title: Abnormalities of middle longitudinal fascicle and disorganization in patients with schizophrenia.
abstract: BACKGROUND
  The middle longitudinal fascicle (MdLF) is a long association fiber connecting the superior temporal gyrus (STG) and temporal pole with the angular gyrus through the white matter of the STG, structures which are known to play a crucial role in the pathology of schizophrenia. Functions of MdLF are thought to be related to language and thought processing in the left hemisphere, and with attention in the right hemisphere. While deficits of these functions are core clinical features of schizophrenia, no study has investigated the structural abnormalities of MdLF in schizophrenia.
  
  
  METHODS
  3T diffusion tensor data was acquired from twenty-six patients with schizophrenia and twenty-five healthy control subjects. Streamline tractography technique was used to extract MdLF. Fractional anisotropy (FA) was compared between the two groups. In addition, relationships were investigated between FA in the left MdLF and the Disorganized Thoughts Factor derived from the Positive and Negative Symptom Scale five factor model, and between FA in the right MdLF and the Poor Attention.
  
  
  RESULTS
  Relative to control subjects, the patients with chronic schizophrenia showed significant mean FA reductions in the bilateral MdLF. The FA of the left MdLF demonstrated a significant negative association with the Disorganized Thoughts Factor, and the FA of the right MdLF showed a significant negative relationship with the Poor Attention.
  
  
  CONCLUSIONS
  This study provides new evidence for structural deficits in the bilateral MdLF in patients with chronic schizophrenia. It further demonstrates the contribution of these abnormalities to the core clinical features - especially to disorganization and attention deficit.
authors.affiliation: Laboratory of Neuroscience, Clinical Neuroscience Division, Department of Psychiatry, Boston Veterans Affairs Healthcare System, Brockton Division, Harvard Medical School, Brockton, MA, USA.
authors.forename: Takeshi
authors.initials: T
authors.lastname: Asami
authors.forename: Yukiko
authors.initials: Y
authors.lastname: Saito
authors.forename: Thomas J
authors.initials: TJ
authors.lastname: Whitford
authors.forename: Nikos
authors.initials: N
authors.lastname: Makris
authors.forename: Margaret
authors.initials: M
authors.lastname: Niznikiewicz
authors.forename: Robert W
authors.initials: RW
authors.lastname: McCarley
authors.forename: Martha E
authors.initials: ME
authors.lastname: Shenton
authors.forename: Marek
authors.initials: M
authors.lastname: Kubicki
mesh_terms: D000328:Adult; D002908:Chronic Disease; D056324:Diffusion Tensor Imaging / Q000295:instrumentation / Q000379:methods*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009434:Neural Pathways / Q000473:pathology / Q000503:physiopathology; D010296:Parietal Lobe / Q000473:pathology* / Q000503:physiopathology; D012559:Schizophrenia / Q000473:pathology* / Q000503:physiopathology; D012565:Schizophrenic Psychology; D013702:Temporal Lobe / Q000473:pathology* / Q000503:physiopathology; D055815:Young Adult