title: Altered integrity of perisylvian language pathways in schizophrenia: relationship to auditory hallucinations.
abstract: BACKGROUND
  Functional neuroimaging supports the hypothesis that auditory verbal hallucinations (AVH) in schizophrenia result from altered functional connectivity between perisylvian language regions, although the extent to which AVH are also associated with an altered tract anatomy is less clear.
  
  
  METHODS
  Twenty-eight patients with schizophrenia subdivided into 17 subjects with a history of AVH and 11 without a history of hallucinations and 59 age- and IQ-matched healthy controls were recruited. The number of streamlines, fractional anisotropy (FA), and mean diffusivity were measured along the length of the arcuate fasciculus and its medial and lateral components.
  
  
  RESULTS
  Patients with schizophrenia had bilateral reduction of FA relative to controls in the arcuate fasciculi (p < .001). Virtual dissection of the subcomponents of the arcuate fasciculi revealed that these reductions were specific to connections between posterior temporal and anterior regions in the inferior frontal and parietal lobe. Also, compared with controls, the reduction in FA of these tracts was highest, and bilateral, in patients with AVH, but in patients without AVH, this reduction was reported only on the left.
  
  
  CONCLUSIONS
  These findings point toward a supraregional network model of AVH in schizophrenia. They support the hypothesis that there may be selective vulnerability of specific anatomical connections to posterior temporal regions in schizophrenia and that extensive bilateral damage is associated with a greater vulnerability to AVH. If confirmed by further studies, these findings may advance our understanding of the anatomical factors that are protective against AVH and predictive of a treatment response.
authors.affiliation: Department of Forensic and Neurodevelopmental Sciences, King's College London, Institute of Psychiatry, London, United Kingdom. m.catani@iop.kcl.ac.uk
authors.forename: Marco
authors.initials: M
authors.lastname: Catani
authors.forename: Michael C
authors.initials: MC
authors.lastname: Craig
authors.forename: Stephanie J
authors.initials: SJ
authors.lastname: Forkel
authors.forename: Richard
authors.initials: R
authors.lastname: Kanaan
authors.forename: Marco
authors.initials: M
authors.lastname: Picchioni
authors.forename: Timothea
authors.initials: T
authors.lastname: Toulopoulou
authors.forename: Sukhwinder
authors.initials: S
authors.lastname: Shergill
authors.forename: Steve
authors.initials: S
authors.lastname: Williams
authors.forename: Declan G
authors.initials: DG
authors.lastname: Murphy
authors.forename: Philip
authors.initials: P
authors.lastname: McGuire
mesh_terms: D000328:Adult; D001303:Auditory Cortex / Q000502:physiology* / Q000503:physiopathology; D001306:Auditory Pathways / Q000502:physiology* / Q000503:physiopathology; D001931:Brain Mapping; D016022:Case-Control Studies; D056324:Diffusion Tensor Imaging; D005260:Female; D007839:Functional Laterality / Q000502:physiology*; D006212:Hallucinations / Q000503:physiopathology*; D006801:Humans; D007802:Language; D008297:Male; D016555:Matched-Pair Analysis; D008875:Middle Aged; D012016:Reference Values; D012559:Schizophrenia / Q000503:physiopathology*; D012565:Schizophrenic Psychology; D018709:Statistics, Nonparametric