tVNS Responsiveness Testing With Pupil Size

Completed · Not applicable · Has a placebo group

Conditions studied: Stroke

In brief

The goal of this study is to learn about the acute pupil response to transcutaneous vagus nerve stimulation (tVNS) in stroke survivors and healthy adults. The main question it aims to answer is whether pupil size response is greater with bilateral tVNS compared to unilateral tVNS. Participants will receive tVNS and sham at the outer ear unilaterally and bilaterally in resting condition. The pupil size of the participants will be recorded during tVNS.

Key facts

Study ID: NCT06335199
Run by: Georgia Institute of Technology
People needed: 21
Starts: 2024-11-14
Expected to finish: 2025-10-27
Last updated by the study team: 2025-10-29

Who can join

Age: 18 and older, up to 89. Sex: any. Healthy volunteers: accepted.

You may qualify if…

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.

You may not qualify if…

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

Where it is running

Human Neuromuscular Physiology Lab — Atlanta, Georgia, United States

Full record on ClinicalTrials.gov

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