THERMAL ORAL-PHARYNGEAL STIMULATION AND ELICITATION OF SWALLOWING

The influence of thermal stimulation of the oral and pharyngeal mucosa on the elicitation of swallowing was studied in 14 healthy volunteers . The Repeated Dry Swallowing Test was used to study the ability to el icit swallows. The test consists of 11 manometrically recorded dry swa llows performed at maximum speed. The time between swallows 1 and 11 ( Swallowing Test Time) is considered a measure of the ease of eliciting the swallowing reflex. The study includes two controlled experiments, each consisting of an active test done immediately after a cold stimu lus and a control done after a stimulus at body temperature. In one ex periment the stimulus consisted of stimulation of the fauces with a la ryngeal mirror and in the other of swallowing water. Each subject serv ed as his or her own control. The order of the tests was randomized an d the results read blindly. In the mirror experiment, the swallowing t est times obtained after application of a cold laryngeal mirror did no t differ significantly from those obtained after stimulation at body t emperature. In the water experiment, swallowing test times were shorte r after swallowing cold water compared to those after swallowing water at body temperature in 11 of the 14 volunteers (n.s.). The concept th at swallowing is significantly facilitated by cold applied to the oral -pharyngeal mucosa was thus not supported by the present study. The im portance of these findings is discussed.