tVNS Responsiveness Testing With Pupil Size

Stroke Clinical Trial

Official title:

Movement-Associated tVNS and Responsiveness Testing for Personalized Rehabilitation

Clinical Trial Details — Status: Not yet recruiting

Administrative data

• NCT number: NCT06335199
• Other study ID #: H24109
• Secondary ID: 5P2CHD086844-09
• Status: Not yet recruiting
• Phase: N/A
• Start date: May 1, 2024
• Est. completion date: April 30, 2025

Study information

• Verified date: March 2024
• Source: Georgia Institute of Technology
• Contact: Minoru Shinohara, Ph.D.
• Phone: 404-894-1030
• Email: shinohara[@]gatech.edu
• Is FDA regulated: No
• Study type: Interventional

Clinical Trial Summary

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.

Description:

Participants will wear surface electrodes on the outer ear on both sides and a finger device that monitors heart rate. The attachment sites are the tragus or the cymba concha (depending on the shape and size of the ear) for tVNS and the ear lobe for sham. The electrical current will have a pulse duration of 0.1 ms at 30 Hz with an intensity below the pain threshold or 5 milliamp, whichever is lower, for a duration of 0.5 s. The experimental stimulation intensity will be determined as just below the pain threshold. Participants will receive multiple blocks of unilateral and bilateral stimulations to the sham or tVNS electrodes at rest, during which their pupil size will be recorded. The order of unilateral/bilateral and sham/tVNS stimulation will be randomized.

Recruitment information / eligibility

• Status: Not yet recruiting
• Enrollment: 16
• Est. completion date: April 30, 2025
• Est. primary completion date: March 31, 2025
• Accepts healthy volunteers: Accepts Healthy Volunteers
• Gender: All
• Age group: 18 Years to 60 Years

Eligibility

Inclusion Criteria:

• 18-60 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 60 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 60 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 right upper extremity (UE)
• No residual UE voluntary movement
• A first stroke less than 4 months prior to the participation
• Hemorrhagic stroke
• Cerebellar stroke
• Serious uncontrolled medical conditions
• Severe apraxia of speech
• Excessive pain in any joint of the more affected extremity
• Receiving any anti-spasticity drugs orally at the time of expected participation, 3 months prior, or wish to or is scheduled to receive injections prior to study completion
• Received phenol injections less than 12 months prior to receiving therapy
• 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
• A score outside of 19-55 on the upper limb portions of the Fugl Meyer Assessment.
• Clinical judgment of excessive frailty or lack of stamina (e.g., cannot attend to instructions, stay awake, engage in functional activities, etc.)
• Serious uncontrolled medical conditions
• Excessive pain in any joint of the more affected extremity that could limit ability to cooperate with the intervention, as judged by the examining clinician

Related Conditions & MeSH terms

• Stroke

Intervention

Procedure:
• Unilateral tVNS stimulation
Electrical stimulation to the cymba concha or tragus (depending on the ear dimension) of the outer ear on the left side after successful trials.
• Bilateral tVNS stimulation
Electrical stimulation to the cymba concha or tragus (depending on the ear dimension) of the outer ear on both sides after successful trials.
• Unilateral Sham stimulation
Electrical stimulation to the earlobe of the outer ear on the left side after successful trials.
• Bilateral Sham stimulation
Electrical stimulation to the earlobe of the outer ear on both sides after successful trials.

Locations

Country	Name	City	State
United States	Human Neuromuscular Physiology Lab	Atlanta	Georgia

Sponsors (3)

Lead Sponsor	Collaborator
Georgia Institute of Technology	Emory University, Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD)

Country where clinical trial is conducted

United States, 

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	Pupil size change	Acute change in pupil size in response to electrical stimulation, relatively expressed as a percent change from the baseline	Day 1