Successful outcome of episodes of status epilepticus after vagus nerve stimulation: a multicenter study

Background and purpose: Vagus nerve stimulation (VNS) has been reported to be a safe and effective treatment for drug-resistant epilepsy. The aim of this study is to describe the effect of VNS in patients with a history of repeated episodes of status epilepticus (SE) before implantation.

Methods: From a total of 83 adult patients with drug-resistant epilepsy who had VNS implanted in four tertiary centers in Spain between 2000 and 2010, eight had a previous history of repeated episodes of SE. We performed a retrospective observational study analyzing the outcome of seizures and episodes of SE after implantation. Stimulation was started at the usual settings, and intensity increased according to clinical response and tolerability.

Results: Regarding the eight patients with a history of SE, the mean age at time of VNS implantation was 25.1 [14-40] years. Duration of epilepsy until the implantation was 21.7 [7-39.5] years, and they had been treated with a mean of 12 antiepileptic drugs [10-16]. Mean follow-up since implantation was 4.15 [2-7.5] years. Average seizure frequency decreased from 46 to 8.2 per month. Interestingly, four of the eight patients remained free of new episodes of SE after implantation, and in two additional patients, the frequency decreased by >75%. Adverse effects were mild or moderate in intensity and included mainly coughing and dysphonia.

Conclusion: In those patients with refractory epilepsy and history of SE who are not surgical candidates, VNS is a safe and effective method to reduce seizure frequency and episodes of SE.