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 laboratory-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. 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.
This study looks to characterize gradients of dysfunction in the autonomic nervous system after spinal cord injury. To accomplish this, we are enrolling both individuals with and without spinal cord injuries (see inclusion criteria). Individuals will undergo the listed diagnostics as part of a battery of laboratory testing. These will be correlated to clinical histories of autonomic dysfunction the ADFSCI and COMPASS-31 surveys (noted in outcome measures).
Study Type
INTERVENTIONAL
Allocation
NON_RANDOMIZED
Purpose
DIAGNOSTIC
Masking
NONE
Enrollment
69
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.
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).
Cold pressor test of the foot and bladder pressor response (in individuals with SCI) will be tested.
Mayo Clinic
Rochester, Minnesota, United States
RECRUITINGValsalva 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.
Time frame: During laboratory diagnostic testing session
Beat-to-beat heart rate
Electrocardiogram will record continuous measures with changes in R-R interval (ms) quantified and compared to baseline.
Time frame: During laboratory diagnostic testing session
Beat-to-beat blood pressure
Non-invasive continuous blood pressure monitors will be used, with changes in systolic and diastolic pressure (in mmHg) from resting baseline measured.
Time frame: During laboratory diagnostic testing session
Continuous galvanic skin response
Changes from resting state conductance with be quantified with a smartwatch.
Time frame: During laboratory diagnostic testing session
Continuous wrist temperature
Changes from resting state temperature with be quantified with a smartwatch.
Time frame: During laboratory diagnostic testing session
Quantify autonomic dysreflexia and orthostatic hypotension
Participants will be given the Autonomic Dysfunction Following Spinal Cord Injury questionnaire (score range 0-436, with higher scores indicating more autonomic dysfunction).
Time frame: Baseline, prior to laboratory diagnostic testing session
Quantify secondary autonomic complications
Participants will be given the Composite Autonomic Symptom Score (range 0-100, with higher scores indicating more autonomic dysfunction).
Time frame: Baseline, prior to laboratory diagnostic testing session
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