The vocal cords act like a valve regulating airflow within the voice box as they open for breathing and temporarily close for producing sound. This valve is opened and closed by small muscles within the voice box, which in turn receive signals from the right and left recurrent laryngeal nerves (RLNs). These nerves start at the base of the brain, travel within the neck, loop around the main arteries in the upper chest and then return back up into the voice box, passing near the esophagus, trachea and the thyroid gland. Therefore, tumors or surgeries in any one of these areas can compromise their function and adversely affect the voice and/or breathing.
- Unilateral vocal cord paralysis occurs when one of the vocal cords fails to move properly as a result of nerve damage. The result can be a leaking valve, which leads to inefficient sound production often resulting in vocal fatigue, as well as a breathy and/or raspy voice.
- Bilateral vocal cord paralysis occurs when both of the vocal cords do not move properly as a result of nerve damage and typically results in difficulty breathing.
Treatment of Unilateral Vocal Cord Paralysis
The treatment of unilateral vocal cord paralysis depends on when the paralysis began to cause vocal impairment and on each patient's individual vocal needs.
Vocal Cord Injections
In many cases, when unilateral vocal cord paralysis first occurs, there is often a chance of spontaneous return of the vocal cord movement and restoration of voice. Nerve recovery can take many months to complete, however. For patients who desire immediate vocal improvement, an alternative exists to enduring a poor voice while waiting for spontaneous recovery.
At the Voice Center, an injection laryngoplasty can often be performed in the office in a matter of minutes, without the need to undergo general anesthesia in the operating room. This type of vocal cord injection places a temporary material to reposition the paralyzed vocal cord toward the middle of the airway, reducing the leak in the leaking valve. The result can be a dramatic vocal improvement almost immediately after treatment.
There are some medical studies, one of which NorthShore’s Aaron D. Friedman, MD, authored, suggesting that individuals with unilateral vocal cord paralysis who never recover vocal cord motion but who received an injection laryngoplasty soon after their paralysis began may have less of a need for a permanent surgery to correct their voices than those who did not have an injection.
The longer a patient has unilateral vocal cord paralysis, the less the chance of spontaneous recovery. Patients who have a poor voice resulting from a longterm leaking vocal cord valve during speech can have a surgery called a medialization laryngoplasty, which can permanently improve the voice.
During this procedure, an implant is precisely placed next to the paralyzed vocal cord in order to push it towards the middle of the airway and improve the leaking vocal valve. This is performed under local anesthesia so that the patient can be awake to try out his or her new voice and help determine the best implant placement.
Depending on the position of the paralyzed vocal cord, a special additional surgical procedure, called an adduction arytenopexy, may be required as a part of the medialization laryngoplasty operation in order to produce the best possible vocal outcome. Dr. Friedman is one of only a handful of laryngeal surgeons in the country with experience in this advanced technique.
Treatment of Bilateral Vocal Cord Paralysis
At present, medical techniques to reliably restore movement to paralyzed vocal cords remain experimental. When both vocal cords are immobile, the laryngeal airway is typically narrowed to the point of creating breathing difficulty. A tracheotomy, which is a reversible surgical procedure to bypass airway obstruction, will preserve vocal cord tissue without limiting future techniques that might one day artificially restore vocal cord movement. Although it can typically be performed with minimal impact on the voice, the artificial tube will require routine maintenance once placed.
An alternative treatment involves removal of the back portion of one or both vocal cords (partial cordectomy) to increase the size of the narrowed laryngeal airway. While this procedure can help avoid a permanent tracheotomy, it irreversibly changes the vocal cord tisue and will result in a permanently diminshed voice.