Abstracts

Although excellent short-term results of resective epilepsy surgery have been established, less is known about long term outcomes other than seizures. In this study we report evidence-based estimates of long-term epilepsy surgery outcomes regarding antiepileptic drugs (AEDs), cognitive function and psychosocial aspects. [italic]Data Sources.[/italic] We searched Medline, index medicus, the Cochrane database, bibliographies of pertinent reviews, original articles and book chapters, and consulted with experts. [italic]Study selection. [/italic]Two reviewers independently applied the following inclusion criteria: studies published between 1991 and 2004 with more than 20 patients undergoing resective or non-resective epilepsy surgery; outcomes reported after a mean/median follow-up 5 years. We considered all outcomes in children and adults. [italic]Data extraction.[/italic] Two investigators independently extracted data, resolving disagreements through discussion. All 158 potentially eligible articles were reviewed in full text and 89 fulfilled eligibility criteria. Thirty eight studies reported on temporal epilepsy (43%), 32 (36%) on temporal and extratemporal surgery, 13 (15%) on other resections, and 6 (7%) on non-resective surgery. Long term discontinuation of AEDs in temporal lobe surgery occurred in 12% of patients (range 9-15) and 51% achieved monotherapy (range 47-55). In temporal and extratemporal surgery 35% of patients (range 32-37) discontinued AEDs and 43% (range 40-47) achieved monotherapy. No patients in the control groups discontinued AEDs. Long-term cognitive assessment unearthed no changes in intelligence, but memory loss was greater and sustained after left temporal lobectomy. All studies evaluating psychosocial outcomes showed an improvement in quality of life. Six controlled studies demonstrated sustained benefit of surgery as compared with the medical group in most aspects. There is substantial variation in outcome definition and methodology among studies. However, after adjusting for sources of heterogeneity some studies yield similar long term outcomes. Most surgical effects observed on short term studies are maintained after five years or more (up to 22 years). The median proportion of patients free of medication on the long term ranged from 12 to 35%. No patients on the medical group stopped medications. Psychosocial benefit is sustained after surgery, but so is memory loss incurred with dominant temporal lobe resection.