Reviews and feature articles

Use of videography in the diagnosis of exercise-induced vocal cord dysfunction: A case report with video clips

The first practice parameter on exercise-induced bronchoconstriction (EIB) was published in 2010. This updated practice parameter was prepared 5 years later. In the ensuing years, there has been increased understanding of the pathogenesis of EIB and improved diagnosis of this disorder by using objective testing. At the time of this publication, observations included the following: dry powder mannitol for inhalation as a bronchial provocation test is FDA approved however not currently available in the United States; if baseline pulmonary function test results are normal to near normal (before and after bronchodilator) in a person with suspected EIB, then further testing should be performed by using standardized exercise challenge or eucapnic voluntary hyperpnea (EVH); and the efficacy of nonpharmaceutical interventions (omega-3 fatty acids) has been challenged. The workgroup preparing this practice parameter updated contemporary practice guidelines based on a current systematic literature review. The group obtained supplementary literature and consensus expert opinions when the published literature was insufficient. A search of the medical literature on PubMed was conducted, and search terms included pathogenesis, diagnosis, differential diagnosis, and therapy (both pharmaceutical and nonpharmaceutical) of exercise-induced bronchoconstriction or exercise-induced asthma (which is no longer a preferred term); asthma; and exercise and asthma. References assessed as relevant to the topic were evaluated to search for additional relevant references. Published clinical studies were appraised by category of evidence and used to document the strength of the recommendation. The parameter was then evaluated by Joint Task Force reviewers and then by reviewers assigned by the parent organizations, as well as the general membership. Based on this process, the parameter can be characterized as an evidence- and consensus-based document.

Belastungsinduzierte asthmatische Symptome und Asthma werden häufig bei hochtrainierten Athleten diagnostiziert. Ein belastungsinduziertes Asthma (EIA) und eine belastungsinduzierte Bronchokonstriktion (EIB) treten, je nach Sportart, in 15-45% aller Hochleistungssportler auf. Das EIA tritt nicht selten auch zusammen mit einer Vocal Cord Dysfunktion (VCD) in Erscheinung, die auch eigenständig als Differentialdiagnose in Betracht gezogen werden muss. Die Therapie basiert auf antiinflammatorischer Medikation (inhalative Glukokortikosteroide) und inhalativen Bronchodilatatoren (z.B. ß2-Agonisten). Im Allgemeinen dürfen, gemäß der Verbotsliste der Welt-Anti-Doping-Agentur (WADA), ß2-Agonisten bei Sportlern nicht zur Anwendung gelangen. Allerdings enthält die WADA-Liste spezifische ß2-agonistische Substanzen, die zur inhalativen Therapie verwendet werden dürfen.

Exercise induced asthma- like symptoms and asthma are frequently seen in highly trained athletes. Exercise induced asthma (EIA) and exercise induced bronchoconstriction (EIB) are estimated to be found in 15-45% of elite athletes. EIA is often experienced concurrently with vocal cord dysfunction (VCD), which needs to be considered as a differential diagnosis, in combination as well as a stand-alone diagnosis. The therapy is based on anti-inflammatory drugs (e.g. inhaled glucocorticosteroids) and inhaled bronchodilators (e.g. ß2-agonists). Generally, athletes may not use ß2-agonists according to the Prohibited List of the World Anti-Doping Agency (WADA). However, the WADA-List contains specific ß2-agonistic substances which are permitted to be used by inhalation.

La dysfonction des cordes vocales (DCV) correspond à une adduction paradoxale non intentionnelle des cordes vocales. Le diagnostic passe par la réalisation d’une laryngoscopie sus-glottique. Il n’existe pas de critères précis pour le confirmer avec certitude. L’objectif de ce travail était d’évaluer une méthode simple d’analyse du comportement des cordes vocales à l’effort permettant d’établir le diagnostic de DCV l’exercice.

Cette étude monocentrique, prospective, a été réalisée entre avril 2012 et mars 2013. Le critère d’inclusion principal était l’existence d’un asthme mal contrôlé avec dyspnée d’effort inexpliquée. Quinze patients ayant un asthme mal contrôlé (13 femmes et 2 hommes) ont été inclus et les données recueillies ont été comparées à celles de patients dyspnéiques non asthmatiques (groupe témoin). Le bilan réalisé comportait une exploration fonctionnelle à l’exercice ainsi qu’une endoscopie sus-glottique sur bicyclette avec mesure de l’angle d’ouverture des cordes vocales (AOCV) à différents temps de l’effort, à l’aide d’un logiciel permettant de définir des critères endoscopiques pour le diagnostic de DCVIE.

L’endoscopie sus-glottique sur bicyclette était parfaitement tolérée. L’analyse du groupe témoin permettait de définir la valeur normale de l’AOCV (> 49°). Les patients asthmatiques avaient des valeurs de l’AOCV maximal au temps inspiratoire plus basses que les témoins à partir de 50 % de la puissance maximale atteinte (respectivement, 52,8 ± 13,3° et 64,5 ± 8,3°). Quatre patients asthmatiques (26 %) avaient une DCV avec un AOCV au pic de l’effort inférieur à 49°.

L’apport de données objectives avec la mesure de l’AOCV est une nouvelle approche simplifiée dans l’exploration de la DCV. La prévalence de DCV à l’exercice chez les patients asthmatiques mal contrôlés est importante (26 % dans notre série). La DCV, sous-diagnostiquée, est probablement un facteur aggravant la maladie asthmatique, son diagnostic et sa prise en charge permettent d’éviter l’escalade thérapeutique des patients asthmatiques concernés. La DCV fait partie des facteurs d’aggravation de l’asthme. Cette méthode d’analyse du comportement des cordes vocales à l’exercice permet de l’objectiver avec précision.

Vocal cord dysfunction (VCD) is an under-recognized cause of dyspnea and is difficult to diagnose. The symptoms caused by exercise-induced VCD (IEVCD) often falsely suggest asthma, but there is sometimes a real association between the two diseases. The objective of this study was to evaluate a new, simple method for analyzing vocal cord behavior in the diagnosis of IEVCD, and to clarify the prevalence of IEVCD in an uncontrolled asthma population with unexplained exertional dyspnea.

This single-center study was conducted prospectively between April 2012 and March 2013. The main inclusion criterion was uncontrolled asthma with unexplained dyspnea. The assessment included cardiopulmonary exercise testing and supraglottal laryngoscopy during exercise with measurement of the vocal cord-opening angle (VCOA).

Data from 15 asthmatic patients were compared with those from 10 non-asthmatic dyspneic patients (controls) to define specific criteria for the endoscopic diagnosis of IEVCD.

Endoscopy during bicycle exercising was well tolerated. Normal value of inspiratory VCOA (itVCOA) was > 49°. Values for the itVCOA were lower for asthmatics than for controls when exercising at 50% maximal power (52.8° ± 13.3° and 64.5° ± 8.3°, respectively). Four of the 15 asthmatics (26%) demonstrated IEVCD characterized with itVCOA_peak of less than 49°.

Measurement of VCOA represents a new, simple method for obtaining objective data in the exploration of VCD. The prevalence of IEVCD in uncontrolled asthmatic patients is important (26% in our small sample). IEVCD is probably an under-diagnosed aggravating factor in asthma, and its diagnosis and management could avoid the therapeutic climbing in asthma. This method of analysis may help to accurately and objectively assess vocal cord dysfunction.

Vocal cord dysfunction (VCD) is a respiratory disorder characterized by inappropriate vocal cord adduction during inspiration. The diagnosis of VCD is challenging, because expected flow volume loop abnormalities are uncommonly noted, and laryngoscopy must be timed to coincide with symptoms.

We wanted to determine the potential role of impulse oscillometry (IOS) in the diagnosis of VCD.

We conducted an analysis of six patients in which the diagnosis of VCD was being considered as well as seven healthy subjects and five subjects with asthma. All were evaluated with IOS and spirometry, and patients underwent laryngoscopy. Two patients with suspected VCD who did not exhibit symptoms or abnormal pulmonary function at baseline underwent exercise challenge and repeat studies. One patient with suspected VCD underwent an additional irritant challenge.

VCD was diagnosed by laryngoscopy in three of the six patients in whom the diagnosis of VCD was entertained. These three patients as a group all exhibited higher amplitude (mean, 9.3 cm H₂0/L/second) and more variable spikes (SD, 4.8 cm H₂0/L/second) on IOS impedance during inspiration, whereas the three patients in whom the diagnosis was not confirmed by endoscopy did not show these findings (mean, 2.0 cm H₂0/L/second; P < .0002; SD, 0.8 cm H₂0/L/second; P < .0001). This pattern was also not observed in the healthy volunteers (mean ± SD, 1.8 ± 0.7 cm H₂0/L/second) and patients with asthma at baseline (mean, 4.2 ± 1.2 cm H₂0/L/second) or after exercise challenge (mean, 1.5 ± 0.5 cm H₂0/L/second).

These findings support the conclusion that IOS displays a characteristic pattern in patients with VCD and thus may offer a rapid and noninvasive adjunct to the assessment and diagnosis of patients suspected to have this disorder.