Transcutaneous Spinal Cord Neuromodulation to Normalize Autonomic Phenotypes
Study Details
Study Description
Brief Summary
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.
| Condition or Disease | Intervention/Treatment | Phase |
|---|---|---|
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N/A |
Study Design
Arms and Interventions
| Arm | Intervention/Treatment |
|---|---|
| Experimental: Individuals with spinal cord injury
|
Diagnostic Test: Tests of sympathetic inhibition
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.
Diagnostic Test: Tests of sympathetic activation
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).
Diagnostic Test: Testing of autonomic dysreflexia
Cold pressor test of the foot and bladder pressor response (in individuals with SCI) will be tested.
Device: Transcutaneous spinal cord stimulation
Transcutaneous spinal cord stimulation will be applied at T7-L1 spinal segments to assess alterations in autonomic neuroregulation.
|
| Experimental: Individuals without spinal cord injury
|
Diagnostic Test: Tests of sympathetic inhibition
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.
Diagnostic Test: Tests of sympathetic activation
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).
Device: Transcutaneous spinal cord stimulation
Transcutaneous spinal cord stimulation will be applied at T7-L1 spinal segments to assess alterations in autonomic neuroregulation.
|
Outcome Measures
Primary Outcome Measures
- Valsalva Maneuver Phase II [Through study completion, average 3 months]
Presence or absence of phase II on Valsalva maneuver testing, which takes approximately 15 seconds to complete. This will be repeated x3.
Secondary Outcome Measures
- Muscle sympathetic nerve activity [Through study completion, average 3 months]
Microneurography will be performed to characterize cardiovascular autonomic phenotypes between uninjured controls and individuals with spinal cord injury. This will be quantified by spike frequency.
- Beat-to-beat heart rate [Through study completion, average 3 months]
Electrocardiogram will record continuous measures with changes in R-R interval (ms) quantified and compared to baseline.
- Beat-to-beat blood pressure [Through study completion, average 3 months]
Non-invasive continuous blood pressure monitors will be used, with changes in systolic and diastolic pressure (in mmHg) from resting baseline measured.
- Continuous galvanic skin response [Through study completion, average 3 months]
Changes from resting state conductance with be quantified with a smartwatch.
- Quantify autonomic dysreflexia and orthostatic hypotension [Baseline, prior to initial laboratory diagnostic testing session]
Participants will be given the Autonomic Dysfunction Following Spinal Cord Injury questionnaire (score range 0-436, with higher scores indicating more autonomic dysfunction).
- Quantify secondary autonomic complications [Baseline, prior to initial laboratory diagnostic testing session]
Participants will be given the Composite Autonomic Symptom Score (range 0-100, with higher scores indicating more autonomic dysfunction).
Eligibility Criteria
Criteria
Inclusion Criteria:
All participants
- age 18-30 years old.
Participants with spinal cord injury
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Adult onset, traumatic spinal cord injury.
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Time since injury 1 year, in an effort to limit baroreflex desensitization.
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American Spinal Injury Association Impairment Scale, A, to limit potential confounders.
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Neurological level of injury, T1-T6, as defined by the International Standards for Neurological Classification of Spinal Cord Injury.
Exclusion Criteria:
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History of cardiovascular disease, hypertension, neurologic disorders (with exception of spinal cord injury), or diabetes.
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Women who are pregnant or lactating.
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Currently taking blood thinners.
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Taking anti-hypertensive or other medication that could influence any of the dependent autonomic variables.
Contacts and Locations
Locations
| Site | City | State | Country | Postal Code | |
|---|---|---|---|---|---|
| 1 | Spaulding Rehabilitation Hospital | Boston | Massachusetts | United States | 02129 |
Sponsors and Collaborators
- Spaulding Rehabilitation Hospital
- Medical University of South Carolina
Investigators
- Principal Investigator: Ryan Solinsky, MD, Spaulding Rehabilitation Hospital / Harvard Medical School
Study Documents (Full-Text)
None provided.More Information
Publications
None provided.- 2021P001100