Purpose

This study looks to characterize gradients of dysfunction in the autonomic nervous system after spinal cord injury. The autonomic nervous system plays key roles in regulation of blood pressure, skin blood flow, and bladder health- all issues that individuals with spinal cord injury typically suffer. Focusing on blood pressure regulation, the most precise metric with broad clinical applicability, the investigators will perform a combination of laboratory, ambulatory, and imaging-based tests to probe the body's ability to generate autonomic responses. For both individuals with spinal cord injury and uninjured controls, laboratory-based experiments will utilize multiple parallel recordings to identify how the autonomic nervous system is able to inhibit and activate signals. The investigators anticipate that those with autonomic dysfunction after spinal cord injury will exhibit abnormalities in these precise metrics. The investigators will further have research participants wear a smart watch that tracks skin electrical conductance, heart rate, and skin temperature, which can all provide clues as to the degree of autonomic dysfunction someone may suffer at home. The investigators will look to see if any substantial connections exist between different degrees of preserved autonomic function and secondary autonomic complications from spinal cord injury. Finally, functional magnetic resonance imaging scans will be attained to characterize patterns of connectivity within the injured spinal cord. In a similar manner, the investigators will look to see if different patterns of spinal cord connectivity are more closely related to groupings of secondary autonomic complications. In accomplishing this, the investigators hope to give scientists important insights to how the autonomic nervous system works after spinal cord injury and give physicians better tools to manage these secondary autonomic complications.

Conditions

Eligibility

Eligible Ages
Between 18 Years and 50 Years
Eligible Genders
All
Accepts Healthy Volunteers
Yes

Inclusion Criteria

All subjects - age 18-50 years old. Participants with spinal cord injury - Adult onset, traumatic spinal cord injury. - Time since injury restricted to 1-5 years, in an effort to limit baroreflex desensitization. - American Spinal Injury Association Impairment Scale, A-D, to encompass a spectrum of autonomic dysfunction after spinal cord injury. - Neurological level of injury, C1-T12, as defined by the International Standards for Neurological Classification of Spinal Cord Injury. Incorporating level of injury down to T12 to encompass a broad range of autonomic dysfunction.

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. - Pacemaker, implanted defibrillator, or intrathecal pump incompatible with MRI scanning. - Cognitive issues preventing informed consent for participation. - Body mass index >30 kg/m2 for controls, in an effort to limit effects of early cardiovascular disease and diabetes in control population. Body mass index has not proven to be a good estimate of these factors following spinal cord injury.

Study Design

Phase
N/A
Study Type
Interventional
Allocation
Non-Randomized
Intervention Model
Parallel Assignment
Primary Purpose
Diagnostic
Masking
None (Open Label)

Arm Groups

ArmDescriptionAssigned Intervention
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.
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).
  • Diagnostic Test: Testing of autonomic dysreflexia
    Cold pressor test of the foot and bladder pressor response (in individuals with SCI) will be tested.

Recruiting Locations

Spaulding Rehabilitation Hospital
Boston, Massachusetts 02129
Contact:
Ryan Solinsky, MD
rsolinsky@mgh.harvard.edu

More Details

Status
Recruiting
Sponsor
Spaulding Rehabilitation Hospital

Study Contact

PI
16179525299
rsolinsky@partners.org

Notice

Study information shown on this site is derived from ClinicalTrials.gov (a public registry operated by the National Institutes of Health). The listing of studies provided is not certain to be all studies for which you might be eligible. Furthermore, study eligibility requirements can be difficult to understand and may change over time, so it is wise to speak with your medical care provider and individual research study teams when making decisions related to participation.