Abstracts

Rationale: Vagus nerve stimulation (VNS) has been used to treat drug refractory epilepsy for more than 20 years; however, one of the limitations of this method is generation of side effects that limit the increase of current amplitude, hence its ultimate potential. Methods: A new VNS system (FitNeS™ BioControl Medical Ltd, Yehud, Israel) is based on a proprietary cuff electrode, a design that facilitates implantation and reduces leakage of current to neighboring tissues. The electrode composition enables preferentially unidirectional stimulation, while using parameters that are similar to the ones used by other commercially available VNS systems in terms of amplitude, frequency and pulse width. Results: We have uneventfully implanted 5 patients whose condition was refractory to multiple anti-epileptic drugs. Two had previously undergone resective epilepsy surgery and the other 3 were evaluated for epilepsy surgery but deemed not operable. After implantation with FitNesTM all patients have been followed for at least 6 months, (range 6 months to 1 year). With the exception of one patient who suffers slight hoarseness, which does not correlate with stimulations, there are no other side effects that are either self-reportable or noted by relatives or friends or the treating physician. At this time, seizure frequency reduction versus baseline is 25% in one and >50% in the other 4 subjects, at current strengths between 1.5 - 2.0 mA. Conclusions: This is the first experience with the FitNeS™ system for the treatment of epilepsy. The positive outcome in efficacy and the absence of side effects experienced by the patients even at relatively high currents is encouraging. Further studies are recommended. Because patients do not seem to be aware of the stimulation, a double blind study of the efficacy of VNS would now be feasible.