Vocal cord dysfunction (VCD) syndrome, a notorious asthma mimic, was first described in 1983 by doctors from the National Jewish Hospital in Denver, Colorado.
VCD is the result of abnormal paradoxical vocal cord movement. Humans have two vocal cords located in the larynx, or voice box, which is an organ in the upper neck. The vocal cords are crucial to speech and sound production. The two vocal cords come together in a V-shaped configuration and are joined at the base of the V. The anatomy of the cords permits them to move closer together, closing the V-shaped space between them.
When you breathe in, the vocal cords assume an even wider V shape and spread further apart to allow air into the trachea and lungs. In active VCD, however, the vocal cords close instead of opening normally during inspiration. Because the cords swing together instead of moving apart, the flow of air into the trachea and lungs becomes compromised. Wheezing occurs as air is forced through the abnormally narrowed vocal cord opening. Other symptoms of VCD include a change in voice quality, hoarseness, throat or chest tightness, and difficulty swallowing.
VCD is often misdiagnosed as asthma, especially as difficult-to-control, or refractory, asthma. Clues to its diagnosis include non-response to asthma treatment, a preponderance of throat and voice symptoms, as well as the absence of nocturnal symptomatology that is so characteristic of asthma. VCD can occur in childhood, adolescence, or adulthood, but is more common in people who are in their 20s to 40s. In younger patients, VCD may occur during competitive sports and seems to have an association with a driven or high-achieving personality style. Psychological factors may be important in adults as well. Among adult patients, women pre-dominate, as do female healthcare workers, for reasons that are not understood.
If VCD is suspected, referral to a specialized center familiar with diagnosis and treatment of VCD should be strongly considered. It is especially important to deter-mine whether VCD is present alone, or whether there is a dual diagnosis of asthma and VCD, as they can occasionally exist together. Treatment of VCD includes dis-continuance of any non-indicated medication, particularly steroids. Specialized speech therapy is the mainstay of treatment and is accompanied, when appropriate, by relaxation exercises and psychological support.