Early surgical therapy for drug-resistant temporal lobe epilepsy: a randomized trial

Abstract

Context: Despite reported success, surgery for pharmacoresistant seizures is often seen as a last resort. Patients are typically referred for surgery after 20 years of seizures, often too late to avoid significant disability and premature death.

Objective: We sought to determine whether surgery soon after failure of 2 antiepileptic drug (AED) trials is superior to continued medical management in controlling seizures and improving quality of life (QOL).

Design, setting, and participants: The Early Randomized Surgical Epilepsy Trial (ERSET) is a multicenter, controlled, parallel-group clinical trial performed at 16 US epilepsy surgery centers. The 38 participants (18 men and 20 women; aged ≥12 years) had mesial temporal lobe epilepsy (MTLE) and disabling seizues for no more than 2 consecutive years following adequate trials of 2 brand-name AEDs. Eligibility for anteromesial temporal resection (AMTR) was based on a standardized presurgical evaluation protocol. Participants were randomized to continued AED treatment or AMTR 2003-2007, and observed for 2 years. Planned enrollment was 200, but the trial was halted prematurely due to slow accrual.

Intervention: Receipt of continued AED treatment (n = 23) or a standardized AMTR plus AED treatment (n = 15). In the medical group, 7 participants underwent AMTR prior to the end of follow-up and 1 participant in the surgical group never received surgery.

Main outcome measures: The primary outcome variable was freedom from disabling seizures during year 2 of follow-up. Secondary outcome variables were health-related QOL (measured primarily by the 2-year change in the Quality of Life in Epilepsy 89 [QOLIE-89] overall T-score), cognitive function, and social adaptation.

Results: Zero of 23 participants in the medical group and 11 of 15 in the surgical group were seizure free during year 2 of follow-up (odds ratio = ∞; 95% CI, 11.8 to ∞; P < .001). In an intention-to-treat analysis, the mean improvement in QOLIE-89 overall T-score was higher in the surgical group than in the medical group but this difference was not statistically significant (12.6 vs 4.0 points; treatment effect = 8.5; 95% CI, -1.0 to 18.1; P = .08). When data obtained after surgery from participants in the medical group were excluded, the effect of surgery on QOL was significant (12.8 vs 2.8 points; treatment effect = 9.9; 95% CI, 2.2 to 17.7; P = .01). Memory decline (assessed using the Rey Auditory Verbal Learning Test) occurred in 4 participants (36%) after surgery, consistent with rates seen in the literature; but the sample was too small to permit definitive conclusions about treatment group differences in cognitive outcomes. Adverse events included a transient neurologic deficit attributed to a magnetic resonance imaging-identified postoperative stroke in a participant who had surgery and 3 cases of status epilepticus in the medical group.

Conclusions: Among patients with newly intractable disabling MTLE, resective surgery plus AED treatment resulted in a lower probability of seizures during year 2 of follow-up than continued AED treatment alone. Given the premature termination of the trial, the results should be interpreted with appropriate caution.

Trial registration: clinicaltrials.gov Identifier: NCT00040326.

Conflict of interest statement

Conflict of Interest Disclosures: All authors have completed and submitted the ICMJE Form for Disclosure of Potential Conflicts of Interest. Mss Gardiner and Dewar and Dr Erba report no disclosures.

Figures

Figure 1

Participant Flow

Figure 2

Adjusted Mean QOLIE-89 Overall T-Score Over Time by Treatment Group Bars indicate 95% CIs for the adjusted means. The adjusted means were obtained from a repeated-measures analysis of covariance model that included side of ictal onset and baseline Quality of Life in Epilepsy 89 (QOLIE-89) overall T-score as covariates.