Abstracts

Rationale: Obesity has become a global epidemic. 2003-2004 National Health and Nutrition Examination Survey (NHANES) data shows that 66% of United States adults are overweight or obese, with an increase in obesity from 15% in 1976-1980 to 32.9% in 2003-2004. Increased body mass index (BMI) has been associated with multiple health issues, including coronary artery disease, hypertension, diabetes, and stroke. Given the health risks of obesity, an increased BMI may have significant effects on surgical outcomes. An increased rate of obesity has been documented in patients with epilepsy, which is in part due to medications (Neurology 2004;63:S24-29). Several antiepileptic medications are associated with changes in weight. This study evaluated the effect of increased BMI on the outcome of patients after temporal lobe epilepsy surgery. Methods: This retrospective analysis included 140 adult patients who underwent mesial temporal lobe epilepsy surgery at Mayo Clinic in Rochester, MN between November 1989 and November 1996. The mean age at surgery was 36 years (range, 18-68). These patients were followed for at least one year after surgery. The mean duration of follow-up was 6 years (range, 1-17). Charts were reviewed for preoperative demographics, co-morbidities, and preoperative seizure management. The study evaluated perioperative morbidity, mortality, and long-term seizure control based on modified Engel classification. Data for patients with normal BMI was compared with data for those with BMI > 25 (overweight) and BMI > 30 (obese) to determine whether differences existed in the surgical outcome. Results: Fifty four percent of the patients in this series had a BMI of 25 or greater, and 28% had a BMI of at least 30. The 140 patients did not have significant co-morbidity that precluded epilepsy surgery. There was no significant difference for ICU stay, overall hospital stay, perioperative morbidity, or long-term seizure control between the groups (p> .05). Two patients with BMI greater than 40 could not undergo preoperative MRI due to size restrictions; one of these patients had a class 1 outcome and the other had a class 4 outcome. Twelve deaths occurred in the study period; none were perioperative. Mortality during postoperative follow-up was increased for the morbid obese patients (BMI > 40). Three of the 7 patients with morbid obesity died less than 7 years following surgery. The mean age at the time of death in the 3 patients was 51 years (range, 40-56). Conclusions: Patients undergoing epilepsy surgery in this study were less likely to have an increased BMI compared to the general population. This may reflect patient selection for surgery. There did not appear to be a significant difference in seizure outcome or postoperative complications based on weight. However, long-term mortality was increased in the morbid obesity patients. The effect of morbid obesity on long-term quality of life after epilepsy surgery may need to be considered in selecting operative candidates.