Effects of External Ear Stimulation on Pain Perception and Mood
- Conditions
- Pain in Healthy Participants
- Interventions
- Device: The Twin Stim Plus, 3rd EditionDevice: Medoc Pathway System
- Registration Number
- NCT02821741
- Brief Summary
Background:
The vagus nerve runs from the brain to many organs. Stimulating it can affect the experience of pain. The nerve can be stimulated on the surface of the left ear. Researchers want to study how this stimulation affects the perception of pain. They also want to study how mood affects the experience of pain.
Objective:
To study the effects of mood and vagus nerve stimulation on the experience of pain.
Eligibility:
Healthy people ages 18 and older who are fluent in English
Design:
Participants will be pre-screened with a 15-minute phone call.
Participants will have three 2-hour visits.
At the screening visit, participants will be screened with:
Medical and psychiatric history
Physical and psychological exams
Questionnaires about physical and psychiatric health and mood
Urine tests
A heat probe on the forearm. The temperature will be increased until it is painful
but tolerable.
Participants will have 2 testing sessions within 7 days. Before the testing, they cannot do the following:
Eat, use nicotine, or exercise for at least 2 hours
Drink alcohol for 24 hours
Take certain medicines for 3 days
Testing includes:
Urine drug screening
Left ear stimulation: In one session, the vagus nerve will be stimulated. In the other, an area
of the ear away from the vagus nerve will be stimulated. This will be done with mild electric
shocks that cause a tingling, pricking, or itchy feeling.
Heat applied to the forearm until it is painful but tolerable
Completing several forms on a computer or on paper about how they are feeling
Monitors on the chest and a finger clip to monitor heart, breathing, and blood pressure
- Detailed Description
This double-blind, randomized, controlled, cross-over study on healthy participants will evaluate the perceptual differences of pain and changes in mood in response to peripheral nerve stimulation over two regions of the left external ear. A series of short and long duration heat stimuli will be applied to the participants forearms and they will be asked to rate their current mood state, the intensity of the pain, and whether it was pleasant or unpleasant. The series of heat stimuli will be applied before, during, and after mild electrical stimulation of the left external ear using a commercially available TENS unit. There are two study sessions. Session 1 involves eligibility screening, a brief practice session, followed by the testing session. In Session 2 (no more than 7 days later), the testing session will be repeated with the exception of the location of ear stimulation. Up to 76 people, ages 18-50 years old, will be enrolled in the study.
Recruitment & Eligibility
- Status
- RECRUITING
- Sex
- All
- Target Recruitment
- 76
Not provided
Not provided
Study & Design
- Study Type
- INTERVENTIONAL
- Study Design
- CROSSOVER
- Arm && Interventions
Group Intervention Description Cymba Conchae Medoc Pathway System Mild electrical stimulation is applied to the cymba conchae of the left ear, and thermal stimulation is applied to the arms. Cymba Conchae The Twin Stim Plus, 3rd Edition Mild electrical stimulation is applied to the cymba conchae of the left ear, and thermal stimulation is applied to the arms. Ear Lobe Medoc Pathway System Mild electrical stimulation is applied to the earlobe of the left ear, and thermal stimulation is applied to the arms. Ear Lobe The Twin Stim Plus, 3rd Edition Mild electrical stimulation is applied to the earlobe of the left ear, and thermal stimulation is applied to the arms.
- Primary Outcome Measures
Name Time Method The difference in pain ratings collected for each subject during the two types of left ear stimulation (cymba conchae and earlobe). End of study See measures
- Secondary Outcome Measures
Name Time Method Mood and anxiety, as measured by questionnaires taken at the beginning and end of both study sessions. End of study See measures
The effect of tVNS on pain threshold, pain unpleasantness, and mood as measured by visual analogue scales (VAS). End of Study See measures
Autonomic measures will be analyzed to determine whether tVNS has an effect on heart rate variability. End of study See measures
Trial Locations
- Locations (1)
National Institutes of Health Clinical Center
🇺🇸Bethesda, Maryland, United States