Abstract
Vocal cord dysfunction (VCD) and dysfunctional breathing (DB) disorders may mimic
or coexist with asthma, leading to overtreatment with corticosteroids with consequent
morbidity. Iatrogenic complications can be averted by early and correct diagnosis.
VCD, also termed paradoxical vocal fold motion disorder (PVFMD), is characterized
by intermittent paradoxical adduction of the vocal cords, mainly during inspiration,
leading to airflow obstruction and dyspnea. Patients with VCD may have repetitive
emergency room visits due to acute dyspnea (mimicking exacerbations of asthma). In
the seminal descriptions of VCD, young women (often with psychiatric issues) predominated;
however, other groups at increased risk for developing VCD include elite athletes,
military recruits, and individuals exposed to irritants (inhaled or aspirated). Chronic
postnasal drip, laryngopharyngeal reflux (LPR), and gastroesophageal reflux (GER)
may lead to laryngeal hyperresponsiveness. The diagnosis of VCD may be difficult because
physical exam and spirometry may be normal between episodes. During symptomatic episodes,
spirometry typically reveals variable extrathoracic airway obstruction (truncated
inspiratory flow volume loop). The gold standard for identifying VCD is flexible fiberoptic
rhinolaryngoscopy. Management of VCD includes identification and treatment of underlying
disorders (eg, chronic postnasal drip, LPR, GER, anxiety, depression) and a multidisciplinary
approach (including highly trained speech therapists). Speech therapy and biofeedback
play a critical role in teaching techniques to override various dysfunctional breathing
habits. When postnasal drip, LPR, or GER coexist, these disorders should be aggressively
treated. With successful therapy, corticosteroids can often be discontinued. During
severe, acute episodes of VCD, therapeutic strategies include heliox (80% helium/20%
oxygen), topical lidocaine, anxiolytics, and superior laryngeal blocks with Clostridium botulinum toxin.
DB is a poorly understood disorder with features that overlap with VCD and asthma.
The dysfunctional pattern may reflect abnormalities in the rate or depth of breathing
or in breathing mechanics that may involve the nasal passages, oropharynx, larynx,
or chest wall muscles. Not unlike VCD, patients with DB are often diagnosed with asthma,
and their symptoms do not improve on asthma medicines. There is no consensus regarding
diagnostic criteria or appropriate testing for DB. The pathophysiology of DB is poorly
understood, but psychological or physiological stress may precipitate episodes in
some patients. Treatment requires a multidisciplinary approach (including speech therapy
and psychological support). Prognosis is usually good.
Keywords
vocal cord dysfunction - dysfunctional breathing - asthma - upper airway obstruction
