Abstract
Disrupted white matter integrity and abnormal cortical thickness are widely reported in the pathophysiology of obsessive-compulsive disorder (OCD). However, the relationship between alterations in white matter connectivity and cortical thickness in OCD is unclear. In addition, the heritability of this relationship is poorly understood. To investigate the relationship of white matter microstructure with cortical thickness, we measure fractional anisotropy (FA) of white matter in 30 OCD patients, 19 unaffected siblings and 30 matched healthy controls. Then, we take those regions of significantly altered FA in OCD patients compared with healthy controls to perform fiber tracking. Next, we calculate the fiber quantity in the same tracts. Lastly, we compare cortical thickness in the target regions of those tracts. Patients with OCD exhibited decreased FA in cingulum, arcuate fibers near the superior parietal lobule, inferior longitudinal fasciculus near the right superior temporal gyrus and uncinate fasciculus. Siblings showed reduced FA in arcuate fibers near the superior parietal lobule and anterior limb of internal capsule. Significant reductions in both fiber quantities and cortical thickness in OCD patients and their unaffected siblings were also observed in the projected brain areas when using the arcuate fibers near the left superior parietal lobule as the starting points. Reduced FA in the left superior parietal lobule was observed not only in patients with OCD but also in their unaffected siblings. Originated from the superior parietal lobule, the number of fibers was also found to be decreased and the corresponding cortical regions were thinner relative to controls. The linkage between disrupted white matter integrity and the abnormal cortical thickness may be a vulnerability marker for OCD.
Highlights
Obsessive-compulsive disorder (OCD) is a chronically debilitating psychiatric disorder with a prevalance of approximately 2% [1]
Post hoc tests found that patients with OCD had higher scores than healthy controls or siblings in total scores for the Yale-Brown Obsessive-Compulsive Scale (Y-BOCS), Obsessive-Compulsive Inventory-Revised (OCI-R), Beck Depression Inventory (BDI), and State-Trait Anxiety Inventory (STAI)
fractional anisotropy (FA) group analysis Group comparisons showed a pattern of reduced FA in patients with OCD compared with healthy controls, which includes the cingulum, arcuate fibers near the superior parietal lobule, inferior longitudinal fasciculus (ILF) near the right superior temporal gyrus and uncinate fasciculus
Summary
Obsessive-compulsive disorder (OCD) is a chronically debilitating psychiatric disorder with a prevalance of approximately 2% [1]. Alterations in brain structures as well as disrupted connectivity in cortico-striato-thalamo-cortical circuitry have been implicated as pathophysiological mechanisms of OCD [4]. Valente et al reported that patients with OCD showed increased grey matter in the left posterior orbitofrontal cortex, anterior insula, bilateral parahippocampal gyrus, and right fusiform gyrus, and decreased grey matter in the left anterior cingulate gyrus and medial frontal gyrus, compared with healthy controls [6]. Many studies of grey matter provide support for the role of cortico-striato-thalamo-cortical circuitry, other brain regions outside of the classical circuit have been hypothesized to play a key role in the neurobiology of the disorder, such as the parietal regions [6,7,12,13]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
