Seizure worsening and its predictors after epilepsy surgery

Abstract

Purpose: This study aims to investigate seizure worsening and its predictors after epilepsy surgery.

Methods: A retrospective chart review of patients who underwent unilobar epilepsy surgery between 1990 and 2007 and had recurrence of at least one seizure was performed. Seizure worsening was defined as an increase in total average monthly seizure frequency, average monthly generalized tonic-clonic seizures (GTCS), new-onset GTCS, or new-onset status epilepticus. The occurrence of sudden unexpected death in epilepsy (SUDEP) was captured. Multivariate logistic regression analysis was used to identify predictors of worsening.

Key findings: A total of 276 patients with postoperative seizure recurrence were identified. Monthly average seizure frequency worsening occurred in 9.8%, GTC worsening in 8.0%, new-onset GTCs in 1.4%, new-onset status epilepticus in 2.2%, and death from SUDEP in 1.4%. A higher risk of worsening was seen with extratemporal resections as compared to temporal lobe surgeries (odds ratio [OR] 3.11, 95% confidence interval [CI] 1.21-7.95; p = 0.018), and in patients with low preoperative seizure frequency <30 seizures/month (OR 14.82, 95% CI 2.81-275.41; p = 0.0003). Predictors of increased GTCs included an incomplete resection (OR 3.98, 95% CI 1.39-12.59; p = 0.010) and multiple recorded ictal patterns (OR 5.91, 95% CI 1.20-26.96; p = 0.030). Multiple seizure semiologies correlated with worsening after temporal lobe resections.

Significance: The most vulnerable patients for seizure worsening following epilepsy surgery include those with extratemporal resections, incomplete resections, and multiple recorded ictal patterns.