WISCONSIN CARD SORTING TASK (WCST) ERRORS AND CEREBRAL BLOOD-FLOW IN OBSESSIVE-COMPULSIVE DISORDER (OCD)

We compared Wisconsin Card Sorting Task (WCST) performance in 19 obses sive-compulsive disorder (OCD) patients and 19 individually matched he althy controls. Measures of intelligence and mood were taken into acco unt for all participants. Within the patient group, factors such as du ration and severity of symptoms (as assessed using the Yale-Brown Obse ssive-Compulsive Scale, Y-BOCS) were considered. We explored the relat ionship between OCD WCST errors and regional cerebral blood flow (rCBF ) on brain dedicated, high resolution, single photon emission tomograp hy (SPET). We used uptake of Tc-99m-hexamethylpropylamine oxime (HMPAO ) on SPET to estimate rCBF, and regional values were quantified as rat ios of cerebellar blood flow. WCST results confirmed OCD patients were significantly impaired when compared with age-and sex-marched healthy volunteers. Patients made significantly more trials, more perseverati ve errors, and more null-sorts. OCD patients Y-BOCS 'obsessive' subtot al significantly correlated with many WCST errors. Furthermore OCD WCS T null-sorts correlated significantly with SPET OCD left inferior fron tal cortical rCBF (r(18) = .47, p = .05) and left caudate rCBF (r(18) = .72, P = .01). The implications of these findings are discussed in t he context of other studies which examine functional imaging and neuro psychology in OCD.