Localization of cerebral functional deficits in patients with obsessive-compulsive disorder: a resting-state fMRI study.

BACKGROUND Abnormality of orbitofronto-striatal circuits was postulated in obsessive-compulsive disorder (OCD). The aim of this study is to test the abnormality hypothesis of orbitofronto-striatal circuits and explore whether there are any other dysfunctional brain regions in OCD using a resting-state functional magnetic resonance imaging (fMRI), and further investigate the relationship between the whole-brain voxel-based spontaneous neuronal activity of patients with OCD and clinical characteristics. METHODS 23 patients with OCD and 23 age- and gender-matched normal controls were examined using resting-state fMRI, and amplitude of low-frequency fluctuation (ALFF) approach was used to analyze fMRI data. RESULTS Compared with normal controls, patients with OCD presented increased ALFF in the bilateral orbitofrontal cortex (OFC), anterior cingulate cortex (ACC) as well as decreased ALFF in the bilateral cerebellum and parietal cortex (P<0.01, corrected). Additionally, the ALFF values in bilateral OFC were positively correlated with total Y-BOCS scores (P<0.005, uncorrected). CONCLUSION Our findings added an expanding literature to the abnormality hypothesis of orbitofronto-striatal circuits and showed the changed spontaneous neuronal activity of the parietal cortex and cerebellum may also play an important role in the pathophysiology in patients with OCD.