Testing pupil response to vagus nerve stimulation in stroke survivors

Movement-Associated tVNS and Responsiveness Testing for Personalized Rehabilitation

Not applicable Interventional Georgia Institute of Technology · NCT06335199

This study tests how different types of ear stimulation affect pupil size in stroke survivors and healthy adults to see if it has any impact.

Quick facts

PhaseNot applicable
Study typeInterventional
Enrollment16 (estimated)
Ages18 Years to 89 Years
SexAll
SponsorGeorgia Institute of Technology Academic / other
Locations1 site (Atlanta, Georgia)
Trial IDNCT06335199 on ClinicalTrials.gov

What this trial studies

This study aims to investigate the acute pupil response to transcutaneous vagus nerve stimulation (tVNS) in stroke survivors and healthy adults. Participants will undergo both unilateral and bilateral tVNS and sham stimulation while their pupil size is monitored. The study will utilize surface electrodes placed on the outer ear and a heart rate monitoring device to assess the effects of different stimulation methods. The order of stimulation will be randomized to ensure unbiased results.

Who should consider this trial

Good fit: Ideal candidates include adults aged 18-89 who are stroke survivors with persistent hemiparesis and some residual upper extremity voluntary movement.

Not a fit: Patients with a history of cardiac disease, vision problems, or any brain-related conditions may not benefit from this study.

Why it matters

Potential benefit: If successful, this study could enhance understanding of tVNS effects, potentially leading to improved treatments for stroke survivors.

How similar studies have performed: While the specific approach of using pupil size response to tVNS is novel, similar studies have shown promise in understanding vagus nerve stimulation effects.

Eligibility criteria

Show full inclusion / exclusion criteria
Inclusion Criteria:

* 18-89 years old across all races, genders, and ethnicities.
* Post-stroke subjects will have persistent hemiparesis on the upper extremity (UE) with some residual UE voluntary movement.

Exclusion Criteria:

Able-bodied subjects:

* Younger than 18 years old or older than 89 years old
* Current or history of cardiac disease
* Have a vision problem not corrected by glasses or contact lenses
* Have an implanted device such as a neurostimulator or cochlear implant
* Current or history of tympanic membrane perforation
* Had a stroke or lesion (including tumor) in your brain
* Had a head injury or brain surgery
* Suffer from frequent or severe headaches
* Had a fainting spell or syncope
* Have any metal in the head such as shrapnel, surgical clips, or fragments from welding or metal work
* Have any implanted device such as cardiac pacemakers, medical pumps, or intra-cardiac lines
* Had any brain-related conditions (i.e. multiple sclerosis, Parkinson, Alzheimer)
* Had any illness that caused brain injury (i.e. meningitis, aneurysm, brain tumor)
* Had any head trauma that was associated with a loss of consciousness or diagnosed as a concussion
* Being treated for any psychiatric condition (i.e. depression, anxiety, PTSD, schizophrenia)
* Suspected of pregnancy

Post-stroke subjects:

* Younger than 18 years old or older than 89 years old
* Current or history of cardiac disease
* Have a vision problem not corrected by glasses or contact lenses
* Have any implanted devices such as a neurostimulator or cochlear implant
* Current or history of tympanic membrane perforation
* No persistent hemiparesis on the upper extremity (UE)
* No residual UE voluntary movement
* A first stroke less than 4 months prior to the participation
* Serious uncontrolled medical conditions
* Excessive pain in any joint of the more affected extremity
* Unable to stand independently for 2 min., transfer independently to and from the toilet or perform sit-to-stand
* Suffer from frequent or severe headaches
* Had a fainting spell or syncope
* Have any metal in the head such as shrapnel, surgical clips, or fragments from welding or metal work
* Have any implanted device such as cardiac pacemakers, medical pumps, or intra-cardiac lines
* Had any illness that caused brain injury (i.e. meningitis, aneurysm, brain tumor)
* Had any head trauma that was associated with a loss of consciousness or diagnosed as a concussion
* Being treated for any psychiatric condition (i.e. depression, anxiety, PTSD, schizophrenia)
* Suspected of pregnancy
* A score of less than 24 on the Folstein Mini-Mental State Examination
* Excessive frailty or lack of stamina (e.g., cannot attend to instructions, stay awake, engage in functional activities, etc.)
* Excessive pain in any joint of the more affected extremity that could limit ability to cooperate with the intervention

Where this trial is running

Atlanta, Georgia

Study contacts

How to participate

  1. Review the eligibility criteria above with your treating physician.
  2. Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
  3. Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.
Conditions Stroke
Last reviewed 2026-06-13 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.