Transauricular Vagus Nerve Stimulation and Electroencephalographic Assessment in Disorders of Consciousness

We aim to evaluate the clinical and neurophysiological effects of transauricular vagus nerve stimulation in patient with disorder of consciousness using standardized EEG and behavioral protocols.

We use wearable transauricular vagus nerve stimulation stimulators, EEG system for monitoring neural responses, and quantitative scales, like CRSR, to assess clinical improvement in disorders of consciousness.

We face a challenge in standardizing stimulation protocol, separating genuine and neural recovery from placebo effects and ensuring the reliable longitudinal electrocardiographic power correlation across this heterogeneous patient population. We found that transauricular vagus nerve stimulation can improve coma recovery scale revised score, emulate electrocardiographic marker, like alpha power and P3, supporting its potential as therapeutic tool In disorder of consciousness. We will explore how transauricular vagus nerve stimulation modulates brain network dynamic and investigate whether electrocardiographic based predictor can guide personalized neuro in patient with disorder of consciousness.

[Narrator] To begin, position the patient comfortably in a chair or on a bed. Use additional straps or cushions to maintain a stable posture and prevent body movement during stimulation. Select the appropriate region on the ear to stimulate the auricular branch of the vagus nerve, such as the tragus. Clean the electrodes before placing them on the tragus for the experimental group. Using an alcohol impregnated wipe, clean the targeted ear skin to remove oils or debris. Now, apply a thin layer of conductive gel or paste to the targeted area. Place the anode electrode on the selected ear region, such as the tragus. On the stimulation device, select the appropriate parameterization for transcutaneous auricular vagus nerve stimulation. Set the session duration to 30 minutes and choose a duty cycle of 30 seconds on and 30 seconds off. Start with a current intensity of three milliampers. Select a current intensity of 1.5 milliamperes to avoid any disconformity without adjusting with the Nociception Coma Scale. If the Denociception Coma Scale revised score increases by three points, blood oxygenation drops to 95% or heart rate increases by 20%, reduce the current intensity. After the stimulation session, remove the electrodes from the ear. This study included six unresponsive wakefulness syndrome patients and eight minimally conscious state patients who underwent the treatment with Coma Recovery Scale Revised or CRSR assessments. The mean CRSR score in unresponsive wakefulness syndrome patients remained unchanged at seven across baseline after four weeks of treatment and at the four week follow up. The mean CRSR score in minimally conscious state patients was 11 at baseline, did not significantly change after four weeks of transcutaneous auricular vagus nerve stimulation treatment but showed a significant increase to 12 at the four-week follow up.