Quantitative morphology of the corpus callosum in obsessive-compulsive disorder.

Neuroimaging studies have implicated the corpus callosum (CC) in the pathophysiology of obsessive-compulsive disorder (OCD). Putative dysfunctions in prefrontal cortical regions suggest anomalies in anterior segments of the CC. However, recent studies have also implicated the middle and posterior CC. The present study soughts to examine the CC using parcellation scheme informed by diffusion tensor imaging. Anatomic brain magnetic resonance scans were obtained from 21 OCD subjects (mean age=26.9 ± 9.93) and 42 healthy age- and sex-matched controls (mean age=26.6 ± 9.46) between the ages of 14 and 49. Area and volume measures of five subregions of the CC were obtained via manual tracings. A multivariate analysis of variance (after correcting for multiple comparisons) identified smaller area and volume in the mid-anterior region of the CC in OCD patients relative to controls. These findings implicate medio-frontal regions of the cortex in the pathophysiology of OCD.