Abstracts

Rationale: Executive function means a series of cognitive activities to effectively achieve a purpose, and the impairment of this function is caused by frontal lobe dysfunction. Epilepsy is also known to impair executive function. We examined Changes of executive functions after epilepsy surgery using the Wisconsin Card Sorting Test (WCST). Methods: Among the patients who underwent epilepsy surgery since 2007, we listed forty patients (17 male, 23 female; average age 29 years old) who received neuropsychological evaluation including WCST before and 2 years after surgery. The categories achieved (CA), total errors (TE), and· perseverative error of Milner/Nelson sustainability (PEM/PEN) was evaluated. Results: There were 31 patients with temporal lobe epilepsy (TLE: 19 right, 12 left), 2 with parietal lobe epilepsy (PLE), and 3 with occipital lobe epilepsy (OLE). Remaining 4 patients suffered suspected focal seizures which received vagal nerve stimulation (VNS). CA and TE at 2 years after operation were improved at 60% (24/40) and 63% (25/40) respectively, and decreased at 23% (9/40) and 30% (12/40) respectively. PEM/PEN was improved or maintained, except for cases where CA and TE both decreased. Improvement rate by seizure type is 75% (9/12) in left TLE, 53% (10/19) in right TLE, 60% (3/5) in PLE and OLE, 25% (1/4). By outcome, improvements in executive functions were obtained at 64% (18/28) in Engel outcome scale class I, 67% (2/3) in class II, in class III at 60% (3/5), and 20% (1/4) in class III/IV of VNS. There was no correlation between the change of WCST and the change of WAIS-R / III and WMS-R. Conclusions: Executive function was improved in 64% of patients after resection surgery, but was only 20% after VNS. Tissue resection with higher epileptic activity would contribute the improvement of executive function. Funding: no