Vocal cord dysfunction (VCD) is a disorder that occurs when the vocal cords move toward each other when a person breathes, narrowing the airway and causing wheezing and difficulty breathing.
VCD is also called paradoxical vocal cord motion (PVCM).
VCD is often misdiagnosed as either asthma or exercise-induced bronchospasm.
As a result, many individuals with VCD are treated with inhalers and steroids for asthma, which do not help control VCD and which have potentially harmful side effects.
The number of people with VCD in the general U.S. population is unknown.
Several small studies have found that about 40 percent of individuals who have VCD also have asthma and that about 10 to 15 percent of individuals whose asthma does not respond to aggressive treatment (refractory asthma) actually have VCD.
VCD has been found in individuals as young as three and as old as 82.
VCD is much more common in females than in males.
In children under 18, about 85 percent of individuals diagnosed with VCD are girls.
VCD was first recognized in 1842, when it was thought that hysteria, a common designation at that time for several psychological conditions, brought about spasm of the muscles of the larynx.
By 1900, it was generally accepted that VCD was the physical expression of stress or other psychological conditions.
As of 2004, the causes of VCD was not completely clear.
The symptoms of a VCD attack are varied, but most strongly imitate those of asthma.
Its similarity to asthma, along with the fact that some people with VCD actually also have asthma, complicates diagnosis.
VCD can mimic the symptoms of severe asthma, allergic reactions (anaphylaxis), spasm of the larynx (laryngospasm), or a foreign object lodged in the throat.
VCD is often a diagnosis of exclusion, which means that other possibilities are considered first, and when these are eliminated, VCD is considered.
The best way to determine if an individual has VCD is by doing a laryngoscopy.
Individuals cannot voluntarily produce symptoms of VCD, so they are usually exposed to an irritant or undergo an exercise stress test in order to bring on a VCD attack.
Most people go through a series of other tests and often get other diagnoses, most commonly refractory (unresponsive) asthma, before they have a laryngoscopy and receive a definite diagnosis of VCD.
A methacholine provocation test, which stimulates a response in asthmatics, but not in persons with VCD, also helps narrow the diagnosis.
Speech therapy and teaching abdominal breathing techniques have been quite successful in preventing VCD attacks.
If an individual does not respond adequately to speech therapy, psychotherapy is recommended, as in many people anxiety and stress are linked to VCD attacks.
Some individuals have found biofeedback very helpful in controlling or moderating VCD attacks.
The long-term outcome for VCD is not known and probably varies among individuals depends on the underlying cause of the disorder.
Only a handful of people with VCD have been followed for 10 or more years, and all of them continued to have symptoms of the disorder.
Although the physical conditions that cause VCD cannot be prevented, individuals can be educated not to panic and to use certain breathing techniques when they begin to feel symptoms of VCD.
Many medical professionals are only marginally familiar with VCD, because this problem is much less common than asthma.
Parents may want to suggest additional testing for VCD if their child is being treated for asthma without success.
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