title: Shape abnormalities of caudate nucleus in schizotypal personality disorder.
abstract: BACKGROUND
  Previously, we reported abnormal volume and global shape in the caudate nucleus in schizotypal personality disorder (SPD). Here, we use a new shape measure which importantly permits local in addition to global shape analysis, as well as local correlations with behavioral measures.
  
  
  METHODS
  Thirty-two female and 15 male SPDs, and 29 female and 14 male normal controls (NCLs), underwent brain magnetic resonance imaging (MRI). We assessed caudate shape measures using spherical harmonic-point distribution model (SPHARM-PDM) methodology.
  
  
  RESULTS
  We found more pronounced global shape differences in the right caudate in male and female SPD, compared with NCLs. Local shape differences, principally in the caudate head, survived statistical correction on the right. Also, we performed correlations between local surface deformations with clinical measures and found significant correlations between local shape deflated deformations in the anterior medial surface of the caudate with verbal learning capacity in female SPD.
  
  
  CONCLUSIONS
  Using SPHARM-PDM methodology, we found both global and local caudate shape abnormalities in male and female SPD, particularly right-sided, and largely restricted to limbic and cognitive anterior caudate. The most important and novel findings were bilateral statistically significant correlations between local surface deflations in the anterior medial surface of the head of the caudate and verbal learning capacity in female SPD. By extension, these local caudate correlation findings implicate the ventromedial prefrontal cortex (vmPFC), which innervates that area of the caudate, and demonstrate the utility of local shape analysis to investigate the relationship between specific subcortical and cortical brain structures in neuropsychiatric conditions.
authors.affiliation: Laboratory of Neuroscience, Department of Psychiatry, Veterans Affairs Boston Healthcare System, Brockton Division, Harvard Medical School, Brockton, MA, USA. james_levitt@hms.harvard.edu
authors.forename: James J
authors.initials: JJ
authors.lastname: Levitt
authors.forename: Martin
authors.initials: M
authors.lastname: Styner
authors.forename: Marc
authors.initials: M
authors.lastname: Niethammer
authors.forename: Sylvain
authors.initials: S
authors.lastname: Bouix
authors.forename: Min-Seong
authors.initials: MS
authors.lastname: Koo
authors.forename: Martina M
authors.initials: MM
authors.lastname: Voglmaier
authors.forename: Chandlee C
authors.initials: CC
authors.lastname: Dickey
authors.forename: Margaret A
authors.initials: MA
authors.lastname: Niznikiewicz
authors.forename: Ron
authors.initials: R
authors.lastname: Kikinis
authors.forename: Robert W
authors.initials: RW
authors.lastname: McCarley
authors.forename: Martha E
authors.initials: ME
authors.lastname: Shenton