title: Altered white matter connectivity in never-medicated patients with schizophrenia.
abstract: Numerous diffusion tensor imaging (DTI) studies have implicated white matter brain tissue abnormalities in schizophrenia. However, the vast majority of these studies included patient populations that use antipsychotic medication. Previous research showed that medication intake can affect brain morphology and the question therefore arises to what extent the reported white matter aberrations can be attributed to the disease rather than to the use of medication. In this study we included 16 medication-naïve patients with schizophrenia and compared them to 23 healthy controls to exclude antipsychotic medication use as a confounding factor. For each subject DTI scans and magnetization transfer imaging (MTI) scans were acquired. A new tract-based analysis was used that combines fractional anisoptropy (FA), mean diffusivity (MD) and magnetization transfer ratio (MTR) to examine group differences in 12 major white matter fiber bundles. Significant group differences in combined FA, MD, MTR values were found for the right uncinate fasciculus and the left arcuate fasciculus. Additional analysis revealed that the largest part of both tracts showed an increase in MTR in combination with an increase in MD for patients with schizophrenia. We interpret these group-related differences as disease-related axonal or glial aberrations that cannot be attributed to antipsychotic medication use.
authors.affiliation: Rudolf Magnus Institute of Neuroscience, Department of Psychiatry, University Medical Center Utrecht, Heidelberglaan 100, Utrecht, The Netherlands. rmandl@umcutrecht.nl
authors.forename: René C W
authors.initials: RC
authors.lastname: Mandl
authors.forename: Monica
authors.initials: M
authors.lastname: Rais
authors.forename: Gertrudis Caroline M
authors.initials: GC
authors.lastname: van Baal
authors.forename: Neeltje E M
authors.initials: NE
authors.lastname: van Haren
authors.forename: Wiepke
authors.initials: W
authors.lastname: Cahn
authors.forename: René S
authors.initials: RS
authors.lastname: Kahn
authors.forename: Hilleke E
authors.initials: HE
authors.lastname: Hulshoff Pol
mesh_terms: D056324:Diffusion Tensor Imaging; D005260:Female; D006801:Humans; D007090:Image Interpretation, Computer-Assisted; D008297:Male; D009413:Nerve Fibers, Myelinated / Q000473:pathology*; D009434:Neural Pathways / Q000473:pathology*; D012559:Schizophrenia / Q000473:pathology*; D055815:Young Adult