Body Temperature in Persons With Tetraplegia When Exposed to Cold
The ability to maintain normal body core temperature (Tcore = 98.6°F) is impaired in persons with tetraplegia. Despite the known challenges to 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.
The aim of this study is to determine if exposure of up to 2 hrs to cool temperatures (64°F) causes body core temperature to decrease in persons with tetraplegia and if that decrease is related to a decrease in mental performance.
After sitting in a cool (64°F) room for up to 2 hours the investigators hypotheses are:
Hypotheses (1): Tcore of most of the persons with tetraplegia will decline approximately 1.8°F (e.g., 98.6 to 96.8°F) while Tcore of controls will not decline at all; (2) Most of the persons with tetraplegia will show a decline in mental performance (memory or clear-headedness) while only some of AB controls will show a decline.
The second aim of this study is to determine if a 10 mg dose of an approved blood pressure raising medicine (midodrine hydrochloride) will (1) reduce the decrease in body core temperature and (2) prevent or delay the decline in mental performance in the group with tetraplegia compared to the exact same procedures performed on the day with no medicine (Visit 1) in the same group.
Hypotheses (3 & 4): The changes in blood flow to the skin caused by taking a one-time dose of midodrine will lessen the decline in Tcore and prevent or delay the decline in mental performance compared to the changes in Tcore and mental performance during cool temperature exposure without midodrine in the group with tetraplegia.
Mild Cognitive Impairment
Drug: Midodrine hydrochloride
|Study Design:||Allocation: Non-Randomized
Intervention Model: Factorial Assignment
Masking: Open Label
|Official Title:||Core Temperature During Cold Exposure in Persons With Tetraplegia|
- Visit 1: Percent Change in Core Body Temperature [ Time Frame: Baseline, Up to 2 hours ] [ Designated as safety issue: Yes ]We will test the effects of cool temperature (64°F) exposure, of up to 120 minutes, on the ability to maintain a constant body temperature (e.g., core temperature of 98.6°F) in persons with tetraplegia through comparing the percent changes in core body temperatures between groups from baseline to after cool exposure.
- Visit 2: Percent Change in Core Body Temperature With Midodrine [ Time Frame: Baseline, Baseline Post-midodrine, Up to 2 hours ] [ Designated as safety issue: No ]We will test the effects of midodrine on the ability to maintain a constant body temperature (e.g., core temperature of 98.6°F) after exposure to cool temperatures (64°F) in persons with tetraplegia through comparing the percent changes in core body temperature during visit 1 to percent changes in core body temperature during visit 2.
- Visit 1: Percent Changes in Cognitive Performance - Stroop Interference [ Time Frame: Baseline, Up to 2 hours ] [ Designated as safety issue: No ]Cognitive performance will be evaluated using the Interference T-Scores obtained using the Stroop Color and Word Test. We will measure the change in cognitive performance in persons with tetraplegia after exposure to a cool environment (64°F) of up to 120 min in the seated position. Note: Interference T-Scores are derived from the difference between the raw Color-Word score and the projected Color-Word score (which is, in turn, based on the raw scores obtained in the Word and Color portions of the Test). Lower scores indicate poorer performance, and a positive percent change in T-scores indicates improved performance.
- Visit 1: Percent Changes in Cognitive Performance - Delayed Recall [ Time Frame: Baseline, Up to 2 hours ] [ Designated as safety issue: No ]Cognitive performance will be evaluated using the Delayed Recall obtained using the Memory section of the Montreal Cognitive Assessment (MoCA). We will measure the change in cognitive performance in persons with tetraplegia after exposure to a cool environment (64°F) of up to 120 min in the seated position. Note: Scores are based on individual performance. All subjects are asked to remember two lists of five words (one list during baseline, and one list during cool Challenge). Lower scores indicate poorer performance, and a positive percent change in indicates improved cognitive performance.
|Study Start Date:||July 2011|
|Study Completion Date:||October 2015|
|Primary Completion Date:||October 2015 (Final data collection date for primary outcome measure)|
No Intervention: No Drug: Tetraplegia
Tetraplegia: Lesion level T1 and above, American Spinal Injury Association (ASIA) impairment levels A and B, ages 18-68 years.
Exposure of up to 2 hours in a cool room.
No Intervention: No Drug: AB Controls
AB Controls: Matched for age and gender to subjects with tetraplegia. Exposure of up to 2 hours in a cool room.
Experimental: Drug (midodrine): Tetraplegia
Persons with tetraplegia who completed Visit 1 (no drug). Participants are administered midodrine hydrochloride (10 mg tablet) by a physician before exposure of up to 2 hours in a cool room. (Visit 2)
Drug: Midodrine hydrochloride
Midodrine hydrochloride is an approved medication used to treat low blood pressure. We are using a standard dose of 10 mg (tablet) only one time to determine if the effects of this drug improve the ability to maintain body core temperature in a cool environment (off-label use). A physician will administer the drug once before the cool thermal challenge in subjects with tetraplegia only(Visit 2)
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Please refer to this study by its ClinicalTrials.gov identifier: NCT01822535
|United States, New York|
|Center of Excellence for the Medical Consequences of SCI, JJP VAMC, 7A-13|
|Bronx, New York, United States, 10468|
|Principal Investigator:||John P Handrakis, PT, DPT, EdD||James J Peters VA MC|