Vocal cord dysfunction, or more commonly known as VCD, can be a very irritating and painful problem for those it affects. Most people have never heard of it, yet it affects more people than you may realize.
This problem is commonly known as paradoxical vocal fold motion, and can be characterized as an abnormal adduction of the vocal cords during the respiratory cycle that produces airflow obstruction at the level of the larynx.
It often mimics persistent asthma, and is often treated with high-dose inhaled or systemic corticosteroids, bronchodilators, multiple emergency department visits, hospitalizations, and, in some cases, tracheostomies, and intubation. It can be quite painful, and very irritating.
The people affected by this problem are considered to have problems associated with abnormal vocal cord movement, without an organic basis. Flow-volume loops obtained during symptomatic periods of wheezing show a limitation of inspiratory flow, suggestive of variable extrathoracic obstruction.
When the patients are symptomatic, tests such as a laryngoscopy can be performed to determine the paradoxical vocal cord motion, and confirm a diagnosis. The clinical history provides limited opportunity to distinguish between patients with VCD, and patients with asthma.
This is because both groups present with symptoms of wheezing, cough, and dyspnea in most cases. The localization of airflow obstruction to the laryngeal area is an important clinical discriminatory feature in patients with this problem.
Another clinical clue may be that those with vocal cord dysfunction often seem to have refractory asthma, with poor response to beta-agonists or inhaled corticosteroids. Objectively, the data revealed an absence of hypoxemia in this subset, as compared to those who have asthma.
The way to diagnose the issue most effectively is through rhinolaryngoscopy. An abnormal chink is present along the posterior portion of the vocal cords, while the anterior portion of the vocal cords is adducted.
During the normal cycle of breath, the vocal cords partially abducts with inhalation, and partially adducts with end-exhalation. This vocal cord movement is physiologic, and it allows the unimpeded movement of air inward to the lungs, and outward to the atmosphere while maintaining the alveolar patency of the lungs by providing positive airway pressure during exhalation.
In this way, the larynx serves as an upper airway valve to help keep the lungs expanded. For this function, the larynx is richly innervated, and its size is regulated by the activation of striated muscles that are under voluntary and reflexive control.
Both laryngeal and respiratory motor neurons influence its size, and they, in turn, may be influenced by reflex activity arising from pulmonary and laryngeal receptors. The mechanisms that cause glottic chink narrowing or intermittent closing during inspiration, independent of any changes in lower airway caliber, are still unknown as of this point.
In those who are affected with this disorder, the integrated function of the vocal cords ceases episodically, leading to acute intermittent episodes of functional airway obstruction. The clinical signs and symptoms resemble those observed in disorders such as vocal cord paralysis, asthma, laryngospasm,
Recent case reports have described other causes of this issue, such as an inlet patch of heterotopic gastric mucosa in the upper esophagus, and exposure to agents such as chlorine inhalation by swimmers or divers. The problem appears to be part of the spectrum of airway disorders caused by occupational exposures, including irritant exposures and psychological stressors, at the World Trade Center disaster, for example.
A recent study evaluating the role of formal psychological testing in patients with paradoxical vocal cord dysfunction, found a pattern consistent with conversion disorder in some patients. However, a subset of patients did not appear to be associated with psychological factors at all.
The exact cause of this condition is not clearly evident, and may be the result of a number of factors, some controllable, some not. One possibility is that mediation of the vagus nerve may alter the laryngeal tone, and lower the threshold for stimuli to produce vocal cord spasm or to precipitate the abnormal adduction of vocal cords.
Recent literature suggests a greater emphasis on organic causes such as gastroesophageal reflux and laryngopharyngeal reflux, since the laryngopharynx is highly sensitive to gastric acid irritation. If you feel you may be suffering from this problem, talk to your doctor right away about your symptoms-you may be able to find a swift solution.
Tommy Greene has worked in surgical equipment sales for the past 15 years. He has great advice and information on Electrosurgery Equipment.
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