3-D Morphometric Study of Brain MRI with Obsessive-Compulsive Disorder

Kong, Seog Weon; Song, In Chang; Han, Moon Hee; Jang, Kee Hyun; Lyoo, In Kyoon; Kwon, Jun Soo

Abstract

OBJECTIVES
Neurobiological models for obsessive-compulsive disorder(OCD) have consistently implicated prefrontal-striatal circuits in the pathophysiology of this disorder. But, prior studies have inconsistently found alteration in caudate and frontal lobe volumes in patients with OCD. This study was undertaken in the hope that semi-automated linear transformation methods would elucidate the morphometric differences of various parts of brain between OCD and normal control group.
METHODS
Thirteen patients meeting the DSM-IV criteria for OCD, and 9 psychiatrically normal comparison subjects participated in the study. 3-D brain MRIs using Spoiled gradient-recalled (SPGR) sequence were acquired for each subjects. After spatially normalized according to Talairach and Tournoux's coordinates, the gray and white matters were segmented by semiautomated methods using fuzzy algorithm. Each lobal volumes was measured according to Talairach and Tournoux's coordinates, and the region of interests of caudate nuclei was manually traced. The frontal lobe was divided into 3 subregions; dorsolateral prefrontal cortex, orbital frontal cortex, mesial frontal cortex accoring to the coordinates and Broadman's cytoarchitectonics.
RESULTS
Only the volume of left and right frontal gray matter showed a significant difference between OCD and normal subjects. In OCD, the frontal gray matter volume was increased in tendency. There's no difference in laterality and no coorelation with clinical severities.
CONCLUSION
Findings of increased frontal gray matter volumes in patients implicate a structural abnormality of these brain regions in the pathophysiology of OCD. The increased frontal gray matter volumes reflect a epiphenomena due to increased cerebral blood flows and metabolic rates before the structural changes may occur.