Transcutaneous Vagus Nerve Stimulation in Patients With Severe Traumatic Brain Injury: A Feasibility Trial.

Author: Hakon J1,2, Moghiseh M1, Poulsen I1,3, Øland CML1, Hansen CP1, Sabers A4
Affiliation: <sup>1</sup>Research Unit on Brain Injury Rehabilitation Copenhagen (RUBRIC), Department of Neurorehabilitation, TBI Unit, Copenhagen University Hospital Rigshospitalet, Copenhagen, Denmark. <sup>2</sup>Department of Neurosurgery, Rigshospitalet, Copenhagen, Denmark. <sup>3</sup>Research Unit Nursing and Health Care, Health, Aarhus University, Aarhus, Denmark. <sup>4</sup>The Epilepsy Clinic, Department of Neurology, Copenhagen University Hospital Rigshospitalet, Copenhagen, Denmark.
Conference/Journal: Neuromodulation.
Date published: 2020 Mar 29
Other: Special Notes: doi: 10.1111/ner.13148. [Epub ahead of print] , Word Count: 227

OBJECTIVES: Preclinical studies have shown that surgically implanted vagus nerve stimulation (VNS) promotes recovery of consciousness and cognitive function following experimental traumatic brain injury (TBI). The aim of this study is to report the feasibility and safety of a noninvasive transcutaneous vagus nerve stimulation (tVNS) in patients with persistent impairment of consciousness following severe TBI.

MATERIALS AND METHODS: The feasibility of tVNS was evaluated in five patients presenting with diffuse axonal injury and reduced dominant EEG activity one month following severe TBI. tVNS was applied to the left cymba conchae of the external ear using a skin electrode four hours daily for eight weeks. Possible effects of tVNS on physiological parameters and general side effects were recorded. In addition, we report the rate of recovery using coma recovery scale revised (CRS-R).

RESULTS: The tVNS regime of four hours daily for eight weeks was feasible and well tolerated with little side effects and no clinically relevant effects on physiological parameters. Three patients showed improvements (>3 points) in the CRS-R following eight weeks tVNS.

CONCLUSION: We demonstrated that tVNS is a feasible and safe VNS strategy for patients following severe TBI. Controlled studies are needed to clarify whether tVNS has a potential to promote recovery of consciousness following severe TBI.

© 2020 International Neuromodulation Society.

KEYWORDS: Transcutaneous vagus nerve stimulation; feasibility study; traumatic brain injury; vagus nerve stimulation

PMID: 32227429 DOI: 10.1111/ner.13148