title: Positive symptoms and white matter microstructure in never-medicated first episode schizophrenia.
abstract: BACKGROUND
  We investigated cerebral structural connectivity and its relationship to symptoms in never-medicated individuals with first-onset schizophrenia using diffusion tensor imaging (DTI).
  
  
  METHODS
  We recruited subjects with first episode DSM-IV schizophrenia who had never been exposed to antipsychotic medication (n=34) and age-matched healthy volunteers (n=32). All subjects received DTI and structural magnetic resonance imaging scans. Patients' symptoms were assessed on the Positive and Negative Syndrome Scale. Voxel-based analysis was performed to investigate brain regions where fractional anisotropy (FA) values significantly correlated with symptom scores.
  
  
  RESULTS
  In patients with first-episode schizophrenia, positive symptoms correlated positively with FA scores in white matter associated with the right frontal lobe, left anterior cingulate gyrus, left superior temporal gyrus, right middle temporal gyrus, right middle cingulate gyrus, and left cuneus. Importantly, FA in each of these regions was lower in patients than controls, but patients with more positive symptoms had FA values closer to controls. We found no significant correlations between FA and negative symptoms.
  
  
  CONCLUSIONS
  The newly-diagnosed, neuroleptic-naive patients had lower FA scores in the brain compared with controls. There was positive correlation between FA scores and positive symptoms scores in frontotemporal tracts, including left fronto-occipital fasciculus and left inferior longitudinal fasciculus. This implies that white matter dysintegrity is already present in the pre-treatment phase and that FA is likely to decrease after clinical treatment or symptom remission.
authors.affiliation: Department of Psychiatry, University of Hong Kong, Pokfulam, SAR China.
authors.forename: V
authors.initials: V
authors.lastname: Cheung
authors.forename: C P Y
authors.initials: CP
authors.lastname: Chiu
authors.forename: C W
authors.initials: CW
authors.lastname: Law
authors.forename: C
authors.initials: C
authors.lastname: Cheung
authors.forename: C L M
authors.initials: CL
authors.lastname: Hui
authors.forename: K K S
authors.initials: KK
authors.lastname: Chan
authors.forename: P C
authors.initials: PC
authors.lastname: Sham
authors.forename: M Y
authors.initials: MY
authors.lastname: Deng
authors.forename: K S
authors.initials: KS
authors.lastname: Tai
authors.forename: P-L
authors.initials: PL
authors.lastname: Khong
authors.forename: G M
authors.initials: GM
authors.lastname: McAlonan
authors.forename: S-E
authors.initials: SE
authors.lastname: Chua
authors.forename: E
authors.initials: E
authors.lastname: Chen
mesh_terms: D000328:Adult; D001921:Brain / Q000648:ultrastructure*; D016022:Case-Control Studies; D056324:Diffusion Tensor Imaging; D005260:Female; D005625:Frontal Lobe / Q000648:ultrastructure; D006179:Gyrus Cinguli / Q000648:ultrastructure; D006801:Humans; D008297:Male; D011569:Psychiatric Status Rating Scales; D012559:Schizophrenia / Q000473:pathology*; D012565:Schizophrenic Psychology; D013702:Temporal Lobe / Q000648:ultrastructure