White Matter Abnormalities in Patients With Obsessive-Compulsive Disorder and Their First-Degree Relatives

Abstract

These findings indicate that OCD is associated with white matter abnormalities in parietal and frontal regions. Similar abnormalities in unaffected first-degree relatives suggest these may be white matter endophenotypes for OCD.

White matter microstructure in patients with obsessive–compulsive disorder

“…Despite not being part of traditional OCD networks, there is increasing evidence for parietal lobe abnormalities in patients with OCD, and OCD has been reported in patients with right parietal multiple sclerosis. 5,7,35 The parietal lobe was also found to be the only region in which white matter connectivity was decreased in relatives of patients with OCD. 5 Neuro cognitive studies also suggest parietal dysfunction in patients with OCD.…”

“…5,7,35 The parietal lobe was also found to be the only region in which white matter connectivity was decreased in relatives of patients with OCD. 5 Neuro cognitive studies also suggest parietal dysfunction in patients with OCD. 36 In this study, we did not find any white matter deficit of the parietal lobe itself, but this might reflect the fact that TBSS only assesses the most common fibre pathways across individuals, typically excluding fibres penetrating the cortical mantle; thus, our methodology may have limited sensitivity in regions near the grey/white matter boundary.…”

“…For example, fractional anisotropy was reported to be both decreased and increased for the anterior cingulum bundle. 5,18,21 Methodological differences can explain some of these findings: only 1 of these studies 5 corrected their findings, and the sample sizes of most studies have been small (n < 15). Potential misalignment of the white matter tracts, medication effects and differences in the content and severity of obsessive-compulsive symptoms might be other issues that can explain inconsistent findings.…”

“…[1][2][3][4] However, recent studies employing whole-brain analyses also indicate more distributed neuroimaging alterations in patients with OCD, implicating par ietal, insular and cerebellar regions. [5][6][7][8][9] One potential explanation of these findings might be abnormality in white matter tracts, which can lead to abnormal connectivity between diverse brain regions.…”

“…[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.…”