MINT is a single-site, prospective, randomized, double-blind, sham-controlled pilot trial evaluating the safety and feasibility of transcutaneous auricular vagus nerve stimulation (taVNS) in patients with moderate to severe traumatic brain injury (GCS 3-12). Participants will be randomized to receive either active taVNS or sham stimulation using the same device. The primary objective is to assess the safety and feasibility of taVNS implementation in the acute TBI setting. Secondary objectives include exploratory measurement of serum inflammatory and neuronal injury biomarkers and assessment of functional outcome using the Extended Glasgow Outcome Scale at hospital discharge.

MINT is a pilot randomized controlled trial designed to establish the safety and feasibility of taVNS in acute moderate to severe TBI prior to a larger efficacy trial. Sixteen patients with GCS 3-12 admitted to University Hospital, San Antonio will be randomized 1:1 to active taVNS or sham stimulation. Patients entering the University Hospital trauma bay who are diagnosed with traumatic brain injury (TBI) will be prescreened according to inclusion/exclusion criteria for entrance into this study. Participants will be randomized to receive either treatment with active taVNS or sham treatment. A blood draw will be performed prior to initiating auricular vagus nerve stimulation.

Patients will undergo standard of care treatment according to attending physicians, and the investigators will continue taVNS treatment during the course of the patients' admissions. The control group will undergo sham stimulation using the same device placed at the same location. Both active and sham stimulations will be administered under the supervision of study staff, and both patients and treating clinicians will be blinded to group assignment. Patients will be stimulated twice daily with periodic blood draws for up to 7 days.

Inclusion Criteria:

• Age 18-75 years old
• Glasgow Coma Scale (GCS) Score 3-12
• Expected Intensive Care Unit (ICU) stay > 48 hours
• Presenting with acute Traumatic Brain Injury (TBI) within 24 hours

Exclusion Criteria:

• Pregnant
• Any electrical implanted device
• Immunomodulatory medication
• Human Immune Deficiency Virus (HIV) patients
• Autoimmune disease
• Known cancer immunotherapy
• Past medical history of symptomatic bradycardia
• Penetrating brain injury
• Clinical team assessment of prognosis and imminent risk of death such as Decision to withdraw life-sustaining measures
• Current incarceration
• Trauma/Laceration to the left ear

After primary publication, de-identified data may be shared with other researchers upon reasonable request, in accordance with NIH data sharing policies and procedures described in the informed consent document.

At study completion after data analysis are complete and a publication is accepted to a journal.

Double-blind design with participants (when cognitively able), outcome assessors, clinical teams, and laboratory personnel blinded to treatment assignment. Unblinded study personnel will program devices but not assess outcomes.