taVNS Cold Pressor

Study Overview
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Brief Summary
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This study explores the use of transcutaneous auricular vagus nerve stimulation (taVNS), a new form of neuromodulation which stimulates the ear. 24 healthy subjects without a past medical or psychiatric history will be recruited to participate in a phone screen followed by 1 lab visit. During the lab visit, subjects will participate twice in a validated stress induction technique called the cold pressor test, while concurrently receiving either active or sham taVNS. The cold pressor test consists of subjects placing their feet in an ice bath for a short period of time. Researchers will measure participant's heart rate while they receive taVNS (ear stimulation) and participate in the cold pressor test. Assessments of mood, anxiety, and stress will be collected at the beginning and end of the visit.

Official Title
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Assessing the Physiologic Effect of taVNS During a Cold Pressor Test

Conditions
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taVNS, Brain Stimulation

Intervention / Treatment
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* Device: Active taVNS
* Device: Sham taVNS


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Ages 18-65 years English speaking Non-treatment-seeking community members Exclusion Criteria: Diagnosis of COVID-19 in the past 14 days Facial or ear pain or recent ear trauma. Metal implant devices in the head, heart or neck. History of brain stimulation or other brain surgery. History of myocardial infarction or arrhythmia, bradycardia. Use of B-blockers, antiarrhythmic medication (sodium/potassium/calcium-channel blockers), or blood pressure medications. Active respiratory disorder. Personal or family history of seizure or epilepsy or personal use of medications that substantially reduce seizure threshold (e.g., olanzapine, chlorpromazine, lithium). Personal history of head injury, concussion, or self-report of moderate to severe traumatic brain injury. Individuals suffering from frequent/severe headaches. Individuals with a reported history of any mental health disorder or taking any psychotropic medications. Moderate to severe alcohol or substance use disorder. Pregnancy

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 65 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Basic Science
Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Active taVNS then Sham taVNS<br>Participants will receive active then sham (placebo) ear stimulation. | Device: Active taVNS<br>* Electrodes will be attached to the participant's ear with a small sticker or clip, which will deliver mild stimulation. These electrodes will be plugged into the Digitimer DS7a device, which is a device that delivers transcutaneous auricular vagus nerve stimulation or taVNS. Stimulation will be delivered randomly to participant's tragus (the small cartilage knob before the ear canal) for up to 5 minutes while you participate in the stress induction test (by putting both feet into an ice bath).<br>Device: Sham taVNS<br>* Electrodes will be attached to the participant's ear with a small sticker or clip, which will deliver mild stimulation. These electrodes will be plugged into the Digitimer DS7a device, which is a device that delivers transcutaneous auricular vagus nerve stimulation or taVNS. Stimulation will be delivered randomly to participant's tragus (the small cartilage knob before the ear canal) for up to 5 minutes while you participate in the stress induction test (by putting both feet into an ice bath). During sham (placebo) stimulation, ear electrodes will be attached to the participant's ear but they will not receive any stimulation.<br>|
| Experimental: Sham taVNS then Active taVNS<br>Participants will receive sham (placebo) then active ear stimulation. | Device: Active taVNS<br>* Electrodes will be attached to the participant's ear with a small sticker or clip, which will deliver mild stimulation. These electrodes will be plugged into the Digitimer DS7a device, which is a device that delivers transcutaneous auricular vagus nerve stimulation or taVNS. Stimulation will be delivered randomly to participant's tragus (the small cartilage knob before the ear canal) for up to 5 minutes while you participate in the stress induction test (by putting both feet into an ice bath).<br>Device: Sham taVNS<br>* Electrodes will be attached to the participant's ear with a small sticker or clip, which will deliver mild stimulation. These electrodes will be plugged into the Digitimer DS7a device, which is a device that delivers transcutaneous auricular vagus nerve stimulation or taVNS. Stimulation will be delivered randomly to participant's tragus (the small cartilage knob before the ear canal) for up to 5 minutes while you participate in the stress induction test (by putting both feet into an ice bath). During sham (placebo) stimulation, ear electrodes will be attached to the participant's ear but they will not receive any stimulation.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Mean Heart Rate (Before CPT/taVNS) | Heart rate will be measured with EKG electrodes before concurrent stress test and ear stimulation. | Baseline (up to 10 minutes prior to concurrent stress test and ear stimulation) | 
| Mean Heart Rate (During CPT/taVNS) | Heart rate will be measured with EKG electrodes during concurrent stress test and ear stimulation. | During concurrent stress test and ear stimulation (average duration of 5 minutes) | 
| Mean Heart Rate (After CPT/taVNS) | Heart rate will be measured with EKG electrodes after concurrent stress test and ear stimulation. | After concurrent stress test and ear stimulation (up to 10 minutes after concurrent stress test and ear stimulation) | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Mean Score of Pain (Before CPT/taVNS) | Pain will be assessed using a 0-10 scale (where 0 represents no pain at all and 10 represents the worst pain possible) before concurrent stress test and ear stimulation. | Baseline (up to 10 minutes prior to concurrent stress test and ear stimulation) | 
| Mean Score of Pain (During CPT/taVNS) | Pain will be assessed using a 0-10 scale (where 0 represents no pain at all and 10 represents the worst pain possible) during concurrent stress test and ear stimulation. | During concurrent stress test and ear stimulation (average duration of 5 minutes) | 
| Mean Score of Pain (After CPT/taVNS) | Pain will be assessed using a 0-10 scale (where 0 represents no pain at all and 10 represents the worst pain possible) after concurrent stress test and ear stimulation. | After concurrent stress test and ear stimulation (up to 10 minutes after concurrent stress test and ear stimulation) | 
| Mean Score of Anxiety (Before CPT/taVNS) | Anxiety will be assessed using a 0-10 scale (where 0 represents no anxiety at all and 10 represents the worst anxiety possible) before concurrent stress test and ear stimulation. | Baseline (up to 10 minutes prior to concurrent stress test and ear stimulation) | 
| Mean Score of Anxiety (During CPT/taVNS) | Anxiety will be assessed using a 0-10 scale (where 0 represents no anxiety at all and 10 represents the worst anxiety possible) during concurrent stress test and ear stimulation. | During concurrent stress test and ear stimulation (average duration of 5 minutes) | 
| Mean Score of Anxiety (After CPT/taVNS) | Anxiety will be assessed using a 0-10 scale (where 0 represents no anxiety at all and 10 represents the worst anxiety possible) after concurrent stress test and ear stimulation. | After concurrent stress test and ear stimulation (up to 10 minutes after concurrent stress test and ear stimulation) | 
| Mean Score of Distress (Before CPT/taVNS) | Distress will be assessed using a 0-10 scale (where 0 represents no distress at all and 10 represents the worst distress possible) before concurrent stress test and ear stimulation. | Baseline (up to 10 minutes prior to concurrent stress test and ear stimulation) | 
| Mean Score of Distress (During CPT/taVNS) | Distress will be assessed using a 0-10 scale (where 0 represents no distress at all and 10 represents the worst distress possible) during concurrent stress test and ear stimulation. | During concurrent stress test and ear stimulation (average duration of 5 minutes) | 
| Mean Score of Distress (After CPT/taVNS) | Distress will be assessed using a 0-10 scale (where 0 represents no distress at all and 10 represents the worst distress possible) after concurrent stress test and ear stimulation. | After concurrent stress test and ear stimulation (up to 10 minutes after concurrent stress test and ear stimulation) |