Vagus Nerve Stimulation in Intractable Epilepsy.

Abstract

To investigate and compare the efficacy and safety of vagus nerve stimulation (VNS) therapy in different types of epilepsy. Patients, who were implanted with VNS between the years 2005 and 2020, were retrospectively included in the study. Age, gender, age at seizure onset, epilepsy types, VNS implantation year, replacement year, pre and post-VNS seizure frequency, number of responders, number of antiseizure medication and adverse events were recorded. In total, 41 patients were included in the study. The number of patients with focal epilepsy was 21 (51.2%). 10 patients (24.4%) had generalized epilepsy and 10 patients (24.4%) had ?combined generalized and focal epilepsy? (Lennox-Gastaut, Dravet syndrome). The Pre-VNS median seizure frequency was 1.5/day in the focal group, 0.6/day in the generalized group and 6/day in the combined group. Seizure frequencies dropped to 0.3/day in the focal group, 0.2/day in the generalized group and 3.0/day in the combined group at the 12th month after VNS (p < 0.001, p=0.004, p < 0.001). The response rate was found to be 68.3% at the 12th month after VNS. The number of antiseizure medications was decreased from 3.6/day to 3.1/day at the 12th months after VNS (p < 0.001). Two patients? (4.9%) VNS therapy was discontinued due to adverse events. The study indicates that VNS therapy is safe and effective in focal, generalized and combined epilepsy types. Despite having a low seizure freedom rate, VNS is a good alternative treatment option for patients who for any reason are not candidates for resective surgery.