Optimizing the modulation paradigm of transcutaneous auricular vagus nerve stimulation in patients with disorders of consciousness: A prospective exploratory pilot study protocol

Abstract

BackgroundTranscutaneous auricular vagus nerve stimulation (taVNS) is a non-invasive neuromodulation technique. Several studies have reported the effectiveness of taVNS in patients with disorders of consciousness (DOC); however, differences in the modulation paradigm have led to inconsistent treatment outcomes.Methods/designThis prospective exploratory trial will include 15 patients with a minimally conscious state (MCS) recruited according to the coma recovery scale-revised (CRS-R). Each patient will receive 5 different frequencies of taVNS (1, 10, 25, 50, and 100 Hz); sham stimulation will be used as a blank control. The order of stimulation will be randomized, and the patients’ CRS-R scores and resting electroencephalography (EEG) before and after stimulation will be recorded.DiscussionThe overall study of taVNS used in treating patients with DOC is still in the preliminary stage of exploration. Through this experiment, we aim to explore the optimal stimulation frequency parameters of taVNS for the treatment of DOC patients. Furthermore, we expect to achieve a stable improvement of consciousness in DOC patients by continuously optimizing the neuromodulation paradigm of taVNS for the treatment of DOC patients.Clinical trial registrationhttps://www.chictr.org.cn/index.aspx, identifier ChiCTR 2200063828.

Stimulation of vagus nerve for patients with disorders of consciousness: a systematic review

“…Consequently, it is justifiable to argue that, in light of the absence of reported adverse effects in the study conducted by Hakon et al (2020) and the theoretical framework proposed in animal studies, stimulation of vagus nerve holds promise as a potential treatment for patients with DOCs, as supported by our own clinical experience with these individuals. Currently, there is an increasing number of reported study protocols for non-invasive taVNS in the context of DOCs ( Cheng et al, 2023 ; Zhai et al, 2023 ). These protocols aim to design randomized controlled trials with large multicenter samples to assess the efficacy and safety of taVNS therapy for DOCs, as well as investigate the neural anatomy associated with taVNS during the process of consciousness recovery.…”

Transcutaneous auricular vagus nerve stimulation in the treatment of disorders of consciousness: mechanisms and applications

“…Comprehensive controlled studies are essential to determine the impacts of different stimulation frequencies. Some researchers have already unveiled their study protocols in which patients undergo taVNS at five distinct frequencies (1, 10, 25, 50, and 100 Hz) to pinpoint the most effective stimulation frequency for treating DOC patients ( Zhai et al, 2023 ).…”