title: Possible dysregulation of cortical plasticity in auditory verbal hallucinations-A cortical thickness study in schizophrenia.
abstract: BACKGROUND
  Investigations of gray matter changes in relation with auditory verbal hallucinations (AVH) have reported conflicting results. Assuming that alterations in gray matter might be related to certain symptoms in schizophrenia this study aimed to investigate changes in cortical thickness specific to AVH. It was hypothesized that schizophrenia patients suffering from persistent AVH would show significant differences in cortical thickness in regions involved in language-production and perception when compared to schizophrenia patients which had never experienced any hallucinations.
  
  
  METHODS
  Using cortical thickness analysis the present study investigated ten schizophrenic patients suffering from AVH, ten non-hallucinating schizophrenic patients, and ten healthy control subjects. Anatomical data were acquired on a 3 T MRI system, transformed into standard space and cortically aligned to investigate local differences in whole brain cortical thickness between the two patient groups. Based on this comparison, brain regions with alterations specific for the patients with AVH were identified and then used as regions of interest to compare both patient groups to the healthy subjects respectively.
  
  
  RESULTS
  Hallucinating patients showed gray matter reductions in the dominant hemisphere predominantly in sensory language areas relevant for speech processing. Increased cortical thickness was found in regions related to self-monitoring.
  
  
  CONCLUSIONS
  Gray matter reductions in chronic schizophrenic patients may be the sequel of synaptic derangement or disease-related deregulation of language circuits. In order to clarify the ambiguous information processing additional demands might be put on cortical structures responsible for self-monitoring processes leading to changes in cortical thickness in the sense of neural plasticity.
authors.affiliation: Dept. of Psychiatric Neurophysiology, University-Hospital of Psychiatry Bern, Bolligenstrasse 111, Bern, Switzerland.
authors.forename: Claudia
authors.initials: C
authors.lastname: van Swam
authors.forename: Andrea
authors.initials: A
authors.lastname: Federspiel
authors.forename: Daniela
authors.initials: D
authors.lastname: Hubl
authors.forename: Roland
authors.initials: R
authors.lastname: Wiest
authors.forename: Chris
authors.initials: C
authors.lastname: Boesch
authors.forename: Peter
authors.initials: P
authors.lastname: Vermathen
authors.forename: Roland
authors.initials: R
authors.lastname: Kreis
authors.forename: Werner
authors.initials: W
authors.lastname: Strik
authors.forename: Thomas
authors.initials: T
authors.lastname: Dierks
mesh_terms: D000328:Adult; D001931:Brain Mapping; D002540:Cerebral Cortex / Q000473:pathology* / Q000503:physiopathology; D005260:Female; D005583:Fourier Analysis; D006212:Hallucinations / Q000150:complications* / Q000175:diagnosis; D006801:Humans; D021621:Imaging, Three-Dimensional; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D011569:Psychiatric Status Rating Scales; D012559:Schizophrenia / Q000150:complications* / Q000175:diagnosis / Q000473:pathology*; D012565:Schizophrenic Psychology