An interventional study of Active taVNS and sham taVNS in Consciousness Disorder, Minimally Conscious State and Vegetative State, sponsored by University of Liege. Completed at 2 sites in Belgium. Open to participants aged 18 Years to 99 Years. Per ClinicalTrials.gov, last updated 2026-05-01.
Sponsored by University of Liege · Not applicable, Interventional, and Treatment
Non-invasive brain stimulations techniques have recently shown promising results in patients with disorders of consciousness. Notably, a case reported improvement of level of consciousness using transcutaneous auricular vagal nerve stimulation in a patient in unresponsive wakefulness syndrome.
Here we aim to assess the effects of transcutaneous auricular vagal nerve stimulation on post-coma patients with disorders of consciousness in a first randomized controlled trial. To measure these effects, behavioral (Coma recovery scale revised - CRS-R -primary outcome) and neuro-electrophysiological (electroencephalography - EEG - secondary outcome) data will be recorded in severely brain-injured patients with DOC.
Currently, therapeutic options for severely brain-injured patients with disorders of consciousness (DOC), including patients in unresponsive wakefulness syndrome (UWS) and minimally conscious state (MCS), are limited and still need to be improved to influence long-term outcomes. Non-invasive brain stimulations (NIBS) techniques have recently shown promising results in DOC.
Transcutaneous auricular vagal nerve stimulation (taVNS-R, tVNS Technologies GmbH, Germany) seems to be a promising approach. In a recent case report, a patient in UWS improved to MCS using this therapeutic technique.
To confirm this positive result, we propose a first randomized double-blind controlled trial. The patients will be randomized in the active stimulation group and will receive bilateral stimulations of the cymba conchae or in the sham stimulation group and will receive bilateral stimulations of the ear lobe. All stimulations will be performed for 45 minutes bilaterally for 5 consecutive days, between 7 and 90 days post-injury in severely brain-damaged patients with disorders of consciousness. The stimulation will start at 3 mA and will be decreased if signs of pain were observed (more than 4/9 according to the Nociceptive Coma Scale-Revised - NCS-R) until stimulation stays under pain threshold.
Behavioral assessments will be performed using the Coma Recovery Scale-Revised before and after the first and last session by an investigator blinded to the treatment allocation. Fifteen minutes of high-density EEG will also be recorded directly before and after the first and last stimulation session. During this same period of time, electrocardiography (EKG) will be recorded to measure parasympathetic indirect signs of vagal stimulation.
3 months after the last stimulation session, an outcome follow-up will be done, using the Glasgow Outcome Scale Extended (GOS-E) and the Disability Rating scale (DRS).
290 studies on the registry are indexed under Consciousness Disorders; 109 are open to participants now.
This study's enrollment of 44 is close to the median of 47 across 191 interventional studies indexed under Consciousness Disorders.
Browse Consciousness Disorders studies →University of Liege is the lead sponsor of 251 studies on the registry; 50 are open to participants now.
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Exclusion Criteria:
Patients will receive 5 days of transcutaneous auricular vagal nerve stimulation (taVNS) bilaterally, at the cymba conchae, the active localization. It will be preceded and followed by a clinical assessment (Coma Recovery Scale- Revised) and a neurophysiological assessment (128/256 channels EEG and electrocardiograph) the first and last day of stimulation.
Device: Active taVNS
Patients will receive 5 days of transcutaneous auricular vagal nerve stimulation (taVNS) bilaterally, at the ear lobe, the sham localization. It will be preceded and followed by a clinical assessment (Coma Recovery Scale- Revised) and a neurophysiological assessment (128/256 channels EEG and electrocardiograph) the first and last day of stimulation.
Device: sham taVNS
Patients will receive transcutaneous auricular vagal nerve stimulation (taVNS) for 5 consecutive days, at the cymba conchae, bilaterally, during 45 minutes (alternating 30 s on and 30 s off periods). Current intensity: 3 mA or less according to the participant's pain threshold, width: 200-300 μsec.
Patients will receive transcutaneous auricular vagal nerve stimulation (taVNS) for 5 consecutive days, at the ear lobe, bilaterally, during 45 minutes (alternating 30 s on and 30 s off periods). Current intensity: 3 mA or less according to the participant's pain threshold, width: 200-300 μsec.
Change in CRS-R total score and index score
Behavioral improvement measured by standardized scale. This scale is ranging from 0 to 23, highest score represents more signs of consciousness. The index score is ranging from 0 to 100.
Time frame: Before the installation of the EEG equipment in the pre-stimulation period and 5 minutes after the post-stimulation resting state EEG (immediately after removing the equipment).
Change in EEG
Improvement in cerebral activity (i.e. power spectrum in the alpha and theta band and connectivity) as measured by EEG
Time frame: 15 min before the stimulation period and 15 min after the stimulation period.
Plan to share: No
Ran from Feb 2022 to primary completion in Sep 2024, 31 months.
Of 89 non-industry interventional studies with no phase under Consciousness Disorders, half reached primary completion within 20 months of starting (the median), counting those still running; a quarter within 9 and three quarters within 52. This study's 31 months is above that.
Counting every sponsor, half of 94 studies reached it within 19 months; a quarter within 8 and three quarters within 52.
How these figures are worked out, and which studies are left out of them.
This study is completed, as verified in Apr 2026. You cannot join it, but the record below documents what was studied.
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