title: Auditory verbal hallucinations and the interhemispheric auditory pathway in chronic schizophrenia.
abstract: OBJECTIVE
  The interhemispheric auditory pathway has been shown to play a crucial role in the processing of acoustic stimuli, and alterations of structural and functional connectivity between bilateral auditory areas are likely relevant to the pathogenesis of auditory verbal hallucinations (AVHs). The aim of this study was to examine this pathway in patients with chronic schizophrenia regarding their lifetime history of AVHs.
  
  
  METHODS
  DTI scans were acquired from 33 healthy controls (HC), 24 schizophrenia patients with a history of AVHs (LT-AVH) and nine schizophrenia patients without any lifetime hallucinations (N-LT-AVH). The interhemispheric auditory fibre bundles were extracted using streamline tractography. Subsequently, diffusivity indices, namely Fractional Anisotropy (FA), Trace, Mode, Axial and Radial diffusivity, were calculated.
  
  
  RESULTS
  FA was decreased over the entire pathway in LT-AVH compared with N-LT-AVH. Moreover, LT-AVH displayed decreased FA and Mode as well as increased radial diffusivity in the midsagittal section of the fibre tract.
  
  
  CONCLUSIONS
  These findings indicate complex microstructural changes in the interhemispheric auditory pathway of schizophrenia patients with a history of AVHs. Alterations appear to be absent in patients who have never hallucinated.
authors.affiliation: Department of Psychiatry, Psychiatry Neuroimaging Laboratory, Brigham and Women's Hospital, Harvard Medical School , Boston, MA , USA.
authors.forename: Marlene
authors.initials: M
authors.lastname: Wigand
authors.forename: Marek
authors.initials: M
authors.lastname: Kubicki
authors.forename: Christian
authors.initials: C
authors.lastname: Clemm von Hohenberg
authors.forename: Gregor
authors.initials: G
authors.lastname: Leicht
authors.forename: Susanne
authors.initials: S
authors.lastname: Karch
authors.forename: Ryan
authors.initials: R
authors.lastname: Eckbo
authors.forename: Paula E
authors.initials: PE
authors.lastname: Pelavin
authors.forename: Kathryn
authors.initials: K
authors.lastname: Hawley
authors.forename: Dan
authors.initials: D
authors.lastname: Rujescu
authors.forename: Sylvain
authors.initials: S
authors.lastname: Bouix
authors.forename: Martha E
authors.initials: ME
authors.lastname: Shenton
authors.forename: Christoph
authors.initials: C
authors.lastname: Mulert
mesh_terms: D000161:Acoustic Stimulation; D000328:Adult; D016880:Anisotropy; D001303:Auditory Cortex / Q000503:physiopathology*; D001306:Auditory Pathways / Q000502:physiology*; D001931:Brain Mapping; D016022:Case-Control Studies; D002908:Chronic Disease; D056324:Diffusion Tensor Imaging; D005260:Female; D006212:Hallucinations / Q000503:physiopathology*; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D012559:Schizophrenia / Q000503:physiopathology*
keywords: MRI; auditory verbal hallucinations; brain imaging; diffusion tensor imaging; schizophrenia