Vocal Cord Paralysis

What is vocal cord paralysis?

Vocal cord paralysis (also referred to as “vocal fold” paralysis by physicians) is a condition in which the vocal cords cannot move on one side (unilateral) or both sides (bilateral). This is usually happens when the nerve impulses to the vocal cords are interrupted.

Vocal cord paralysis often causes one vocal cord to be unable to reach the other. When this happens, there is a gap between the vocal cords (glottic gap), which can impact your child’s ability to speak and even to breath. 

Signs and symptoms

Unilateral vocal fold paralysis may lead to:

  • A breathy, weak voice
  • A weak cry in babies
  • Aspiration of liquids into the windpipe (trachea)
  • Noisy breathing (stridor)


Injury from heart surgery is the most common cause of one-sided vocal cord paralysis. More rarely, a tumor along the length of the nerve to the voice box may lead to a paralysis. Sometimes, the cause of vocal cord paralysis is unknown (idiopathic).

Vocal cord paralysis is the second most common congenital defect of the larynx (voice box), accounting for about 10 to 15 percent of congenital laryngeal disorders.

Testing and diagnosis

The diagnosis of vocal cord paralysis is usually made by laryngoscopy or stroboscopy, tests that examine the voice box.

  • Laryngoscopy: A doctor will place a spaghetti-like camera in your child’s nose and down the throat. This allows our team to look at your child’s voice box, or larynx.
  • Stroboscopy: A small, thin, flexible endoscope with a camera is gently inserted through the nose to the area in the back of the throat above the vocal cords. The study evaluates the motion of your child’s vocal cords when there are concerns regarding the strength, pitch and quality of his voice.

Most of the time, these exams can be done while your child is awake and in an office setting.

A laryngeal electromyography (EMG) may also be needed to evaluate the condition of the muscle of the vocal cords. An EMG can also help your child’s doctors see if there is a healthy nerve signal to the vocal cords or if there is chronic loss of signal (denervation).

Magnetic Resonance Imaging (MRI) of the brain, neck and chest may also be recommended if the cause of the vocal cord paralysis is not known.


In most circumstances, your child may need no immediate treatment if she is diagnosed with one-sided vocal cord paralysis.

Some children may have improvement in their vocal cord movement over time, and some have improvement in the voice from compensation of the opposite vocal cord, where the vocal cords are able to contact one another. This improves the voice and swallowing and in most cases no further treatment is needed.

When there is no adequate compensation between the two vocal cords, surgical intervention may be needed.

If your child is experiencing a weak, breathy or hoarse voice from unilateral vocal cord paralysis, we can perform procedures to make your child’s voice louder. At The Children's Hospital of Philadelphia, surgeons use two treatment approaches for single-sided paralysis:

Alternative approaches may be needed if your child is aspirating fluid into the lungs. Our speech pathologist will ensure that your child is safe from a feeding standpoint, and may recommend one of the following approaches if there is aspiration:

  • For babies younger than 1 year, we recommend dietary modifications (such as thickening foods) or placing a nasogastric tube (NG tube) to help your baby feed and grow.
  • For children closer to 3 years of age, the reinnervation procedure and injection laryngoplasty can be used for managing aspiration if the issue has not resolved. We are still developing practice suggestions for how young children can safely undergo these surgeries.


For those children who undergo a reinnervation procedure, the outlook is excellent. We have been pleased with our results at The Children's Hospital of Philadelphia.

All cases are not identical, and there may be factors that could affect the results of your child's reinnervation procedure. This would be addressed on a case-by-case basis with the family.

Some children with vocal cord paralysis will not have any related voice or swallowing issues and will have normal quality of life without treatment. However, in other children who do not undergo treatment for vocal cord paralysis, there is a significant impact on the ability to communicate: It may be hard to hear your child speak or to understand her due to a raspy or breathy-sounding voice.

Follow-up care

If your child was diagnosed with unilateral vocal cord paralysis as an infant, his follow-up care will include clinic visits approximately one month after discharge from the hospital and then every six months until he reaches about 3 years of age.

Once your child’s language skills are attained, it will be possible to evaluate your child’s voice capacity in the voice clinic. If a surgical intervention is not needed, then CHOP’s Pediatric Voice Program team will be seeing your child every six to 12 months for voice therapy.

If a surgical intervention is recommended, your child will be seen about one to two months after surgery, and then every three to six months after surgery until the voice normalizes (about 18-20 months after a reinnervation procedure).

Why choose CHOP?

Our voice team at The Children’s Hospital of Philadelphia is a dynamic multidisciplinary group of professionals with years of experience managing pediatric voice difficulties. We have one of the largest populations of pediatric patients with unilateral vocal cord paralysis who come from all over the world to our voice clinic for surgical management and voice rehabilitation.

Next Steps
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Why Choose CHOP

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