Full-Length Original Research
Timing of early and late seizure recurrence after temporal lobe epilepsy surgery
Version of Record online: 6 NOV 2013
Wiley Periodicals, Inc. © 2013 International League Against Epilepsy
Volume 54, Issue 11, pages 1933–1941, November 2013
How to Cite
Epilepsia, 54(11):1933–1941, 2013
- Issue online: 6 NOV 2013
- Version of Record online: 6 NOV 2013
- Manuscript Accepted: 21 AUG 2013
- Epilepsy surgery;
- Temporal lobe epilepsy;
Seizure recurrence after epilepsy surgery has been classified as either early or late depending on the recurrence time after operation. However, time of recurrence is variable and has been arbitrarily defined in the literature. We established a mathematical model for discriminating patients with early or late seizure recurrence, and examined differences between these two groups.
A historical cohort of 247 consecutive patients treated surgically for temporal lobe epilepsy was identified. In patients who recurred, postoperative time until seizure recurrence was examined using an receiver-operating characteristic (ROC) curve to determine the best cutoff for predicting long-term prognosis, dividing patients in those with early and those with late seizure recurrence. We then compared the groups in terms of a number of clinical, electrophysiologic, and radiologic variables.
Seizures recurred in 107 patients (48.9%). The ROC curve demonstrated that 6 months was the ideal time for predicting long-term surgical outcome with best accuracy, (area under the curve [AUC] = 0.761; sensitivity = 78.8%; specificity = 72.1%). We observed that patients with seizure recurrence during the first 6 months started having seizures at younger age (odds ratio [OR] = 6.03; 95% confidence interval [CI] = 1.06–11.01; p = 0.018), had a worse outcome (OR = 6.85; 95% CI = 2.54–18.52; p = 0.001), needed a higher number of antiepileptic medications (OR = 2.07; 95% CI = 1.16–9.34; p = 0.013), and more frequently had repeat surgery (OR = 9.59; 95% CI = 1.18–77.88; p = 0.021). Patients with late relapse more frequently had seizures associated with trigger events (OR = 9.61; 95% CI = 3.52–26.31; p < 0.01).
Patients with early or late recurrence of seizures have different characteristics that might reflect diversity in the epileptogenic zone and epileptogenicity itself. These disparities might help explain variable patterns of seizure recurrence after epilepsy surgery.