title: White matter microstructure in schizophrenia: associations to neurocognition and clinical symptomatology.
abstract: BACKGROUND
  Diffusion tensor imaging (DTI) studies in schizophrenia report widespread aberrations in brain white matter (WM). These appear related to poorer neurocognitive performance and higher levels of negative and positive symptomatology. However, identification of the most salient WM aberrations to neurocognition and clinical symptoms is limited by relatively small samples with divergent results.
  
  
  METHODS
  We examined 53 well-characterized patients with schizophrenia and 62 healthy controls. All participants were administered a computerized neurocognitive battery, which evaluated performance in several domains. Patients were assessed for negative and positive symptoms. Fractional anisotropy (FA) of WM cortical regions and WM fiber tracts were compared across the groups. FA values were also used to predict neurocognitive performance and symptoms.
  
  
  RESULTS
  We confirm widespread aberrant WM microstructure in a relatively large sample of well-characterized patients with schizophrenia in comparison to healthy participants. Moreover, we illustrate the utility of FA measures in predicting global neurocognitive performance in healthy participants and schizophrenia patients, especially for reaction time. FA was less predictive of clinical symptomatology.
  
  
  CONCLUSIONS
  Using a standardized computerized neurocognitive battery and diffusion tensor imaging we show that behavioral performance is moderated by a particular constellation of WM microstructure in healthy individuals that differs in schizophrenia.
authors.affiliation: Neuropsychiatry Section, Department of Psychiatry, University of Pennsylvania Perelman School of Medicine, United States. Electronic address: roalf@upenn.edu.
authors.forename: David R
authors.initials: DR
authors.lastname: Roalf
authors.affiliation: Neuropsychiatry Section, Department of Psychiatry, University of Pennsylvania Perelman School of Medicine, United States; Department of Radiology, University of Pennsylvania Perelman School of Medicine, United States.
authors.forename: Raquel E
authors.initials: RE
authors.lastname: Gur
authors.affiliation: Department of Radiology, University of Pennsylvania Perelman School of Medicine, United States.
authors.forename: Ragini
authors.initials: R
authors.lastname: Verma
authors.affiliation: Department of Radiology, University of Pennsylvania Perelman School of Medicine, United States.
authors.forename: William A
authors.initials: WA
authors.lastname: Parker
authors.affiliation: Neuropsychiatry Section, Department of Psychiatry, University of Pennsylvania Perelman School of Medicine, United States.
authors.forename: Megan
authors.initials: M
authors.lastname: Quarmley
authors.affiliation: Neuropsychiatry Section, Department of Psychiatry, University of Pennsylvania Perelman School of Medicine, United States.
authors.forename: Kosha
authors.initials: K
authors.lastname: Ruparel
authors.affiliation: Neuropsychiatry Section, Department of Psychiatry, University of Pennsylvania Perelman School of Medicine, United States; Department of Radiology, University of Pennsylvania Perelman School of Medicine, United States.
authors.forename: Ruben C
authors.initials: RC
authors.lastname: Gur
mesh_terms: D000328:Adult; D016880:Anisotropy; D003072:Cognition Disorders / Q000209:etiology*; D056324:Diffusion Tensor Imaging; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008297:Male; D008875:Middle Aged; D009413:Nerve Fibers, Myelinated / Q000473:pathology*; D009483:Neuropsychological Tests; D011569:Psychiatric Status Rating Scales; D012559:Schizophrenia / Q000150:complications* / Q000473:pathology*; D066127:White Matter / Q000473:pathology*
keywords: Clinical symptoms; Diffusion-tensor imaging; Neurocognition; Schizophrenia