• TUESDAY Q & A: Exact cause of vocal cord paralysis often difficult to determine

DEAR MAYO CLINIC: My 55-year-old brother-in-law has developed a vocal cord palsy out of the blue. What can cause this and what can be done to restore his voice?  

ANSWER: Vocal cord palsy, more commonly called vocal cord paralysis, happens when vocal cord muscles become paralyzed. This condition comes from a disruption in the nerve impulses to the voice box, or larynx. There are a variety of possible causes, including injury, stroke, tumors and infections. Treatment depends on how severe the symptoms are and how long they last.  

Your vocal cords are inside your voice box, located in the throat between the base of your tongue and the top of your windpipe, or trachea. The vocal cords are two folds made up of muscle and soft tissue that act like a gate between your airway and mouth. When you breathe, your vocal cords open. When you speak, they come together and vibrate, creating the sound of your voice.  

In most cases of vocal cord paralysis, only one vocal cord is paralyzed. The result is often hoarseness with a breathy quality to the voice. Vocal cord paralysis can make swallowing difficult. Some people with this disorder feel a need to clear their throat frequently. They also may need to stop and take a breath often while they speak.  

Many health problems can lead to vocal cord paralysis. The most common cause is a viral infection. Also common is injury to the nerve as a result of surgery such as thyroidectomy or an operation on the chest or mediastinum (the space behind the breast bone or sternum). Tumors in the chest or neck can also affect the nerve to the larynx and vocal cord. In many cases, though, it can be hard for doctors to pinpoint the exact cause of vocal cord paralysis.  

For some people with the disorder, vocal cord paralysis may go away on its own. Other people who have mild symptoms may choose not to have treatment. When symptoms are more severe, treatment usually is needed.  

As a first step, voice therapy may be useful. The therapy typically includes exercises that improve breath control during speech, protect the airway during swallowing, and prevent tension in muscles around the paralyzed vocal cord. If a person’s voice is very breathy and weak, voice therapy may not provide any benefit.  

Surgery is often necessary to improve the voice. This involves repositioning the paralyzed vocal cord to bring it closer to the middle of the voice box, which allows the other vocal cord to make closer contact with the paralyzed cord when speaking or swallowing.  

The repositioning may be accomplished with an injection of a substance that bulks up the vocal cord. Or, an implant may be used to reposition the vocal cord. If a large gap remains between the vocal cords that makes speaking difficult, it may be necessary to surgically reposition the back part of the vocal cord, also called the arytenoid cartilage.  

Another option is to replace the damaged nerve with a healthy nerve from a different area of the neck. It can take as long as six months before a new nerve starts working. Some doctors combine this surgery with a bulk injection.  

It is important for those affected with vocal cord paralysis to talk with a doctor who has experience treating this disorder. A thorough review of possible causes, as well as a comprehensive evaluation of a person’s medical history and symptoms, can help the care team create a treatment plan that best fits that individual’s situation. Dale Ekbom, M.D., Laryngology and Voice Disorders, Mayo Clinic, Rochester, Minn.