http://dailynews.yahoo.com/h/kitv/20010719/lo/862809_1.html

Friday July 20 01:05 AM EDT

The vocal cords are two elastic bands of tissue in the voice box (larynx). Normally, they remain in a relaxed (open) position for air to pass into the lungs. When a person speaks, the vocal cords tighten and vibrate as air passes between the two bands of tissue. Sounds coming from the throat are modified by the tongue, palate, and lips to produce speech. Pitch and volume of the sound are controlled by the tension of the vocal cords.

Vocal cord paralysis is a condition that occurs when one or both of the vocal cords can’t open or close properly. That may cause changes in voice quality, hoarseness, and discomfort or pain from straining the vocal cords. Patients may also experience swallowing problems or choking because food or liquids pass through the windpipe to the lungs.

The most common cause of one-sided (unilateral) vocal cord paralysis is trauma or injury to the nerve that controls movement of the band of tissue. Vocal cord paralysis (including bilateral, or two-sided, paralysis) can be caused by head injury, viral infection, stroke, lung or thyroid cancer, or certain neurologic diseases (such as multiple sclerosis or Parkinson’s disease).

Treating One-Sided Vocal Cord Paralysis

Sometimes patients with vocal cord paralysis recover on their own. So, many physicians wait 6 to 12 months before considering any drastic measures. In the meantime, a patient may be referred for voice therapy. A speech therapist may be able to teach the patient exercises to strengthen the vocal cords, improve breath control, or talk differently to improve speech clarity.

Some surgeons are using a different technique to treat patients with one-sided vocal cord paralysis - using a nerve that normally controls movement of the tongue. An incision is made in the middle of the neck. First, doctors locate the nerve that controls the paralyzed cord and trace the cord into the chest, and cut the damaged nerve. Next, the surgeons locate one of the two major nerves that control movement of the tongue. The end of the tongue nerve is cut and sewn to a healthy segment of the damaged nerve. Hopefully, the tongue nerve will provide control for the vocal cord, restoring the patient’s voice.

Doctors say most patients eventually get back their voice with the new surgery, but it can take six to eight months for the voice box to recover function. In the meantime, patients may get a temporary injection that pushes the paralyzed cord closer to the healthy cord, allowing the two cords to vibrate to some degree. The injected substance is gradually resorbed by the body, giving the patient some vocal cord function while he/she is waiting for the nerve to recover from the surgery. Patients don’t notice any changes of movement in the tongue from the loss of one of the nerves.

For information on vocal cord paralysis: National Institute on Deafness and Other Communication Disorders, National Institutes of Health (news - web sites), 31 Center Drive, MSC 2320, Bethesda, MD 20892-2320