Thermoregulation and Cognition During Cool Ambient Exposure in Tetraplegia

• Status: Active, not recruiting
• Trial end date: 2021-12-01
• Target enrollment: 0
• Participant gender: All

Summary

The ability to maintain normal core body temperature (Tcore = 98.6°F) is impaired in persons with a cervical spinal cord injury (tetraplegia). Despite the known deficits in the ability of persons with spinal cord injury (SCI) to maintain Tcore, and the effects of hypothermia to impair mental function in able-bodied (AB) persons, there has been no work to date addressing these issues in persons with tetraplegia.

Primary Aim: To determine if exposure of up to 2 hours to cool temperatures (64°F) causes Tcore to decrease in persons with tetraplegia, and if that decrease is associated with a decrease in cognitive function.

Primary Hypotheses: Based on our pilot data: (1) 66% of persons with tetraplegia and none of the matched controls will demonstrate a decline of 1.8°F in Tcore; (2) 80% of persons with tetraplegia and 30% of controls will have a decline of at least one T-score in Stroop Interference scores (a measure of executive function).

Secondary Aim: To determine the change in: (1) distal skin temperature, (2) metabolic rate, and (3) thermal sensitivity.

Secondary Hypothesis: Persons with tetraplegia will have less of a percent change in average distal skin temperatures and metabolic rate, and report lower thermal sensitivity ratings compared with AB controls.

Tertiary Aim: To determine if a 10 mg dose of an approved blood pressure-raising medicine (midodrine hydrochloride) will (1) reduce the decrease in Tcore and (2) prevent or delay the decline in cognitive performance in the group with tetraplegia compared to the exact same procedures performed on the day with no medicine (Visit 1) in that same group.

Tertiary Hypothesis: Through administering a one-time dose of midodrine, the medicine-induced decreased blood flow to the skin will lessen the decline in Tcore and prevent or delay the associated decline in cognitive performance compared to the changes in Tcore and cognitive performance during cool temperature exposure without midodrine in the same group with tetraplegia.

• Phase: Phase 4
• Accepts Healthy Volunteers?: Accepts Healthy Volunteers

Details

• Lead Sponsor: James J. Peters Veterans Affairs Medical Center
• Collaborator: The Craig H. Neilsen Foundation
• Treatments: Midodrine

Criteria

Inclusion Criteria:

• Duration of SCI ≥1 year;

• Level of SCI C3-T1, AIS A & B;

• Age between 18 and 65 years.

Exclusion Criteria:

• Evidence of sympathetic integrity below the lesion level by the skin axon-reflex vasodilatation (SkARV) test;

• Known allergies to midodrine hydrochloride;

• PMH of diagnosed heart, kidney, peripheral vascular, or cerebral vascular disease, or diabetes mellitus;

• Hypertension (BP>140/90 mmHg);

• Untreated thyroid disease;

• Acute illness or infection;

• Current smoker;

• Pregnancy.