Neuropsychiatric tests and cognitive functions before and after epilepsy surgery in patients with drug-resistant...

Background: Patients with refractory epilepsy may benefit from epilepsy surgery. However, cognitive decline following epilepsy surgery is a significant concern. In this study, we investigated the effect of epilepsy surgery on cognitive function. Methods: In this pre-post study, we used a census method to include 15 patients diagnosed with intractable epilepsy based on International League Against Epilepsy (ILAE) criteria, aged 10-65 years, and eligible for epilepsy surgery. We used the Rey Auditory Verbal Learning Test (RAVLT) and Delis-Kaplan Executive Function System (D-KEFS) to evaluate patients' cognitive function. The Wilcoxon test was used to compare cognitive function before and one month after surgery. Results: Fifteen patients (mean age: 34.2 ± 11.1) were included. The Wechsler Symbol Digit Modalities Test and Wisconsin Card Sorting Test (WCST)/Condition 2-1 (3.26 ± 1.83 to 4.13 ± 2.03, +26.7%, P = 0.01) and WCST/Condition 2-2 (3.33 ± 2.05 to 3.86 ± 2.03, 15.0%, P = 0.021) were the only tests in the total population that showed significant improvement. RAVLT/Step 1-5 (31.00 ± 10.87 to 33.72 ± 13.12, +8.8%, P = 0.02), RAVLT/Step 6 (6.00 ± 3.06 to 7.36 ± 3.66, +22.7%, P = 0.04). Trail Making Tests (TMT)/Number Sequencing (93.40 ± 52.24 to 68.50 ± 50.54, -26.7%, P = 0.028), WCST/Condition 1-1 (3.63 ± 1.91 to 4.09 ± 2.25, +12.7%, P = 0.023), WCST/Condition 2-1 (2.90 ± 1.70 to 3.72 ± 2.10, +28.3%, P = 0.039), and WCST/Condition 2-2 (3.36 ± 1.91 to 3.90 ± 2.02, +16.1, P = 0.014) demonstrated significant improvements in patients who underwent right-sided surgery. The only significant improvement in the left-sided surgery group was the TMT/switching score (175.50 ± 70.00 to 128.50 ± 74.24, -26.8%, P < 0.05). Conclusion: Surgery can benefit patients with refractory seizures. We observed that surgical treatment of epilepsy did not impair cognitive function. Postponing epilepsy surgery because of concerns about cognitive deterioration is unnecessary. However, it is important to note the limitations of our study, and future larger studies are needed to confirm and extend our findings.