Prognosis after late relapse following epilepsy surgery

Objectives: To assess prognosis after late relapse in patients who are seizure free for the first 5 years after epilepsy surgery. Methods: Patients who were seizure free for the first 5 years after resective epilepsy surgery were included. Date of first seizure recurrence, current seizure status, medication, age, and type of surgery were prospectively registered. Non-parametric statistics were used. Results: One hundred and fifty-nine patients were studied. Thirty-two had at least one recurrent seizure. Time to event analysis showed an annual relapse rate of 4% between years 5 and 10 after surgery. At study termination, 143 of 159 patients (89.9%) were in terminal remission. For 30 patients with late relapse and at least 1-year follow-up thereafter, 53% were in terminal remission and 30% had experienced only rare or nocturnal seizures. Medication use was not associated either with likelihood of relapse or entering remission after relapse. Conclusions: Patients who are seizure free for the first 5 years after epilepsy surgery remain at risk for seizure recurrence. These relapses are often isolated events, and the tong-term prognosis after relapse is often good. Relapse rates were similar in patients on and off AEDs, but the relation between AED taper and relapse is uncertain since patient groups may not be similar. (C) 2007 Elsevier B.V. All rights reserved.