Definition
The term vocal fold paresis describes a paralysis (paresis) of the muscles that move the vocal folds in the larynx. This results in the fact that the vocal folds, which are arranged in pairs, are limited in their movement and thus speaking and possibly also breathing are made more difficult. The larynx contains a number of small muscles that are involved in the movement and tension of the vocal folds. If the nerves that control these muscles are damaged, vocal fold paresis occurs. This can occur on one side or both sides, but vocal fold paresis is an emergency due to the obstruction of the airways.
Causes
The causes of vocal fold paresis can be very diverse. Common to all of them is that as a consequence the nervous supply of the muscles involved is disturbed. The most common causes of vocal fold paresis are direct nerve damage.
The affected nerve is the laryngeal recurrens nerve (short: recurrent nerve), which is present on both sides and controls almost all laryngeal muscles of one side. During surgical interventions on the thyroid gland or the carotid artery, this nerve can be injured due to the close anatomical relationships, resulting in a so-called recurrent paresis. Therefore, this complication is always pointed out before such operations.
Other operations on the neck, such as those performed to treat tumors of the larynx or esophagus, can also damage the nerve. The tumor itself can also cause vocal fold paresis. Another cause of vocal fold paresis is a bulging of blood vessels, called an aneurysm.
Located at the carotid artery or the aorta, these can irritate the recurrens. In addition, any injury or trauma in the neck area is a possible cause of vocal fold paresis. In addition, a stroke can affect areas of the brain that control the larynx. In rare cases, inflammation and viral diseases have been observed as causes of vocal fold paresis
Symptoms
A vocal fold paresis causes a number of typical symptoms. For the proper formation of speech, the vocal folds must be completely closed, which is not possible in vocal fold paresis. The main symptom is hoarseness, which occurs in unilateral vocal fold paralysis, which is more common than bilateral vocal fold paralysis.
One side of the vocal folds functions normally, whereas the other side is paralyzed and does not resonate properly with the voice. This causes hoarseness, which can be mild or very pronounced. With bilateral vocal fold paresis, speaking is actually not possible. The bigger problem, however, is that the airways can be severely constricted or even blocked due to paralysis of both sides, which can lead to massive shortness of breath.
