Dysfunction of the recurrent laryngeal nerve and the potential of gene therapy

Injury to the recurrent laryngeal nerve causes vocal fold paresis or paralysis resulting in poor voice quality, and possibly swallowing dysfunction and/or airway compromise. Injury can occur as part of a neurodegenerative disease process or can be due to direct nerve trauma or tumor invasion. Management depends upon symptoms, the cause and severity of injury, and the prognosis for recovery of nerve function. Surgical treatment techniques can improve symptoms, but do not restore physiologic motion. Gene therapy may be a useful adjunct to enhance nerve regeneration in the setting of neurodegenerative disease or trauma. Remote injection of viral vectors into the recurrent laryngeal nerve is the least invasive way to deliver neurotrophic factors to the nerve's cell bodies within the nucleus ambiguus, and in turn to promote nerve regeneration and enhance both nuclear and nerve survival. The purpose of this review is to discuss the potential role for gene therapy in treatment of the unsolved problem of vocal fold paralysis.