There are two nerves attached to the larynx (voice box). If either nerve is damaged, the patient may lose his or her voice or have trouble breathing.

Injury to the laryngeal nerves is uncommon. However, it may occur:

• As a complication of surgery in the neck or chest, especially thyroid, lung, or heart surgery
• While placing a breathing tube in the windpipe (endotracheal tube) or while positioning the head and neck prior to placing such a tube
• From tumors in the neck or upper chest, such as thyroid or lung cancers

The most common symptoms are hoarseness and difficulty speaking. Difficulty swallowing may also occur.

If both the left and right laryngeal nerves are injured, this urgent situation can leads to difficulty breathing.

Two procedures, laryngoscopy and bronchoscopy, allow the doctor to see if the vocal cords have an abnormal motion. This usually means a laryngeal nerve is injured.

An x-ray or CT scan of the chest may be done to detect any abnormalities in the mediastinum that might be responsible for the injury.

Treatment depends on the cause of the injury. In some instances, no treatment may be required and the nerve may recover on its own. Voice therapy is useful in some cases.

If surgery is needed, the goal is generally to change the position of the paralyzed vocal cord to improve the voice. This can be done by injecting collagen, gelfoam, or some other substance, or through procedures like thyroplasty or arytenoid adduction. If both left and right nerves are damaged, an immediate tracheotomy may be required to help the patient breathe, followed by definitive surgery at a later date.

The outlook depends on the cause of the injury. In some cases, the nerve rapidly returns to normal. However, sometimes the damage is permanent.

Call your health care provider if you have unexplained hoarseness that persists for a long time, or if you have difficulty breathing.