Vocal cords are the tissues that help in producing sound. However, some disorders of the vocal cord can affect the sound and speech of a person. In this article, we discuss the risk factors, complications, and treatment of vocal cord paralysis.
Vocal cords are the group of membranous tissue found in the throat which has folds and project towards the lumen of the windpipe. They emerge from the wall of the larynx forming a slit. The edges of these membranes vibrate when the air passes through them to produce sound. The muscles which support the movement of these vocal cords are supplied with laryngeal nerves. These nerves are the branches of a nerve usually called a wandering nerve that is Vagus. Any kind of damage to the vocal cords and related tissues where the individual finds difficulty in producing sound or speech is called vocal cord paralysis.
Risk Factors of Vocal Cord Paralysis
Vocal cord paralysis is a result of damage to the nerves and tissues supporting them. Some people may be at great risk of getting affected more than others. Some of the risk factors of vocal cord paralysis include the following,
Some factors increase the risk of having vocal cord paralysis. It includes:
- Aging and other medical conditions like diabetes or hypertension1
- The patients who have multiple sclerosis or Parkinson’s disease are prone to this condition.
- The patients who are undergoing surgery have the chances of becoming victims of this condition. The breathing tubes inserted in such conditions sometimes may bring severe damage to the vocal cords.
- Some studies regarding cardiovascular surgery have shown that aortic procedures and prolonged operation increase the risk of vocal cord paralysis.2
Complications of Vocal Cord Paralysis
Complications of vocal cord paralysis may occur at different stages. In the mild form, the hoarse voice may be a simple irritation to the patient and also to the listener.
However, in severe forms, it also can be life-threatening. In the patients suffering from vocal cord damage, the windpipe is kept open or closed. This may result in aspiration of liquid or food which is dangerous. It can also lead to a rare but serious complication like pneumonia which expects immediate hospital support.
Causes for Vocal Cord Paralysis
Vocal cord paralysis is caused due to lesions in the vagal nerves or the laryngeal nerves. Damage to the nerves related to these vocal cords or to the brain can also cause vocal cord paralysis. There are of course different reasons for the damage to the nerve cords, which can be to causes of vocal cord paralysis. These include
Congenital Diseases: Vocal cords are affected in some congenital diseases like Arnold Chiari malformation, Moebius syndrome, tracheoesophageal fistula, Charcot Marie Tooth, hydrocephalus, etc.
Tumors as Causes for Vocal Cord Paralysis: Growth of abnormal cells in some parts of the body is called tumors. It may be cancerous or noncancerous. Tumors in vagus, thyroid, esophagus, lungs or neck region may cause paralysis of vocal cords.
Thyroid: In some diseases of the thyroid gland, like hypothyroidism, thyroiditis and/or goiter damage to the vocal cords are seen.
Injury: In some patients with intubation or who have recently had surgery for the thyroid gland, vagal nerve stimulator implantation or any kind of trauma to the neck region damages the vocal cords.
Infections: Some viruses causing Epstein Barr disease, Lyme disease and herpes are found to damage the vocal cords leading to paralysis in several conditions.
Symptoms of Vocal Cord Paralysis
The commonest symptoms of vocal cord paralysis include,
- Hoarseness of voice
- Breathing would induce sound
- Difficulty in coughing
- Loss of vocal pitch
- Frequent breaths in between speech
- Inability to speak loudly
- Feeling like clearing the throat frequently
- Inability to remove the mucus secretion in the larynx
Treatment of Vocal Cord Paralysis
Treatment of vocal cord paralysis depends on the causes, symptoms, and the severity of damage occurred. Some of the treatment modalities for vocal cord paralysis include:
Medications: In case of damage of vocal cords during infections, medications can be given to reduce the symptoms. The infection usually resolves after running its course.
Diaphragmatic Breathing: Treatment of vocal cord paralysis may also include training in breathing. Some professions depend upon the speech and voice of individuals. In these professions, damage to the voice is not expected. Such cases are trained well to support breathing. Actually, the awareness of breathing is shifted to the diaphragmatic region which reduces the risk of over functioning of vocal cords and to minimize the stress given to muscles.
Building Sub-glottal Pressure: This method involves building up of pressure below the folds of vocal cords prior to the pronunciation of a vowel.
Tongue and Lip Trills: It helps in coordinating the muscles for using different functions like phonation, articulation, and respiration.
Half-swallow Boom: Here, the patient takes a breath and then performs the act of swallowing by forcefully saying ‘boom’. This produces a clear and loud sound. This helps for bringing back the vocal cords to the normal position.
Voice Therapy: The over functioning of glottis muscles is checked in this therapy by narrowing the passage of glottis. This therapy aims at improving muscle strength and abdominal support.
Surgery: As a last resort, surgery is considered, when none of the therapies help in improving the condition. This procedure involves the injection of several materials to keep the folds to the midline of the glottis. The common materials used during this therapy are collagens, hydroxyapatite, autologous fat, hyaluronates, and Teflon. The doctor selects the required material depending on various factors. Generally, voice therapy is done after the swelling subsides mostly 1 to 2 months of surgery. Voice therapy in the post-surgical stage is required to restore the coordination of the muscles and to increase muscle strength.
Vocal cords are very essential in verbal communication, phonation, and particularly of more importance in certain professions. Being aware of the risk factors, complications, and treatment of vocal cord paralysis helps to deal with the condition better. It is difficult to communicate comfortably when they are damaged. Hence it is very essential to keep the vocal cords in good condition. Taking care of the vocal cords and avoiding infections is the best way to keep them healthy.