Seizure outcomes and associated factors in adults with unilateral mesial temporal lobe epilepsy undergoing surgery

Objective: To analyze postoperative seizure outcomes and factors associated with unfavorable seizure control (Engel III-IV) in adults with drug-resistant unilateral mesial temporal epilepsy who underwent temporal lobectomy.

Methods: This was an observational, longitudinal, and retrospective study. A descriptive analysis of sociodemographic, clinical, and paraclinical characteristics was performed. The incidence rate of inadequate seizure control was calculated, and a Kaplan-Meier curve was reported. Cox regression analysis was conducted to identify factors associated with unfavorable outcomes.

Results: A total of 285 patients were included, 56.4% were women, and 49.12% underwent standard temporal lobectomy. Engel I were achieved in 70.87% of patients, while 6.31% experienced postsurgical complications. The estimated incidence rate of unfavorable outcomes was 3.87 cases per 100 person-years (95% CI: 3.51-4.27). Cox regression analysis indicated that patients with a temporal functional deficit zone, as identified by neuropsychological testing, had a 55.34% lower risk of an unfavorable outcome (adjusted HR: 0.4466, 95% CI: 0.236-0.854) compared to those with non-conclusive or extratemporal deficits. Concordance between video-electroencephalogram and brain magnetic resonance imaging findings in patients with right-sided lesions was also a protective factor (adjusted HR: 0.1868, 95% CI: 0.06-0.578). Discontinuation of anti-seizure treatment significantly increased the risk of an unfavorable outcome (adjusted HR: 6.718, 95% CI: 3.309-13.64).

Conclusion: Temporal lobe epilepsy surgery can achieve long-term seizure control in a significant proportion of patients. Neuropsychological assessment and concordance between MRI and video-EEG are essential presurgical factors for favorable outcomes. Additionally, patients should continue with antiepileptic treatment post-surgery to prevent seizure recurrence.