Fiber tracking of white matter integrity connecting the mediodorsal nucleus of the thalamus and the prefrontal cortex in schizophrenia: a diffusion tensor imaging study.

The goal of this study was to detect abnormalities in white matter integrity connecting the mediodorsal nucleus of the thalamus and the prefrontal cortex using fiber-tracking technique. Diffusion tensor imaging was acquired in 20 patients with schizophrenia and 20 normal comparison subjects. Fiber tracking was performed on the anterior thalamic peduncle, and the tractography was used to determine the cross-sectional area, mean fractional anisotropy, and standard deviation of fractional anisotropy for every step separately in the right and left hemispheres. Compared with normal subjects, patients showed a significant reduction in the cross-sectional area of the left anterior thalamic peduncle. There were no significant differences for the mean fractional anisotropy bilaterally between the two groups, but significant differences for the standard deviation of fractional anisotropy in both hemispheres. Reduction in the cross-sectional area of the left anterior thalamic peduncle suggests the presence of the failure of left-hemisphere lateralization. In schizophrenic patients a significant increase of the standard deviation of fractional anisotropy raise the possibility that the inhomogeneity of white matter integrity, which is densely or sparsely distributed by site. These findings might provide further evidence for disruption of white matter integrity between the thalamus and the prefrontal cortex in schizophrenia.