Abstracts

Rationale: Obesity is a major risk factor for multiple medical comorbidities and the number one health problem in the US. Recently there has been increased interest in mechanisms that regulate body weight and obesity. Multiple studies have shown that the amygdala and its associated circuits play a crucial role in regulating the behavioral and neural mechanism of feeding behavior. The purpose of this study is to investigate the effect of amygdala resection on weight gain in patients with intractable epilepsy. . Methods: This is a retrospective chart review to include patients older that 18 who underwent amygdalo-hippocampectomy at our institution between 2002 and 2012. Demographics, type of surgery, surgical site, pathology and follow up data were collected. Results: 60 patients (36 female, 24 male) who had either selective amygdalohippocampectomy or cortical amygdalohippocampectomy for intractable epilepsy were included in this retrospective study. 36 patients had left temporal lobe epilepsy surgery, and 24 had the same procedure on the right side. Initial and follow up weight was recorded for group comparison. In the left sided surgical patients, 19 out of 22 (86%) females and 9 out of 14 (64%) males gained weight. In the right sided surgical patient 9 out of 14 (64%) female patients and 7 out of 10 (70%) male patients lost weight. In total 73% showed weight changes either by gaining or losing weight depending on their surgical side. There was no significant change in their reported mood to explain the weight changes. In addition this appeared to have no relationship with seizure reduction or freedom reported by patients or antiepileptic medication being used. Conclusions: Previous studies in humans and animal models have shown that amgydala lesions influence the weight and mood changes. Our study shows that there is a difference between left and right sided amygdala regulating mechanisms on feeding behavior and weight gain. This is significant and it cannot be attributed to normal weight gain due to aging as studies have shown that people gain weight approximately 0.23-0.39kg/y depending upon their age over 20 year periods. There is limited research on weight changes after amgydala surgery for temporal lobe epilepsy and and our study suggest a possible relation between surgical side and weight changes. This observation needs to be explored in the future.