title: White matter structural alterations in pediatric obsessive-compulsive disorder: relation to symptom dimensions.
abstract: The aims of this study were to identify gray matter (GM) and white matter (WM) volume abnormalities in pediatric obsessive-compulsive patients, to examine their relationship between these abnormalities and the severity of disorder, and to explore whether they could be explained by the different symptom dimensions.
  
  
  METHODS
  62 child and adolescent OCD patients (11-18years old) and 46 healthy subjects of the same gender and similar age and estimated intellectual quotient were assessed by means of psychopathological scales and magnetic resonance imaging (MRI). Axial three-dimensional T1-weighted images were obtained in a 3T scanner and analyzed using optimized voxel-based morphometry (VBM).
  
  
  RESULTS
  Compared with healthy controls, OCD patients showed lower white matter (WM) volume in the left dorsolateral and cingulate regions involving the superior and middle frontal gyri and anterior cingulate gyrus (t=4.35, p=0.049 FWE (family wise error)-corrected). There was no significant correlation between WM and the severity of obsessive-compulsive symptomatology. There were no regions with lower gray matter (GM) volume in OCD patients than in controls. Compared with healthy controls, only the "harm/checking" OCD dimension showed a cluster with a near significant decrease in WM volume in the right superior temporal gyrus extending into the insula (t=5.61, p=.056 FWE-corrected).
  
  
  CONCLUSIONS
  The evidence suggests that abnormalities in the dorsolateral prefrontal cortex, anterior cingulate cortex, temporal and limbic regions play a central role in the pathophysiology of OCD. Moreover, regional brain volumes in OCD may vary depending on specific OCD symptom dimensions, indicating the clinical heterogeneity of the condition.
authors: Department of Child and Adolescent Psychiatry and Psychology, Institute of Neurosciences, Hospital Clínic Universitari, Barcelona, Spain; IDIBAPS (Institut d'Investigacions Biomèdiques August Pi i Sunyer), Barcelona, Spain; Department of Psychiatry and Clinical Psychobiology, University of Barcelona, Spain; CIBERSAM, Spain. Electronic address: llazaro@clinic.ub.es.
authors: L
authors: L
authors: Lázaro
authors: Department of Child and Adolescent Psychiatry and Psychology, Institute of Neurosciences, Hospital Clínic Universitari, Barcelona, Spain.
authors: A G
authors: AG
authors: Ortiz
authors: Magnetic Resonance Image Core Facility, IDIBAPS (Institut d'Investigacions Biomèdiques August Pi i Sunyer), Barcelona, Spain.
authors: A
authors: A
authors: Calvo
authors: Department of Child and Adolescent Psychiatry and Psychology, Institute of Neurosciences, Hospital Clínic Universitari, Barcelona, Spain.
authors: A E
authors: AE
authors: Ortiz
authors: Department of Child and Adolescent Psychiatry and Psychology, Institute of Neurosciences, Hospital Clínic Universitari, Barcelona, Spain.
authors: E
authors: E
authors: Moreno
authors: Department of Child and Adolescent Psychiatry and Psychology, Institute of Neurosciences, Hospital Clínic Universitari, Barcelona, Spain; IDIBAPS (Institut d'Investigacions Biomèdiques August Pi i Sunyer), Barcelona, Spain; CIBERSAM, Spain.
authors: A
authors: A
authors: Morer
authors: Department of Child and Adolescent Psychiatry and Psychology, Institute of Neurosciences, Hospital Clínic Universitari, Barcelona, Spain; CIBERSAM, Spain.
authors: R
authors: R
authors: Calvo
authors: CIBERSAM, Spain; Magnetic Resonance Image Core Facility, IDIBAPS (Institut d'Investigacions Biomèdiques August Pi i Sunyer), Barcelona, Spain; Image Diagnostic Center, Hospital Clínic, Barcelona, Spain.
authors: N
authors: N
authors: Bargallo
mesh_terms: D000293:Adolescent; D001921:Brain / Q000473:pathology*; D002648:Child; D005260:Female; D066128:Gray Matter / Q000473:pathology; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging; D008297:Male; D009771:Obsessive-Compulsive Disorder / Q000473:pathology* / Q000523:psychology; D009929:Organ Size; D011569:Psychiatric Status Rating Scales; D066127:White Matter / Q000473:pathology*
keywords: Children and adolescents; Obsessive–compulsive disorder; Symptom dimensions; Voxel-based morphometry