BOLUS AGGREGATION IN THE OROPHARYNX DOES NOT DEPEND ON GRAVITY

Objective: To determine whether bolus aggregation in the oropharynx (b efore swallowing) depends on gravity. Design: Before-during trial, wit h subjects serving as their own controls. Setting: Hospital radiology suite. Participants: Five asymptomatic adult volunteers. Interventions : Videofluorography was performed while subjects ate soft and hard foo ds containing barium, first seated upright and then kneeling face down (quadruped position). Main Outcome Measures: Duration of food process ing in the oral cavity, bolus aggregation in the valleculae, and phary ngeal swallow. Results: Transport of chewed solid food from the oral c avity to the oropharynx (stage II transport) typically started several seconds before onset of swallow, regardless of head position or initi al food consistency. Bolus aggregation in the valleculae (between the epiglottis and the tongue) began an average of 1.7 +/- 2.5sec before t he onset of the pharyngeal swallow (p < .001). Stage II transport was driven by tongue-palate contact. Conclusions: Transport of chewed soli d food from the oral cavity to the pharynx is driven actively by tongu e-palate contact and does not depend on gravity. A bolus may accumulat e in the valleculae for several seconds before the swallow. (C) 1998 b y the American Congress of Rehabilitation Medicine and the American Ac ademy of Physical Medicine and Rehabilitation.