Transcutaneous vagus nerve stimulation for the treatment of drug‐resistant epilepsy: a meta‐analysis and systematic review

Background The transcutaneous vagus nerve stimulation (tVNS) is a newly developed non‐invasive technique in the treatment of drug‐resistant epilepsy and results in positive effects for patients who cannot tolerate invasive vagus nerve stimulation. In this study, we aim to define the relationship between tVNS and seizure control, quality of life (QOL) and some other factors. Methods We found articles by searching through PubMed and Web of Science, and a total of three articles with 280 patients overall were included. These eligible studies include two randomized double‐blinded trials and one randomized single‐blinded trial. Meta‐analysis and systematic review were performed, analysing the association between tVNS and seizure frequency using the available data. The responder rate, QOL and adverse effects were also analysed. Results The results showed a significant difference in seizure frequency between treatment group and control group (Z = 2.14, P = 0.03, 95% confidence interval (CI) −6.31 to −0.27; I2 = 10%). However, only two studies provided the data of responders, and the result failed to figure out a significant difference (Z = 0.75, P = 0.45, 95% CI (odds ratio) 1.47 (0.54–4.02); I2 = 61%). It is difficult to define whether tVNS improved QOL between treatment and control groups using the available data. The adverse effects seem to be very few, with the most common being headache. Conclusion tVNS is an effective procedure to control the frequency of seizures according to the available data, especially for those patients who do not want to tolerate a surgical procedure.