The thalamus, an important subcortical brain region connecting limbic and prefrontal
cortices, has a significant role in sensory and cortical processing. Although inconsistently,
previous studies have demonstrated neuroanatomical abnormalities in the thalamus of
schizophrenic patients.
This structural magnetic resonance imaging study, based on segmentation of contiguous
coronal 1.5-mm images, compared thalamic brain volumes of 15 chronic, male schizophrenic
patients with 15 normal controls matched on age, sex, handedness, and parental socioeconomic
status.
There were no significant differences between patients and controls in thalamic volumes,
right or left, adjusted for total brain volume; however, there were significantly
different correlations of thalamic volumes with prefrontal white matter and lateral
ventricles among patients, but not among controls. Thalamic volumes among patients
were also significantly correlated with bizarre behavior, hallucinations, and thought
disorder.
Findings suggest that connectivity between thalamic nuclei and prefrontal cortical
areas are abnormal in chronic male schizophrenic patients. In addition, ventricular
enlargement may be, in part, due to subtle reduction in thalamic volume and/or in
volume of thalamocortical and corticothalamic fibers secondary to thalamic abnormalities.
Finally, correlations with positive symptomatology underscore the role of the thalamus
in gating or filtering of sensory information and coordination of cortical processing.