Effects of mechanical, cold, gustatory, and combined stimulation to the human anterior faucial pillars

Tactile-Thermal Application (TTA) is a therapy technique designed to enhance the swallowing response in persons with dysphagia. In this study, TTA was broken down into each component stimulus (i.e., Cold, Mechanical, Gustatory), and all combinations thereof, to study the effects of each condition on measurable parameters of the normal human swallow response. Using surface electromyography (EMG), latency to swallow-specific activity and duration of submental EMG activity were measured to examine the following questions: (1) Are there stimulus-dependent differences in onset latencies and contraction durations of the submental muscle activity? (2) Which stimulus components are responsible for this response? (3) How long do the effects of stimulation last on the response? (4) Are there response differences according to age and gender? Between-subjects multivariate analysis of variance showed that the main effects for Treatment, Gender, and Age were significant. Latency to swallow-specific activity was significantly shorter following Mechanical + Cold + Gustatory condition compared to No Stimulation. The effect of stimulation on the swallow response lasted for only one swallow.