Cause Unknown In Most Cases of Vocal Cord Paralysis

"The larynx, or voice box, does three primary jobs: it allows air to get to the lungs, it protects the lungs from food going down the wrong chute, and it produces voice," says Joel H. Blumin, MD, Medical College of Wisconsin Associate Professor of Otolaryngology and Communication Sciences.

In vocal cord paralysis, nerve damage to the muscles of the voice box causes one or both of the vocal cords (also called vocal folds) to malfunction.

"When we make a sound, the vocal cords come together, and when we breathe they come apart," explains Dr. Blumin. When the cords fit together closely, they produce better sound.

Unilateral (one-sided) paralysis is more common than bilateral paralysis, in which both sets of vocal cords are involved. In unilateral paralysis, "the one good vocal cord can't quite meet the bad one, so air leaks out and the patient will have a breathy, weak, or hoarse voice," says Dr. Blumin.

In cases of bilateral vocal cord paralysis, "the paralyzed vocal cords basically get stuck together and they don't move, limiting the amount of room through which people can breathe," says Dr. Blumin, who serves as Chief of the Division of Laryngology & Professional Voice.

Causes
"The majority of patients I see come in with idiopathic vocal cord paralysis," says Dr. Blumin, meaning that there is no apparent cause for the condition. There are many possible reasons, however, including:

• Infection
• Injury to the nerves that control the vocal cords during surgery
• Trauma to the neck or chest such as gunshots, stabbings and choking
• Skull tumors
• Diseases of the nervous system

Signs and Symptoms
Vocal cord paralysis almost always results in vocal changes that can range from mild to profound, depending on the severity of the condition.

The most common issue Dr. Blumin sees with his patients is decreased vocal endurance. "They are able to speak well, but they tire at the end of a conversation or at the end of the day," he says.

A hoarse or breathy voice could indicate a more serious case of paralysis. "Some people compensate in such a way for a breathy, weak voice, that they can have a 'Minnie or Mickey Mouse sound' to their voice," says Dr. Blumin.

In severe cases of vocal cord paralysis, some patients experience airway problems and swallowing difficulties. Airway problems can cause shortness of breath with exertion, noisy breathing, and an ineffective or poor cough. Swallowing problems include choking or coughing when swallowing food, drink, or even saliva, and food sticking in the throat.

"Because of their critical biological function, we would treat breathing and swallowing problems first, before voice problems," notes Dr. Blumin. In treating patients with bilateral vocal cord paralysis, "Our goal is to get the patient's airway open enough so they can breathe through the normal route," says Dr. Blumin. "We want to minimize how much we alter the voice and swallowing."

Diagnosis
Vocal cord paralysis is usually diagnosed by an otolaryngologist - an ear, nose and throat specialist. The doctor will ask patients about their symptoms and lifestyle, listen to their voices and obtain thorough histories of any voice problems. In the office, the doctor will use an endoscope (a tube with a light at the end) to look directly into the throat. This exam helps to determine if there are any abnormalities in one or both vocal cords.

Treatment
Treatments for vocal cord paralysis can include voice therapy, surgery, or both. Voice therapy, typically the first treatment option, involves meeting with a speech therapist to learn exercises to help strengthen the vocal cords and improve breath control during speech.

Some people do well with speech therapy alone. "It won't change the nerve damage causing the paralysis, but if we can teach patients to use limited voice function better and more efficiently, they may not need further treatment," Dr. Blumin says.

If voice therapy alone does not help, doctors will talk with their patients about surgical options. According to the American Academy of Otolaryngology-Head and Neck Surgery (AAO-HNS), the decision to have surgery depends on symptoms, the cause of paralysis, if known, the vocal needs of the patient, the position of paralyzed vocal cords, and the prognosis for recovery. Surgical treatments for vocal cord paralysis can improve the ability to speak and to swallow.

Surgery may involve adding bulk to the paralyzed vocal cord or changing its position. The added bulk reduces the space between the vocal cords so the non-paralyzed cord can make closer contact with the paralyzed cord and thus improve the voice. To add bulk, a laryngologist injects a substance into the paralyzed cord. "The most common substance I use is collagen," says Dr. Blumin. "Other substances currently used are calcium hydroxyapatite (the same mineral that forms bones) and body fat."

"We may also do reinnervation surgery, where we disconnect the bad nerve, bring in a new nerve and plug it into the voice box," Dr. Blumin says. To fine-tune the voice, patients may undergo voice therapy after surgery.

Prognosis
Vocal cord paralysis can be a frustrating and sometimes debilitating condition for patients, but help is available. "The procedures that we do are all highly successful … they work about 95% of the time," states Dr. Blumin. "Many patients will heal on their own and for the ones that don't, we can offer a variety of other options, with positive outcomes."

The Medical College of Wisconsin has a very active and productive Division of Laryngology & Professional Voice. Dr. Blumin is one of fewer than one hundred doctors in the country who is Fellowship trained in Laryngology and does this type of work on a full time, day-to-day basis. "My goal is to provide patients with a special service to help them with their voices," he concludes. "I have an inherent respect for voice and for what it means to a person's identity."

This article contains information from the National Institute on Deafness and Other Communication Disorders.

Susan Hunnicut
HealthLink Contributing Writer

MCW Health News presents up-to-date information on patient care and medical research by the physicians of the Medical College of Wisconsin.