Brain imaging as a tool in establishing a theory of brain pathology in obsessive compulsive disorder.

Positron emission tomography (PET) studies using 18F-2-deoxy-2-fluoro-D-glucose (FDG) to determine glucose metabolic rates have been used recently to correlate the symptoms of obsessive compulsive disorder (OCD) with neuroanatomically localized brain dysfunctions. These studies, as well as data from other techniques and other disease states, suggest that the orbital cortex and the striatum are dysfunctional in OCD. This information can be used to construct a theory of how the symptoms of OCD and the related Gilles de la Tourette's syndrome and chronic motor tics are mediated by the central nervous system.