Vocal Cord Paralysis

The vocal cords are two elastic bands of muscle  tissue located in the larynx (voice box) directly  above the trachea (windpipe). The vocal cords  produce voice when air held in the lungs is  released and passed through the closed vocal cords,  causing them to vibrate. When a person is not speaking, the vocal cords remain apart to allow the person to breathe.

Someone who has vocal cord paralysis often has  difficulty swallowing and coughing because food or  Search this liquids slip into the trachea and lungs. This  site happens because the paralyzed cord or cords remain  open, leaving the airway passage and the lungs  unprotected.

What Causes Vocal Cord Paralysis?

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.

What Are the Symptoms?

People who have vocal cord paralysis experience  abnormal voice changes, changes in voice quality,  and discomfort from vocal straining. For example,  if only one vocal cord is damaged, the voice is  usually hoarse or breathy. Changes in voice  quality, such as loss of volume or pitch, may also  be noticeable. Damage to both vocal cords, although  rare, usually causes people to have difficulty  breathing because the air passage to the trachea is  blocked.

How Is Vocal Cord Paralysis Diagnosed?

Vocal cord paralysis is usually diagnosed by an  otolaryngologist- a doctor who specializes in ear,  nose, and throat disorders. Noting the symptoms the  patient has experienced, the otolaryngologist will  ask how and when the voice problems started in  order to help determine their cause. Next, the  otolaryngologist listens carefully to the patient's  voice to identify breathiness or harshness. Then,  using an endoscope-a tube with a light at the  end-the otolaryngologist looks directly into the  throat at the vocal cords. A speech-language  pathologist may also use an acoustic spectrograph,  an instrument that measures voice frequency and  clarity, to study the patient's voice and document  its strengths and weaknesses.

How Is Vocal Cord Paralysis Treated?

There are several methods for treating vocal cord  paralysis, among them surgery and voice therapy. In  some cases, the voice returns without treatment  during the first year after damage. For that  reason, doctors often delay corrective surgery for  at least a year to be sure the voice does not  recover spontaneously. During this time, the  suggested treatment is usually voice therapy, which  may involve exercises to strengthen the vocal cords  or improve breath control during speech. Sometimes,  a speech-language pathologist must teach patients  to talk in different ways. For instance, the  therapist might suggest that the patient speak more  slowly or consciously open the mouth wider when  speaking.

Surgery involves adding bulk to the paralyzed vocal  cord or changing its position. To add bulk, an  otolaryngologist injects a substance, commonly  Teflon, into the paralyzed cord. Other substances  currently used are collagen, a structural protein;  silicone, a synthetic material; and body fat. The  added bulk reduces the space between the vocal  cords so the nonparalyzed cord can make closer  contact with the paralyzed cord and thus improve  the voice.

Sometimes an operation that permanently shifts a  paralyzed cord closer to the center of the airway  may improve the voice. Again, this operation allows  the nonparalyzed cord to make better contact with  the paralyzed cord. Adding bulk to the vocal cord  or shifting its position can improve both voice and  swallowing. After these operations, patients may  also undergo voice therapy, which often helps to  fine-tune the voice.

Treating people who have two paralyzed vocal cords  may involve performing a surgical procedure called  a tracheotomy to help breathing. In a tracheotomy,  an incision is made in the front of the patient's  neck and a breathing tube (tracheotomy tube) is  inserted through a hole, called a stoma, into the  trachea. Rather than breathing through the nose and  mouth, the patient now breathes through the tube.  Following surgery, the patient may need therapy  with a speech-language pathologist to learn how to  care for the breathing tube properly and how to  reuse the voice.

What Research Is Being Done on Vocal Cord Paralysis?

The National Institute on Deafness and Other  Communication Disorders (NIDCD) supports research  studies that may help provide new clinical  measurements to diagnose vocal cord paralysis. For  instance, computer software is being developed that  can describe important aspects of the health of a  person's larynx by analyzing the sounds it  produces. By measuring instabilities in the motion  of the vocal cords, the software may allow  scientists and treatment clinics to relate these  measurements to the study of the misuse of the  voice and help diagnose disorders such as muscle  paralysis and tissue loss.

Currently, the treatment for patients with damage  to both vocal cords involves a tracheotomy, which  may, however, cause voice production problems and  decrease protection of the lungs in an effort to  improve the airway. Recent studies show that  another feasible approach to laryngeal  rehabilitation may be using an electrical  stimulation device to activate the reflexes of the  paralyzed muscles that open the airway during  breathing.

Where Can I Get Help?

If you notice any unexplained voice changes or  discomfort, you should consult an otolaryngologist  or a speech-language pathologist for evaluation and  possible treatment.

June 1999  NIH Pub. No. 99-4306