What is Vocal Cord Paralysis?
Vocal Cord Paralysis is a pathological condition of the larynx or the voice box in which there is disruption of nerve impulses which carry information to and from the brain to the larynx resulting in paralysis of the muscles of the vocal cords. Vocal Cord Paralysis is a serious condition in the sense that it can affect an individual's ability to speak and in some cases even breathe normally. This is because the vocal cords not only produce sound but also prevent foreign debris like food, water, saliva from entering into the airway passage of the wind pipe which if it does may cause an individual to choke.
Vocal cord paralysis can occur due to a variety of reasons to include nerve damage during surgery, viral infections, or certain forms of cancers. The most preferred form of treatment for vocal cord paralysis is surgery. Apart from this speech therapy is also of great value in treatment of vocal cord paralysis.
What Causes Vocal Cord Paralysis?
As stated above, Vocal Cord Paralysis is caused due to disruption of nerve impulses in the larynx or the voice box causing paralysis of the vocal cord muscles. There is no one specific cause in regard to this but there are various factors which may result in nerve damage resulting in vocal cord paralysis. These factors are:
Vocal Cord Paralysis Caused Due to Vocal Cord Injury: The nerves in the vocal cord may get injured or damaged as a result of some surgery done around the region such as the surgery done near the neck or the upper half of the chest can result in damage to the nerves going to the larynx causing disruption of the nerve impulses resulting in Vocal Cord Paralysis. Some other surgeries which can cause Vocal Cord Paralysis are surgeries to the thyroid glands and the esophagus.
Vocal Cord Paralysis Caused Due to Neck and Chest Injury: Any type of trauma or injury to the neck or chest area such as a stab or a gunshot wound due to an altercation, a severe motor vehicle crash may result in nerve damage to the nerves serving the larynx.
Stroke: Stroke is yet another cause for Vocal Cord Paralysis. As a result of stroke there is interruption of blood flow to the brain and may result in damage to that part of the brain which sends signals to the larynx resulting in Vocal Cord Paralysis.
Tumors: Certain type of tumors both malignant and benign which may grow around the muscles of the vocal cords may also cause Vocal Cord Paralysis.
Viral Infections: There are certain viral infections which may also cause Vocal Cord Paralysis. These viral infections are Lyme disease, Epstein-Barr and herpes.
What are the Symptoms of Vocal Cord Paralysis?
The vocal cords contain two bands of muscle tissue which are located at the tip of the trachea. These bands of muscle tissue come close together to produce a sound when an individual speaks and are separated otherwise. In Vocal Cord Paralysis, only one vocal cord gets paralyzed and is not able to function. In case of both the vocal cords get paralyzed then the affected individual will not only have trouble speaking but will also have trouble breathing and swallowing. Some of the symptoms of Vocal Cord Paralysis are:
- Hoarseness of voice
- Noisy breathing
- Loss of pitch when speaking
- Choking while swallowing food or drinking water
- The need to take frequent breaths when speaking
- Inability to speak in a louder tone
- Needing to clear the throat frequently.
How is Vocal Cord Paralysis Diagnosed?
In order to diagnose Vocal Cord Paralysis, the physician will first take a detailed history of the symptoms and based on the history and the severity and duration of the symptoms the following tests may be done to confirmatively diagnose Vocal Cord Paralysis. These tests are:
Laryngoscopy: This is a test done to look at the internal structures around the vocal cords and evaluate the vocal cords to look for signs of paralysis. In this procedure a flexible tube with a camera is inserted through the mouth to the tip of the trachea. The images of the vocal cords will be seen clearly on the monitor via the camera and the physician will be able to easily determine the movement of the vocal cords and determine if one or both the vocal cords are damaged or paralyzed.
Laryngeal Electromyography: This test gives information as to how severe the damage is done to the vocal cords and what will be the prognosis of the patient and whether he or she will be able to recover from this injury. This test does not in any way change the treatment course for the patient. This test is done by inserting needles through the neck into the vocal cords and passing electric charges through the vocal cords and measuring the readings.
Additionally, there may be blood tests and advanced imaging in the form of CT and MRI scans done to look at the internal structures so as to identify the cause of Vocal Cord Paralysis.
How is Vocal Cord Paralysis Treated?
The treatment for Vocal Cord Paralysis is quite complex and depends on the duration and severity of the symptoms. The treatment may include voice therapy, injections to increase the bulk of the paralyzed vocal cords, surgery and in some cases a combination of all these. There have been some cases where an individual gets relief of symptoms without requiring any form of surgery and hence it is the norm for every physician to delay surgery for Vocal Cord Paralysis for at least up to a year to see whether symptoms get better on with noninvasive treatments.
While the individual awaits surgery for Vocal Cord Paralysis, the physician may send the patient to voice therapy where the patient is taught exercises which strengthen the vocal cords and improves breathing while speaking. It also helps protect the wind pipe when swallowing while the paralyzed nerve is in the process of healing. In some cases, this is all the patient requires and once the nerve heals the patient regains the normal voice.
Another form of treatment for vocal cord paralysis is increasing the bulk of the vocal cord that has been paralyzed. This is done injecting the vocal cords with collagen, fat and other materials which increase the bulk of the paralyzed vocal cord and moves closer to the normally working vocal cord during speaking, breathing, and swallowing and making it much easier to do these things. This form of treatment is called Bulk Injections.
Thyroplasty: This is a surgical procedure in which an implant is used in the vocal cord to reposition the paralyzed vocal cord and bringing it closer to the unaffected vocal cord during speaking and swallowing.
Nerve Replacement: In this procedure, the damaged nerve of the vocal cord is replaced by replacing it with a healthy nerve from some other region of the body. Postsurgery, it may take as long as a year for the quality of the voice to improve with this procedure.
Tracheotomy: This is a procedure done exclusively for patients with both vocal cords paralyzed due to which they have trouble breathing. In this a hole is made just above the trachea thus allowing the air to bypass the paralyzed vocal cords and allowing the patient to breathe normally despite Vocal Cord Paralysis.