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Understanding the Effects of Non-Invasive Transauricular Vagus Nerve Stimulation on EEG and HRV

Published: January 19th, 2024



1Neuromodulation Center and Center for Clinical Research Learning, Spaulding Rehabilitation Hospital and Massachusetts General Hospital, Harvard Medical School, 2Physical Therapy Department, Federal University of Sao Carlos, 3Vicerrectorado de Investigación, Universidad de Investigación para la Generación y Síntesis de Evidencia en Salud, Universidad San Ignacio de Loyola, 4Department of Medical Sciences, Graduate School of Medicine, Korea University, 5Neurive Co., Ltd., 6Department of Otorhinolaryngology-Head and Neck Surgery, Korea University Medical Center

This protocol provides information on how to apply transcutaneous auricular vagus nerve stimulation (taVNS) in a clinical trial, including potential biomarkers such as EEG metrics and heart rate variability (HRV) to measure the effect of this treatment on the autonomic nervous system.

Several studies have demonstrated promising results of transcutaneous auricular vagus nerve stimulation (taVNS) in treating various disorders; however, no mechanistic studies have investigated this technique's neural network and autonomic nervous system effects. This study aims to describe how taVNS can affect EEG metrics, HRV, and pain levels. Healthy subjects were randomly allocated into two groups: the active taVNS group and the sham taVNS group. Electroencephalography (EEG) and Heart Rate Variability (HRV) were recorded at baseline, 30 min, and after 60 min of 30 Hz, 200-250 µs taVNS, or sham stimulation, and the differences between the metrics were calculated. Regarding vagal projections, some studies have demonstrated the role of the vagus nerve in modulating brain activity, the autonomic system, and pain pathways. However, more data is still needed to understand the mechanisms of taVNS on these systems. In this context, this study presents methods to provide data for a deeper discussion about the physiological impacts of this technique, which can help future therapeutic investigations in various conditions.

Transauricular vagus nerve stimulation (taVNS) is a recent neuromodulation technique that does not require surgery and utilizes a non-invasive stimulation device placed at the concha or tragus of the ear. Consequently, it is more accessible and safer for patients1. In recent years, the taVNS field has rapidly expanded, primarily focusing on clinical trials demonstrating potential therapeutic advantages for various pathological conditions, including epilepsy, depression, tinnitus, Parkinson's disease, impaired glucose tolerance, schizophrenia, and atrial fibrillation2. There is much to discuss about taVNS and its effects ....

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All study procedures were performed at the Spaulding Neuromodulation Center/Spaulding Cambridge Hospital. Ethical approval for this protocol was obtained from Mass General Brigham IRB (Number Protocol #:2022P003200). Informed consent was obtained from all subjects using the encrypted Research Electronic Data Capture (REDCap) platform (see Table of Materials). Trial registration number: NCT05801809.

1. Subject selection and screening

  1. Identify potent.......

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We performed a preliminary descriptive analysis of the first randomized subject without unblinding the study. For this reason, which arms this subject was allocated to is unknown. The first subject is a 69-year-old woman, non-Hispanic, Caucasian, with a college degree, who did not report any adverse event during or after the stimulation session. The clinical data are displayed in Table 2.

Besides, a topographic distribution of scalp plots was created in resting-state EEG for t.......

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Transauricular Vagus Nerve Stimulation (taVNS) is emerging as a promising therapeutic avenue for addressing several neuropsychiatric conditions. Mood disorders, such as depression and anxiety, pose a significant global health burden, especially after the COVID-19 pandemic19. Recent studies exploring taVNS have exhibited the potential to alleviate symptoms associated with these disorders.

The vagus nerve plays a pivotal role in the brain-gut axis and the regulation of e.......

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The author is grateful to the research team (Maria Fernanda Andrade, Allison Kim, Robin Heemels).


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NameCompanyCatalog NumberComments
Articulated armElectrical Geodesics, Inc.20090645
Baby shampooDynarex1396
Charge CableNEURIVE Co.HV12303003
Condutive eartipNEURIVE Co.HV12303003
EarsetNEURIVE Co.HV12303003
EEG 64-channel cap Electrical Geodesics, Inc.H11333
Heart rate sensorPolarM311370175396
Net Amps 300Electrical Geodesics, Inc.A09370244
Peltier thermodeAdvanced Medical Systems, Ramat Yishai, Isreal
Potassium Chloride (dry)Electrical Geodesics, Inc.820127755
RallyMass General Brigham Researchonline platform
Research Electronic Data Capture (REDCap)Vanderbiltweb-based software platform
Thermosensory StimulatorMedoc Ltd1241
Transauricular vagus nerve stimulatorNEURIVE Co.HV12303003

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