Mechanisms involved in postdeglutition retention in the elderly.

This study examines possible quantifiable causes of postdeglutition pharyngeal retention in the elderly. Manofluorography and computer processing of video images are performed. Retention in the valleculae and in the piriform sinuses is associated with a markedly reduced pharyngeal shortening, a low tongue driving force (TDF), and a diminished amplitude of the pharyngeal contraction. There is no relationship with the hypopharyngeal suction pump (HSP). Retention limited to the valleculae is associated with a low TDF, and retention restricted to the piriform sinuses is accompanied by a reduced pharyngeal shortening.