A diffusion tensor imaging study of white matter in obsessive–compulsive disorder

Abstract

Our objective was to test for differences between subjects with obsessive-compulsive disorder (OCD) and healthy controls with respect to white matter architecture within the cingulum bundle (CB) and anterior limb of the internal capsule (ALIC). We studied eight subjects with active OCD and 10 matched healthy controls using diffusion tensor magnetic resonance imaging (DT-MRI) at 1.5 T (Tesla). Fractional anisotropy (FA) was evaluated in both CB and ALIC. Both voxelwise and region-of-interest methods of analysis were employed. Within both the left CB and the left ALIC, subjects with OCD exhibited significantly greater FA than healthy controls. In the right CB, subjects with OCD exhibited significantly decreased FA versus healthy control subjects. Additionally, the OCD group exhibited abnormal asymmetry (left > right) of FA in the CB. These results provide preliminary evidence for abnormal architecture within the CB and ALIC in OCD. FA differences in these areas are consistent with the presence of abnormal connections between the nodes linked by these tracts. This could explain why surgically severing these tracts is therapeutic. Additional studies are needed to replicate these findings and to clarify their pathological and clinical significance.

Loss of erbB signaling in oligodendrocytes alters myelin and dopaminergic function, a potential mechanism for neuropsychiatric disorders

“…Our results have implications for psychiatric disorders given that a significant fraction of patients have white matter defects (10)(11)(12)(13)(14). It is worth noting that some of the human findings, reductions in the numbers of OLs and damage to the myelin sheath (13), are different from those obtained in the CNP-DN-erbB4 mice.…”

“…Significant alterations in white matter are found in schizophrenia, bipolar disorder, major depression, anxiety, and obsessivecompulsive disorder (10)(11)(12)(13)(14), and genes expressed by OLs have been linked with some of these diseases (15,16). Interestingly, NRG1-erbB signaling regulates OL development in vitro (17), although this has not been shown in the intact organism.…”

Evidence for fractional anisotropy and mean diffusivity white matter abnormalities in the internal capsule and cingulum in patients with obsessive–compulsive disorder

“…First, voxel-based morphometry (VBM) studies have pointed to the involvement of the anterior limb of the internal capsule (ALIC) and cingulum bundle (for example, see Cannistraro and colleagues 5 ). Second, neurosurgical reports have emphasized the importance of the ALIC and the cingulum in OCD by implicating these as target sites for the neurosurgical treatment of OCD using ablative procedures (see the review by Rauch 6 ).…”

White matter microstructure in patients with obsessive–compulsive disorder

“…[12][13][14][15] To date, 8 studies have examined white matter pathology in patients with OCD using DTI. 5,[16][17][18][19][20][21][22] However, the findings of these studies have been variable (Table 1), and no study has examined whether axonal injury or abnormal myelination explains the observed findings. In this study, our aim was to extend previous work and to examine alterations in fractional anisotropy as well as measures of axial and radial diffusivity in a sample of patients with OCD and healthy controls using a well-validated Tract-Based Spatial Statistics (TBSS) technique.…”