Abnormal anterior cingulum integrity in bipolar disorder determined through diffusion tensor imaging

Department of Psychiatry, Yale University School of Medicine, New Haven, CT 06511, USA.
The British Journal of Psychiatry (Impact Factor: 7.34). 09/2008; 193(2):126-9. DOI: 10.1192/bjp.bp.107.048793
Source: PubMed

ABSTRACT Convergent evidence implicates white matter abnormalities in bipolar disorder. The cingulum is an important candidate structure for study in bipolar disorder as it provides substantial white matter connections within the corticolimbic neural system that subserves emotional regulation involved in the disorder.
To test the hypothesis that bipolar disorder is associated with abnormal white matter integrity in the cingulum.
Fractional anisotropy in the anterior and posterior cingulum was compared between 42 participants with bipolar disorder and 42 healthy participants using diffusion tensor imaging.
Fractional anisotropy was significantly decreased in the anterior cingulum in the bipolar disorder group compared with the healthy group (P=0.003); however, fractional anisotropy in the posterior cingulum did not differ significantly between groups.
Our findings demonstrate abnormalities in the structural integrity of the anterior cingulum in bipolar disorder. They extend evidence that supports involvement of the neural system comprising the anterior cingulate cortex and its corticolimbic gray matter connection sites in bipolar disorder to implicate abnormalities in the white matter connections within the system provided by the cingulum.

Download full-text


Available from: Gaolang Gong, Mar 26, 2015
1 Follower
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Structural abnormality of both gray and white matter has been detected in patients with bipolar disorder (BD). But results were greatly inconsistent across studies which were most likely attributed to heterogeneous populations as well as processing techniques. The present study aimed to investigate brain structural and microstructural alterations in a relative homogenous sample of bipolar mania. 3D T1-weighted magnetic resonance imaging (MRI) and diffusion tensor imaging (DTI) were conducted in 18 patients with BD and 27 healthy volunteers. Gray matter (GM) and white matter (WM) differences were evaluated using voxel-based morphometry (VBM) and voxel-based analysis of fractional anisotropy (FA) maps derived from DTI, respectively. Patients with BD had a larger volume of GM in the left thalamus and bilateral basal ganglia, including the bilateral putamen and extending to the left claustrum, as well as reduced FA values in the left posterior corona radiata. By combined analysis, alterations in subcortical GM areas and part of the corresponding association fiber area were detected. Compared with observations in homogeneous samples, our findings indicate that disruption of the limbic network may be intrinsic to BD.
    Progress in Neuro-Psychopharmacology and Biological Psychiatry 11/2011; 36(2):231-8. DOI:10.1016/j.pnpbp.2011.11.002 · 4.03 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: In bipolar disorder, white matter abnormalities have been reported with region-of-interest and voxel-based methods; however, deficits in specific white matter tracts cannot be localized by these methods. Therefore, in this study, we aimed to investigate the white matter tracts that mediate connectivity of the frontal cortex using diffusion tensor imaging (DTI) tractography. Eighteen patients with bipolar disorder and sixteen age- and gender-matched healthy subjects underwent DTI examinations. Frontal cortex white matter tracts, including the anterior thalamic radiation (ATR), uncinate fasciculus (UF), superior longitudinal fasciculus (SLF), cingulum, and inferior fronto-occipital fasciculus (IFO) were reconstructed by DTI tractography, and we calculated the mean fractional anisotropy (FA) for each fiber tract. The values were compared between groups by repeated measures analysis of variance with age and gender as covariates, which allowed us to investigate significant differences between the tracts. When compared with healthy controls, the patients with bipolar disorder showed significantly decreased FA in the ATR and UF, and a trend towards lower FA in the SLF and cingulum. However, there were no FA differences between groups in the IFO. Our study indicates that bipolar patients show abnormalities within white matter tracts connecting the frontal cortex with the temporal and parietal cortices and the fronto-subcortical circuits. These findings suggest that alterations in the connectivity of white matter tracts in the frontal cortex might contribute to the neuropathology of bipolar disorder.
    Journal of Affective Disorders 06/2011; 131(1-3):299-306. DOI:10.1016/j.jad.2010.12.018 · 3.71 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Recent studies have suggested that some variants of bipolar disorder (BD) may be due to hyperconnectivity between orbitofrontal (OFC) and temporal pole (TP) structures in the dominant hemisphere. Some initial MRI studies noticed that there were corpus callosum abnormalities within specific regional areas and it was hypothesized that developmentally this could result in functional or effective connectivity changes within the orbitofrontal-basal ganglia-thalamocortical circuits. Recent diffusion tensor imaging (DTI) white matter fiber tractography studies may well be superior to region of interest (ROI) DTI in understanding BD. A "ventral semantic stream" has been discovered connecting the TP and OFC through the uncinate and inferior longitudinal fasciculi and the elusive TP is known to be involved in theory of mind and complex narrative understanding tasks. The OFC is involved in abstract valuation in goal and sub-goal structures and the TP may be critical in binding semantic memory with person-emotion linkages associated with narrative. BD patients have relative attenuation of performance on visuoconstructional praxis consistent with an atypical localization of cognitive functions. Multiple lines of evidence suggest that some BD alleles are being selected for which could explain the enhanced creativity in higher-ability probands. Associations between ROI's that are not normally connected could explain the higher incidence of artistic aptitude, writing ability, and scientific achievements among some mood disorder subjects.
    Neuropsychiatric Disease and Treatment 01/2009; 4(6):1129-53. DOI:10.2147/NDT.S4329 · 2.15 Impact Factor