Ear-based vagus nerve stimulation for chronic whiplash-associated disorder

The Safety and Feasibility of Transauricular Vagus Nerve Stimulation Therapy in Chronic Whiplash-Associated Disorders: A Randomized Pilot Trial

This study will test whether mild electrical stimulation of the vagus nerve through the ear can help people with chronic whiplash-associated disorder reduce pain and stress-related symptoms.

Quick facts

• Phase: Not applicable
• Study type: Interventional
• Enrollment: 40 (estimated)
• Ages: 18 Years to 65 Years
• Sex: All
• Sponsor: University of Calgary (Academic / other)
• Locations: 1 site (Calgary, Alberta)
• Trial ID: NCT07055373 on ClinicalTrials.gov

What this trial studies

This interventional project uses transauricular vagus nerve stimulation (taVNS) delivered through the ear to target autonomic nervous system imbalance thought to contribute to chronic whiplash-associated disorder (WAD). The initial focus is on safety and feasibility, with participants meeting criteria for chronic WAD (symptoms 3 months to under 10 years, average pain ≥4/10, and Neck Disability Index >28%). Participants with implanted electronic devices, severe bradycardia, recent concussion, or open ear wounds are excluded for safety. Outcomes include autonomic measures, pain and disability scores, and monitoring for adverse effects.

Who should consider this trial

Good fit: Ideal candidates are adults with chronic WAD grade I–III lasting at least 3 months but less than 10 years, average pain of 4/10 or higher, and a Neck Disability Index above 28%, who do not have contraindicated implants, severe bradycardia, concussion symptoms, or open ear wounds.

Not a fit: Patients with WAD grade IV, recent concussion, severe bradycardia, or active/close implanted electronic or metallic devices (including near the ear) are unlikely to benefit or may be excluded for safety reasons.

Why it matters

Potential benefit: If successful, taVNS could reduce pain, disability, and stress-related symptoms by improving autonomic balance in people with chronic WAD.

How similar studies have performed: taVNS has shown benefit in some other pain and autonomic disorders such as chronic low back pain and postural tachycardia syndrome, but its use specifically for chronic WAD is novel and unproven.

Eligibility criteria

Inclusion Criteria:

1. Symptom duration ≥3 months and \<10 years; and
2. Classifiable as WAD grade I (neck pain without physical impairments) or II (neck pain \& impairment such as movement loss and/or tenderness) or III (neck pain \& neurological deficit evident on physical exam);
3. Average pain intensity (over one week) ≥ 4/10;
4. Neck Disability Index score \> 28% (14/50).

Exclusion Criteria:

1. WAD IV injury (no neurological deficit, fracture, or dislocation);
2. Concussion symptoms;
3. Patients who have undergone cervical vagotomy;
4. Patients diagnosed with severe bradycardia;
5. Patients with a permanent implanted metallic or electronic device or jewellery at close proximity to the ear tragus;
6. Patients with any active implanted device (including electronic and/or medical devices) e.g. cochlear implant, cerebral shunts, invasive vagus nerve stimulators, or non-active but potentially interacting with the nervous system (e.g., metal implants);
7. Open wounds or rashes, swollen, red, infected, or inflamed areas or skin eruptions (e.g., phlebitis, thrombophlebitis, varicose veins); or cancerous lesions in the area of stimulation
8. Using medications associated with ANS function such as Beta Blockers;
9. Adverse general health factors such as presence of a neurological disorder (e.g., multiple sclerosis), inflammatory condition (e.g., rheumatoid arthritis), cardiovascular disorder (known severe coronary disease or recent myocardial infarction (within 5 years)); metabolic disorder (e.g., diabetes), visual deficit or disease process (e.g. cataracts, double or blurred vision), known or suspected serious spinal pathology (e.g. metastatic disease of the spine), pregnancy, or previous spinal surgery or recurrent treatment for spinal disorders;
10. History of any mental health conditions prior to the MVC, such as bipolar disorder, schizophrenia, anxiety, PTSD or severe depression;
11. People who are unable to complete the questionnaires.

Where this trial is running

Calgary, Alberta

• Vivo Cura Health — Calgary, Alberta, Canada (Recruiting)

Study contacts

• Principal investigator: Ashley Smith — University of Calgary
• Study coordinator: Jennifer Laxshimalla

Conditions Whiplash Associated Disorder; Vagus Nerve Stimulation; Parasympathetic Nervous System; Sympathetic Nervous System; Post-traumatic Stress; Central Sensitization; Heart Rate Variability; Pupillometry