Vocal fold paralysis (immobility of the vocal fold) and vocal fold paresis (impaired movement of the vocal folds) really represents several disorders all causing similar symptoms. For example, vocal fold paralysis usually results from injury to the recurrent laryngeal nerve. The recurrent laryngeal nerve is the nerve responsible for movement of the vocal fold. The paralysis that results from injury to this nerve causes symptoms of breathy hoarseness. Sometimes the vocal fold may be immobile from another reason (scar or injury to the joint) and to the observer, the result is the same – immobile vocal fold and breathy hoarseness.
Vocal fold paralysis can be unilateral or bilateral. It is very important to understand that unilateral and bilateral vocal fold paralysis differ in their symptoms, causes, treatments, and implications.
Unilateral vocal fold paralysis
Unilateral vocal fold paralysis usually has an identifiable cause. Most often it occurs as a result of surgery. Despite our best efforts to care for people who are being put to sleep for surgery, we are unable to avoid vocal fold paralysis altogether. It may result from placement of the endotracheal tube during induction of general anesthesia, result from retraction during surgery of the neck or chest, occur as a result of bleeding or direct irritation from IVs placed in the neck, or result from direct injury to the nerve during cancer resection. There are many other important causes a unilateral vocal fold paralysis including viral inflammation, neurologic diseases, and cancers.
Unilateral vocal fold paralysis usually causes breathy hoarseness. It also may cause difficulty swallowing (dysphasia) especially for thin liquids like water or coffee. The vocal folds spring apart when we breathe in and close together in the middle when we produce a voice. If one vocal fold it is not moving it is not able to meet and press tightly against the opposing vocal fold. This results in air escape and breathiness. The treatment of unilateral vocal fold paralysis involves restoring a good medial position of the vocal fold. By placing the immobile vocal fold in the midline or middle, the other vocal fold is able to tightly close against it. This is usually accomplished by injection medialization or thyroplasty. Injection medialization of the weak or paralyzed vocal fold can be performed in the office inawake patients under appropriate circumstances. Currently there is no perfect, permanent filler material. Various materials are available and are usually chosen on the clinical circumstances and the surgeon’s experience. Your surgeon should be able to discuss the various filler materials and their benefits. Thyroplasty is a surgery designed to correct the position of the vocal fold permanently. This technique may be combined with another technique called arytenoid adduction. This is a complicated topic requiring considerable experience and judgment on the surgeon’s part.
Bilateral vocal fold paralysis
Bilateral vocal fold paralysis is similar to unilateral vocal fold paralysis in that the vocal folds become immobile. The implications however are different. Since the vocal folds are no longer able to move, patients with bilateral vocal fold paralysis usually have more difficulty with moving them farther apart in order to breathe comfortably. Obviously if you feel like UR breathing through a very restrictive area with each breath, your voice may become a secondary concern. Treatment of vocal fold paralysis usually focuses on improving a person’s airway while maintaining an acceptable voice.