Effect of chronic electrical stimulation of laryngeal muscle on voice.

Conventional surgical therapies for bilateral laryngeal paralysis sacrifice voice to enlarge the airway. Electrical pacing of the posterior cricoarytenoid (PCA) muscle to restore glottal opening and allow ventilation offers a new treatment approach. The purpose of this investigation was to determine whether long-term stimulation of the PCA muscle altered perceptual, acoustic, and aerodynamic parameters of voice. Two patients underwent implantation of a Medtronic Itrel II laryngeal pacemaker. Voice evaluation was performed before surgery and at monthly postoperative sessions with the pacemaker off. Months of PCA stimulation did not change perceptual descriptors of voice quality. Measures of fundamental frequency and intensity, upper and lower limits of the dynamic frequency and intensity range, and phonatory flow rates were largely unaltered. The results indicated that there was no effect of laryngeal pacing on voice.