Vocal Cord Dysfunction (VCD)
DC 6516Medical Rationale
Vocal cord dysfunction (VCD), or paradoxical vocal fold motion (PVFM), develops in 19-50% of patients with difficult-to-control asthma. The mechanism involves laryngeal hyperresponsiveness triggered by chronic airway inflammation, inflammatory mediators from the lower airways sensitize vagal afferent C-fibers in the laryngeal mucosa, producing reflexive paradoxical adduction of the vocal folds during inspiration. Additionally, chronic cough from poorly controlled asthma causes mechanical trauma to the vocal folds, producing edema and contact granulomas that alter airflow dynamics and promote abnormal fold motion. Gastroesophageal reflux, highly prevalent in asthma patients, further irritates the posterior larynx and exacerbates VCD. VCD presents with inspiratory stridor, throat tightness, and dyspnea that is frequently misdiagnosed as refractory asthma.
Key Studies
Newman KB et al. (1995) Am J Respir Crit Care Med (VCD in asthma patients, clinical features); Morris MJ et al. (2006) Respir Med (vocal cord dysfunction in military populations, prevalence and diagnosis).
Filing Tips
Laryngoscopy during a symptomatic episode documenting paradoxical vocal fold adduction during inspiration (gold standard diagnosis). Pulmonary function testing with inspiratory flow-volume loop showing truncated inspiratory limb. Speech-language pathology evaluation. Pulmonology or ENT nexus letter addressing the laryngeal hyperresponsiveness mechanism linking asthma to VCD. Note the Morris et al. (2006) study specifically documenting VCD prevalence in military populations. File under DC 6516 (laryngitis, chronic) or consider under respiratory disability.
