Acute and Chronic Repercussion of Spinal Cord Stimulation After Spinal Cord Injury

Mayo Clinic80 enrolled

Overview

The purpose of this research is to learn about how the participant's body is able to balance changes in blood pressure, and how spinal cord stimulation affects these changes as well as immune \& cardiovascular function in participants with spinal cord injury.

Study Type

INTERVENTIONAL

Allocation

NON_RANDOMIZED

Purpose

DIAGNOSTIC

Masking

NONE

Enrollment

Conditions

Spinal Cord Injuries

Interventions

Tests of sympathetic inhibitionDIAGNOSTIC_TEST

Bolus phenylephrine infusion using the Oxford technique will generate the need to inhibit sympathetic activity. Similarly, resting state Mayer waves will be assessed with regard to heart rate and blood pressure responses.

Tests of above level sympathetic activationDIAGNOSTIC_TEST

Cold pressor test of the hand will be used to cause sympathetic activation. Valsalva's maneuver will assess the ability to buffer against blood pressure fall (phase II).

Testing of below level sympathetic activationDIAGNOSTIC_TEST

Cold pressor test of the foot and bladder pressor response (in individuals with SCI) will be tested.

Eligibility

Sex: ALLMin age: 18 YearsMax age: 50 YearsHealthy volunteers:

Medical Language ↔ Plain English

Inclusion criteria * Age 18-50. * American Spinal Injury Association Impairment Scale A-D,64 to encompass a representational spectrum of autonomic dysfunction after spinal cord injury. * Neurological level of injury, C6-T8, as defined by the International Standards for Neurological Classification of Spinal Cord Injury.64 Incorporating level of injury over this broad range to capture the spectrum of autonomic dysfunction. Individuals with injuries below T8 will not be included to ensure transcutaneous spinal cord stimulation does not occur over the injury/glial scar, where it may have altered properties. The C6 level was chosen to ensure hand cold pressor stimuli triggers above level sympathetic activation. * Time since injury of greater than six months, given early changes in spinal cord connectivity and recovery prior to this. * Both individuals with and without currently implanted epidural spinal cord stimulators will be enrolled. * Twenty uninjured controls will also be enrolled. Exclusion criteria * History of clinically diagnosed cardiovascular disease, diabetes, autonomic neuropathies, neurological disorders (with exception of spinal cord injury for individuals in those cohorts), or are active smokers. * Individuals who are taking betablockers, antihypertensives, or other sympathetically active medications which they are unable to hold. * Women who are pregnant or lactating, given known hormonal influences on autonomic regulation.65,66 * Cognitive issues preventing informed consent for participation. * Body mass index \>30 kg/m2 for the uninjured controls only given increased risk of prediabetes and potential confounding normative values. * taking or being administered a medication known to potentially have adverse interactions with phenylephrine * in the judgement of the principal investigator, any illness or condition that will interfere with the patient's ability to comply with the protocol, compromise patient safety, or interfere with the interpretation of the study results

Locations (1)

Mayo Clinic

Rochester, Minnesota, United States

RECRUITING

Outcomes

Primary Outcomes

Valsalva Maneuver Phase II

Presence or absence of phase II on Valsalva maneuver testing, which takes approximately 15 seconds to complete. This will be repeated x3.