title: Abnormalities of white matter microstructure in unmedicated obsessive-compulsive disorder and changes after medication.
abstract: BACKGROUND
  Abnormalities of myelin integrity have been reported in obsessive-compulsive disorder (OCD) using multi-parameter maps of diffusion tensor imaging (DTI). However, it was still unknown to what degree these abnormalities might be affected by pharmacological treatment.
  
  
  OBJECTIVE
  To investigate whether the abnormalities of white matter microstructure including myelin integrity exist in OCD and whether they are affected by medication.
  
  
  RESULTS
  Parameter maps of DTI, including fractional anisotropy (FA), axial diffusivity (AD), radial diffusivity (RD) and mean diffusivity (MD), were acquired from 27 unmedicated OCD patients (including 13 drug-naïve individuals) and 23 healthy controls. Voxel-based analysis was then performed to detect regions with significant group difference. We compared the DTI-derived parameters of 15 patients before and after 12-week Selective Serotonin Reuptake Inhibitor (SSRI) therapies. Significant differences of DTI-derived parameters were observed between OCD and healthy groups in multiple structures, mainly within the fronto-striato-thalamo-cortical loop. An increased RD in combination with no change in AD among OCD patients was found in the left medial superior frontal gyrus, temporo-parietal lobe, occipital lobe, striatum, insula and right midbrain. There was no statistical difference in DTI-derived parameters between drug-naive and previously medicated OCD patients. After being medicated, OCD patients showed a reduction in RD of the left striatum and right midbrain, and in MD of the right midbrain.
  
  
  CONCLUSIONS
  Our preliminary findings suggest that abnormalities of white matter microstructure, particularly in terms of myelin integrity, are primarily located within the fronto-striato-thalamo-cortical circuit of individuals with OCD. Some abnormalities may be partly reversed by SSRI treatment.
authors.affiliation: Shanghai Mental Health Center, School of Medicine, Shanghai Jiao Tong University, Shanghai, China.
authors.forename: Qing
authors.initials: Q
authors.lastname: Fan
authors.forename: Xu
authors.initials: X
authors.lastname: Yan
authors.forename: Jijun
authors.initials: J
authors.lastname: Wang
authors.forename: Ying
authors.initials: Y
authors.lastname: Chen
authors.forename: Xuemei
authors.initials: X
authors.lastname: Wang
authors.forename: Chunbo
authors.initials: C
authors.lastname: Li
authors.forename: Ling
authors.initials: L
authors.lastname: Tan
authors.forename: Chao
authors.initials: C
authors.lastname: You
authors.forename: Tianhong
authors.initials: T
authors.lastname: Zhang
authors.forename: Sai
authors.initials: S
authors.lastname: Zuo
authors.forename: Dongrong
authors.initials: D
authors.lastname: Xu
authors.forename: Kemin
authors.initials: K
authors.lastname: Chen
authors.forename: Jodie Marie
authors.initials: JM
authors.lastname: Finlayson-Burden
authors.forename: Zeping
authors.initials: Z
authors.lastname: Xiao
mesh_terms: D000293:Adolescent; D000328:Adult; D001369:Axons / Q000187:drug effects / Q000473:pathology; D001931:Brain Mapping; D016022:Case-Control Studies; D003342:Corpus Striatum / Q000187:drug effects / Q000473:pathology*; D056324:Diffusion Tensor Imaging; D004334:Drug Administration Schedule; D005260:Female; D005625:Frontal Lobe / Q000187:drug effects / Q000473:pathology*; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008297:Male; D009186:Myelin Sheath / Q000378:metabolism; D009413:Nerve Fibers, Myelinated / Q000187:drug effects / Q000473:pathology; D009771:Obsessive-Compulsive Disorder / Q000188:drug therapy / Q000473:pathology*; D009778:Occipital Lobe / Q000187:drug effects / Q000473:pathology*; D010296:Parietal Lobe / Q000187:drug effects / Q000473:pathology*; D017367:Selective Serotonin Reuptake Inhibitors / Q000008:administration & dosage* / Q000627:therapeutic use
chemical_list: D017367:Selective Serotonin Reuptake Inhibitors