BACKGROUNDVagus nerve stimulation (VNS) is an alternative treatment for drug-resistant epilepsy (DRE). The study aimed to explore the potential factors of prognosis, safety and effect of VNS treatment in patients with DRE.

METHODSWe retrospectively examined 45 cases of DRE that received VNS treatment in our center from June 2004 to June 2010 and analyzed the parameters (age of patient receiving VNS, seizure frequency before and after VNS as well as treatment duration) by Student's t test, Fisher's exact and Mann-Whitney U tests, and multivariate Logistic regression.

RESULTSThe overall response rate was 64% (29/45), 67% (6/9) for adults and 64% (23/36) for children, with no significant difference (P = 0.28). Twenty-two cases had been in VNS therapy for over 1 year with a treatment efficacy of 73% (16/22), whereas 23 cases had been in VNS therapy no more than 1 year with a treatment effecacy of 57% (13/23), and has statistically significant difference (P = 0.03). The main side effect included hoarseness of voice and cough. One patient's device was removed due to infection. One patient's VNS was half-way terminated due to seizure aggravation. One patient died due to status epilepticus.

CONCLUSIONSVNS is a safe and effective treatment for DRE. Duration of VNS therapy may be a crucial factor on prognosis.