Postoperative seizure outcomes and antiseizure medication utilization based on histopathological diagnosis: A retrospective cohort study.

OBJECTIVE

Analyze the association between histopathology, seizure outcomes, and drug load of antiseizure medications (ASMs) 5-8 years after epilepsy surgery to inform preoperative decision-making and consultation.

METHODS

In this retrospective, non-interventional, single-center study, patients who visited the epilepsy clinic at West China Hospital, Sichuan University from Jan 1, 2015 to Dec 31, 2020 were assessed. Patients with postoperative histopathology after epilepsy resection were included and categorized into 13 etiological groups. The primary outcomes were achieving Engel class 1 at 1, 2, 3, 5, and 8 years postoperative. Secondary outcomes included the use of ASMs and comparison of postoperative seizure outcomes between adults and children. Univariate and multivariable analyses were conducted to explore the association between clinical characteristics such as histopathology and seizure outcomes.

RESULTS

A total of 315 patients were include. Patients with embryonic dysplastic neuroepithelial tumor (DNT) achieved the best seizure outcomes (84.6 % Engel class 1). DNT (odds ratio, OR=0.103, 95 %CI=0.012-0.899), cavernous hemangiomas (OR=0.140, 95 %CI=0.024-0.819) and meningioma (OR=0.137, 95 %CI=0.021-0.910) were independently associated with a higher probability of seizure-free outcome. The results of epileptic seizures in adult and pediatric groups with different pathologies were significantly different, and the preoperative and postoperative ASM dosages were also different among adult patients with various etiologies. Additionally, multivariate analysis showed that early age at onset (adjusted hazard ratio (HR) = 1.754, 95 % CI=1.049-2.934, P=0.032), late surgical age (HR=0.569, 95 %CI=0.339-0.954, P=0.032), and longer duration from seizure onset to surgery (HR=1.735, 95 % CI=1.028-2.928, P=0.039) were independent predictors of unfavorable outcomes in epileptic seizures.

CONCLUSIONS

we demonstrated that the seizure outcomes of focal epilepsy have high pathological specificity, with histopathological diagnosis serving as a crucial and independent determinant of seizure outcome. Surgical assessment should be contemplated for all patients with presumed refractory focal epilepsy, irrespective of their age.