Relation of bolus size and pharyngeal swallow

Abstract

To study the influence of bolus size on pharyngeal swallow, 20 dysphagic patients and 10 nondysphagic volunteers were examined cineradiographically while swallowing a bolus of 2.5, 5, 10, and 20 ml. Ten patients and 10 volunteers swallowed boluses in increasing volume while 10 patients swallowed boluses of decreasing volume. The movement of the hyoid bone occurred in a two-step fashion irrespective of the bolus size, and in all individuals. The speed of the apex of the bolus through the pharynx, measured by frame counting, increased with increasing size of the bolus. The speed of the peristaltic wave, as measured between vallecula and the PE segment, did not change with bolus size. Boluses of 10 or 20 ml caused penetration of barium into the larynx in 7 of the patients but in none of the volunteers. Our results suggest that pharyngeal constrictor activity, in terms of speed of peristalsis, is constant and not influenced by bolus volume.