Clinical investigation of vagus nerve stimulation for treatment of drug-resistant epilepsy

Abstract

Objective To explore the effectiveness and surgical procedures of vagus nerve stimulation (VNS) therapy in patients with drug-resistant epilepsy.Methods Fourteen patients with drug-resistant epilepsy,admitted to our hospital from January 2007 to January 2011,including 6 with epilepsy after cephalitis,3 with epilepsy after head trauma and 5 with idiopathic epilepsy,were chosen in our study; their clinical data were retrospectively analyzed.VNS was performed in all the patients; the initial programming settings were as follows:output current 0.25 mA,frequency 30 Hz,pluse width 500 μs,ON 30 s and OFF 5 min.The optimum settings for each patient should balance the goals of maximizing efficacy,minimizing side effects,and preserving better life.Results The patients experienced a median seizure frequency reduction of 63.6％ after 6-44 months of VNS therapy,including 3 patients having ＜50％ seizure reduction,11 (78.6％) having ＞or=50％ seizure reduction,6 (42.3％)having ＞80％ seizure reduction,and 2 (14.3％) having seizure free.Seizure termination or seizure diminution was reported in 5 (35.7％) patients after using the magnet.Conclusion VNS is a safe and effective therapy and could improve the quality of life in patients with drug-resistant epilepsy; VNS is also effective for patients with symptomatic generalized epilepsy. Key words: Epilepsy; Vagus nerve; Electrical stimulation therapy