Transcutaneous vagus nerve stimulation therapy for refractory epileptic encephalopathy with spike-wave activation in...

The aim of this study was to prospectively investigate the efficacy of transcutaneous vagus nerve stimulation (t-VNS) in drug-resistant epileptic encephalopathy with spike-wave activation in sleep (EE-SWAS) pediatric patients.

We prospectively reviewed 11 drug-resistant epilepsy pediatric patients who underwent a 3-month t-VNS. We used a weighted phase lag index (wPLI) measure to assess the change in connectivity measures that quantify electroencephalogram (EEG) synchronization before and after stimulation. We measured the change in non-rapid eye movement (NREM) and seizure frequency following t-VNS, and cognitive functions were assessed before and after stimulation using the Chinese Wechsler Intelligence Scale for Children (C-WISC) and the Chinese Wechsler Preschool and Primary Scale of Intelligence (C-WPPSI).

Our results show that 63.63% of EE-SWAS patients were responders to the 3- month t-VNS, with 4 being seizure-free, and resulted in a reduction of NREM, seizure frequency, and coupling strength. More specifically, there was a significant decrease in coupling strength in the frontal-occipital and central-occipital regions in the theta band; frontal-parietal, central-parietal, parietal, parietal-occipital, parietal-temporal, occipital-temporal, and temporal regions in the alpha band; and lastly, frontal-occipital, central-parietal, parietal-occipital, and occipital-temporal regions in the beta band. There were no statistically significant changes in total intelligence before and after t-VNS.

This study presents evidence that t-VNS is a safe and effective non-invasive treatment for refractory EE-SWAS. Despite the relatively short stimulation period, t-VNS resulted in a decrease in NREM, seizure frequency, and in an alteration in brain functional connectivity strength. Future studies with a larger cohort and longer stimulation duration may be necessary to substantiate our findings.