Vocal cord paralysis is the inability to move the muscles that control the vocal cords.
Vocal cord paralysis may affect one or both vocal cords. Females are affected more often than males. Paralysis can result from brain disorders, such as brain tumors, strokes, and demyelinating diseases, or damage to the nerves that lead to the larynx. Nerve damage may be caused by noncancerous (benign) and cancerous (malignant) tumors; injury; a viral infection of the nerves; Lyme disease; or neurotoxins (substances that poison or destroy nerve tissue), such as lead, mercury, arsenic, or the toxins produced in diphtheria.
Symptoms and Diagnosis
Vocal cord paralysis may affect speaking, breathing, and swallowing. Paralysis may allow food and fluids to be inhaled into the windpipe (trachea) and lungs. If only one vocal cord is paralyzed, the voice is hoarse and breathy. Usually, the airway is not obstructed because the normal cord on the other side opens sufficiently. When both vocal cords are paralyzed, the voice is reduced in strength but otherwise sounds normal. However, the space between the paralyzed cords is very small, and the airway is inadequate so that even moderate exercise causes difficulty in breathing and a harsh, high-pitched sound with each breath.
A doctor tries to find the cause of the paralysis. Examination of the larynx, bronchial tubes, or esophagus with a thin, flexible viewing tube may be performed. Magnetic resonance imaging (MRI) or computed tomography (CT) of the head, neck, chest, and thyroid gland and x-rays of the esophagus also may be needed.
If only one side is paralyzed, an operation can be done to move the paralyzed vocal cord to the best position for more normal speech. The operation may involve inserting an adjustable spacer near the paralyzed cord or injecting a substance into the paralyzed cord to move the cords closer together.
When both sides are paralyzed, keeping the airway open adequately is difficult. A tracheostomy (surgery to create an opening into the trachea through the neck) may be needed. The tracheostomy opening may be permanent or may be used only when the person has an upper respiratory tract infection. In another procedure, called an arytenoidectomy, the vocal cords are permanently separated, thus widening the airway. However, this procedure may worsen voice quality. Laser removal of part of one or both vocal cords is preferred to arytenoidectomy and helps widen the airway. If performed correctly, laser removal can preserve satisfactory voice quality and eliminate the need for a tracheostomy.
Last full review/revision July 2008 by Clarence T. Sasaki, MD