NCT04437498 · VA Office of Research and Development
Vagal Nerve Stimulation in mTBI
(VNS mTBI)
What this study is about
Mild traumatic brain injury (mTBI) and posttraumatic stress disorder (PTSD) are important conditions for the Veterans Administration (VA) that frequently occur together in combat Veterans from the conflicts in Afghanistan and Iraq. In many Veterans these become chronic, raising the risk the burden of neurotrauma can worsen over time.
View original scientific description
Mild traumatic brain injury (mTBI) and posttraumatic stress disorder (PTSD) are important conditions for the Veterans Administration (VA) that frequently occur together in combat Veterans from the conflicts in Afghanistan and Iraq. In many Veterans these become chronic, raising the risk the burden of neurotrauma can worsen over time. This study will examine a new intervention called non-invasive Vagal Nerve Stimulation (nVNS) and its effects on memory and symptoms of PTSD and mTBI as well as brain and physiology in Veterans with mTBI and PTSD.
Interventions
DEVICE
sham stimulation
non invasive vagal nerve stimulation
DEVICE
nVNS
active vns stimulation
Primary outcome measures
CAPS
Time frame: three months
The Clinician Administered Posttraumatic Stress Disorder (PTSD) Scale (CAPS) is a measure of PTSD symptoms with a range of 0-80 and higher score indicating more severe PTSD symptoms. The investigators will compare change from baseline to post treatment with active vagal nerve stimulation (VNS) or sham stimulation twice daily.
insula
Time frame: 10 minutes
Blood flow in the insula is measured with positron emission tomography (PET) and radiolabelled water during the performance of stress tasks. The investigators will compare blood flow in the insula to whole brain blood flow ratio during stress tasks (listening to personalized traumatic scripts) versus control tasks in the VNS versus sham groups with hypothesis of blocked insula blood flow with VNS
HVLT-R % retention
Time frame: baseline versus three months
The Hopkins Verbal Learning Test-Revised (HVLT-R) is a test of declarative memory learning that involves the learning of 12 nouns, four from each of three semantic categories, learned over three learning trials, followed 20 minutes later by a delayed free recall trial and recognition trial composed of 24 words with 12 false positives. The percent (%) retention is calculated by dividing the delayed recall trial by the higher of learning trial 2 or 3. HLVT-R % retention has a range of 0-100 with 100 being best and 0 worst performance. Baseline and three months post treatment paired with sham or active stimulation are compared.
Change in IL6 Concentration in Blood with Stress
Time frame: Baseline to 120 minutes after stress
Interleukin-6 (IL6) response to stress paired with active or sham stimulation. IL6 is an inflammatory biomarker measured in blood. The investigators will compare IL6 response to stress in VNS versus sham treated groups.
hippocampal activation
Time frame: 10 minutes
Blood flow in the hippocampus is measured with positron emission tomography (PET) and radiolabelled water during the performance of declarative memory tasks. The investigators will compare blood flow in the hippocampus to whole brain blood flow ratio during memory tasks versus control tasks in the VNS versus sham groups with hypothesis of increased hippocampal blood flow with VNS
Who can participate
This study lists these criteria on ClinicalTrials.gov. A study coordinator reviews eligibility during screening — this page does not determine whether you qualify.
Inclusion criteria
- Veterans with mTBI and PTSD
Exclusion criteria
- amnesia for the inciting event lasted longer than 24 hours
- Glasgow Coma Scale Score after 30 minutes was less than 13
- loss of consciousness more than 30 minutes
- positive pregnancy test
- meningitis or other neurological disorder other than mTBI
- alcohol or substance abuse use disorder based on the SCID within the past 12 months
- current or lifetime history of schizophrenia, schizoaffective disorder, bipolar disorder, anorexia nervosa or bulimia, based on the SCID
- active suicidal ideation based on criteria outlined below
- a history of serious medical or neurological illness, such as cardiovascular, gastrointestinal, hepatic, renal, neurologic or other systemic illness
- active neuroleptic, opiate, or benzodiazepine treatment
- structural abnormality on brain MRI or CT
Where
- Decatur, Georgia
Collaborators
Atlanta VA Medical Center
Related conditions & keywords
Frequently asked questions
What is a clinical trial?
A clinical trial is a research study that tests new medical treatments, drugs, devices, or procedures to determine their safety and effectiveness. Trials are carefully designed and monitored to protect participants while advancing medical knowledge.
Is it safe to participate?
Clinical trials follow strict safety guidelines and ethical standards. Trials must be reviewed and approved, and participants are closely monitored by medical professionals throughout the study. You can withdraw at any time if you choose.
Will I be compensated?
Many clinical trials offer compensation for your time, travel expenses, and inconvenience. The specific compensation varies by study and will be discussed during the screening process. All study-related medical care is typically provided at no cost to participants.
Will I receive a placebo instead of treatment?
When effective treatment exists, participants typically receive either the standard treatment plus the study intervention, or the standard treatment plus placebo. You would not be denied effective care. Placebos are primarily used when no proven treatment is available, or in addition to standard care. Your trial consent form will clearly explain what treatments you may receive.
Can I leave a trial if I change my mind?
Absolutely. Participation in clinical trials is completely voluntary. You have the right to withdraw from the study at any time, for any reason, without penalty or loss of benefits to which you are otherwise entitled.
How long does a clinical trial last?
Trial duration varies widely depending on the study design and purpose. Some trials last just a few weeks, while others may continue for months or years. The study coordinator will provide specific timeline information during your screening call.
Data: ClinicalTrials.gov · synced Oct 24, 2025 · Source of record for eligibility and locations