Article

Brain structural abnormalities in obsessive-compulsive disorder: Converging evidence from white matter and grey matter.

Center for Studies of Psychological Application, South China Normal University, China
Asian journal of psychiatry 12/2012; 5(4):290-6. DOI: 10.1016/j.ajp.2012.07.004
Source: PubMed

ABSTRACT Specific cortico-striato-thalamic circuits are hypothesised to underlie the aetiology of obsessive-compulsive disorder (OCD). However, findings from neuroimaging studies have been inconsistent. In the current study, we attempted to provide a complete overview of structural alterations in OCD by conducting signed differential mapping (SDM) meta-analysis on grey matter and white matter studies of patients with OCD based on voxel-based morphometry (VBM) studies and diffusion tensor imaging (DTI) studies.
Fifteen VBM and seven DTI case-control studies were included in this meta-analysis. SDM meta-analyses were performed to assess grey matter volume and white matter integrity changes in OCD patients and healthy controls.
We found that OCD patients had smaller grey matter volume than health controls in the frontal eye fields, medial frontal gyrus and anterior cingulate cortex. However, we showed that there was an increase in the grey matter volume in the lenticular nucleus, caudate nucleus and a small region in the right superior parietal lobule. OCD patients also had a lower fractional anisotropy (FA) in the cingulum bundles, inferior fronto-occipital fasciculus, and superior longitudinal fasciculus, while increased FA in the left uncinate fasciculus.
The current findings confirm the structural abnormalities of cortico-striato-thalamic circuits in OCD.

Download full-text

Full-text

Available from: Eric F C Cheung, Jul 05, 2015
0 Followers
 · 
132 Views
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: This article will explore recent studies that have identified alterations in brain regions in individuals with obsessive–compulsive disorder (OCD). Specifically, alterations have been found in the cortical surface anatomy, the white matter, the gray matter, the cerebellum, the olfactory-processing structures, the temporal lobe, the prefrontal cortex, and the amygdala. Although some emerging data implicate these brain regions in OCD, the cortico–striatal–thalamic–cortical circuitry remains the prime focus of research. This article will also give an overview of studies that have found different symptom dimensions in individuals with OCD to have distinct neural correlates.
    Brain Mapping An Encyclopedic Reference, Edited by Editor-in-Chief: Arthur W. Toga, 02/2015: chapter Volume 3: Social Cognitive Neuroscience, Cognitive Neuroscience, Clinical Brain Mapping: pages Pages 993–1000; Elsevier Inc.., ISBN: ISBN: 978-0-12-397316-0
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Obsessive-compulsive disorder (OCD) occurs in ∼1-3% of the general population, and its often rather early onset causes major disabilities in the everyday lives of patients. Although the heritability of OCD is between 35-65%, many linkage, association, and genome-wide association studies have failed to identify single genes that exhibit high effect sizes. Several neuroimaging studies have revealed structural and functional alterations mainly in cortico-striato-thalamic loops. However, there is also marked heterogeneity across studies. These inconsistencies in genetic and neuroimaging studies may be due to the heterogeneous and complex phenotypes of OCD. Under the consideration that genetic variants may also influence neuroimaging in OCD, researchers have started to combine both domains in the field of imaging genetics. Here, we conducted a systematic search of PubMed and Google Scholar literature for articles that address genetic imaging in OCD and related disorders (published through March 2014). We selected 8 publications that describe the combination of imaging genetics with OCD, and extended it with 43 publications of comorbid psychiatric disorders. The most promising findings of this systematic review point to the involvement of variants in genes involved in the serotonergic (HTTLPR, HTR2A), dopaminergic (COMT, DAT), and glutamatergic (SLC1A1, SAPAP) systems. However, the field of imaging genetics must be further explored, best through investigations that combine multimodal imaging techniques with genetic profiling, particularly profiling techniques that employ polygenetic approaches, with much larger sample sizes than have been used up to now.
    Progress in neurobiology 07/2014; 121. DOI:10.1016/j.pneurobio.2014.07.003 · 9.14 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: White matter abnormalities have long been suspected in obsessive-compulsive disorder (OCD) but the available evidence has been inconsistent. We conducted the first multimodal meta-analysis of white matter volume (WMV) and fractional anisotropy (FA) studies in OCD. All voxel-wise studies comparing WMV or FA between patients with OCD and healthy controls in the PubMed, ScienceDirect, Google Scholar, Web of Knowledge and Scopus databases were retrieved. Manual searches were also conducted and authors were contacted soliciting additional data. Thirty-four datasets were identified, of which 22 met inclusion criteria (five of them unpublished; comprising 537 adult and pediatric patients with OCD and 575 matched healthy controls). Whenever possible, raw statistical parametric maps were also obtained from the authors. Peak and raw WMV and FA data were combined using novel multimodal meta-analytic methods implemented in effect-size signed differential mapping (ES-SDM). Patients with OCD showed widespread white matter abnormalities, but findings were particularly robust in the anterior midline tracts (crossing between anterior parts of cingulum bundle and body of corpus callosum), which showed both increased WMV and decreased FA, possibly suggesting an increase of fiber crossing in these regions. This finding was also observed when the analysis was limited to adult participants, and especially pronounced in samples with a higher proportion of medicated patients. Therefore, patients with OCD may have widespread white matter abnormalities, particularly evident in anterior midline tracts, though these changes might be, at least in part, attributable to the effects of therapeutic drugs.Neuropsychopharmacology accepted article preview online, 10 January 2014. doi:10.1038/npp.2014.5.
    Neuropsychopharmacology: official publication of the American College of Neuropsychopharmacology 01/2014; DOI:10.1038/npp.2014.5 · 7.83 Impact Factor