Risk Factors Analyses for Seizure Recurrence in Different Periods After Refractory Epilepsy Surgery: A Prospective Single-Center Study

Abstract

Objective: To evaluate the potential risk factors associated with seizure recurrence in different periods after epilepsy surgery.

Methods: A total of 303 patients with refractory epilepsy after epilepsy surgery were included. The Kaplan-Meier method with log-rank test and univariate and multivariate Cox proportional hazards model were performed to calculate the comparison of survival curves between groups and identify the risk factors associated with seizure recurrence in different periods after surgery.

Results: The significant predictors of seizure recurrence were determined, including duration of epilepsy (P = 0.018), seizure types (P = 0.009), magnetic resonance imaging findings (P = 0.007), intracranial electroencephalographic recordings (P = 0.002), sides of epileptogenic zone (P = 0.025), and types of surgery (P = 0.002). Moreover, the significant predictors of seizure recurrence within 12 months after surgery were also included, such as gender (P = 0.007), duration of epilepsy (P = 0.013), intracranial electroencephalographic recordings (P = 0.003), and types of surgery (P < 0.001). Our results indicated that the variables of magnetic resonance imaging findings (P = 0.015), sides of epileptogenic zone (P = 0.004), and seizure relapse within 12 months after surgery (P < 0.001) were significantly associated with seizure recurrence in 12-36 months after surgery. Seizure relapse within 12 months after surgery (P < 0.001) was also associated with seizure recurrence >36 months after surgery.

Conclusions: We reconfirmed the well-known risk factors associated with seizure recurrence and also identified the controversial variables. In addition, we found that the risk factors associated with seizure recurrence were different in different periods after epilepsy surgery.

Keywords: Epilepsy; Follow-up; Intractable; Predictors of surgical outcome; Seizure free.