[Dutch Collaborative Epilepsy Surgery Program: reduction of seizures, operative complications and tapering of medication in 338 patients, 1973-1998]

Abstract

Objective: To determine the results of surgical treatment in patients with drug-resistant epilepsy, referred to the Dutch Epilepsy Surgery Program, who were treated in the University Medical Centre Utrecht, the Netherlands, in the period January 1973-December 1998.

Design: Retrospective descriptive.

Method: A total of 338 patients were operated on; 269 underwent temporal lobe resection, 41 extratemporal resection, 12 a functional hemispherectomy and 10 callosotomy. Six patients were treated with vagus nerve stimulation. For seven of the patients no follow-up data was available.

Results: After a minimum follow-up of 1 year class I or class II results (in accordance with the University of California in Los Angeles classification (UCLA) where class I = seizure-free and class II < or = 3 seizures per year) were obtained in 91% of patients who underwent temporal lobe resections, 67% of patients who underwent extratemporal resections, 81% of patients who underwent functional hemispherectomy and 10% of patients who underwent anterior callosotomy. In five of these patients an improvement in their behaviour occurred. Of the 6 patients who underwent vagus nerve stimulation only I experienced a beneficial seizure reduction (UCLA class III). Transient physical complications occurred in 4% of the patients treated and permanent damage in 1%. Postoperative psychiatric complications occurred almost exclusively following temporal resections; in 11% of which 7% de novo. After 4 postoperative years this had decreased to 5%. In a group of 143 patients who were seizure-free for 2 or more years, post-surgery medication was tapered in 75 cases, stopped in 33 cases and remained unchanged in 35 cases. The relapse rate following a tapering or stopping of the medication was 30% and with unchanged medication 17%. Although the majority of patients were once again seizure-free upon restarting the medication, a significant number continued to experience seizures.

Conclusion: For a number of carefully selected epilepsy patients with intractable seizures, surgery is a successful treatment with few serious complications.