Diagnostic criteria for the classification of vocal cord dysfunction

Vocal cord dysfunction (VCD) is a syndrome characterized by paroxysms of glottic obstruction due to true vocal cord adduction resulting in symptoms such as dyspnea and noisy breathing. Since first described as a distinct clinical entity in 1983, VCD has inadvertently become a collective term for a variety of clinical presentations due to glottic disorders. Despite an increased understanding of laryngeal function over the past 25 years, VCD remains a poorly understood and characterized entity. Disparities in the literature regarding etiology, pathophysiology, and management may be due to the historic approach to this patient population. Additionally, disorders clearly not due to paroxysms of true vocal cord adduction, such as laryngomalacia, vocal cord paresis, and CNS causes, need to be differentiated from VCD. Although a psychologic origin for VCD has been established, gastroesophageal reflux disease (GERD), nonspecific airway irritants, and exercise have also been associated with intermittent laryngeal obstruction with dyspnea and noisy breathing. VCD has been repeatedly misdiagnosed as asthma; however, the relationship between asthma and VCD is elusive. There are numerous case reports on VCD, but there is a paucity of prospective studies. Following an in-depth review of the medical literature, this article examines the available retrospective and prospective evidence to present an approach for evaluation of VCD including: (1) evaluation of factors associated with VCD, (2) differential diagnosis of movement disorders of the upper airway, and (3) clinical, spirometric, and endoscopic criteria for the diagnosis.