Outcome predictors in patients with temporal lobe epilepsy after temporal resective surgery

Temporal lobe epilepsy is one of the most common types of partial epilepsy. Although surgical treatment has led to significant improvements in seizure-free rates, nearly one-third of patients still have poor seizure control after surgery. Moreover, the long-term outcome is less favorable compared to short-term outcome, with 48-58% of patients experiencing seizures five years after surgery. The aim of this study was to investigate the surgical outcomes and the predictive value of prognostic factors associated with poor surgical outcomes in temporal lobe epilepsy patients receiving surgery.

We retrospectively reviewed 94 patients undergoing temporal resective surgery in the Epilepsy Center of Guangdong Provincial Hospital of Traditional Chinese Medicine between July 2016 and July 2020. Patient information including age, gender, personal and family history, as well as preoperative and postoperative clinical data (clinical type and duration of disease) was collected.

The differences of postoperative clinical efficacy in both seizure free group and non-seizure free group patients were observed. A log-rank test was used for univariate analysis, and a Cox proportional hazard model was used for multivariate analysis. Ninety-four patients were followed up for at least 1 years. At 12 months of follow-up, 71 (75.5%) patients achieved Engel class I, 5 (5.3%) patients were classified as Engel class II, 5 (5.3%) patients were classified as Engel class III, and 13 (13.8%) patients were classified as Engel class IV. Univariate analysis and multivariate Cox regression analysis indicated that the postoperative EEG abnormalities were significantly correlated with seizure recurrence and were significant independent predictive factors, with a hazard ratio of 12.940.

The relapse rate in our study was similar to commonly reported overall rates in temporal lobe epilepsy patients receiving surgery. Anterior temporal lobectomy is a reliable treatment option for temporal lobe epilepsy patients. Postoperative electroencephalograph abnormalities are independent risk factors for poor surgical prognosis.