral ventricles among patients, but not among controls. Thalamic vol umes among patients were also significantly correlated with bizarre be havior, hallucinations, and thought disorder. Conclusions: Findings su ggest that connectivity between thalamic nuclei and prefrontal cortica l areas are abnormal in chronic male schizophrenic patients. In additi on, ventricular enlargement may be, in part, due to subtle reduction i n thalamic volume and/or in volume of thalamocortical and corticothala mic fibers secondary to thalamic abnormalities Finally, correlations w ith positive symptomatology underscore the role of the thalamus in gat ing or filtering of sensory information and coordination of cortical p rocessing. (C) 1998 Society of Biological Psychiatry.