Frontal lobe and basal ganglia metabolism studied with PET in patients with incapacitating obsessive-compulsive disorder undergoing capsulotomy

Regional cerebral metabolic rates of glucose (rCMRgl) were determined with positron emission tomography (PET) in five patients with chronic, treatment-resistant, incapacitating obsessive-compulsive disorder (OCD) undergoing psychosurgery. Preoperative values were compared with rates observed in healthy volunteers examined with the same PET system. Here we report primary data pertaining to the orbital gyri and the caudate nuclei, regions in which disordered metabolism has been observed in OCD. In contrast to previous reports, our patients did not display increased rCMRgl relative to controls, a possible reflection of the particularly malignant forms of OCD which they had. Our findings neither address the issue of the causes of OCD nor preclude that other brain regions may be dysfunctional in that illness