“VCD has been described as a confounder of severe asthma. However, the influence of VCD among less severe asthmatics has not been previously studied in detail, which was the goal of the study,” says Dr. Jonathan Parsons, associate director of The Ohio State University Medical Center’s Asthma Center, and principal investigator of the study.
The study results, appearing in a recent issue of the journal Respiratory Medicine, show that VCD occurs across the spectrum of asthma severity and not only in severe asthmatics as commonly thought. The research also shows symptoms were diverse and not easily distinguished from common symptoms of asthma.
“The study highlights the need for a high index of suspicion for VCD in patients with all severities of asthma,” adds Parsons.
Vocal cord dysfunction occurs when there is abnormal movement of the vocal cords that causes obstruction of airflow to the lungs. Typical symptoms of VCD include stridor, which is described as a high-pitched sound and also a sign of respiratory obstruction, as well as hoarseness and wheezing.
Pulmonary and critical care researchers at Ohio State’s Medical Center analyzed medical records of 59 patients with pulmonologist-diagnosed asthma who were referred for testing. Seventy-five percent of the patients (44 patients) had both asthma and VCD, while 25 percent (15 patients) had a negative test. Seventy-eight percent of the patients who were referred for testing had mild-to-moderate asthma and 72 percent had VCD. Few patients from either group displayed “classic” VCD symptoms, and gastroesophageal reflux disease (GERD) and rhinitis were common in both groups.
According to Parsons, further studies are needed to better determine the impact of the diagnosis and treatment of VCD on asthma control and asthma-related quality of life. A similar trial, performed in a controlled, prospective design, would more thoroughly investigate the relationship between VCD and asthma.
Along with Parsons, other Ohio State researchers who participated in the study were Cathy Benninger, Miles Hawley, Gary Philips, L. Arick Forest and John Mastronarde.