Vagal Nerve Stimulation to Reduce Inflammation and Hyperadrenergia

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.


Eligibility Criteria:
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)