Effect of Transcutaneous Auricular Vagus Nerve Stimulation on Patients With Disorders of Consciousness
taVNS
Effects of Pairing Transcutaneous Auricular Vagus Nerve Stimulation on Patients With Disorders of Consciousness: An Exploratory Single-Center Randomized Controlled Trial
1 other identifier
interventional
20
1 country
1
Brief Summary
Consciousness disorders following severe brain injury refer to a series of disturbances in arousal and cognition secondary to organic brain diseases, including Unresponsive Wakefulness Syndrome (UWS) (also termed Vegetative State, VS) and Minimally Conscious State (MCS). Disorders of consciousness(DoC) is listed in the International Statistical Classification of Diseases and Related Health Problems, though it is not currently recognized as an independent and consistent diagnostic category. According to epidemiological surveys, conservative estimates suggest that 70,000 to 100,000 new cases of DoC are reported annually in China, posing significant challenges for clinical diagnosis and treatment. Accurately assessing DoC, understanding its neurobiological underpinnings, and developing effective rehabilitation strategies remain subjects requiring further investigation through both clinical and basic neuroscience research. Transcutaneous Auricular Vagus Nerve Stimulation (taVNS) is a non-invasive brain stimulation technique that delivers electrical impulses to the auricular branch of the vagus nerve. Substantial evidence indicates that taVNS serves as a therapeutic intervention for various neurological and psychiatric disorders, such as epilepsy, treatment-resistant depression, migraines, and cognitive impairments. As an emerging neurostimulation technique, taVNS has been investigated for its potential to promote the recovery of awareness in patients with DoC. However, clinical evidence remains limited, underscoring the need for further trials to substantiate its efficacy. Developed from traditional implanted Vagus Nerve Stimulation(VNS), taVNS offers high safety and minimal to negligible side effects, presenting a promising therapeutic avenue for patients with severe traumatic brain injury and disorders of consciousness. Methods: This study is a single-arm trial. A total of 20 patients are planned to be enrolled. Each patient will receive taVNS twice daily over a period of 10 consecutive days, totaling 20 sessions. Primary and secondary outcome measures will be assessed at baseline and after the completion of taVNS treatment. The primary efficacy endpoint will be the change in behavioral responses as evaluated by the Coma Recovery Scale-Revised (CRS-R). Additionally, resting-state high-density electroencephalography (EEG) and combined transcranial magnetic stimulation with EEG (TMS-EEG) recordings will be utilized to investigate the neurophysiological correlates of taVNS intervention. Discussion: This study will provide valuable insights to inform the selection of treatment approaches for patients with disorders of consciousness. By employing a pre-post within-subject comparison design, it aims to validate the therapeutic role of Closed-Loop Transcutaneous Auricular Vagus Nerve Stimulation (CL-taVNS) in this patient population.
Trial Health
Trial Health Score
Automated assessment based on enrollment pace, timeline, and geographic reach
participants targeted
Target at below P25 for not_applicable
Started May 2024
Typical duration for not_applicable
1 active site
Health score is calculated from publicly available data and should be used for screening purposes only.
Trial Relationships
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Study Timeline
Key milestones and dates
Study Start
First participant enrolled
May 1, 2024
CompletedFirst Submitted
Initial submission to the registry
December 3, 2025
CompletedFirst Posted
Study publicly available on registry
December 16, 2025
CompletedPrimary Completion
Last participant's last visit for primary outcome
May 1, 2026
CompletedStudy Completion
Last participant's last visit for all outcomes
May 31, 2027
ExpectedMarch 31, 2026
December 1, 2025
2 years
December 3, 2025
March 25, 2026
Conditions
Outcome Measures
Primary Outcomes (1)
Change from Baseline JKF Coma Recovery Scale-Revised(CRS-R)
The CRS-R comprises six subscales designed to assess auditory, visual, oromotor, communication,and arousal processes. Each CRS-R subscale score is determined based on the presence or absence of specific behavioral responses to sensory stimuli. The total score ranges from 0 to 23, with higher scores indicating a higher level of consciousness in patients with DoC.
immediately after 10 days TaVNS session
Secondary Outcomes (2)
Change from Baseline Resting-State EEG
immediately after 10 days TaVNS session
Change from Baseline TMS-EEG
immediately after 10 days TaVNS session
Study Arms (1)
Closed-Loop transcutaneous auricular vagus nerve stimulation
EXPERIMENTALStimulation will be delivered on the left cymba conchae using a silicone electrode
Interventions
The stimulation protocol consisted of pulse trains at a frequency of 100 Hz. A total of 400 paired RAVANS pulses were delivered per session. The intervention was administered twice daily for 10 consecutive days, resulting in a total of 20 sessions.
Eligibility Criteria
You may qualify if:
- Aged 18-70 years, with a disease duration exceeding 28 days but not longer than 1 year.
- Patients diagnosed with disorders of consciousness (DoC), specifically classified as either vegetative state (VS) or minimally conscious state (MCS) according to the Coma Recovery Scale-Revised (CRS-R) based on international guidelines.
- No prior history of neuropsychiatric disorders.
- Absence of contraindications to transcutaneous auricular vagus nerve stimulation (taVNS) or electroencephalography (EEG), and no concurrent use of sedatives or medications that may interfere with cerebral stimulation-including Na⁺ or Ca²⁺ channel blockers or NMDA receptor antagonists.
- Intact skin at the auricular site.
You may not qualify if:
- Participation in other trials involving non-invasive or invasive neuromodulation.
- Uncontrolled epilepsy, defined as seizures occurring within 4 weeks prior to enrollment.
- Presence of cranial metal implants, pacemakers, craniotomy at the stimulation site, implanted brain devices, or similar conditions.
- Cardiac arrhythmia or other significant cardiovascular abnormalities;
- History of respiratory disorders, including dyspnea, asthma, or hyperventilation.
- History of vasovagal syncope.
Contact the study team to confirm eligibility.
Sponsors & Collaborators
Study Sites (1)
Zhujiang Hospital of Southern Medical University
Guangzhou, Guangdong, 510280, China
MeSH Terms
Conditions
Condition Hierarchy (Ancestors)
Central Study Contacts
Study Design
- Study Type
- interventional
- Phase
- not applicable
- Allocation
- NA
- Masking
- NONE
- Purpose
- TREATMENT
- Intervention Model
- SINGLE GROUP
- Sponsor Type
- OTHER
- Responsible Party
- PRINCIPAL INVESTIGATOR
- PI Title
- principal investigator
Study Record Dates
First Submitted
December 3, 2025
First Posted
December 16, 2025
Study Start
May 1, 2024
Primary Completion
May 1, 2026
Study Completion (Estimated)
May 31, 2027
Last Updated
March 31, 2026
Record last verified: 2025-12
Data Sharing
- IPD Sharing
- Will not share