Long‐Term Outcome After Epilepsy Surgery

In considering the long-term outcome of patients undergoing epilepsy surgery, we are concerned not only with the effect on seizures, but also with the effect on quality of life (QOL). Interpreting published reports is difficult because of several methodological issues. First, there is no standard classification with regard to seizures or other aspects of outcome. Second, seizure outcome is almost always considered in terms of frequency, and severity is not assessed. Third, duration of follow-up varies considerably but is usually only 1-2 years. Because most patients at most centers have been operated on recently, most reports are skewed toward more recent outcomes, thus minimizing longer term changes. Fourth, surgical groups are commonly mixed and include patients with both extratempcral and temporal lobe epilepsy of diverse causes. Fifth, different surgeons use different operative techniques, and the extent of both temporal and extratemporal resections can vary greatly from center to center. Finally, patient selection and evaluation for various operative procedures has varied not only over time but among individual centers. Therefore, performing a meaningful analysis of the long-term outcome of a patient who has undergone epilepsy surgery is difficult. The only substantive study that compared epilepsy surgery patients with a matched group of medically treated patients with similarly refractory epilepsy suggests that there is some reason to be concerned about the outcome of epilepsy surgery. In 1991, Guldvog et al. published a retrospective, parallel, longitudinal cohort study of 185 medically managed and 201 surgically managed patients with uncontrolled epilepsy (1,2). The medical and surgical groups were matched for age, year at treatment and at diagnosis, seizure type and frequency, and neurological status. Patients had been followed for