The effects of transcutaneous auricular vagus nerve stimulation in epilepsy comorbid with migraine on the EEG power spectrum: A randomized controlled trial

Jinyuan Du¹Shuai Ma¹Cheng Luo²Xiao Wu¹Linli Liu²Tingting Liu¹Xin Zhang¹Lili Yang¹Yi Luo³Sheng Zhang³Qiong Zhu^1*

• ¹Department of Neurology, Sichuan Provincial People's Hospital, University of Electronic Science and Technology of China, Chengdu, China., Chengdu, China
• ²The Clinical Hospital of Chengdu Brain Science Institute, MOE Key Lab for Neuroinformation, School of Life Science and Technology, University of Electronic Science and Technology of China., Chengdu, China
• ³Department of Neurology, Enyang district Peoples Hospital of Bazhong, Sichuan, China, Bazhong, China

Background: Migraine is a common comorbidity in patients with epilepsy, with a comorbidity rate ranging from 9.3% to 34.7%. Transcutaneous auricular vagus nerve stimulation (taVNS) is an emerging therapy used in both epilepsy and migraine treatment. However, there are currently no randomized controlled studies (RCTs) using taVNS for epilepsy complicated with migraine. Objective: In this study, we evaluated the effect of taVNS as an adjuvant therapy on patients with comorbid epilepsy and migraine. Methods: Forty comorbid patients (taVNS n = 20, tanVNS n = 20) were recruited and randomly grouped. The taVNS group received the true stimulus, whereas the tanVNS group received a pseudostimulus. Outcome assessment was performed at baseline and 24 weeks after initiation. We used t-test and non-parametric tests to analyse the data. Results: The frequencies of migraine attacks and seizures significantly decreased in the taVNS group from baseline to 24 weeks (migraine attack frequency, P = 0.002; seizure frequency, P = 0.004), and so did in self-rating anxiety scale (SAS) score (P < 0.001) and self-rating depression scale (SDS) score (P < 0.001). The QOLIE-31 scores increased after 24 weeks of taVNS treatment (P = 0.028). Moreover, taVNS reduced the EEG power spectrum in four frequency bands at 16 electrode locations in comparison between groups (P < 0.05). Conclusion: In comorbid patients in our groups, taVNS can decrease the frequency of seizures, improve mood and quality of life, and reduce the EEG power spectrum.