Regional cerebral blood flow in obsessive-compulsive patients with and without a chronic tic disorder. A SPECT study.

The main goal of the present study was to explore whether regional cerebral blood flow (rCBF) differs between obsessive-compulsive disorder (OCD) pati ents without chronic motor tic disorder and those OCD patients with a comor bid chronic tic disorder. Twenty-seven patients suffering from OCD (DSM-IV criteria), including 7 OCD patients who met DSM-IV criteria for simple chro nic motor dic disorder, and 16 healthy volunteers were examined at rest usi ng a high resolution SPECT. Seven regions of interest (ROIs) were manually traced and quantified as a percentage of the mean cerebellar uptake. Severi ty of obsessive-compulsive symptoms (OCS), anxiety and depressive symptoms and presence of motor ties were assessed with the Y-BOCS, MRS-A, HRS-D, MAD RS, and Yale Global Ties Severity Scale, respectively. We found a significa nt relative decrease in rCBF in OCD patients without motor ties compared to healthy volunteers in the right orbitofrontal cortex (OCD without ties = 0 .87; healthy volunteers = 0.94; p = 0.02). No significant differences in rC BF were seen when OCD patients with and without chronic ties were directly compared. A lower severity of OCS in OCD patients with chronic ties was fou nd. These results are consistent with previous functional neuroimaging stud ies at rest that have widely involved the orbitofrontal cortex in the patho physiology of the OCD. However, our results do not support the idea that OC D patients with chronic ties may constitute a biological subgroup within th e OCD.