tVNS Responsiveness Testing With Pupil Size

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.

Conditions

• Stroke

Interventions

PROCEDURE

Bilateral Sham stimulation

Electrical stimulation to the earlobe of the outer ear on both sides after successful trials.

PROCEDURE

Unilateral Right tVNS stimulation

Electrical stimulation to the cymba concha or tragus (depending on the ear dimension) of the outer ear on the right side after successful trials.

PROCEDURE

Unilateral Right Sham stimulation

Electrical stimulation to the earlobe of the outer ear on the right side after successful trials.

PROCEDURE

Unilateral Left 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.

PROCEDURE

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.

PROCEDURE

Unilateral Left Sham stimulation

Electrical stimulation to the earlobe of the outer ear on the left side after successful trials.

Sponsors & Collaborators

• Emory University

  collaborator OTHER

• Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD)

  collaborator NIH

• Georgia Institute of Technology

  lead OTHER

Principal Investigators

• Minoru Shinohara, Ph.D. · Georgia Institute of Technology

Study Design

Allocation

RANDOMIZED

Purpose

BASIC_SCIENCE

Masking

DOUBLE

Model

SINGLE_GROUP

Eligibility

Min Age

18 Years

Max Age

89 Years

Sex

ALL

Healthy Volunteers

Yes

Timeline & Regulatory

Start

2024-11-14

Primary Completion

2025-10-27

Completion

2025-10-27

Countries

• United States

Study Locations