An optimized voxel-basedmorphometry study of gray matter abnormalities in patients with obsessive-compulsivedisorder

：Objective To explorechanges of gray matter volume in patients with obsessivecompulsive disorder (OCD) inChinese Han population using optimized voxel-based morphometry (VBM) ,and investigate itsrelationship with clinical symptoms. Methods Twenty patients with OCD and 20 age,sex andhandedness matched healthy controls were scanned using 3D-T1 images on a 3.0 T MR system.The high resolution T1WI was preprocessed according to the optimized VBM protocol inStatistical Parametric Mapping (SPM5). Two-sample t test was performed to characterize thedifferences of the gray matter volume (GMV) between the OCD patients and healthy controls,and the correlations between the GMV and symptom severity and cumulative illness durationwere examined using Pearson correlation in SPSS 16. 0, respectively.Results Compared tocontrols, OCD patients demonstrated increased GMV in left thalamus, right thalamus andleft cerebellum after false discovery rate (FDR) correction. No areas of significantlydecreased GMV was observed in OCD patients in relative to healthy controls. The meaneigenvalue ranged from 0. 5782 to 0. 889 representing the left thalamus volume of OCDpatients was 0. 6813 ± 0. 0718, and that ranged from 0. 5546 to 0. 9062 was 0. 6869 ± 0.0808 tor right thalamus. The mean eigenvalues were positively correlated in bilateralthalamus (r = 0. 94, P ＜ 0. 01). Conclusion Using optimized VBM, the currentresearch indicates that the pathophysiology of OCD is associated with GMV abnormalitiesnot only in corticostriato-thalamo-cortical (CSTC) circuit, but also in the cerebellum. Key words: Compulsive personality disorder;  Magnetic resonanceimaging;  Brain