Functional Role of Human Laryngeal Nerve Connections

Objectives/Hypothesis: Current knowledge of the functional role of human laryngeal nerves is based on traditional laryngeal neuroanatomic descriptions or contradictory electromyographic studies. The aim of this study was to clarify the functional role of neural connections between laryngeal nerves by correlating the different electromyographic patterns observed after laryngeal stimulation and the existence of different neural connections. Study Design: Descriptive. Methods: Electromyographic and morphologic study in 13 patients during total laryngectomy procedure. Results: Seven patients showed an additional evoked response from the cricothyroid muscle after recurrent laryngeal nerve stimulation. External laryngeal nerve stimulation resulted in additional responses from the posterior cricoarytenoid muscle in three cases and from the arytenoid muscle in one. The presence of a neural connection was confirmed in all patients who showed an unexpected electromyographic response. Conclusions: The different connections between laryngeal nerves are at least partially of motor nature and play a role in the mobility of vocal folds.