Hyoid bone and larynx movements during electrical stimulation of motor points in laryngeal elevation muscles: A preliminary study

Objectives: This study aimed to determine the laryngeal elevation muscle motor points, evaluate the movement of hyoid bone and larynx during stimulation of the motor points, and examine the potential for treating severe dysphagia by functional electrical stimulation. Methods: The motor points of the laryngeal elevation muscles were anatomically determined from four cadavers. Those motor points in two healthy subjects and one lateral medullary syndrome patient were electrically stimulated by surface or implanted electrodes. Results: The movements elicited by electrical stimulation of the motor points were greater in implanted than in surface electrodes. Elevation of the hyoid bone and the larynx in a lateral medullary syndrome patient were achieved with the implanted electrodes, but the upper esophageal sphincter opening was not obtained unless an additional cricopharyngeus muscle block was provided. Conclusion: The hyoid bone and larynx were elevated by electrically stimulating the motor points of the laryngeal elevation muscles.