Comparison between esophageal and intestinal temperature responses to upper-limb exercise in individuals with spinal cord injury

Objective: Individuals with spinal cord injuries (SCI) may present with impaired sympathetic control over thermoregulatory responses to environmental and exercise stressors, which can impact regional core temperature (Tcore) measurement. The purpose of this study was to investigate whether regional differences in Tcore responses exist during exercise in individuals with SCI. Setting: Rehabilitation centre in Wakayama, Japan. Methods: We recruited 12 men with motor-complete SCI (7 tetraplegia, 5 paraplegia) and 5 able-bodied controls to complete a 30-minute bout of arm-cycling exercise at 50% V̇ O2peak. Tcore was estimated using telemetric pills (intestinal temperature; Tint) and esophageal probes (Teso). Heat storage was calculated from baseline to 15 and 30 minutes of exercise. Results: At 15 minutes of exercise, elevations in Teso (Δ0.39±0.22°C; P<0.05), but not Tint (Δ0.04±0.18°C; P=0.09), were observed in able-bodied men. At 30 minutes of exercise, men with paraplegia and able-bodied men both exhibited increases in Teso (paraplegia: Δ0.56±0.30°C, P<0.05; able-bodied men: Δ0.60±0.31°C, P<0.05) and Tint (paraplegia: Δ0.38±0.33°C, P<0.05; able-bodied men: Δ0.30±0.30°C, P<0.05). Teso began rising 7.2 min earlier than Tint (pooled, P<0.01). Heat storage estimated by Teso was greater than heat storage estimated by Tint at 15 minutes (P=0.02) and 30 minutes (P=0.03) in men with paraplegia. No elevations in Teso, Tint, or heat storage were observed in men with tetraplegia. Conclusions: While not interchangeable, both Teso and Tint are sensitive to elevations in Tcore during arm-cycling exercise in men with paraplegia, although Teso may have superior sensitivity to capture temperature information earlier during exercise

A comparison of static and dynamic cerebral autoregulation during mild whole-body cold stress in individuals with and without cervical spinal cord injury: a pilot study

Study design: Experimental study. Objectives: To characterize static and dynamic cerebral autoregulation (CA) of individuals with cervical spinal cord injury (SCI) compared to able-bodied controls in response to moderate increases in mean arterial pressure (MAP) caused by mild whole-body cold stress. Setting: Japan Methods: Five men with complete autonomic cervical SCI (sustained>5y) and six age-matched able-bodied men participated in hemodynamic, temperature, catecholamine and respiratory measurements for 60 min during three consecutive stages: baseline (10 min; 330C water through a thin-tubed whole-body suit), mild cold stress (20 min; 250C water) and post-cold recovery (30 min; 330C water). Static CA was determined as the ratio between mean changes in middle cerebral artery blood velocity and MAP, dynamic CA as transfer function coherence, gain and phase between spontaneous changes in MAP to middle cerebral artery blood velocity. Results: MAP increased in both groups during cold and post-cold recovery (mean differences: 5 to 10 mm Hg; main effect of time: p=0.001). Static CA was not different between the able-bodied vs the cervical SCI group (mean [95% CI] of between-group difference: -4 [-11 to 3] and -2 [-5 to 1] cm/s/mmHg for cold (p=0.22) and post-cold (p=0.24), respectively). At baseline, transfer function phase was shorter in the cervical SCI group (mean [95% CI] of between-group difference: 0.6 [0.2 to 1.0] rad; p=0.006), while between-group differences in changes in phase were not different in response to the cold stress (interaction term: p=0.06). Conclusions: This pilot study suggests that static CA is similar between individuals with cervical SCI and able-bodied controls in response to moderate increases in MAP, while dynamic CA may be impaired in cervical SCI due to disturbed sympathetic control

The inflammatory response to a wheelchair half-marathon in people with a spinal cord injury - the role of autonomic function

This study investigates the relationship between autonomic function and the inflammatory response to a wheelchair half-marathon in people with a spinal cord injury (SCI). Seventeen wheelchair athletes with a cervical SCI (CSCI, N = 7) and without CSCI (NON-CSCI, N = 10) participated in a wheelchair half-marathon. Blood was taken prior, post and 1 h post-race to determine the concentrations of adrenaline, noradrenaline, extracellular heat shock protein 72 (eHsp72) and interleukin-6 (IL-6). A sit-up tilt test was performed to assess autonomic function at rest. CSCI showed a lower supine ratio of the low and high frequency power of the variability in RR intervals (LF/HF RRI, p = 0.038), total and low frequency power of the systolic blood pressure variability (TP SBP, p 81%, p < 0.012). In summary, the dampened acute inflammatory response to a wheelchair half-marathon in CSCI was strongly associated with the autonomic dysfunction present in this group

Hot water immersion induces an acute cytokine response in cervical spinal cord injury

Purpose: The dysfunctional sympathetic nervous system in individuals with cervical spinal cord injury (CSCI) impairs adrenergic responses and may, therefore, contribute to the blunted post-exercise cytokine response. The purpose of this study was to investigate an alternative way to exercise to induce an acute cytokine response by passive core temperature elevation in CSCI. Methods: Seven male participants with a motor complete CSCI and 8 male able-bodied controls were immersed for 60 min in water set at a temperature 2 °C above the individuals’ resting oesophageal temperature. Blood was collected pre, post, and every hour up to 4 h post-immersion. Results: Hot water immersion resulted in an IL-6 plasma concentration mean increase of 133 ± 144 % in both groups (P = 0.001). On a group level, IL-6 plasma concentrations were 68 ± 38 % higher in CSCI (P = 0.06). In both groups, IL-8 increased by 14 ± 11 % (P = 0.02) and IL-1ra by 18 ± 17 % (P = 0.05). Catecholamine plasma concentrations were significantly reduced in CSCI (P < 0.05) and did not increase following immersion. Conclusions: Passive elevation of core temperature acutely elevates IL-6, IL-8 and IL-1ra in CSCI despite a blunted adrenergic response, which is in contrast to earlier exercise interventions in CSCI. The present study lays the foundation for future studies to explore water immersion as an alternative to exercise to induce an acute cytokine response in CSCI

Noninvasive positive pressure ventilation enhances the effects of aerobic training on cardiopulmonary function - Fig 4

<p>Percent changes in <b>(A)</b> hemoglobin (Hb), <b>(B)</b> hematocrit (Ht), and <b>(C)</b> plasma volume (PV) at 24 hour after last training (post-training) under NPPV and non-NPPV, compared with pre-training values. Data are mean±SD.</p

Baseline data.

<p>Baseline data.</p

The effects of local versus systemic passive heating on the acute inflammatory, vascular and glycaemic response

The aim of this study was to compare the acute cardiometabolic and perceptual responses between local and whole-body passive heating. Using a water-perfused suit, ten recreationally active males underwent three 90 min conditions: heating of the legs with upper-body cooling (LBH), whole-body heating (WBH) and exposure to a thermoneutral temperature (CON). Blood samples were collected before and up to 3h post-session to assess inflammatory markers, while a 2h oral glucose tolerance test was initiated 1h post-session. Femoral artery shear rate and perceptual responses were recorded at regular intervals. The interleukin (IL)-6 incremental area under the curve (iAUC) was higher for LBH (1096±851 pg/mL*270min) and WBH (833±476 pg/mL*270min) compared with CON (565±325 pg/mL*270min; p<0.047). Glucose concentrations were higher after WBH compared with LBH and CON (p<0.046). Femoral artery shear rate was higher at the end of WBH (1713±409 L/min) compared with LBH (943±349 L/min; p<0.001), and higher in LBH than CON (661±222 L/min; p=0.002). Affect and thermal comfort were more negative during WBH compared with LBH and CON (p<0.010). In conclusion, local passive heating elevated shear rate and the IL-6 iAUC. However, while resulting in more positive perceptual responses, the majority of the included cardiometabolic markers were attenuated compared with WBH

Transverse movement of the median nerve during digit movement.

<p>Data are mean±SD. *P<0.001, compared between median nerve transverse movement during flexion of each finger.</p

Ultrasonographic measurement of the median nerve at rest (n = 30).

<p>Values are mean±SD.</p

Median nerve cross-sectional area during digit movement. Data are mean±SD.

<p>Median nerve cross-sectional area during digit movement. Data are mean±SD.</p