Axon reflex-related hyperemia induced by short local heating is reproducible

Increasing acclimation period improves the reproducibility of short-heating local thermal hyperemia

“…The acclimation period has been reported to be as short as 20-30 min in some reproducibility studies (Agarwal et al, 2010;Roustit et al, 2010a,b), but it was longer (i.e., up to 90 min) in another study (Tew et al, 2011). In our intra-session experiment of short heating for 5 min, the AR flare was reproducible after 30 min acclimation when the recording sites were fixed with holders and the test-retest interval was 45 min (Huang et al, 2012). However, still unknown is whether the short-heating LTH assessment is reproducible with 30 min acclimation when relocating the recording site after a longer interval.…”

“…The acclimation period for intersession testing needed to be increased to 60 min to achieve acceptable LTH reproducibility on both sides of forearm in the present study, whereas our previous study revealed that a 30 min acclimation period was sufficient for intra-session testing, in which the recording sites were fixed by holders (Huang et al, 2012). In addition to that relocating the recording sites may cause some variations of the capillary density and sensory innervations, the interday variations of physiological conditions may be greater than intraday variations.…”

“…The periods of blood flux measurement for data analysis were the same as our previous study (Huang et al, 2012). During the 5 min baseline measurement, the mean CVC of the last 2 min recording before heating was evaluated (Fig.…”

“…According to the data from the intra-session study, the ICCs analyzed by peak CVC change were 0.80-0.86 and averaged 0.83 (Huang et al, 2012). Since we hoped that the ICC of intersession reproducibility could be 0.75 and the acceptable ICC was at least 0.40, the estimated number of subjects needed in each group was 22 (α =0.05, β = 0.2) (Walter et al, 1998).…”

Laser Doppler Flare Imaging and Quantitative Thermal Thresholds Testing Performance in Small and Mixed Fiber Neuropathies

“…LDI Flare technique was used to measure heat induced axon reflex-mediated neurogenic vasodilation, which might be influenced by sympathetic activity and basal levels of nitric oxide[9]. Temperature on the dorsum foot temperature was standardized to 32°C using a warm blanket for at least 20 minutes.…”