Table of Contents
Epilepsy Research and Treatment
Volume 2016, Article ID 7982494, 7 pages
http://dx.doi.org/10.1155/2016/7982494
Research Article

Predictors of Postoperative Seizure Recurrence: A Longitudinal Study of Temporal and Extratemporal Resections

1Department of Neurology and Neurotherapeutics, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
2Comprehensive Epilepsy Center, NYU Langone Medical Center, New York, NY 10016, USA
3Seton Brain and Spine Institute, The University of Texas at Austin, Austin, TX 78701, USA
4Department of Neurology, Baylor College of Medicine Medical Center, Houston, TX 77030, USA
5Neurology Consultants of Dallas, PA, Dallas, TX 75231, USA
6Department of Neurosurgery, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA

Received 29 October 2015; Revised 16 February 2016; Accepted 16 February 2016

Academic Editor: Morten I. Lossius

Copyright © 2016 Hai Chen et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

Objective. We investigated the longitudinal outcome of resective epilepsy surgery to identify the predictors of seizure recurrence. Materials and Methods. We retrospectively analyzed patients who underwent resections for intractable epilepsy over a period of 7 years. Multiple variables were investigated as potential predictors of seizure recurrence. The time to first postoperative seizure was evaluated using survival analysis and univariate analysis at annual intervals. Results. Among 70 patients, 54 (77%) had temporal and 16 (23%) had extratemporal resections. At last follow-up (mean 48 months; range 24–87 months), the outcome was Engel class I in 84% () of patients. Seizure recurrence followed two patterns: recurrence was “early” (within 2 years) in 82% of patients, of whom 83% continued to have seizures despite optimum medical therapy; recurrence was “late” (after 2 years) in 18%, of whom 25% continued to have seizures subsequently. Among the variables of interest, only resection site and ictal EEG remained as independent predictors of seizure recurrence over the long term (). Extratemporal resection and discordance between ictal EEG and resection area were associated with 4.2-fold and 5.6-fold higher risk of seizure recurrence, respectively. Conclusions. Extratemporal epilepsy and uncertainty in ictal EEG localization are independent predictors of unfavorable outcome. Seizure recurrence within two years of surgery indicates poor long-term outcome.