Vocal fold paralysis is a condition in which a vocal fold does not move. Normally, there are two vocal folds, both of which move from an open to a closed position to vibrate and produce sound. In vocal cord paralysis one vocal fold does not move to the closed position. The vocal cords are left unable to come together to the closed position causing hoarseness, a weak cough and even difficulty swallowing.
Vocal fold paralysis is typically due to a problem with the recurrent laryngeal nerve, the nerve that controls motion of the vocal fold. The recurrent laryngeal nerve travels from the brain, through the neck, into the chest and back to the voice box. When the nerve to the vocal fold is affected, it leaves the vocal cord immobile and paralyzed.
Causes of vocal cord paralysis include:
- Injury to the recurrent laryngeal nerve during surgery. This occurs during surgeries that take placed close to the recurrent laryngeal nerve in the brain, chest or neck.
- Thyroid surgery
- Lung Surgery
- Esophageal surgery
- Brain surgery
- Cardiac Surgery
- PDA (patent ductus arteriosus) ligation
- ACDF (anterior cervical disc fusion)
- Carotid endarterectomy
- Pressure on the nerve from a mass in the neck or chest, such as a thyroid cancer, esophageal cancer, or lung cancer.
- Swelling of the nerve for unknown reasons. This is also known as “idiopathic” vocal cord paralysis and occurs is responsible for paralysis approximately 30% of the time.
Vocal fold paralysis can cause symptoms including:
- Breathy voice
- Weak voice
- Difficulty while swallowing
- Choking while swallowing
- Sensation of “phlegm in the throat”
- Frequent clearing of the throat
- Sensation of feeling “out of breath”
The symptoms of vocal fold paralysis occur because the vocal folds are unable to meet in the midline. Sound production is weak and patients feel out of breath because they have a constant air escape from the lungs through the voice box.
The symptoms of vocal fold paralysis are not always obvious. Patients may experience varying degrees of hoarseness, from mild to severe.
Diagnosis of vocal fold paralysis is made during laryngoscopy and stroboscopy.
To evaluate for the cause of a vocal fold paralysis, a CT or MRI is used to examine the entire course of the nerve, from the skull to the chest. Occasionally a thyroid cancer, lung cancer, or even aortic aneurysm is unexpectedly diagnosed during this study and found to be causing vocal fold paralysis.
In cases in which vocal fold paralysis is potentially reversible, such as a when idiopathic, or when the nerve is inflamed (but not cut) after surgery, paralysis may resolve up to one year after injury.
If the nerve is cut, or if a year has passed since injury and the vocal cord is not moving, permanent intervention is suggested.
The treatments of vocal fold paralysis move the paralyzed vocal fold to the midline. Treatments do not restore the mobility of the vocal fold.
A vocal fold injection is a procedure in which a filling agent is injected into the vocal fold. This bulks the paralyzed vocal fold, moving it to the midline. This may be done in the office or the operating room.
A thyroplasty is a surgery in which the voice box is entered and an implant is used to push the vocal fold to the midline.
Laryngeal reinnervation is a surgery is which the recurrent laryngeal nerve is cut, and then connected to another nerve. This allows the vocal fold to strengthen, moving the vocal fold to the midline, improving symptoms.