Figure 10 - Pharyngeal paresis.

Frontal view shows asymmetry of distention, with the left piriform sinus (ps) bulging much more than the right piriform sinus because of weakness of the constrictor muscles. A small amount of contrast medium is present in the laryngeal vestibule (arrow), and a moderate flow defect (arrowheads) can be seen. (Source: Gore RM, Levine MS, Laufer I, eds. Textbook of Gastrointestinal Radiology. Philadelphia: WB Saunders, 1994, with permission from Elsevier Science.)