Thermoregulation and Cognition During Cool Ambient Exposure in Tetraplegia
Status:
Active, not recruiting
Trial end date:
2021-12-01
Target enrollment:
Participant gender:
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.