Wisconsin Card Sorting Test performance before and after temporal lobectomy

Wisconsin Card Sorting Test (WCST) performance was studied before and after patients underwent right (n = 34) or left (n = 34) temporal lobectomy. Patients had hemisphere language dominance judged on intracarotid amobarbital testing and were free of space-occupying lesional pathology by magnetic resonance imaging (MRI). Right and left lobectomy patients did not differ before or after surgery on WCST parameters: categories completed, perseverative errors, total correct responses, total errors, nonperseverative errors, and perseverative responses. There was no relationship between WCST performance and MRI-determined hippocampal volumes or age of recurrent seizure onset. These findings are contrary to previous reports, suggesting the presence of laterality effects on preoperative WCST performance, relationships between WCST performance and age of seizure onset, and association of WCST performance and degree of mesial temporal sclerosis. Data from this study are consistent with a report on a larger group of temporal lobectomy patients, which found no laterality effect on WCST performance. The WCST seems to be of no value when attempting to lateralize seizure onset in nonlesional temporal lobe epilepsy.