Ear Stimulation for Post-Stroke Pain

Overseen By Xiaolong Peng, PhD

Age: 18+

Sex: Any

Trial Phase: Academic

Sponsor: Medical University of South Carolina

Disqualifiers: Dementia, Uncontrolled depression, Hypertension, others

No Placebo Group All trial participants will receive the active study treatment (no placebo)

Approved in 3 Jurisdictions This treatment is already approved in other countries

Compensation: Varies

Number of Visits: 1

Duration: 1 day

What You Need to Know Before You Apply

What is the purpose of this trial?

This trial aims to determine if a special type of ear stimulation, called Transcutaneous Auricular Vagus Nerve Stimulation (taVNS), can reduce pain in individuals with ongoing arm pain after a stroke. Participants will receive either active ear stimulation targeting specific parts of the ear or a sham (fake) treatment. The goal is to assess whether the real stimulation results in less pain. This trial is suitable for individuals who had a stroke at least six months ago, experience pain in the right arm, and can provide consent. As an unphased trial, it offers a unique opportunity to explore innovative pain relief methods for stroke survivors.

Will I have to stop taking my current medications?

The trial information does not specify whether you need to stop taking your current medications. It's best to discuss this with the trial coordinators or your doctor.

What prior data suggests that this ear stimulation technique is safe for post-stroke pain?

Previous studies have found that using a device on the ear to stimulate the vagus nerve is generally safe. Research shows that this treatment typically causes only mild and short-lived side effects, which are not serious and usually resolve on their own. Another study found this method effective and safe for alleviating symptoms of depression. No serious problems were reported, suggesting that most people tolerate it well. ^{1 2 3 4 5}

Why are researchers excited about this trial?

Most treatments for post-stroke pain focus on medication or physical therapy to manage symptoms. But Transcutaneous Auricular Vagus Nerve Stimulation (taVNS) works differently, targeting the vagus nerve through gentle electrical stimulation of the ear. This unique approach is exciting because it offers a non-invasive alternative that could potentially modulate pain pathways directly, providing relief without the side effects associated with drugs. Researchers are particularly interested in its ability to fine-tune nerve activity and potentially offer faster relief.

What evidence suggests that transcutaneous auricular vagus nerve stimulation (taVNS) might be an effective treatment for post-stroke pain?

Research has shown that transcutaneous auricular vagus nerve stimulation (taVNS), which participants in this trial may receive, might help reduce pain. One study found that taVNS significantly eased pain from uterine contractions and surgery. Another study demonstrated that taVNS improved survival rates after a stroke, suggesting it may aid stroke recovery. In animal studies, it also reduced the size of strokes. Overall, taVNS appears to be a safe and promising option for managing pain, including post-stroke pain. Participants in this trial may also receive sham auricular stimulation as a comparator. ^{1 4 6 7 8}

Are You a Good Fit for This Trial?

This trial is for up to 20 people who have chronic pain in their arm after a stroke. Participants should be experiencing this specific type of post-stroke pain to qualify.

Inclusion Criteria

I had a stroke more than 6 months ago.

I have pain in my right arm.

I had a stroke that affected the left side of my brain.

Exclusion Criteria

I have a history of untreated or uncontrolled mental health issues.

Pregnancy

I have had a stroke caused by bleeding in the brain.

Timeline for a Trial Participant

Screening

Participants are screened for eligibility to participate in the trial

2-4 weeks

Treatment

Participants receive a single 30-minute session of transcutaneous auricular vagus nerve stimulation (taVNS) or sham stimulation

1 day

1 visit (in-person)

Follow-up

Participants are monitored for changes in pain perception immediately after the intervention

Immediate post-treatment

What Are the Treatments Tested in This Trial?

Interventions

• Sham Auricular Stimulation
• Transcutaneous Auricular Vagus Nerve Stimulation (taVNS)

Trial Overview

The study is testing if transcutaneous auricular vagus nerve stimulation (taVNS), a non-invasive ear stimulation, can help reduce the perception of pain in participants with post-stroke arm pain.

How Is the Trial Designed?

Group I: Auricular Neurostimulation (Active) Active Control 1 Intervention

Participants will receive auricular stimulation of both the 15Hz on cymba conchae and 100Hz on tragus.

Group II: Auricular Neurostimulation (Sham) Placebo Group 1 Intervention

Participants will receive auricular stimulation of 15Hz on their earlobe.

Transcutaneous Auricular Vagus Nerve Stimulation (taVNS) is already approved in United States, European Union, China for the following indications:

Approved in United States as Transcutaneous Auricular Vagus Nerve Stimulation for:

• Post-stroke pain management
• Upper limb rehabilitation post-stroke

Approved in European Union as Transcutaneous Auricular Vagus Nerve Stimulation for:

• Epilepsy
• Depression
• Tinnitus
• Post-stroke upper limb function improvement

Approved in China as Transcutaneous Auricular Vagus Nerve Stimulation for:

• Stroke rehabilitation
• Upper limb functional restoration post-stroke

Who Is Running the Clinical Trial?

Medical University of South Carolina

Lead Sponsor

Trials

994

Recruited

7,408,000+

Published Research Related to This Trial

In a double-blinded randomized controlled trial with 60 acute stroke patients, transcutaneous auricular vagus nerve stimulation (ta-VNS) combined with conventional rehabilitation significantly improved recovery of motor, sensory, and emotional functions compared to sham treatment.

The study found no significant side effects from ta-VNS, indicating that it is a safe and effective noninvasive treatment option for patients recovering from acute ischemic or hemorrhagic strokes.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Efficacy and safety of transcutaneous auricular vagus nerve stimulation combined with conventional rehabilitation training in acute stroke patients: a randomized controlled trial conducted for 1 year involving 60 patients. Li, JN., Xie, CC., Li, CQ., et al.[2022]

Transcutaneous auricular vagus nerve stimulation (taVNS) significantly improved upper limb motor function in 21 subacute ischemic stroke patients compared to a sham treatment, as measured by the Fugl-Meyer assessment and other functional tests after 15 days of intervention.

The study found taVNS to be safe, with only one reported case of skin redness, indicating it may be a beneficial and low-risk option for enhancing recovery in stroke patients.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Effect and Safety of Transcutaneous Auricular Vagus Nerve Stimulation on Recovery of Upper Limb Motor Function in Subacute Ischemic Stroke Patients: A Randomized Pilot Study. Wu, D., Ma, J., Zhang, L., et al.[2021]

Transcutaneous auricular Vagal Nerve Stimulation (taVNS) did not show any significant effects on pain perception or nociception in healthy participants, as measured by event-related potentials and sensory testing across three experiments involving 22 and 15 subjects.

Both taVNS and standard cervical VNS (cVNS) failed to produce objective changes in behavioral and cerebral responses to pain stimuli, suggesting that the analgesic effects of taVNS may not be as effective as previously thought.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Transcutaneous auricular VNS applied to experimental pain: A paired behavioral and EEG study using thermonociceptive CO2 laser. Dumoulin, M., Liberati, G., Mouraux, A., et al.[2021]

Transcutaneous auricular Vagus Nerve Stimulation (taVNS) can be optimized by varying electrode designs, which significantly affects the sensitivity and selectivity of nerve activation in different regions of the ear, as shown through a detailed anatomical model and finite element analysis.

The study found that smaller electrodes increase the electric field strength for a given current, allowing for more targeted stimulation of specific ear regions, which is crucial for enhancing the efficacy of taVNS in clinical applications.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

High-resolution computational modeling of the current flow in the outer ear during transcutaneous auricular Vagus Nerve Stimulation (taVNS). Kreisberg, E., Esmaeilpour, Z., Adair, D., et al.[2023]

Transcutaneous auricular vagus nerve stimulation (taVNS) is a non-invasive and cost-effective method for modulating the vagus nerve, making it a promising alternative to traditional surgical vagus nerve stimulation.

taVNS allows for easy and safe administration, with considerations for proper electrode placement and individual dosing based on perception thresholds, which enhances its potential for treating various central and peripheral diseases.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Laboratory Administration of Transcutaneous Auricular Vagus Nerve Stimulation (taVNS): Technique, Targeting, and Considerations. Badran, BW., Yu, AB., Adair, D., et al.[2020]

Transcutaneous auricular vagus nerve stimulation (taVNS) is a non-invasive treatment method that applies electrical current to the outer ear to stimulate the vagus nerve, which has been explored for its therapeutic potential in various diseases.

Over the past two decades, taVNS has gained attention as an alternative to drug treatments, but the field also faces limitations that need to be addressed for further development.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Transcutaneous Auricular Vagus Nerve Stimulation: From Concept to Application. Wang, Y., Li, SY., Wang, D., et al.[2022]

Non-invasive transcutaneous vagus nerve stimulation (tVNS) has shown promise in improving neurological recovery after stroke, potentially reducing infarct size and enhancing motor function through mechanisms like anti-inflammatory effects and neuroplasticity.

Pilot clinical trials suggest that auricular tVNS, when combined with rehabilitation, may significantly improve upper limb motor and sensory functions in chronic stroke patients, indicating its potential as a viable alternative to invasive vagus nerve stimulation.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Transcutaneous vagus nerve stimulation (tVNS) in stroke: the evidence, challenges and future directions. Baig, SS., Kamarova, M., Ali, A., et al.[2022]

Transcutaneous auricular vagus nerve stimulation (taVNS) is generally safe, with a low incidence of mild and transient adverse effects, such as ear pain, headache, and tingling, reported in only 24.86% of the studies analyzed.

In a systematic review of 177 studies involving 6322 subjects, there was no significant difference in the risk of adverse events between taVNS and control groups, indicating that taVNS is a feasible option for clinical intervention.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Safety of transcutaneous auricular vagus nerve stimulation (taVNS): a systematic review and meta-analysis. Kim, AY., Marduy, A., de Melo, PS., et al.[2023]

Citations

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The survival rate in the taVNS group (75 %, 9/12) significantly increased at 28 days after stroke compared with that in the MCAO group (41.6 %, 5/12), (Fig. 2 A) ...

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This is the first systematic review and meta-analysis of transcutaneous auricular stimulation safety. Overall, taVNS is a safe and feasible option for clinical ...

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ahajournals.org/doi/10.1161/STROKEAHA.123.043414

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Transcutaneous vagus nerve stimulation (tVNS) has shown promising evidence as a tool to reduce infarct size in animal models of hyperacute stroke.

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jamanetwork.com

jamanetwork.com/journals/jamanetworkopen/fullarticle/2838258

Transcutaneous Auricular Vagus Nerve Stimulation for ...

Conclusions and Relevance In this randomized clinical trial, taVNS significantly reduced uterine contraction pain, incisional pain, depression, ...

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pmc.ncbi.nlm.nih.gov

pmc.ncbi.nlm.nih.gov/articles/PMC8192665/

Transcutaneous Auricular Vagus Nerve Stimulation

In the debate on the best stimulation target of taVNS, the current research is based primarily on considerations of safety and effectiveness.

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sciencedirect.com

sciencedirect.com/science/article/pii/S0165032723006857

The efficacy and safety of transcutaneous auricular vagus ...

taVNS is an effective and safe method for alleviating depression scores and had a comparable response rate to ATD.

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frontiersin.org/journals/physiology/articles/10.3389/fphys.2025.1693907/full

Transcutaneous auricular vagus nerve stimulation in ...

Although minor side effects were reported, no serious adverse events were attributed to taVNS parameters used. taVNS could regulate brain ...