EFFECTS OF RLN AND SLN STIMULATION ON GLOTTAL AREA

In vivo canine experiments have demonstrated that vocal fold stiffness varies proportionately with changing levels of recurrent laryngeal ne rve (RLN) and superior laryngeal nerve (SLN) stimulation. This study e valuated the morphologic changes in the glottis at varying levels of n erve stimulation and the presumed effects on laryngeal air particle ve locity. Stroboscopic data from the in vivo canine model of phonation w ere examined under varying conditions of RLN and SLN stimulation. Comp uterized analysis of stroboscopic images was used to reconstruct the g lottal area vs. time waveforms. As RLN stimulation increased, glottal area per cycle decreased (p < 0.05). However, as SLN stimulation incre ased, glottal area per cycle increased (p < 0.05). These results suppo rt the hypothesis that increasing RLN stimulation at similar levels of SLN stimulation produces an increase in air particle velocity, wherea s an increase in SLN stimulation causes a decrease in air particle vel ocity.