Medical Edge Newspaper Column

If Vocal Cords Are Paralyzed, Botox Won't Help

May 9, 2008
Dear Mayo Clinic:
Is there anything on the horizon to correct vocal cord nerve damage following repair of an aortic aneurysm? My son has never recovered full use of his voice following surgery. I have heard that there may be some success using Botox.

Answer:
Your son probably has left-sided vocal cord paralysis. The vocal cord can no longer move or moves only slightly. The nerve that controls the vocal cord on the left runs directly underneath the aortic arch and loops around the bottom of it. That nerve probably was injured during the repair of his aorta.

The vocal cords are two flexible bands of muscle tissue that sit at the entrance to the windpipe (trachea). They consist of two parts. The front part of the vocal cord is soft tissue and muscle, and the back portion is cartilage. When you speak, the bands of muscle come together and vibrate to make sound. When you're silent, the vocal cords are relaxed in an open position, so you can breathe.

A vocal cord that is paralyzed in a closed position reduces airflow into the lungs and may make breathing difficult. Often, patients will describe feeling breathless or that they run out of air when speaking. If the vocal cord is paralyzed in an open position, the voice can sound breathy, hoarse or weak.

I suspect your son's left vocal cord has been paralyzed in the open position, far off the midline. This means that when he tries to speak, the right vocal cord moves to the middle, but the left does not. An opening between the vocal cords remains, and speaking with a strong voice becomes impossible.

Many people with this problem also may have difficulty swallowing. The reason is that, in addition to producing sound, the vocal cords also protect your airway by closing when you swallow to prevent food and drink from entering the windpipe.

If your son's surgery was more than six months ago, he likely has recovered as much of his vocal cord function as possible. If it hasn't been six months, I'd recommend waiting to pursue treatment until that time. He may see some additional improvement.

Botulinum toxin type A (Botox) may be used to treat some voice disorders, but it is rarely used to treat a nerve injury. In this instance, Botox won't help because it blocks the signal from a nerve to a muscle. Very likely, your son already has nerve paralysis on the left side, so blocking more nerve impulses will not improve his condition. Voice therapy, an effective treatment for some voice disorders, also will not be effective with vocal cord paralysis.

For your son's situation, surgery is the most viable treatment option. Although it can't restore normal movement, surgery can move the paralyzed vocal cord closer to the midline. The vocal cord that still moves can then hit against it, closing the airway and allowing the voice to sound stronger. The procedure will also help improve swallowing.

— Nicolas Maragos, M.D., Otorhinolaryngology, Mayo Clinic, Rochester, Minn.