Clinical characteristics of low-grade tumor-related epilepsy and its predictors for surgical outcome

Low-grade tumors are the most common neoplasms inducing focal epilepsy; however, the short- and medium-term efficacy of surgery in epilepsy patients with low-grade tumors remains underappreciated. This study aims to summarize the clinical characteristics of epilepsy patients with low-grade tumors and to identify factors associated with postsurgical seizure-free outcomes.

We retrospectively reviewed consecutive patients with low-grade tumors who underwent subsequent epilepsy surgery in our epilepsy center, between 2012 and 2018 with a minimum follow-up of 1 year. Using Engel's classification and Kaplan-Meier survival analysis, we assessed postoperative seizure freedom over time. Demographical, electroclinical, and other presurgical evaluations were then evaluated for association with postoperative seizure outcome.

The cohort included a total of 132 patients: 79 males and 53 females. Among them, 110 (83.33%) were seizure-free through their last follow-up. The Engel class I outcomes were 90.15%, 87.76%, 85.53%, 82.46%, and 73.17% at the end of the 1st, 2nd, 3rd, 4th, and 5th postoperative years, respectively. Multivariate logistic analysis revealed that longer epilepsy duration (p < 0.001, OR 1.091, 95% CI 1.040-1.144) and incomplete resection (p = 0.009, OR 3.673, 95% CI 1.393-9.684) were independently associated with seizure recurrence through the last follow-up.

Surgical treatment for seizure control in patients with low-grade tumors provides excellent short- and median-term outcomes.