Evidence-Based Guideline Update: Vagus Nerve Stimulation for the Treatment of Epilepsy
In the October 2013 issue of Neurology, Morris and colleagues authored an AAN and AES-supported guideline regarding vagal nerve stimulation. There was only one paper, the initial pivotal trial, that was felt to be better than Class III evidence. All recommendations are Level C. About 55% of patients had > 50% reduction in seizure frequency, whether they had Lennox-Gastaut or a variety of other seizure types. There is some evidence that VNS has increased efficacy over time (at 1 and 5 years). Optimal stimulation settings are unknown. Magnet stimulation during aura seems to abort seizure progression in 25-66% of cases. The infection risk seems to be higher in children than adults. The findings are quite similar to those from the systematic review by Englot et al. in J Neurosurg (2011). However, this paper downgrades the strength of the evidence and is likely to hold more sway with neurologists. Patients should still undergo comprehensive epilepsy evaluations to rule out non-epileptic conditions and treatable, symptomatic epilepsies before considering VNS.