Clinical associations in the diagnosis of vocal cord dysfunction.

Background: Diagnosis of VCD is complicated by its symptom similarities to asthma. Although clinical history, spirometry, and fiberoptic nasolaryngoscopy are used for VCD diagnosis, videostroboscopy is considered the gold standard. However, little is know about patient characteristics that might suggest a VCD diagnosis is more likely.

Objective: To identify clinical characteristics of patients suspected of having VCD that would increase the likelihood of an accurate diagnosis before videostroboscopy.

Methods: Records of 55 patients were reviewed for a cross-sectional, retrospective study. Individuals selected were suspected of having VCD because of poor clinical response to asthma medications, absence of objective criteria for diagnosis of asthma (eg, normal forced expiratory volume in 1 second without reversibility, normal exhaled nitric oxide, equivocal methacholine challenge test), or both. We used χ analyses to determine significant univariate associations of various patient characteristics. Multivariate regression analysis was then performed using those variables identified as being significant predictors by univariate analysis.

Results: A significant association between VCD and age and between VCD and shortness of breath (SOB) was found. Further analysis revealed that at ages younger than 35 years, with every 5-year decrement in age, patients suspected of having VCD in which SOB is the presenting symptom are more likely to have a positive VCD diagnosis by a factor of 1.3.

Conclusion: Clinical presentation of younger patients with SOB in conjunction with lack of objective criteria for an asthma diagnosis, poor response to asthma medications, or both is highly predictive of VCD and should prompt an objective stroboscopic evaluation to confirm the diagnosis.