VOICE, LARYNX & SWALLOWING
Vocal Cord Paralysis
Your voice is produced when you breathe out whilst at the same time moving your vocal cords closer together. As the air from your lungs pushes past your vocal cords it makes them vibrate and they make a noise. This noise is “shaped” by the muscles in your throat and by your tongue, teeth and lips to produce your voice. The vocal cords also play a vital role in preventing foods and fluids form passing into your lungs when you swallow, closing tightly together when swallowing and moving wide apart when you breathe.
Movement of your vocal cords is controlled by 2 sets of nerves, the superior and recurrent laryngeal nerves. The recurrent laryngeal nerves supply most of the important muscles for speech, breathing and swallowing. If these nerves stop working, you may have difficulties with your voice or with breathing and swallowing.
The exact symptoms depend on which nerves are affected and whether they are affected on one side (Unilateral Vocal Cord Paralysis) or both sides ( bilateral vocal cord paralysis).
What are the symptoms of vocal cord paralysis?
Unilateral vocal cord paralysis symptoms can range from mild to severe. Most of the problems are caused because the vocal cords are unable to close tightly together for speech.
Symptoms include:
- Hoarseness
- Inability to speak loudly
- Breathiness of the voice
- Voice that tires easily
- Decreased vocal range
- Choking or coughing while eating
- Aspiration pneumonia (if food or liquid reaches the lungs)
Bilateral Vocal Cord Paralysis is less common, but when it occurs it can be fatal unless treated promptly. The main symptom is difficulty breathing, often with a noisy whistling type of breathing called stridor.
What causes vocal cord paralysis?
Damage to the recurrent laryngeal nerves is the most common cause of vocal cord paralysis. The vagus nerve is an important nerve that originates at the base of your brain. This nerve supplies the vocal cords, via a branch called the recurrent laryngeal nerve an extremely long nerve that is given off in your chest and then passes back up behind the thyroid gland to supply the larynx If there is damage to either the vagus or laryngeal nerve on one side, it may result in vocal cord paralysis on that side. The left recurrent nerve is longer and is therefore more at risk from disease or injury in the chest, making left recurrent laryngeal nerve paralysis more common than right.
Causes of unilateral vocal cord paralysis include:
- Damage during surgery, Thyroid operations, Cervical spine operations, Cardiac and aortic operations can all damage the nerve.
- Cancer in either the neck, thyroid, oesophagus or lung.
- Idiopathic - in many cases no cause is found (idiopathic vocal cord paralysis) most of these cases are caused by a viral infection of the nerve.
Causes of bilateral vocal cord paralysis:
- Neurological Conditions often in combination with swallowing problems.
- Stroke.
- Surgery - usually thyroid surgery.
Restricted vocal cord movement is not always caused by nerve damage. Some patients with rheumatoid arthritis develop problems with the joints that are needed to open and close the vocal cords normally.
How is vocal cord paralysis diagnosed?
Flexible laryngoscopy is used to view and take high-resolution photographs of your vocal cords. Laryngoscopy is done using a thin tube with a camera at the end, which is inserted through your nostril.
Dr McGuinness is also able to perform video stroboscopy during your consultation. Video stroboscopy uses specialised technology to record vibrations of the vocal cords which are too rapid to be seen with the human eye. Video stroboscopy provides extremely precise information about vocal cord movement and is only done by a handful of specialists in New South Wales.
An electrical examination of the laryngeal nerves called an Electromyogram (EMG) may also be recommended. This test measures the electrical currents in the muscles that supply your vocal cords. If one or both of the vocal cords is not moving properly, an underlying cause is sought. Unless the cause is obvious, for example a recent surgical procedure, it is important to rule out a mass or tumour along the course of the Laryngeal nerves and a CT or MRI scans may be required.
How is unilateral vocal cord paralysis treated?
Treatment of vocal cord paralysis depends on the severity of your symptoms. Treatment options include:
- Voice therapy - Voice therapy can help to improve breath control and strengthen your voice.
- Injection medialisation - A minor procedure where Dr McGuinness injects a small amount of a “filler” called Restylane ( commonly used as a wrinkle treatment) into the paralyzed vocal cord which plumps it and pushes it nearer to the middle. This makes it easier for the working vocal cord to contact it and produce a strong voice. Injection medialisation lasts 3- 6 months before the filler is absorbed.
- Thyroplasty surgery - If the problem is likely to be a permanent one, Dr McGuinness may recommend a procedure called medialisation thyroplasty. This a day procedure where a window is cut into the laryngeal cartilage using a micro-drill and a permanent implant inserted to “push” the paralyzed cord towards the middle producing a stronger voice.
Voice problems require the attention of an experienced specialist, who understands the importance of your voice. As a voice expert, Dr McGuinness is well equipped to diagnose and manage vocal cord problems.