Swallowing kinematics and airway protection after palatal local anesthesia in infant pigs

Objectives/Hypothesis Abnormal kinematics during swallowing can result in aspiration, which may become life threatening. We tested the role of palatal sensation in the motor control of pharyngeal swallow in infants. Study Design In eight infant pigs, we reduced palatal sensation using local anesthesia (PLA) and measured the impact on swallowing kinematics and airway protection. Methods The pigs drank milk containing barium while we simultaneously recorded videofluoroscopy and electromyography from fine wire bipolar electrodes in several hyolaryngeal muscles. We compared these results to control feedings and feedings following palatal saline injections. Results After PLA, four pigs had extreme jaw movements and abnormal tongue movement uncharacteristic of sucking. For this reason, we evaluated differences between these group B pigs and the others that could suck normally after PLA (group A). In the four group A pigs, after PLA there was less hyoid elevation (P