Pharyngeal swallowing elicited by fluid infusion: role of volition
and vallecular containment.
Pouderoux, Philippe, Jerilyn A. Logemann, and Peter J. Kahrilas.
Department of Medicine, Department of Communication Sciences and
Disorders, Northwestern University Medical School, Chicago, Illinois
60611
APStracts 2:0188G, 1995.
Non alimentary swallows minimize aspiration by clearing accumulated
fluid from the pharynx. This study aimed to define: 1) the pharyngeal
sensory field to elicit swallowing, and 2) the effect of infusion
rate, volition, taste, and temperature on pharyngeal swallows. Test
solutions were directed into the valleculae at 6.5, 11.5, and 32
ml/min through a catheter in 8 healthy volunteers. Deglutition was
signaled with electromyography and electroglottography. Spatial
distribution of infusate before swallow was studied using
videofluoroscopy coupled with a videotimer. Volitional control was
assessed with rapid or restrained swallows. Pharyngeal swallow
latency decreased as the instillation rate increased, was potently
modified with volition, and was unchanged by infusate taste or
temperature. Water infusion into the valleculae did not trigger
pharyngeal swallowing until liquids overflowed and reached the
aryepiglottic folds or pyriform sinuses. The variation in swallow
latency among flow rates was mainly due to the duration of liquid
containment within the valleculae. This suggests that the valleculae
act to contain pharyngeal secretions and residue and prevent
aspiration by diverting their contents around the larynx prior to
swallowing.
Received 4 January 1995; accepted in final form 28 August 1995.
APS Manuscript Number G8-5.
Article publication pending Am. J. Physiol. (Gastrointest. Liver
Physiology).
ISSN 1080-4757 Copyright 1995 The American Physiological Society.
Published in APStracts on 31 October 95