Vocal Cord Paralysis

Vocal cord paralysis results from disease of or injury to the superior or, most often, the recurrent laryngeal nerve. It may be unilateral or bilateral; unilateral paralysis is most common.

Causes

Vocal cord paralysis may be caused by head trauma, a neurologic insult such as a stroke, a neck injury, lung or thyroid cancer, a tumor pressing on a nerve, or a viral infection. In older people, vocal cord paralysis is a common problem affecting voice production. People with certain neurologic conditions, such as multiple sclerosis or Parkinson's disease, or people who have had a stroke may experience vocal cord paralysis. In many cases, however, the cause is unknown.

Signs and Symptoms

Signs and symptoms of vocal cord paralysis depend on whether the paralysis is unilateral or bilateral and on the position of the cord or cords when paralyzed. A patient with unilateral paralysis, the most common form, may complain of vocal weakness and hoarseness. A patient with bilateral paralysis typically reports vocal weakness and may have incapacitating airway obstruction if the cords become paralyzed in the adducted position. Increased respirations, shortness of breath, dyspnea, decreasing oxygenation saturations, restlessness, decreased breath sounds, and difficulty speaking can occur.

Diagnostic tests

Indirect laryngoscopy shows one or both cords fixed in an adducted or partially abducted position. Bronchoscopy and esophagoscopy (fiber-optic techniques used to visualize the larynx) also may be used.

Treatment

Unilateral vocal cord paralysis is treated under direct laryngoscopy with injection of Teflon into the paralyzed cord. This procedure enlarges the cord and brings it closer to the other cord, usually strengthening the voice and protecting the airway from aspiration.

Bilateral cord paralysis can be a surgical emergency and generally requires a tracheotomy to restore a patent airway. Alternative treatments for adult patients include arytenoidectomy to open the glottis and lateral fixation of the arytenoid cartilage through an external neck incision. Lateralization of the vocal cords negates the need for a tracheostomy. Excision or fixation of the arytenoid cartilage improves airway patency but produces residual voice impairment. Many patients with bilateral cord paralysis prefer to keep a tracheostomy instead of having an arytenoidectomy; their voices generally are better with a tracheostomy alone than after corrective surgery.

Treatment for patients with hysterical aphonia may include psychotherapy and, for some patients, hypnosis.