Deciphering Preserved Autonomic Function After Multiple Sclerosis

Mayo Clinic13 enrolled

Overview

This study looks to characterize gradients of dysfunction in the autonomic nervous system in patients with clinically diagnosed multiple sclerosis. The autonomic nervous system plays key roles in regulation of blood pressure, skin blood flow, and bladder health- all issues that individuals with multiple sclerosis 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 multiple sclerosis 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 with multiple sclerosis will exhibit abnormalities in these precise metrics. The investigators will look to see if any substantial connections exist between different degrees of preserved autonomic function and secondary autonomic complications from multiple sclerosis. In accomplishing this, the investigators hope to give scientists important insights to how the autonomic nervous system works after multiple sclerosis and give physicians better tools to manage these secondary autonomic complications.

Study Type

INTERVENTIONAL

Allocation

NON_RANDOMIZED

Purpose

DIAGNOSTIC

Masking

NONE

Enrollment

Conditions

Multiple Sclerosis

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 will be tested.

Eligibility

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

Medical Language ↔ Plain English

Inclusion Criteria: * 18-50 years old * clinically confirmed diagnosis of multiple sclerosis -OR- uninjured control Exclusion Criteria: * symptoms of cardiovascular (including, but not limited to: hypertension, stroke, chest pain, etc.), respiratory, peripheral neurological or autonomic disease (particularly diabetes mellitus requiring treatment) * women who are pregnant or lactating * having a body mass index (BMI) ≥ 35 kg/m2 * taking or being administered a medication known to potentially have adverse interactions with phenylephrine * in the judgement of the principal investigator or clinical collaborator, 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

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.

Time frame: During single laboratory diagnostic testing session, on average 30 minutes after start of laboratory testing session

Secondary Outcomes

Beat-to-beat heart rate

Electrocardiogram will record continuous measures with changes in R-R interval (ms) quantified and compared to baseline.

Time frame: Continuous recording during single laboratory diagnostic testing session, from baseline to lab session end, average of 3 hours in duration

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: Continuous recording during single laboratory diagnostic testing session, from baseline to lab session end, average of 3 hours in duration

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

Serum Catecholamines

A series of 3 serum catecholamine draws will occur during the study visit at baseline, pre-pressor test, and post-pressor test to evaluate change in stress hormone.

Time frame: 3x during single laboratory diagnostic testing session - collected at Baseline, pre-pressor test, post-pressor test - pre-pressor & post-pressor timepoint labs collected on average 2.5 & 3 hours post-baseline, respectively

Serum Cortisol

A series of 3 serum cortisol draws will occur during the study visit at baseline, pre-pressor test, and post-pressor test to evaluate change in stress hormone.

T-Cell Exhaustion Markers

Blood will be drawn at start of laboratory testing to assess T-cell exhaustion markers by incidence of surface markers including PD-1, TIM-3, LAG3, and CTLA-4 per individual.

Time frame: During single laboratory diagnostic testing session - Baseline