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.
Subject(s)
Humans , Brain , Caudate Nucleus , Diagnostic and Statistical Manual of Mental Disorders , Frontal Lobe , Hope , Magnetic Resonance Imaging , Obsessive-Compulsive Disorder , Orbit , Prefrontal CortexABSTRACT
Bilateral inferior petrosal sinus sampling(IPSS) is known to be useful for the differential diagnosis of ACTH-dependent Cushing's syndrome and for the preoperative localization of pituitary microadenomas.To evaluate the usefulness of IPSS, we performed the procedure in the 17 cases of ACTH-dependent Cushing's syndrome including 2 cases of macroadenomas, 6 of them with CRH stimulation test. A inferior petrosal sinus-to-peripheral ACTH ratio of 2:1 or greater(3:1 after CRH stimulation) indicates a pituitary source of ACTH hypersecretion, and a ratio of the ACTH level in one inferior petrosal sinus to the ACTH level in the other of 1:4 or greater lateralizes the microadenomas to that half of the pituitary gland.With these criteria, we diagnosed Cushing's disease in 15 of 17 cases of ACTH-dependent Cushing's syndrome, and localized the lesion in 8 of 13 cases of microadenoma.In conclusion, IPSS with CRH stimulation has high diagnostic accuracy in the differential diagnosis of ACTH-dependent Cushing's syndrome, but still has the limitations on the localization of microadenoma.