Vagal Nerve Stimulation to Reduce Inflammation and Hyperadrenergia

University of Miami

Overview

The purpose of this research device study is to learn more about the autonomic nervous system. This system uses nerves to send information from the brain to the rest of the body by electrical signaling and has two divisions, the sympathetic and the parasympathetic branches. It has been thought that electrical stimulation devices could be used to restore balance to the nervous system. Because most of the imbalance seems to happen due to too much sympathetic activity, the investigator plans to focus on the parasympathetic branch. Specifically, the investigator hopes to restore balance by targeting the vagus nerve, which is the main communicator of the parasympathetic branch. The study will examine whether the investigator can decrease sympathetic activity and chronic inflammation by increasing parasympathetic activity. This is a device study that will examine the use of non-invasive vagal nerve stimulation to attenuate inflammatory stress and sympathetic hyperactivity in persons with Spinal Cord Injury and Non-Disabled Controls.

Study Type

INTERVENTIONAL

Allocation

RANDOMIZED

Purpose

BASIC_SCIENCE

Masking

SINGLE

Conditions

Spinal Cord Injury

Interventions

InTENsity MicroComboDEVICE

An electrotherapy device.

Eligibility

Sex: ALLMin age: 18 YearsMax age: 65 YearsHealthy volunteers:

Medical Language ↔ Plain English

Group 1 \& 2: Inclusion Criteria: 1. Age 18-65 2. Willingness to participate in the study Exclusion Criteria: 1. Use of an active electrical implant, such as a cardiac pacemaker or cochlear implant 2. Use of a hearing aid in the left ear 3. Use of an implanted insulin or morphine (pain) pump 4. Self-reported history of syncope from known or unknown origins 5. Self-reported history of cardiovascular disease or dysfunction (e.g., cardiovascular disease, arrhythmia, congestive heart failure, or stroke) Group 3: Inclusion Criteria: 1. Age 18-65 2. Overweight, with a BMI ≥ 27 3. Presence of chronic inflammation, with C-reactive protein values \> 3 mg/l 4. Willingness to participate in the study Exclusion Criteria: 1. Use of an active electrical implant, such as a cardiac pacemaker or cochlear implant 2. Use of a hearing aid in the left ear 3. Use of an implanted insulin or morphine (pain) pump 4. Self-reported history of syncope from known or unknown origins 5. Self-reported history of cardiovascular disease or dysfunction (e.g., cardiovascular disease, arrhythmia, congestive heart failure, or stroke) 6. Use of statin drugs Group 4: Inclusion Criteria: 1. Age 18-65 2. ≥ 1-year post-injury 3. Bladder management by clean intermittent catheterization 4. Spinal cord injury resulting in Paraplegia level T1 to T6 and motor-complete (AIS A or B) impairment. Injury level and impairment will be confirmed by an ASIA exam conducted less than 2 years before study entry. If longer than 2 years, we will have a certified rater repeat the exam. 5. Participant report of symptoms related to autonomic dysreflexia during episodes of full bladder or voiding, including elevated BP, mild headache, paresthesia, chills, nasal congestion, flushing of the skin, or diaphoresis. 6. Willingness to participate in the study. Exclusion Criteria: 1. Currently hospitalized 2. American Spinal Injury Association (AIS) C-E 3. Currently using an insulin, morphine (pain), or intrathecal pump 4. Use of an active electrical implant, such as a cardiac pacemaker or cochlear implant 5. Use of a hearing aid in the left ear 6. Self-reported history of syncope from known or unknown origins 7. Self-reported history of cardiovascular disease or dysfunction (e.g., cardiovascular disease, arrhythmia, congestive heart failure, or stroke)

Locations (1)

The Miami Project to Cure Paralysis/ University of Miami

Miami, Florida, United States

Outcomes

Primary Outcomes

Change in parasympathetic activity after vagal nerve stimulation by Heart Rate Variability

Measured by the normal-to-normal QRS complexes of the PQRST waveform of the electrocardiogram (ECG)

Time frame: Baseline to 90 minutes post-vagal nerve stimulation

Secondary Outcomes

Group 1 & 4: Change in acute heart rate response to vagal nerve stimulation

Measured by numerical heart rate in beats per minute

Time frame: Baseline to 90 minutes post-vagal nerve stimulation

Group 1 & 4: Change in acute blood pressure response to vagal nerve stimulation

Measured by diastolic and systolic blood pressure (mm/Hg)

Time frame: Baseline to 90 minutes post-vagal nerve stimulation

Group 1: Change in parasympathetic activity after vagal nerve stimulation by Vagus Somatosensory Evoked Potentials

Measured by far field potentials from the brain stem

Time frame: Baseline to 90 minutes post-vagal nerve stimulation

Group 2 & 4: Change in acute physiological stress response by a change in peripheral cortisol

Measured by cortisol levels in plasma

Time frame: Baseline to 90 minutes post-experimental stimulus

Group 2 & 4: Change in acute physiological stress response by a change in peripheral catecholamines

Measured by catecholamine levels in plasma

Time frame: Baseline to 90 minutes post-experimental stimulus

Group 2 & 4: Change in acute physiological stress response by a change in heart rate

Data from ClinicalTrials.gov

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