RESUMEN
This study was aimed to examine whether transcutaneous auricular vagus nerve electrical stimulation (ta-VNS) at auricular concha area was an effective approach for patients with refractory seizures. Double-blind transcu-taneous nerve electrical stimulation was applied in this study. A pilot study was conducted firstly on 50 patients with refractory seizures to preliminarily observe the therapeutic effect of ta-VNS. Then, a randomized controlled trial (RCT) was conducted on another 144 epilepsy patients who were randomly assigned to the ta-VNS group (n = 98), and the transcutaneous non-auricular vagus nerve electrical stimulation (tn-VNS) control group (n = 46). The treat-ment was performed twice a day for 24 weeks. Patients who were neither in the ta-VNS group nor the tn-VNS group accepted medication at the same time. The seizure frequency and severity were assessed in the 8-week, 16-week and 24-week of the treatment according to the modified Engel scale. The results showed that in the pilot study, after 8-week treatment, 6 out of 50 epilepsy patients were seizure free; and 12 cases had a 50%-89% reduction in seizure frequency. After 24-week treatment, 8 cases were seizure free; 2 cases had a more than 90% reduction in seizure frequency; and 9 cases had a 50%-89% reduction in seizure frequency. In the RCT study of 144 epilepsy patients, after 8-week treatment, 10 out of 98 patients in the ta-VNS group were seizure free; 6 cases had a more than 90% reduction in seizure frequency; and 25 cases had a 50%-89% reduction in seizure frequency. After 24-week treatment, 15 cases were seizure free; 6 cases had a more than 90% reduction in seizure frequency; and 26 cases had a 50%-89% reduction in seizure frequency. After 8-week treatment, in the tn-VNS control group, only 3 out of 46 patients were seizure free; 2 cases had a more than 90% reduction in seizure frequency; and 9 cases had a 50%-89% reduction in seizure frequency. After an additional 16-week treatment of ta-VNS, 7 out of 46 patients were seizure free; 14 had a 50%-89% reduction in seizure frequency. There were significant differences in seizure frequency reduction among groups (P< 0.05). It was concluded that ta-VNS, which had similar therapeutic effect as VNS, was able to suppress epileptic seizures. It is a safe, effective, economic, and applicable treatment option for the treatment of refractory epilepsy.