Effect of Mild Cold Exposure on Cognition in Persons with Tetraplegia

Abstract

86±62 pg/mL vs. 832±431 pg/mL, respectively; p<0.01). SBP increased from BL to Cool Challenge only in controls (123±16 mm Hg to 149±17 mm Hg, respectively; p<0.01). Delayed Recall and Stroop Interference scores both declined in tetraplegics (-55±47.4%; p<0.05 and -3.9±3.8%; p<0.05, respectively), but not in controls. We conclude that persons with tetraplegia lack adequate thermoregulatory mechanisms to prevent downward drift in Tcore on exposure to cool temperatures. This decline in Tcore was associated with deterioration of working memory and executive function.

Patterns of cognitive deficits in persons with spinal cord injury as compared with both age-matched and older individuals without spinal cord injury

“…27 Although the etiology of the cognitive deficits in SCI remains elusive, several factors have been suggested as contributory including concomitant traumatic brain injury (TBI), 2,3,10,11,[28][29][30][31][32][33][34] secondary trauma as a result of cerebral edema, hypoxia and anoxia 27 and cardiovascular and cerebrovascular dysfunction. 7,35,36 Recent studies also suggest that factors such as sleep disordered breathing/sleep apnea, 31 core body temperature dysregulation, 37,38 as well as medications prescribed for symptom management such as pain, 39,40 and neurogenic lower urinary tract dysfunction 41 may contribute to post-SCI cognitive dysfunction. Recent work by Bombardier and colleagues 42 highlight the likelihood that factors other than TBI likely contribute to cognitive deficits post-SCI, because the number of patients reporting cognitive deficits exceeded physician-rated presence of TBI by 80% in their sample of 105 persons with SCI.…”

Self-reported effects of cold temperature exposure in persons with tetraplegia

“…The responses to question 5 are supported by the results of a previous study that exposed 7 persons with tetraplegia and 7 matched able-bodied controls to cool ambient temperature (18°C) for up to 2 hours. 16 The study demonstrated a decline in Tcore, after cool challenge in the group with tetraplegia only. The decline in Tcore was associated with a decline in cognitive performance, in the areas of working memory and executive function.…”

“…The decline in Tcore was associated with a decline in cognitive performance, in the areas of working memory and executive function. 16 There was no such decline in Tcore or cognitive performance in the control group.…”

“…However, in one of our recently published studies, similar levels of subjective discomfort were reported in persons with tetraplegia and controls, even though the average Tcore of those with tetraplegia approached mild hypothermia while the average Tcore of the control group was euthermic. 16 Therefore, we speculate that the Tcore of those subjects with tetraplegia who reported discomfort on the survey may have been approaching mild hypothermia as well.…”

“…Shivering is typically both delayed and limited, 3 thereby attenuating any increases in metabolic rate, 6 and combined with impaired vasoconstriction and lean tissue atrophy, 14 leads to steadily decreasing Tcore following cold exposure (18.0-24.0°C) in persons with tetraplegia. 1,3,6,15,16 The combined effects of these impairments after a high-level SCI (lesion level above T6) 17 results in an increased likelihood of subnormal Tcore (i.e. 35.5-36.5°C) and increased vulnerability to hypothermia (Tcore < 35.0°C), both of which have been reported in veteran in-patients with tetraplegia.…”