Evaluation of laryngeal function after implantation of the vagus nerve stimulation device.

OBJECTIVES

The vagus nerve stimulation device (VNS) is used for the management of seizures. This study evaluated what effect the diameter of the vagus nerve helical electrode might have on true vocal cord (TVC) mobility. The study was prompted after 2 cases of TVC immobility. Electrode nerve compression was suspect.

METHODS

Eighteen patients underwent intraoperative vagus nerve measurement and electrode placement with subsequent voice and TVC evaluation. Electrode selection was based on vagus nerve measurements.

RESULTS

Seven patients had vagus nerves measuring less than 2 mm diameter and received the 2-mm inner diameter electrode. Eleven patients had vagus nerves measuring more than 2 mm in diameter and received the 3-mm inner diameter electrode. No patients experienced transient or permanent hoarseness or paresis/paralysis.

CONCLUSION

Precise vagus nerve measurements and electrode selection appear to decrease the incidence of nerve compression injury and TVC immobility.