Implantation of a Recurrent Laryngeal Nerve Stimulator for the Treatment of Spastic Dysphonia

Spastic dysphonia, a rare speech disorder, is characterized by strained phonation with excessively adducted vocal cords. Recurrent laryngeal nerve section, botulinum toxin injection into the vocalis-thyroarytenoid muscle complex, and other techniques have been used to treat this disorder. We have used percutaneous electrical stimulation of the recurrent laryngeal nerve with good results. Previous dog studies demonstrated the relative safety of an implantable recurrent laryngeal nerve stimulator. In this study, we directly stimulated the recurrent laryngeal nerve and vagus nerve in a dog without change in cardiorespiratory status. A Medtronic peripheral nerve stimulator was implanted in a patient with abductor spastic dysphonia. The cuff electrode was positioned around the recurrent laryngeal nerve and stimulation resulted in improvement in her voice. Extensive cardiopulmonary monitoring did not reveal any adverse response to stimulation and there was no discomfort to the patient. On the basis of the good results of this preliminary study, further study with long-term follow-up is under way.