O papel da estimulação vagal elétrica no tratamento de pacientes com epilepsia refratária

Abstract

Vagus nerve stimulation (VNS) is an adjunctive therapy used to treat patients with refractory epilepsy who are not candidates for resective surgery or have poor results after surgical procedures. There is sufficient evidence nowadays to support its use in patients with focal epilepsy and other seizure types. In order to investigate an approach to optimize therapy and reduce battery consumption, this project aimed at proposing an amendment to the current stimulation protocol, altering it from 30 Hz to 20 Hz, through assessment of two variables: seizures and adverse events. The prospective and double-blind analysis consisted of a 3 month evaluation of 6 patients that had already been implanted with the VNS system, followed by parameter adjustment and follow-up for another month. The results revealed that, with 20 Hz stimulation, there was 68% reduction in seizures (p = 0,054), as well as low incidence of adverse events (only 1 of 6 patients). Therefore, this study was a pilot project with short-term follow-up that indicates the possibility of reducing frequency stimulation to 20 Hz without compromising therapy efficacy and without any increase in complication rates, which could further increase battery life expectancy.