Reverse Phonation: A New Maneuver for Examining The Larynx

In General, phonation is the only maneuver employed in tomography and lateral soft-tissue filming of the larynx. By using inspiration as well as phonation in the clinical mirror examination one determines both the mobility and appearance of the laryngeal structures. Since the introduction of laryngography (5), the value of multiple maneuvers in the radiographic examination also has become evident (1–4, 6). In laryngography the integrity and mobility of laryngeal structures are assessed by fluoroscopic spot-films during inspiration, phonation, modified Valsalva, and Valsalva maneuvers. Additional information about the extent and type of tumor present is obtained by a new maneuver—reverse phonation, whose clinical and radiographic applications are the subject of this report. This maneuver was first used by Powers and his co-workers who called it “inspiratory phonation” in their recent publication (7). The term “reverse phonation” seems preferable as it is less cumbersome and suggests more strongly its difference from normal phonation. Technic Reverse phonation results when the patient makes a continuous phonating “eeee” sound as the breath is taken in. The vocal cords come together as they do in normal phonation and close the glottis. The incoming air is partially obstructed, causing the pressure to drop in the subglottic region. As the tissues of the glottis lateral to the tensed vocal cords give way to the greater atmospheric pressure above, the ventricles distend (Fig. 1). A pressure difference also develops between the hypopharynx and the subglottic region, which produces slight distention of the bottom of the pyriform sinuses. Most patients easily master this maneuver after the examiner demonstrates it. Those having difficulty should be instructed to let their breath out completely and then begin to make a sound at the same time as they breathe in. A good “eeee” sound is not essential. Any continuous sound resulting from apposition of the cords during inspiration will suffice. Patients with extensive vocal cord tumors may be able to produce little more than stridor. Normal Findings The appearance of the vocal cords, ventricles, and false cords during normal phonation is shown in Figure 2,A. During reverse phonation the main change is distention of the ventricles (Fig. 2,B). Other changes are less striking. The vestibule itself may distend slightly, becoming broader in appearance. The medial wall of the pyriform sinus may be more distinct. This is probably the result of more of the wall being tangential to the x-ray beam than during normal phonation. The separation of the larynx from the posterior pharyngeal wall is shown by a lower position of the contrast material that pools behind the larynx (postcricoid line) (1).