title: Functional and structural brain asymmetries in patients with schizophrenia and bipolar disorders.
abstract: OBJECTIVE
  This study aimed to compare the functional and gray matter asymmetries in patients with schizophrenia (SZ), patients with bipolar disorders (BD), and healthy controls (HCs) to test whether decreased leftward functional hemispheric lateralization and gray matter volume asymmetry could mark the boundary between schizophrenia and bipolar disorder.
  
  
  METHODS
  A total of 31 right-handed SZ and 20 right-handed BD underwent a session of functional MRI with a speech listening paradigm. Participants were matched with HCs for gender, age, and education. Functional laterality indices (FLI) and gray matter volume asymmetry indices (GVAI) were computed from the individual functional language network. Correlations between the FLI and GVAI indices were also examined.
  
  
  RESULTS
  SZ exhibited significantly decreased leftward functional hemispheric lateralization whereas BD did not. The GVAIs did not differ significantly between SZ and HCs or between BD and HCs. There were positive correlations between GVAIs and FLIs in all groups.
  
  
  CONCLUSIONS
  Loss of laterality for language comprehension with retention of gray matter volume asymmetry indicates that gray matter loss alone will not account for the pathophysiology of schizophrenia. Impaired leftward functional hemispheric lateralization for language but not gray matter volume asymmetry can be considered a biomarker of SZ.
authors.affiliation: CNRS, UMR 6301 ISTCT, ISTS Team, GIP CYCERON, Bd Henri Becquerel, BP5229, F-14074 Cedex Caen, France.
authors.forename: Céline
authors.initials: C
authors.lastname: Royer
authors.affiliation: CNRS, UMS 3408, GIP CYCERON, Bd Henri Becquerel, BP5229, F-14074 Cedex Caen, France.
authors.forename: Nicolas
authors.initials: N
authors.lastname: Delcroix
authors.affiliation: CNRS, UMR 6301 ISTCT, ISTS Team, GIP CYCERON, Bd Henri Becquerel, BP5229, F-14074 Cedex Caen, France; CHU de Caen, Service de Psychiatrie, Centre Esquirol, Caen, F-14000, France.
authors.forename: Elise
authors.initials: E
authors.lastname: Leroux
authors.affiliation: CNRS, UMR 6301 ISTCT, ISTS Team, GIP CYCERON, Bd Henri Becquerel, BP5229, F-14074 Cedex Caen, France.
authors.forename: Mathieu
authors.initials: M
authors.lastname: Alary
authors.affiliation: CNRS, UMR 6301 ISTCT, ISTS Team, GIP CYCERON, Bd Henri Becquerel, BP5229, F-14074 Cedex Caen, France; Université de Caen Basse-Normandie, IBFA, Caen, F-14000, France.
authors.forename: Annick
authors.initials: A
authors.lastname: Razafimandimby
authors.affiliation: CNRS, UMR 6301 ISTCT, ISTS Team, GIP CYCERON, Bd Henri Becquerel, BP5229, F-14074 Cedex Caen, France; CHU de Caen, Service de Psychiatrie, Centre Esquirol, Caen, F-14000, France; Université de Caen Basse-Normandie, UFR de médecine (Medical School), Caen, F-14000, France.
authors.forename: Perrine
authors.initials: P
authors.lastname: Brazo
authors.affiliation: CNRS, UMR 6301 ISTCT, ISTS Team, GIP CYCERON, Bd Henri Becquerel, BP5229, F-14074 Cedex Caen, France; CHU de Caen, Service de Psychiatrie, Centre Esquirol, Caen, F-14000, France; Université de Caen Basse-Normandie, UFR de médecine (Medical School), Caen, F-14000, France.
authors.forename: Pascal
authors.initials: P
authors.lastname: Delamillieure
authors.affiliation: CNRS, UMR 6301 ISTCT, ISTS Team, GIP CYCERON, Bd Henri Becquerel, BP5229, F-14074 Cedex Caen, France; CHU de Caen, Service de Psychiatrie, Centre Esquirol, Caen, F-14000, France; Université de Caen Basse-Normandie, UFR de médecine (Medical School), Caen, F-14000, France. Electronic address: dollfus-s@chu-caen.fr.
authors.forename: Sonia
authors.initials: S
authors.lastname: Dollfus
mesh_terms: D000328:Adult; D000704:Analysis of Variance; D001714:Bipolar Disorder / Q000473:pathology*; D001921:Brain / Q000098:blood supply / Q000473:pathology*; D016022:Case-Control Studies; D005260:Female; D007839:Functional Laterality; D066128:Gray Matter / Q000098:blood supply / Q000473:pathology; D006801:Humans; D007091:Image Processing, Computer-Assisted; D007802:Language; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D010100:Oxygen / Q000097:blood; D012559:Schizophrenia / Q000473:pathology*; D055815:Young Adult
chemical_list: D010100:Oxygen
keywords: Bipolar disorders; Functional hemispheric lateralization; Gray matter volume asymmetry; Language; MRI; Schizophrenia