Spirometry and provocation tests for vocal fold dysfunction diagnosis: a retrospective case series

Abstract

AIMS Vocal cord dysfunction (VCD) is characterised by paradoxical inspiratory laryngeal motion and is often misdiagnosed as asthma. Definitive diagnosis of VCD is difficult, because laryngoscopy is positive only during symptomatic episodes or upon provocation with exercise or inhaled irritants. The aims of the study were to better characterise the symptomatology of patients with VCD and to evaluate the potential usefulness of less-invasive diagnostic tools, namely provocation tests and spirometry. METHODS Retrospective case series of 84 patients with a typical clinical history of VCD, in whom at least one of the three following diagnostic tests were performed: laryngoscopy, provocation testing, or spirometry. RESULTS The mean age of the patients was 51 years and 74% were women. The principal comorbidities were rhinosinusitis (60%), gastro-oesophageal reflux disease (56%) and atopy (54%). Diagnosis of VCD was confirmed in 73/84 cases (87%), by laryngoscopy (8%), spirometry (84%) and/or provocation tests (68%). CONCLUSIONS VCD remains an underdiagnosed condition. A negative finding on laryngoscopy can lead to false negative diagnosis if it is done when the patient is asymptomatic. Here we show that a clinical suspicion of VCD, evoked by medical history, can be confirmed in many cases by less invasive diagnostic tools such as spirometry and provocation tests. Future well-conducted prospective case-control studies are needed to draw firmer conclusions and to improve the diagnostic accuracy of this condition.

Keywords

• paradoxical vocal cord motion
• extra-thoracic airway hyper-responsiveness
• Asthma
• atopy
• volume-flow loop
• mannitol challenge test