Some patients with severe traumatic brain injury cannot respond at the bedside, yet about 1 in 4 may be aware but unable to show it - a hidden state called cognitive motor dissociation. This study tests a gentle, non-invasive treatment delivered through clips on the left ear that stimulates two nerves at once: the vagus nerve at the inner ear (taVNS) and the trigeminal nerve at the outer ear (taTNS). Each nerve has separately been shown to help people with disorders of consciousness recover, but they have not been combined before. All enrolled patients receive the stimulation for one hour a day, with continuous heart and oxygen monitoring and a pain-protection check used to keep the dose safe. The study measures recovery two ways: the Coma Recovery Scale-Revised (CRS-R), scored by clinicians, and SeeMe, an automated camera system that detects tiny command-driven movements the eye cannot see.
Age ≥ 18 years
Coma, vegetative state/unresponsive wakefulness syndrome (VS/UWS), or minimally conscious state (MCS) as determined by baseline CRS-R
Acute traumatic brain injury with documented intracranial pathology on neuroimaging
Admission to the Neurology or Neurosurgical ICU
Implanted cardiac pacemaker, vagus nerve stimulator, or other active implanted device
Known cardiac arrhythmia (e.g., 2nd-/3rd-degree AV block, atrial fibrillation with uncontrolled rate)
Active seizures not controlled by current antiepileptic regimen
Skin breakdown, infection, or anatomical abnormality of the left ear precluding electrode placement
Single group
Dual-Site Transcutaneous Auricular Nerve Stimulation (taVNS + taTNS)
DeviceDEVICE: Dual-Site Transcutaneous Auricular Nerve Stimulation (taVNS + taTNS). Delivered via ear-clip electrodes on the LEFT ear using the Sparrow Ascent / Sparrow Link tAN System (Spark Biomedical; FDA-cleared K230796), operated as an NSR investigational device. Vagal site (inner ear / cymba conchae): 15 Hz, 250 µs pulse width, 3 mA fixed, duty cycle 5 min on / 10 s off. Trigeminal site (outer ear): 100 Hz, 250 µs pulse width, 3 mA fixed, duty cycle 5 min on / 10 s off. Session: 1 hour/day. Course: 7 consecutive days, extendable to 28 days. Intensity titrated with the Nociception Coma Scale-Revised (NCS-R): step down 0.5 mA if NCS-R \> 4/9, SpO2 ≤ 95%, or HR rises ≥ 20 bpm; continuous cardiac/hemodynamic monitoring with prespecified stopping rules.
Change in Coma Recovery Scale-Revised (CRS-R) Total Score
Change in level of consciousness will be assessed using the Coma Recovery Scale-Revised total score. The outcome will be reported as the within-participant change in total score from baseline to the end of treatment, as scored by a trained assessor. Scores range from 0 to 23, with higher scores indicating better neurobehavioral function and greater recovery of consciousness.
Change in SeeMe-Detected Stimulus-Evoked Voluntary Motor Responses
Change in command-evoked voluntary motor responses will be assessed using the SeeMe automated camera-based detection system. The outcome will be reported as the within-participant change in the percentage of command trials with SeeMe-positive responses from baseline to the end of treatment. Scores range from 0% to 100%, with higher percentages indicating more frequent command-evoked voluntary motor responses. A SeeMe-positive response is defined as a Kolmogorov-Smirnov statistic greater than 0.1 and pixel displacement greater than 400, detected reliably in at least 3 of 10 command trials. SeeMe scoring will be automated and performed blinded to stimulation timing.
Number of Participants With Device- or Stimulation-Related Adverse Events
Adverse events attributed to auricular stimulation will be recorded and graded using CTCAE v5.0, including ear-site skin reactions, bradycardia or other arrhythmia, oxygen desaturation, and hemodynamic instability. Events requiring NCS-R-guided dose reduction or meeting prespecified stopping criteria will be reported.
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Sima Mofakham
Lead sponsor
Stony Brook University
Sponsor institution
National Institute of Mental Health (NIMH)
Collaborator
