Vocal Cord Paralysis
Definition of Vocal Cord Paralysis
Each person is known to have two vocal cords in the voicebox or the larynx. These vocal cords normally vibrate at the moment of speaking in order to produce some voice.
Vocal cord paralysis is a type of voice disorder which occurs when either one vocal cord or both of the vocal cords failed to move, causing the person to experience certain problems of the voice such as swallowing and breathing. Single paralysis of a vocal cord is quite common, but paralysis of both vocal cords rarely happen and can be life threatening.
Image 1 – Unilateral Vocal cord paralysis (left)
Image 2 – Bilateral Vocal cord paralysis
There are various types of this vocal cord paralysis condition that differ in characteristics from each other. First is the paralysis of the bilateral vocal cord situated in a paramedian position, where the vocal cord is left in a halfway position between an open and closed point, and is not visibly moving in any other way.
Another is the paralysis of the unilateral vocal cord, which only involves one side that is paralyzed or impaired in the paramedian position or has a restricted movement. This unilateral vocal cord condition is commonly noted to occur more as compared to bilateral involvement.
Causes of Vocal Cord Paralysis
Paralysis of the vocal cord leads to distortion of the nerve impulses going to the larynx muscle. In most cases, the cause of this condition is unknown. However, there are some known causes such as an injury of the vocal cord during a surgical treatment.
A surgery that is on or close to the upper chest or the neck can cause harm to the nerves that serve the larynx. Surgeries to the parathyroid or thyroid glands, neck, and esophagus can be risky. Stroke can also be a cause since it interferes with the flow of blood in the brain and could impair the part of the brain that delivers messages to the larynx.
An injury of the chest and neck may injure the nerves that serve the vocal cords as well. Other possible causes include viral infections that causes harm to the nerves; tumors that controls the functioning of the voice box; and certain neurological conditions like Parkinson’s disease or multiple sclerosis.
Symptoms & Signs
The clinical symptoms of vocal cord paralysis can involve changes in the voice of an affected person like having a raspy and a breathy voice; breathing problems such as shortness of breath; and having troubles in swallowing due to the food that accidentally goes directly to the windpipe instead of the esophagus.
The quality of the voice may also become different by the loss of pitch or volume. The damage to both vocal cords rarely happens but if it does, it can cause acute problems with breathing.
A broad list of diseases may be the cause of damaged nerve; therefore further tests should be done to identify the exact cause. These include blood tests, CT scans, X-rays, or MRI. Both CT scans and MRI can produce high-resolution images of the voice box and neck structures.
CT scans are important in order for the condition to be fully identified through key finding at aryepiglottic folds and the true vocal cords. Other diagnosis studies are already based on the signs and symptoms.
Treatment of Vocal Cord Paralysis
Treatments for vocal cord paralysis are based on causes, severity of symptoms and time started. Treatment options may cover bulk injections, voice therapy, or surgery when necessary.
Physicians often postpone permanent surgery for a minimum of one year starting from the onset of the impairment. Nevertheless, surgery accompanied with bulk injections that has collagen-like substances is usually done within the first 3 months.
A voice therapy will be most-likely suggested during the waiting period for the surgical treatment in order to use the voice properly, while the nerves restore to healthy status.
There are several cervical procedures that are available and the most common is the repositioning of the vocal cords.
A structural implant is inserted to lead the vocal cords closer to each other and change the position of the laryngeal cartilage.
If both of the vocal cords are paralyzed, tracheotomy is needed to help breathing. Both surgical procedures are followed by additional voice therapy and measures to care for the breathing tube.
References & more information at:
What is vocal fold paralysis? What causes ? What are the symptoms? How is vocal fold paralysis diagnosed? How it is treated? What research is being done & Where can I get help? http://www.nidcd.nih.gov/health/voice/pages/vocalparal.aspx
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Yung KC, Likhterov I, Courey MS. Effect of temporary vocal fold injection medialization on the rate of permanent medialization laryngoplasty in unilateral vocal fold paralysis patients. Laryngoscope. 2011 Jul 6.
Sulica L, Rosen CA, Postma GN, Simpson B, Amin M, Courey M, et al. Current practice in injection augmentation of the vocal folds: indications, treatment principles, techniques, and complications. Laryngoscope. 2010 Feb. 120(2):319-25.