Complex pattern of cortical thinning in schizophrenia: Results from an automated surface based analysis of cortical thickness

Abstract 

A considerable body of evidence from structural brain imaging studies suggests that patients with schizophrenia have significant alterations of gray matter density. Additionally, recently developed surface-based analysis approaches demonstrate reduced cortical thickness in patients with schizophrenia. However, the number of studies employing this relatively new method is still limited. Specifically, little is known about changes in cortical thickness in schizophrenia patients whose duration of illness is relatively short. Therefore, the present study sought to examine cortical thickness in a large sample of patients with adult onset schizophrenia and an average duration of illness of 4.4years, using an automated analysis method over the entire cortex. A significantly decreased cortical thickness in prefrontal and temporolimbic regions as well as parieto-occipital cortical areas was hypothesized. A sample of 58 patients with schizophrenia and 58 age- and sex-matched healthy controls was investigated using high-resolution magnetic resonance imaging (MRI) and an automated algorithm for extraction of the cortical surface in order to assess local cortical thinning across the entire cerebrum. Significant reduction of cortical thickness in schizophrenia was found in a spatially complex pattern of focal anatomical regions. This pattern comprised the dorsolateral prefrontal cortex as well as the medial prefrontal cortex, lateral temporal cortices, left entorhinal cortex, posterior cingulate cortex, precuneus and lingual cortex, bilaterally. A complex fronto-temporo-parietal pattern of reduced cortical thickness in schizophrenia was observed. This pattern is consistent with a disruption of neurofunctional networks previously implicated in the pathophysiology of schizophrenia.

Keywords: Entire cortex analysis, Entorhinal, Temporolimbic, Prefrontal, Parietal, Occipital, Medial surface, FreeSurfer