White matter microstructural abnormalities and gray matter volume alterations in obsessive-compulsive disorder: A coordinate-based meta-analysis

Objective: A comprehensive meta-analysis using correlated coordinate data to explore abnormalities in white matter (WM) microarchitecture and changes in gray matter volume (GMV) in patients with obsessive-compulsive disorder (OCD). Methods: We reviewed 23 reported studies of diffusion tensor imaging (DTI) in OCD patients. The differences in WM fractional anisotropy (FA) between OCD patients and healthy controls (HCs) were investigated using tract-based spatial statistics (TBSS) and voxel-based analysis (VBA), respectively, and the results of the two methods were compared. In addition, we will explore changes in OCD GMV by analyzing studies (n = 21) using the voxel-based morphometry (VBM) approach and comparing the difference between adults and adolescents. Results: In the pooled meta-analysis, WM study results presented that compared with HCs, OCD patients had higher FA in right lenticular nucleus (putamen), and lower FA in corpus callosum (CC), left insula, right cerebellum (hemispheric lobule), right gyrus rectal and left inferior parietal gyri. However, in subgroup analysis, there was a significant difference in FA changes between TBSS and VBA in OCD patients compared with HCs. In addition, we found that the GMV of OCD patients was significantly increased in left striatum and left precentral gyrus, and significantly decreased in right inferior frontal gyrus triangular part, right superior temporal gyrus and right hippocampus. Compared with adolescents, adult patients have increased GMV in left lenticular nucleus putamen. Conclusion: The meta-analysis showed that OCD patients had abnormal WM microarchitecture and altered GMV. These changes may be closely related to the pathophysiological mechanism of the disease.