Contribution of the pharyngeal plexus to vocal cord adduction

Objectives/hypothesis: The aim of this study was to elucidate whether the pharyngeal plexus (PP) contributes to vocal cord adduction in the porcine model.

Study design: Experimental study.

Methods: Thyroarytenoid (TA) muscle contraction was recorded electromyographically with electrical stimulation of the internal branch of the superior laryngeal nerve (iSLN) and PP in seven pigs.

Results: Glottic closure reflex (GCR) was detected with stimulation of the iSLN in all subjects. Electrical stimulation of the PP elicited a response from the TA in six of the seven pigs. In one subject, TA electromyography (EMG) mean latency was noted to be 18.8 msec, approximating that of GCR elicited by iSLN stimulation. Antidromic nerve pulses generated the responses from the TA with a medium latency (mean, 6.32 msec) in three of the seven pigs. TA EMG with a short latency (mean, 1.8 msec) was identified in two of the seven pigs.

Conclusions: Electrical stimulation of both central and distal ends of the PP elicited vocal cord adduction. These results support the promise of future rehabilitative uses of the PP to treat dysfunctions of the iSLN or as a means of addressing many age-related or metabolic causes of protective laryngeal paresis.

Level of evidence: NA.