Thermoregulation in patients with spinal cord injury and cold sensations, an explorative pilot-study

Rationale: Cold sensations are a common complaint in patients with spinal cord injury (SCI) and have a negative effect on quality of life and daily activities. However, the pathophysiology of these sensations and whether patients who experience these sensations have impaired thermoregulatory responses compared to patients who do not, is currently unknown.
Objective and hypothesis: To investigate whether SCI patients with regular complaints of cold sensations have (more) impaired thermoregulatory responses to changes in environmental temperature compared to SCI patients who do not have these cold sensations. We hypothesize that patients with regular complaints of cold sensations have impaired thermoregulatory responses to changes in environmental temperature. We expect that they are not able to stabilize their core body temperature during changes in environmental temperature and that skin temperature will remain stable. Moreover, we expect that patients without these complaints will be able to keep their core body temperature stable by varying their skin temperature (due to better vasomotor control) under the different environmental temperatures.
Study design and methods: This is an observational study of two SCI patient groups, one with and one without regular complaints of cold sensations. Both groups will be exposed to a cold environment (18-19°C) for 120 minutes and subsequently to a warmer environment (24°C) for 60 minutes. During these interventions, core body and skin temperature, thermal sensation, heart rate and blood pressure will be measured.
Study population: We will include 20 patients with SCI at or above thoracic (T) 6 in the chronic phase (>6 months) between 18-65 years of age; 10 with regular complaints of cold sensations and 10 without.
Main study parameters/endpoints: Between group differences in change in core body and skin temperature during cold exposure.
Nature and extent of the burden and risks associated with participation, benefit and group relatedness: Patients will report to the laboratory once for the measurements (4,5hr). Cold exposure and measuring blood pressure can cause some discomfort. For safety, body temperature will be checked regularly and the measurements will be aborted when temperature drops below 35°C. A physician can be contacted in case of emergency. Due to the changes in physiological processes/thermoregulation in SCI, a comparison with healthy subjects would not answer our research question and inclusion of a patient-control group is necessary. A sound sample size calculation is not possible due to the few data that are currently available. Therefore, we use a comparable group-size a previous study used which investigated core body temperature changes in SCI subjects during cold exposure.

We hypothesize that patients with regular complaints of cold sensations have impaired thermoregulatory responses to changes in environmental temperature. We expect that they are not able to stabilize their core body temperature during changes in environmental temperature and that skin temperature will remain stable. Moreover, we expect that patients without these complaints will be able to keep their core body temperature stable by varying their skin temperature (due to better vasomotor control) under the different environmental temperatures.

Baseline and repeated measures during exposure to cold and warmer room temperature