Vocal cord palsy
What are the vocal cords?
The vocal cords (also called vocal folds) are part of the larynx, the voice box. When we talk about the voice box everyone immediately thinks about the voice of course. The vocal cords are what produces the voice. They open and close depending on what the brain tells them to do:
-When we talk, they come close together, they vibrate and that produces the voice.
-When we breathe in, they open to allow air to travel through them, from the mouth to the lungs.
-When we eat and drink they close, because food needs to go down into the gullet and not into the lungs!
So you can see that the larynx and the vocal cords have three really important functions: breathing, voice and swallowing.
What happens in vocal cord palsy?
Vocal cord palsy means that the vocal cords are not moving, they are not opening and closing as they should be. Palsy is a general term that means that a nerve isn’t working as it should be. Because nerves tell muscles what to do, if a nerve isn’t working then the muscle linked to that nerve doesn’t work either.
There are two main types of vocal cord palsy. The first one is congenital vocal cord palsy, which means it is present from birth. The second is acquired, which means that it happens after birth.
Congenital vocal cord palsy
This is vocal cord palsy that is present at birth. Majority of the time, both vocal cords are affected; this is bilateral vocal cord palsy. The baby is noticed to have breathing difficulties immediately or shorly after birth, as well as stridor (see stridor). Sometimes the baby will have other problems as well, but sometimes vocal cord palsy will be the only issue. Often, doctors will organise a scan of the brain to check that the brain is OK, because bilateral vocal cord palsy can be caused by problems in the brain or nerves around the brain.
Bilateral vocal cord palsy in a newborn baby usually causes major breathing difficulties, requiring admission to the neonatal intensive care. Often, babies require a tracheostomy (see tracheostomy page). Some other babies manage without a tracheostomy, but may still need additional breathing support.
Over time, vocal cord palsy will hopefully recover, so that breathing improves, and the tracheostomy (if it was needed) can be removed. The timing of recovery is quite variable, and it is impossible to predict when it will happen.
If the newborn baby has major breathing difficulties, there are unlikey to be any easy alternatives to tracheostomy. But if the tracheostomy is still required after a few years, surgery to improve the airway may be a possibility.
Acquired vocal cord palsy
Majority of the time this is one sided (called unilateral). The nerve that moves the vocal cords starts in the brain, travels through the neck into the upper chest, then turns and travels back up into the neck to the voice box. It is called the recurrent laryngeal nerve. On the left side it goes further into the chest than on the right, going all the way down to the heart. Because the nerve travels through the chest and close to the heart, surgery in that area could potentially result in bruising of the recurrent laryngeal nerve on the left side.
The main problem experienced by children with one-sided vocal cord palsy is weakness of the voice. The voice sounds soft and breathy, and tires easily. Breathing is usually not a major problem.
Some children also find that when they drink, liquids go down the wrong way. This is called aspiration. Because the vocal cord isn’t moving, the child isn’t able to close the vocal cords fully, so when they drink liquids go through the vocal cords and into the chest, instead of into the gullet (in bilateral vocal cord palsy the vocal cords are usually permanently closed, so voice and swallowing are ok, but breathing is a problem).
Hopefully, one-sided vocal cord palsy would be temporary, but it can be permanent. Working with a Speech and Language Therapist is often useful, as they will help your child devlop better speech. Speech and Language Therapists are also experts in swallowing, so if your child is aspirating they will be key professionals involved in helping you manage this. If vocal cord palsy does not recover after a few months, surgery may be helpful for some children.