What is vocal fold paralysis?
Vocal fold paralysis is the most common neurogenic (arising from the nerves) voice disorder. Vocal fold paralysis may be unilateral (one-sided) or bilateral (both sides) and is most commonly caused by nerve involvement of the recurrent laryngeal nerve, or, occasionally (but less commonly) by the superior laryngeal nerve. The location and type of injury along the nerve pathway will determine the type of paralysis and the resultant voice quality.
What causes vocal fold paralysis?
There are many possible causes of vocal fold paralysis, including:
- surgical trauma
- cardiovascular disease
- neurological diseases
- accidental trauma
Additionally, about 30 to 35% of vocal fold paralyses have no known cause. In many of these cases, patients report that hoarseness began following a viral infection or a slight feeling of illness.
What are the symptoms of vocal fold paralysis?
Patients with vocal fold paralysis often complain of vocal fatigue as well as physical fatigue, which is the result of the increased effort to produce voice and the loss of air while voicing due to incomplete glottis closure.
Patients with unilateral vocal fold paralysis will have varied vocal symptoms, which may include:
- mild to severe hoarseness (dysphonia)
- low intensity of the voice
- low pitch to the voice
- breaks in voicing
Patients with bilateral vocal fold paralysis may have additional symptoms depending on where their vocal folds are paralyzed.
Those whose vocal folds are paralyzed in the abducted (open) position will present with essentially no voice or a whisper/breathy quality. They will feel very winded when trying to speak as air is leaking through their vocal folds. Additionally, these patients almost always have difficulty eating/drinking thin liquids or thinner foods (such as soups) as they tend to aspirate (go down their wind pipe). The vocal folds are supposed to be the first layer of protection for the airway, but a patient with a bilateral vocal fold paralysis in the open position cannot close their vocal folds for protection during swallowing.
Patients with a bilateral paralysis in the adducted position (closed position), may present with improved voice quality, but will likely have significant difficulty breathing as they cannot open their vocal folds to take a breath in, depending on the glottic opening (airway size) left from the paralysis. This can be life threatening and these patients will likely require a tracheostomy to breathe.
How is vocal fold paralysis treated?
Treatment for unilateral paralysis can vary greatly, depending on the location of the paralyzed vocal fold and the effect it is having on the patient’s quality of life. Treatment ranges from voice therapy to temporary surgical management to permanent surgical management. These decisions will be made with a skilled surgeon.
For both types of bilateral paralysis, surgical management is almost always required to improve quality of life for voicing and ensure swallowing and breathing.