Purpose: The existing data on the implications of the characteristics of seizures that recur during the first year following epilepsy surgery on subsequent seizure outcome are conflicting. We investigated the impact of recurrent seizures in the first postoperative year and their attributes on long-term seizure outcome.
Methods: We studied the postoperative courses of 492 patients who had completed two or more years of follow-up after temporal lobe resective epilepsy surgery. We used Kaplan-Meier survival curves to define long-term seizure outcome and assessed the predictive value of recurrent seizure characteristics on the outcome by univariate and multivariate proportional hazards regression models.
Key findings: In our patients, seizure recurrences during the first postoperative year, irrespective of the attributes of recurrent seizures (such as provoked vs. unprovoked, and timing and number of recurrences), imparted fourfold to sevenfold increased hazards for continued seizures beyond the first postoperative year. Although patients with complex partial seizures with or without secondary generalized tonic-clonic seizures (CPS/GTCS) had a sixfold increased risk, those with auras alone had only a borderline risk for seizures beyond the first postoperative year. In the multivariate model, CPS/GTCS as the predominant seizure type and three or more seizure recurrences during the first postoperative year independently predicted unfavorable long-term seizure outcome.
Significance: Our study provides valuable information that is helpful in prognosticating and counseling patients, and in making rational decisions on the withdrawal of antiepileptic drugs following surgery. Our findings enhance the general understanding of the etiopathogenesis of surgical failure.
Wiley Periodicals, Inc. © 2011 International League Against Epilepsy.