Effect of temperature on electrophysiological parameters of swallowing

Abstract

Abstract-The effect of three different temperature ranges on the triggering of voluntary-induced swallowing and on the duration of the pharyngeal phase of oropharyngeal swallowing was studied electrophysiologically. The relationship between volume and temperature of liquids swallowed was also explored. This study included 40 nondisabled volunteers (23 male and 17 female). Laryngeal vertical movements and submental electromyographic activity were recorded as each subject swallowed water at three different temperature ranges: normal (23-25 °C), cold (8-10 °C), and hot (58-60 °C). The time for triggering of the pharyngeal phase of swallowing was found to be shorter for cold and hot water than for normal temperature water (p < 0.01). The duration of the pharyngeal phase of oropharyngeal swallowing was also shorter for cold and hot water than for normal temperature water (p < 0.05). The maximum capacity of a single bolus (dysphagia limit) was >20 mL of water in all nondisabled subjects for different temperatures. However, the capacity was significantly less for hot water relative to normal temperature water and cold water (p < 0.05). In conclusion, the temperature ranges used in this study were found to be effective in triggering voluntary-induced swallowing.

Cold thermal oral stimulation produces immediate excitability in human pharyngeal motor cortex

“…Cold 15°C thermal stimulation should potentially activate TRPM8/A1 receptors in peripheral nervous system, contributing to excitability changes in central nervous system as described above. The current result of an increase in pharyngeal MEP amplitude during cold 15°C thermal stimulation compared to warmth 37°C in oral tongue area supports the previous studies which described behavioral facilitation in cold water swallowing . The modulatory changes in the swallowing motor system would thus seem to be dependent on temperature of thermal stimulation in central nervous system.…”

“…The current result of an increase in pharyngeal MEP amplitude during cold 15°C thermal stimulation compared to warmth 37°C in oral tongue area supports the previous studies which described behavioral facilitation in cold water swallowing. 4,17,50 The modulatory changes in the swallowing motor system would thus seem to be dependent on temperature of thermal stimulation in central nervous system.…”

“…The facilitatory effect of cold stimulation on swallowing behavior has been elucidated in some previous studies using a water swallowing test . The peripheral mechanism of perception of thermo‐sensation has been advanced since the discovery of a set of signaling proteins of the transient receptor potential (TRP) family.…”

“…15 The facilitatory effect of cold stimulation on swallowing behavior has been elucidated in some previous studies using a water swallowing test. 4,16,17 The peripheral mechanism of perception of thermo-sensation has been advanced since the discovery of a set of signaling proteins of the transient receptor potential (TRP) family. Of relevance to thermal sensing, cold stimulation below 25°C activates the transient receptor potential melastatin 8 (TRPM8) 18 and transient receptor potential ankyrin 1 (TRPA1) is also activated by stimulation below 17°C 19 while heat thermal stimulation over 43°C activates transient receptor potential vanilloid 1 (TRPV1), which has been confirmed to be expressed in oropharyngeal area in human.…”

Taste and Temperature in Swallowing Transit Time after Stroke

“…Cold and hot temperatures differ from the intraoral mucosal temperature. Such stimuli may increase subject awareness of the bolus, modifying the pharyngeal response [9]. However, some studies did not find changes in the oral or pharyngeal phases with boluses of different taste and temperature [10,11,12].…”