Spinal Cord Injury
Conditions
Keywords
Spinal cord injury, Body temperature, Executive function, Sweat
Brief summary
The deleterious effects of hyperthermia are well appreciated in able-bodied persons. However, the consequences of impaired regulation of normal body temperature on cognitive performance of persons with tetraplegia is not known. This study will provide the preliminary findings necessary for future work to design and explore physical and medical interventions to improve temperature regulation in those with tetraplegia with the goal of improved clinical care, health, and quality of life. The proposed study consists of 1 visit during which 20 subjects (10 with tetraplegia, 10 controls) will be exposed to 81°F for 40 minutes and then 95° F for up to 2 hours. Physiological as well as psychological processes will be monitored in all subjects during the study for safety and to determine differences in responses to exposure to hot ambient temperatures
Detailed description
After a cervical spinal cord injury (SCI) the motor, sensory and autonomic deficits cause, among other detriments, a blunted ability to maintain a constant core temperature. Impaired thermoregulation leaves persons with tetraplegia more susceptible to hyperthermia than able-bodied persons (AB). There has been a paucity of work addressing the thermoregulatory responses of persons with SCI to hot ambient temperatures, and even less study addressing the effect of these temperatures on cognitive performance. The goals of this pilot study are: to improve our understanding of the thermoregulatory mechanisms of individuals with tetraplegia when exposed to heat and to determine the effect of impaired thermoregulatory mechanisms on cognitive performance during exposure to 35°C for up to 2 hours. In order to address our goals we have designed a study methodology which consists of comparing the physiological and psychological responses of the two study groups (tetraplegia versus AB controls) from thermoneutral (27°C) to hot (35°C) environments.
Interventions
OTHERHeat Exposure
Heat exposure of 95 degrees F for up to 2 hours.
Sponsors
James J. Peters Veterans Affairs Medical Center
Study design
Observational model
CASE_CONTROL
Time perspective
PROSPECTIVE
Eligibility
Sex/Gender
ALL
Age
18 Years to 65 Years
Healthy volunteers
Yes
Inclusion criteria
1. Between 18 and 65 years of age; 2. Duration of injury ≥ 1 year; 3. Level of SCI C4-T1; 4. Euhydration (Subjects will be instructed to avoid caffeine and alcohol, maintain normal salt and water intake, and avoid strenuous exercise for 24 hours prior to study); and 5. Age (± 5 years) and gender matched AB control group.
Exclusion criteria
1. Known heart and/or blood vessel disease; 2. High blood pressure; 3. Kidney disease; 4. Diabetes mellitus; 5. Acute illness or infection; 6. Dehydration; 7. Pregnant women; 8. Untreated thyroid disease, and 9. Broken, inflamed, or otherwise fragile skin.
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Core Body Temperature | 2 hours | To determine the change in core body temperature in the seated position from 79 degrees F for 30 minutes to 95 degrees F for up to 2 hours. Hypotheses: Persons with tetraplegia will have a greater increase in core body temperature than able-bodied (AB) control subjects. Core body temperature in AB persons will be maintained. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Cognitive Performance - Stroop Interference T-Scores | 2 hours | To determine the change in cognitive performance as measured by the Stroop Color and Word Interference T-Scores, measured after 30 min at 79 degrees F and after up to 2 hours at 95 degrees F. 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. Hypothesis: Persons with tetraplegia compared with AB will have a greater change in cognitive performance from baseline (79 degrees) to warm exposure (95 degrees). |
Other
| Measure | Time frame | Description |
|---|---|---|
| Sweat Rate | 2 hours | To determine the change in sweat rate using QSweat methodology (WR TestWorks) from 30 minutes at 79 degrees F compared to after up to 2 hours at 95 degrees F. Sweat collection capsules will be placed on the left lateral anterior shoulder, volar aspect of the distal forearm, proximal anterior thigh, and mid-lateral calf (dermatomes C5, T1, L3, L5) for measurement of sweat rate. Hypothesis: Persons with tetraplegia compared with AB will have less of a percent change in average sweat rate after heat exposure. |
Countries
United States
Participant flow
Participants by arm
| Arm | Count |
|---|---|
| Tetraplegia Persons with spinal cord injury, level of injury C4-T1, ASIA levels A-B and duration of injury greater than 1 year. Ages 18-65 years old.
Heat Exposure: Heat exposure of 95 degrees F for up to 2 hours. | 8 |
| Control Age and gender-matched able-bodied controls. Ages 18-65 years old.
Heat Exposure: Heat exposure of 95 degrees F for up to 2 hours. | 9 |
| Total | 17 |
Withdrawals & dropouts
| Period | Reason | FG000 | FG001 |
|---|---|---|---|
| Overall Study | Adverse Event | 1 | 0 |
| Overall Study | Equipment Malfunction | 0 | 1 |
| Overall Study | Protocol Violation | 2 | 0 |
Baseline characteristics
| Characteristic | Tetraplegia | Control | Total |
|---|---|---|---|
| Age, Categorical <=18 years | 0 Participants | 0 Participants | 0 Participants |
| Age, Categorical >=65 years | 0 Participants | 0 Participants | 0 Participants |
| Age, Categorical Between 18 and 65 years | 8 Participants | 9 Participants | 17 Participants |
| Region of Enrollment United States | 8 participants | 9 participants | 17 participants |
| Sex: Female, Male Female | 1 Participants | 2 Participants | 3 Participants |
| Sex: Female, Male Male | 7 Participants | 7 Participants | 14 Participants |
Adverse events
| Event type | EG000 affected / at risk | EG001 affected / at risk |
|---|---|---|
| deaths Total, all-cause mortality | — / — | — / — |
| other Total, other adverse events | 0 / 11 | 0 / 10 |
| serious Total, serious adverse events | 1 / 11 | 0 / 10 |
Outcome results
Primary
Core Body Temperature
To determine the change in core body temperature in the seated position from 79 degrees F for 30 minutes to 95 degrees F for up to 2 hours. Hypotheses: Persons with tetraplegia will have a greater increase in core body temperature than able-bodied (AB) control subjects. Core body temperature in AB persons will be maintained.
Time frame: 2 hours
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Tetraplegia | Core Body Temperature | 2.04 Percent Change | Standard Deviation 0.49 |
| Control | Core Body Temperature | -0.05 Percent Change | Standard Deviation 0.61 |
Comparison: Due to impaired thermoregulatory mechanisms secondary to spinal cord injury, subjects with tetraplegia were hypothesized to have a significant rise in core temperature after exposure to warm ambient temperatures, while control subjects were hypothesized to maintain constant core temperature.~Percent change in core temperature of subjects in each group were compared to determine if they were significantly different from baseline to warm exposure.p-value: 0.0001ANOVA
Secondary
Cognitive Performance - Stroop Interference T-Scores
To determine the change in cognitive performance as measured by the Stroop Color and Word Interference T-Scores, measured after 30 min at 79 degrees F and after up to 2 hours at 95 degrees F. 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. Hypothesis: Persons with tetraplegia compared with AB will have a greater change in cognitive performance from baseline (79 degrees) to warm exposure (95 degrees).
Time frame: 2 hours
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Tetraplegia | Cognitive Performance - Stroop Interference T-Scores | 8.3 Percent change | Standard Deviation 5.9 |
| Control | Cognitive Performance - Stroop Interference T-Scores | 0.3 Percent change | Standard Deviation 6.6 |
Comparison: We hypothesized that subjects with tetraplegia would demonstrate a change in cognitive performance after heat exposure if they had demonstrated a significant increase in core body temperature - as was hypothesized in our primary hypothesis. Cognitive performance was measured, in part, by Interference T-scores derived from the Stroop Color and Word Test.p-value: 0.006ANOVA
Other Pre-specified
Sweat Rate
To determine the change in sweat rate using QSweat methodology (WR TestWorks) from 30 minutes at 79 degrees F compared to after up to 2 hours at 95 degrees F. Sweat collection capsules will be placed on the left lateral anterior shoulder, volar aspect of the distal forearm, proximal anterior thigh, and mid-lateral calf (dermatomes C5, T1, L3, L5) for measurement of sweat rate. Hypothesis: Persons with tetraplegia compared with AB will have less of a percent change in average sweat rate after heat exposure.
Time frame: 2 hours
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Tetraplegia | Sweat Rate | 51.4 Percent change | Standard Deviation 12.6 |
| Control | Sweat Rate | 1030.2 Percent change | Standard Deviation 654.9 |
Comparison: Due to impaired thermoregulatory mechanisms, subjects with tetraplegia were hypothesized to have diminished increases in sweat rate in comparison to controls after heat exposure.p-value: 0.015ANOVA