[F-18] FDG PET STUDY IN OBSESSIVE-COMPULSIVE DISORDER - A CLINICAL METABOLIC CORRELATION STUDY AFTER TREATMENT

Background. We used [F-18]FDG and PET in patients with obsessive-compu lsive disorder (OCD) to evaluate cerebral metabolic involvement before and after treatment with serotonin-specific reuptake inhibitors. Meth od. In 11 untreated, drug-free adults, regional cerebral metabolic rat e for glucose (rCMRglu) was compared with that of 15 age-matched norma l controls. Results. rCMRglu values were significantly increased in th e cingulate cortex, thalamus and pallidum/putamen complex. After treat ment a significant improvement in obsessive-compulsive symptoms on the Y-BOC scale (t=3.59, P<0.01) was associated with a significant bilate ral decrease of metabolism in the whole cingulate cortex (P<0.001). Cl inical and metabolic data were significantly intercorrelated (Kendall' s tau=0.65; P<0.01). Conclusions. These findings indicate that OCD is associated with functional hyperactivity of a selected neuronal networ k and that treatment to reduce symptoms may have a selective neuromodu latory effect on cingulate cortex.