Transcutaneous Spinal Cord Neuromodulation to Normalize Autonomic Phenotypes

Spaulding Rehabilitation Hospital4 enrolled

Overview

This study looks to characterize autonomic nervous system dysfunction after spinal cord injury and identify the potential role that transcutaneous spinal cord stimulation may play at altering neuroregulation. The autonomic nervous system plays key parts in regulation of blood pressure, skin blood flow, and bladder health- all issues that individuals with spinal cord injury typically encounter complications. For both individuals with spinal cord injury and uninjured controls, experiments will utilize multiple parallel recordings to identify how the autonomic nervous system is able to inhibit and activate sympathetic signals. The investigators anticipate that those with autonomic dysfunction after spinal cord injury will exhibit abnormalities in these precise metrics. In both study populations, transcutaneous spinal cord stimulation will be added, testing previously advocated parameters to alter autonomic neuroregulation. In accomplishing this, the investigators hope to give important insights to how the autonomic nervous system works after spinal cord injury and if it's function can be improved utilizing neuromodulation.

Study Type

INTERVENTIONAL

Allocation

NON_RANDOMIZED

Purpose

DIAGNOSTIC

Masking

NONE

Enrollment

Conditions

Spinal Cord Injuries Autonomic Imbalance

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 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 autonomic dysreflexiaDIAGNOSTIC_TEST

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

Transcutaneous spinal cord stimulationDEVICE

Transcutaneous spinal cord stimulation will be applied at T7-L1 spinal segments to assess alterations in autonomic neuroregulation.

Eligibility

Sex: ALLMin age: 18 YearsMax age: 30 YearsHealthy volunteers:

Medical Language ↔ Plain English

Inclusion Criteria: All participants \- age 18-30 years old. Participants with spinal cord injury * Adult onset, traumatic spinal cord injury. * Time since injury 1 year, in an effort to limit baroreflex desensitization. * American Spinal Injury Association Impairment Scale, A, to limit potential confounders. * Neurological level of injury, T1-T6, as defined by the International Standards for Neurological Classification of Spinal Cord Injury. Exclusion Criteria: * History of cardiovascular disease, hypertension, neurologic disorders (with exception of spinal cord injury), or diabetes. * Women who are pregnant or lactating. * Currently taking blood thinners. * Taking anti-hypertensive or other medication that could influence any of the dependent autonomic variables.

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.