Long Term Effects of Vagal Nerve Stimulation on Seizure Control and Quality of Life

Objective: To evaluate long term outcomes for patients in our practice who required a vagal nerve stimulator (VNS) after being classified refractory to medical therapy, and to assess factors relating to the patient’s subjective quality of life. Background: VNS have been proven to be an effective adjunctive therapy that reduces the frequency and severity of epileptic seizures. There have been several studies which have evaluated the effects of VNS on mood and quality of life, but these studies only assessed limited metrics for 2 years post-device implantation. In addition, specific quality of life metrics, which include working and driving, have not been adequately addressed in previous studies. Design/Methods: This study was a retrospective chart review of 46 pediatric and adult patients who had VNS implanted for refractory seizure controls between 1/2011–6/2015. For quality of life study analysis, all children under the age of 18 and patients with developmental delay were excluded. Results: Within 12 months, 57% of patients experienced a decrease in seizure frequency and 80% reported a reduced severity of their seizures. Within 24 months, approximately 75% of patients had a reduced frequency, and 100% had a reduced severity. This effect plateaued at approximately 24 months, and did not change over the subsequent 3 years. In terms of quality of life factors, PHQ-7 and NDDI scores did not change over 5 years. Only 1 of 36 eligible patients became able to drive, and no unemployed patient returned to work. Conclusions: While VNS was successful in reducing seizure frequency and severity, there was no improvement in standardized QOL metrics (PHQ-7 and NDDI). Furthermore, none of our patients were able to return to employment or drive. These findings suggest physicians need to be more aware of the psychosocial issues associated with refractory epilepsy patients, and should consider being more aggressive in the evaluation of their seizures. Disclosure: Dr. Abraham has nothing to disclose. Dr. Balabanov has nothing to disclose.