title: Is there evidence of brain white-matter abnormalities in obsessive-compulsive disorder?: a narrative review.
abstract: OBJECTIVE
  Although several studies have confirmed the occurrence of gray-matter abnormalities in obsessive-compulsive disorder (OCD), the literature on white matter in OCD is more limited. In this study, we reviewed the role of white-matter abnormalities in the pathophysiology of OCD.
  
  
  METHODS
  We reviewed the PubMed studies investigating white-matter integrity in patients with OCD between 1980 and 2010.
  
  
  RESULTS
  Case studies of patients who developed obsessive-compulsive symptoms secondary to multiple sclerosis, cerebrovascular diseases, and paraneoplastic leucoencephalopathy and controlled studies of patients with OCD examined with neuroimaging techniques (eg, structural, diffusion, and spectroscopic magnetic resonance imaging) were all consistent with the existence of abnormalities in specific white-matter tracts (eg, internal capsule, cingulate bundle, and corpus callosum) of individuals with OCD.
  
  
  CONCLUSIONS
  Our review emphasizes that the reported white-matter alterations in OCD complement the broader gray-matter abnormalities identified and may well suggest that OCD is associated with large-scale disruption in brain systems or networks, as opposed to being a consequence of disturbances in isolated brain regions.
authors.affiliation: Melbourne Neuropsychiatry Centre, The University of Melbourne and Melbourne Health, Melbourne, Australia. lfontenelle@gmail.com
authors.forename: Leonardo F
authors.initials: LF
authors.lastname: Fontenelle
authors.forename: Ben J
authors.initials: BJ
authors.lastname: Harrison
authors.forename: Murat
authors.initials: M
authors.lastname: Yücel
authors.forename: Jesus
authors.initials: J
authors.lastname: Pujol
authors.forename: Hironobu
authors.initials: H
authors.lastname: Fujiwara
authors.forename: Christos
authors.initials: C
authors.lastname: Pantelis
mesh_terms: D001921:Brain / Q000473:pathology*; D002986:Clinical Trials as Topic / Q000639:trends; D019317:Evidence-Based Medicine / Q000639:trends*; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D009413:Nerve Fibers, Myelinated / Q000473:pathology*; D009474:Neurons / Q000473:pathology*; D009771:Obsessive-Compulsive Disorder / Q000473:pathology*