Vocal-cord dysfunction presenting as asthma

Vocal cord dysfunction in children

Vocal cord dysfunction is characterised by paradoxical vocal cord adduction that occurs during inspiration, resulting in symptoms of dyspnoea, wheeze, chest or throat tightness and cough. Although the condition is well described in children and adults, confusion with asthma often triggers the use of an aggressive treatment regimen directed against asthma. The laryngoscopic demonstration of vocal cord adduction during inspiration has been considered the gold standard for the diagnosis of vocal cord dysfunction, but historical factors and pulmonary function findings may provide adequate clues to the correct diagnosis. Speech therapy, and in some cases psychological counselling, is often beneficial in this disorder. The natural course and prognosis of vocal cord dysfunction are still not well described in adults or children.

Asthma exacerbations. 5: assessment and management of severe asthma in adults in hospital

It is difficult to understand why there is such a huge discrepancy between the management of severe asthma recommended by evidence-based guidelines and that observed in clinical practice. The recommendations are relatively straightforward and have been widely promoted both in guidelines and reviews. Specialist physicians need to be more proactive in their implementation of such guidelines through the use of locally derived protocols and assessment sheets, reinforced by audit. The common occurrence of severe asthma and its considerable burden to the community would support such an approach.

Respiratory retraining therapy and management of laryngopharyngeal reflux in the treatment of patients with cough and paradoxical vocal fold movement disorder

OBJECTIVES

We describe the outcome of patients with cough and paradoxical vocal fold movement disorder (PVFMD) treated with respiratory retraining therapy and management of laryngopharyngeal reflux (LPR).

METHODS

Twenty patients with the complaint of cough were given a diagnosis of PVFMD and treated with proton pump inhibitors for a minimum of 6 months followed by 3 to 5 sessions of respiratory retraining therapy. Pulmonary function testing (PFT) and subjective rating of cough and reflux (reflux symptom index; RSI) were performed. Also, PFT and rating of cough were performed on a group of 10 healthy volunteers with no complaint of cough.

RESULTS

The study group comprised 13 women and 7 men. The baseline cough rating and ratio of forced inspiratory volume at 0.5 second to forced inspiratory vital capacity (FIV0.5/FIVC) on PFT were significantly worse in the treatment group than in the control group. After therapy, 20 patients (100%) experienced improvement in cough, 19 patients (95%) experienced improvement on PFT, and 17 patients (85%) experienced improvement in the RSI score. The differences were statistically significant.

CONCLUSIONS

Respiratory retraining therapy combined with management of LPR is an effective treatment for patients with cough and PVFMD when a single-modality treatment is not sufficient.

[Difficult asthma]

Difficult asthma is a major issue in pulmonary medicine today because of its cost for patients and society. Difficult asthma is asthma that remains uncontrolled despite optimal specialist management. The validity of the diagnosis must be reconsidered in these cases: associated or differential diagnoses may be involved in the lack of control, and it is always necessary to assess the patient's treatment adhesion. Sufficient time--at least a year--must be taken to get to know the patient and to meet the objectives set. The standard asthma therapies should be tested objectively. Severe asthma is the reality of difficult asthma that endures despite a reaffirmed diagnosis, optimal compliance and controlled comorbidities. Better knowledge is needed of the pathophysiology of these patients' asthma. Improved knowledge of these phenotypes will make it possible to develop innovative treatments. They will need to be validated in clinical research for subsequent use that is wider but more rational because targeted at phenotypes likely to benefit from them.

Methacholine challenge testing in the diagnosis of paradoxical vocal fold motion

OBJECTIVE

The purpose of this study was to determine whether methacholine challenge testing (MCT) combined with serial laryngoscopy could elicit and visualize paradoxical vocal fold motion (PVFM) during asymptomatic periods and suggest laryngeal dysfunction as an etiology of episodic dyspnea.

STUDY DESIGN

A retrospective study of seven adult patients.

METHODS

Medical records of seven adult patients who were referred to an otolaryngology clinic with recurrent episodes of dyspnea or choking and underwent bronchoprovocation testing were reviewed. After initial fiberoptic laryngoscopy and pulmonary function testing (PFT), bronchoprovocation was performed using aerosolized methacholine at increasing concentrations. Each administration was followed by repeated laryngoscopy and PFT. A positive endoscopic test was marked by the visualization of paradoxical adduction of the true vocal folds during inspiration. A positive bronchoprovocation test was marked by a 20% or greater decline in the forced expiratory volume.

RESULTS

All seven patients demonstrated normal upper airway anatomy and function on initial laryngoscopy. In three patients, a positive endoscopic examination demonstrating PVFM was elicited during MCT. In three, the bronchoprovocation test was positive, and asthma was diagnosed. In one patient, both tests were negative. PVFM was seen in all patients whose chief complaint was choking (n = 2) but in only one of five patients whose chief complaint was dyspnea.

CONCLUSIONS

PVFM may be elicited and observed during MCT coupled with serial laryngoscopy. This test holds promise in differentiating vocal cord dysfunction from asthma during asymptomatic periods in patients who present with recurrent episodes of refractory dyspnea.

The Difficult-to-Control Asthmatic: A Systematic Approach

With the judicious use of inhaled corticosteroids, beta2 agonists, and leukotriene modifiers, most patients with asthma are easily controlled and managed. However, approximately 5% of asthmatics do not respond to standard therapy and are classified as "difficult to control." 1 Typically, these are patients who complain of symptoms interfering with daily living despite long-term treatment with inhaled corticosteroids in doses up to 2,000 mug daily. Many factors can contribute to poor response to conventional therapy, and especially for these patients, a systematic approach is needed to identify the underlying causes. First, the diagnosis of asthma and adherence to the medication regimen should be confirmed. Next, potential persisting exacerbating triggers need to be identified and addressed. Concomitant disorders should be discovered and treated. Lastly, the impact and implications of socioeconomic and psychological factors on disease control can be significant and should be acknowledged and discussed with the individual patient. Less conventional and novel strategies for treating corticosteroid-resistant asthma do exist. However, their use is based on small studies that do not meet evidence-based criteria; therefore, it is essential to sort through and address the above issues before reverting to other therapy.

Long-term outcome of vocal cord dysfunction

BACKGROUND

Vocal cord dysfunction (VCD) is an involuntary functional disorder commonly misdiagnosed as asthma. Previous reports describe the disorder and treatment but not the long-term outcome.

OBJECTIVE

To determine the long-term outcome of VCD.

METHODS

A retrospective medical record review identified 49 patients, ages 8 to 25 years, diagnosed as having VCD from 1989 to 2002. Telephone contact was attempted in all.

RESULTS

Of the 49 patients, 41 had previously been treated for asthma; that diagnosis was confirmed by us as a comorbidity in only 12 patients. Two distinct phenotypes of VCD were observed. Symptoms were limited to exercise-induced VCD (EIVCD) in 29 and spontaneously occurring VCD (SVCD) in 20, only 4 of whom additionally had EIVCD. Twenty-eight of the 49 were successfully contacted by telephone. Eight of the 11 contacted patients with SVCD followed the recommendation to see our speech therapist, all of whom learned to control symptoms. However, 2 who also had EIVCD continued with that problem. Pretreatment with an anticholinergic inhaler prevented EIVCD in 6 patients in whom this was tried. Complete absence of symptoms, at times ranging from 1 week to 5 years (median, 5 months), was reported in 26 of the 28 contacted patients.

CONCLUSIONS

VCD continues to be frequently misdiagnosed as asthma. Two phenotypes of VCD are apparent: EIVCD and SVCD. Speech therapy provides relief of symptoms for SVCD. Prevention of EIVCD with an anticholinergic inhaler in 6 patients suggests that a controlled clinical trial is warranted. Regardless of treatment, eventual spontaneous resolution was common.

Role of vocal cord function and dysfunction in patients presenting with symptoms of acute asthma exacerbation

A total of 48 patients presenting to the emergency department as acute asthma exacerbation were prospectively studied. Rhinolaryngoscopy was conducted with simultaneous flow measurements and spirometry performed before and after the procedure. Measurements of the vocal cord opening during various phases of respiration were analyzed. Only 4 of 48 patients had anterior two-thirds closure of the vocal cords with a diamond-shaped opening posteriorly during expiration. One additional patient had inspiratory and expiratory closure of the vocal cords. The previously unreported high incidence of anterior two-thirds closure (10.4%) of the vocal cords suggests that the upper airway has a role to play in a significant number of patients presenting with symptoms of asthma exacerbation.

High levels of medical utilization by ambulatory patients with vocal cord dysfunction as compared to age- and gender-matched asthmatics

STUDY OBJECTIVES

To evaluate medical utilization by ambulatory patients with vocal cord dysfunction (VCD).

DESIGN

Retrospective, case-control study.

SETTING

Pulmonary disease clinic at an army tertiary-care center.

PATIENTS

Twenty-five ambulatory patients with VCD (mean age, 41 years; range, 27 to 69 years) who were age- (+/- 3 years) and gender-matched to 25 control patients with moderate persistent asthma.

MEASUREMENTS AND RESULTS

Medical utilization for the year preceding the diagnosis of VCD or asthma was obtained from a computerized medical record. End points included total outpatient visits, evaluations by subspecialty physicians, presentations for urgent care, hospitalizations, and number of prescriptions. Total physician visits (477 visits vs 267 visits, respectively; p < 0.004) and subspecialty care visits (277 visits vs 118 visits; p < 0.007) were significantly greater among the VCD cohort as compared with the asthmatic cohort. The groups were also found to have comparable utilization of prescriptions (448 prescriptions vs 394 prescriptions, respectively; p < 0.63), frequency of hospitalizations (seven hospitalizations vs five hospitalizations; p < 0.59), and urgent care visits (45 visits vs 20 visits; p < 0.14).

CONCLUSIONS

Ambulatory VCD patients use significantly more medical provider resources and similar pharmaceutical assets as compared to patients with moderate persistent asthma.

Pulmonary disorders in the training room

For the athlete, not only can pulmonary disorders cause significant alterations in training schedules or even prolonged stoppages, they can be life-threatening. Infectious diseases such as acute bronchitis, influenza, and pneumonia conspire to disrupt exercise regimens. Pneumothorax, vocal cord dysfunction, and exercise-induced asthma may present diagnostic and treatment challenges. Obstructive sleep apnea not only causes disruptive symptoms but can be associated with significant cardiovascular morbidity and even mortality. This article addresses the most common pulmonary conditions athletes face and provides a framework for the diagnosis and treatment of these conditions.

Involuntary Glottal Closure during Inspiration in Muscle Tension Dysphonia

OBJECTIVE/HYPOTHESIS

The purpose of this study was to examine respiratory function in a group of patients with muscle tension dysphonia (MTD) DESIGN: Cross-sectional analytical study.

METHODS

Participants included 15 people with a diagnosis of MTD referred to speech pathology for management of their voice disorder, fiberoptic evidence of glottal or supraglottic constriction during phonation with or without posterior chink, or bowing combined and deviation in perceptual voice quality. A second group of 15 participants with no history of voice disorder served as healthy controls. Baseline pulmonary function test measures included forced expiratory volume in the first second (FEV1), FVC, FEF25 to 75, FIF50, FEV1/FVC, ratio and FEF50/FIF50 ratio. Hypertonic saline challenge test measures included FEV1 and FIF50 after provocation, dose response slope, and provocation dose.

RESULTS

Compared with healthy controls, participants with MTD demonstrated a higher prevalence of glottal constriction during inspiration after provocation with nebulized hypertonic saline as demonstrated by a reduction in FIF50 after the hypertonic saline challenge. There was no significant difference between the MTD and healthy control groups in baseline pulmonary function testing. Participants with MTD demonstrated a higher prevalence than healthy controls of abnormal glottic closure during inspiration similar to paradoxical vocal fold movement (PVFM). This suggests that they either had previously undiagnosed coexisting PVFM or that the condition of MTD could be expanded to include descriptions of aberrant glottic function during respiration. This study enhances the understanding of PVFM and MTD by combining research advances made in the fields of otolaryngology and respiratory medicine.

Vocal cord dysfunction concurrent with a nutcracker esophagus and the role of gastroesophageal reflux disease

BACKGROUND

Psychological disorders were originally thought to be the sole cause of vocal cord dysfunction (VCD). Subsequently, other organic diseases, including structural laryngeal abnormalities, have also been reported to be associated with VCD.

OBJECTIVES

To describe the first patient with VCD concurrent with a nutcracker esophagus and to establish the association between VCD and gastroesophageal reflux disease (GERD) by using the Bernstein test.

METHODS

Symptom assessments, neuropsychiatric evaluations, fiberoptic laryngoscopy, pulmonary function tests, allergic skin prick tests, radiographs of the chest and sinuses, esophageal manometry (including 24-hour ambulatory esophageal pH monitoring), and the Bernstein test were performed.

RESULTS

A 36-year-old woman had dyspnea, hoarseness, chest pain, and wheezes without relief for a decade. Neuropsychiatric evaluations disclosed mild depression. Fiberoptic laryngoscopy showed posterior laryngitis and paradoxical vocal cord adduction with audible inspiratory stridor. Pulmonary function tests showed attenuation of the inspiratory limb with notching in both flow-volume loops and a mid-vital capacity expiratory to inspiratory flow ratio of 4. All the symptoms except chest pain were improved dramatically by speech therapy and empirical treatment for GERD. Esophageal manometry revealed a nutcracker esophagus; 24-hour ambulatory esophageal pH monitoring demonstrated multiple short reflux episodes. The Bernstein test was conducted, and all the manifestations were reproduced with 0.1 N hydrochloric acid but not with isotonic sodium chloride infusion.

CONCLUSIONS

This is the first human case report confirming that GERD can trigger an acute attack of VCD and may induce chest pain as a nutcracker esophagus in patients with VCD. It strengthens this association and expands our knowledge of diverse manifestations of this clinical entity.

Differential diagnosis of adult asthma

Although the term "all that wheezes is not asthma" is not new, and the long list of asthma masqueraders has remained essentially the same for several decades, the importance of knowing when to question the accuracy ofa diagnosis of asthma has remained critical for physicians who care for patients with respiratory symptoms. The concepts of "asthma control" and"asthma severity" are currently evolving, although the fundamental hall-marks that define the syndrome of asthma endure and should be mastered by asthma specialists. Asthma masqueraders, including several that may confound a correct diagnosis of asthma, are important to consider when either the presentation of asthma is atypical or the response of the patient to treatment is suboptimal. COPD and VCD head the list of diagnoses most likely to be confused with asthma in everyday practice. Correctly identifying the diagnosis of COPD enables implementation of an up-to-date treatment plan that differs from asthma management. VCD is a vastly under recognized syndrome whose existence is widely accepted but whose pathophysiology is poorly understood, and correctly identifying a VCD component to asthma symptoms enables both a reduction in costly and potentially harmful asthma medications and focus on specific VCD treatment, such as speech therapy. For less common and uncommon asthma masqueraders, it is important to be familiar with their typical clinical presentation and basic diagnostic approaches.

Inspiratory Muscle Training in Exercise-Induced Paradoxical Vocal Fold Motion

The purpose of the study was to determine if inspiratory muscle training (IMT) would result in increased inspiratory muscle strength, reduced perception of exertional dyspnea, and improved measures of maximal exercise effort in an athlete with exercise-induced paradoxical vocal fold motion (PVFM). The participant, an 18-year-old woman, had a 2-year history of acute dyspnea with exertion during soccer games. Spirometry, transnasal flexible laryngoscopy, and patient history supported a PVFM diagnosis. The ABAB within-subject withdrawal design study comprised IMT treatment and withdrawal phases, each lasting 5 weeks. The participant trained 5 days per week, completing five sets of 12 breaths at 75% maximum inspiratory pressure (MIP) per session. Data consisted of MIP, exertional dyspnea ratings, and maximal exercise measures. IMT resulted in increased MIP and decreased dyspnea ratings across both treatment phases. No change in MIP or dyspnea ratings occurred in response to treatment withdrawal. The maximal exercise test revealed minimal changes across phases. At end of the study, the participant reported experiencing no PVFM symptoms when performing the outcome measurement tasks and when playing soccer. Transnasal flexible laryngoscopy, after strenuous exercise and during rapid breathing and phonation tasks, revealed normal laryngeal findings. The findings suggest that IMT may be a promising treatment approach for athletes with exercise-induced PVFM.

The relationship between chronic cough and paradoxical vocal fold movement: a review of the literature

SUMMARY

Chronic cough (CC) and paradoxical vocal fold movement (PVFM) are debilitating conditions. PVFM has been given many labels, including vocal cord dysfunction, Munchausen's stridor, functional inspiratory stridor, nonorganic functional or psychogenic upper airway obstruction, factitious asthma, psychogenic stridor, emotional laryngeal wheezing, and episodic laryngeal dyskinesia. Although CC and PVFM have been considered separate entities in many reports, there is preliminary support for the notion that there may be an underlying link between these two conditions. Speech pathologists have become increasingly involved in the treatment of these patients and therefore need to understand the theoretical background of these disorders, the pathophysiological links between the two, and the impact of voice disorders on these populations. The aim of this article is to review the current literature on CC and PVFM from a speech pathology perspective to provide a model for defining and conceptualizing the disorders and to provide a framework for management and future research.

Vocal cord dysfunction: an uncommon cause of stridor

We present a case of vocal cord dysfunction syndrome (VCDS) presenting as acute angioedema of the upper airway. The presentation of this syndrome and its differentiation from other upper airway conditions that require far different and more urgent treatment is discussed.

Exercise-induced dyspnea in children and adolescents: if not asthma then what?

BACKGROUND

Exercise-induced dyspnea (EID) in children and adolescents is a common manifestation of asthma and is therefore commonly attributed to exercise-induced asthma (EIA) when present in otherwise healthy children.

OBJECTIVE

To report the outcome of evaluations for EID when other symptoms and signs of asthma were absent or if there was no response to previous use of an inhaled beta2-agonist.

METHODS

We reviewed the results of all exercise tests performed in otherwise healthy patients with EID during 1996 to 2003. Physiologic measures included preexercise and postexercise spirometry with the addition of oxygen uptake, carbon dioxide production, continuous oximetry, and electrocardiogram monitoring during most tests. EIA was diagnosed if symptoms were reproduced in association with a 15% or greater decrease in forced expiratory volume in 1 second from baseline. Endoscopy was performed if stridor and/or decreased maximal inspiratory flow were present. Criteria were established for restrictive abnormalities, physical conditioning, exercise-induced hyperventilation, and normal physiologic limitation.

RESULTS

A total of 142 patients met our criteria for inclusion. EID had been present in these patients for a mean duration of 30.2 months (range, <1 to 192 months) before evaluation and had been previously attributed to asthma by the referring physician in 98 of them. Symptoms of EID were reproduced during exercise testing in 117 patients. EIA was identified as the cause of EID in only 11 of those 117. Seventy-four demonstrated only normal physiologic exercise limitation; 48 of these 74 had normal to high cardiovascular conditioning, and 26 had poor conditioning. Other diagnoses associated with reproduced EID included restrictive abnormalities in 15, vocal cord dysfunction in 13, laryngomalacia in 2 (1 of whom had unilateral vocal cord paralysis), primary hyperventilation in 1, and supraventricular tachycardia in 1.

CONCLUSION

The diagnosis of EIA should be questioned as the etiology of EID in children and adolescents who have no other clinical manifestations of asthma and who do not respond to pretreatment with a beta2-agonist. Exercise testing that reproduces symptoms while monitoring cardiac and respiratory physiology is then indicated to identify causes of EID other than EIA.

Common medical problems of the college student

The college health physician cares for college students who present with a wide variety of medical disorders. This article reviews the management of four common medical problems: infectious mononucleosis, asthma, migraine headaches, and urinary tract infections. College students can become ill, and it is important that they have health care services designed to deal with their health care issues.

Eucalyptus as a specific irritant causing vocal cord dysfunction

BACKGROUND

Vocal cord dysfunction (VCD) is a well-recognized clinical entity that frequently mimics asthma and is characterized by inappropriate adduction of the vocal cords during inspiration. The pathogenesis of VCD has not yet been defined. The only previous report suggested that respiratory irritants may trigger paradoxical motion of the vocal cords.

OBJECTIVE

To report the case of a 46-year-old woman with VCD precipitated by eucalyptus exposure.

METHODS

A masked flexible fiberoptic nasolaryngoscopy was performed to confirm whether VCD occurred with eucalyptus and not with other known respiratory irritants. The patient underwent inhalation challenges consisting of water, ammonia, pine oil, and a combination of eucalyptus (dried leaves) and ammonia. Two independent observers before patient challenge could not identify eucalyptus.

RESULTS

Vocal cord dysfunction occurred within minutes of exposure to eucalyptus. This is the first report to prospectively document that a specific irritant, eucalyptus, can precipitate VCD. Negative skin prick test results, total IgE level, and negative IgE eucalyptus-specific antibodies support a nonimmunologic mechanism.

CONCLUSIONS

A new pathogenic mechanism for this clinical entity is supported by our observations. Furthermore, a nonimmunologic mechanism in which respiratory irritants may induce VCD is suspected. Future studies to elucidate this mechanism need to be performed in individuals with irritant-specific VCD.

[Vocal cord dysfunction. An important differential diagnosis to bronchial asthma]

Vocal cord dysfunction (VCD) is described as a functional disorder of the vocal folds which leads to an intermittent, inspiratory 'paradoxical' glottal closure. We report on three women with frequent repetitive shortness of breath attacks caused by VCD. This was diagnosed by transnasal videofiberendoscopy, with glottal closure being seen during inspiration. Because of the different etiologies, one of the patients was treated with breathing and speech therapy, another received Omeprazol for laryngopharyngeal reflux, and the third was treated by intralaryngeal botulinum toxin injections. All three patients showed a reduction in attacks. Clinically, VCD seems to mimic asthma. However, with a thorough patient history and diagnostics, especially with transnasal laryngoscopy during a (triggered) attack, a precise diagnosis seems possible.

Severe obstructive airway disorders and diseases: vocal fold dysfunction

Vocal Fold Dysfunction is a syndrome characterized by abnormal adduction of the focal folds during inspiration and is the cause of a wide spectrum of clinical manifestations ranging from mild inspiratory stridor to an inability to move any air. Patients present with varying degrees of intermittent respiratory difficulty, the most severe caused by intense laryngospasm. Distinguishing Vocal Fold Dysfunction from Refractory Asthma is important to avoid unnecessary pharmacotherapy and intubation. The diagnosis of Vocal Fold Dysfunction can only be made with certainty by flexible fiberoptic laryngoscopy while the patient is symptomatic. Pulmonary function studies and a lack of response to bronchodilators may provide clues to the diagnosis. Most patients with the condition can be managed by speech therapy and the use of breathing strategies that eliminate the abnormal vocal fold movement. Chronic laryngeal irritation may be a trigger for Vocal Fold Dysfunction and conditions such as laryngopharyngeal reflux disease should be aggressively managed in this patient population.

Respiratory Retraining of Refractory Cough and Laryngopharyngeal Reflux in Patients With Paradoxical Vocal Fold Movement Disorder

OBJECTIVES/HYPOTHESIS

The objective was to describe a case series of patients with refractory cough and paradoxical vocal fold movement disorder treated with respiratory retraining therapy.

STUDY DESIGN

Retrospective review of a case series in a tertiary medical care center.

METHODS

Five patients with laryngopharyngeal reflux were identified with refractory cough and paradoxical fold movement disorder on transnasal fiberoptic laryngoscopy by a greater than 50% reduction in airway during inspiration. The were four women and one man (age range, 42-67 y). All patients had normal forced vital capacity and forced expiratory flow but decreased ratio of forced inspiratory volume at 0.5 seconds (FIV(0.5)) to forced inspiratory vital capacity (FIVC) before starting therapy. All patients were treated with more than 6 months of twice-daily proton pump inhibitor therapy with improvement in reflux symptoms but persistent and severe daytime cough. They were subsequently treated with respiratory retraining therapy. Patients were asked to rate subjectively the severity of cough at the onset and conclusion of therapy. All patients underwent pulmonary function testing before and after therapy. Long-term follow-up ranged from 5 to 17 months.

RESULTS

Patients received two to seven sessions of respiratory retraining therapy. The mean severity score changed from 9.2 before therapy to 1.3 after therapy. All patients subjectively described an improvement in the severity of their cough. Transnasal flexible laryngoscopy demonstrated improvement in paradoxical vocal fold movement, and pulmonary function testing showed improvement in the FIV(0.5)/FIVC ratio.

CONCLUSION

Patients with laryngopharyngeal reflux and refractory cough in the absence of pulmonary disease should be evaluated for paradoxical vocal fold movement disorder. Respiratory retraining therapy may represent an effective therapy for cough in the absence of relief from standard management of laryngopharyngeal reflux.

Airway function in women: bronchial hyperresponsiveness, cough, and vocal cord dysfunction

Bronchial hyperreactivity and cough are common medical problems that occur more frequently in women. Differences in size, hormonal effects, density, and sensitivity to receptors and psychologic factors may all play a role, which results in increased expression of upper and lower airway disease. The reason that VCD occurs more commonly in women is not clear but many of the same explanations regarding bronchial hyperreactivity and cough may apply.

Inspiratory activation of the vocal cord adductor, part II: Animal study in the cat

OBJECTIVES/HYPOTHESIS

The authors have shown previously that the vocal cord adductor is activated during inspiration in patients with vocal cord abduction impairment and that this adductor inspiratory activity is abolished by relief from inspiratory tracheal negative pressure by opening the tracheostoma. (Shiba K. Isono S, Sekita Y, Tanaka A. Inspiratory activation of the vocal cord adductor, Part I: human study in patients with restricted abduction of the vocal cords. Laryngoscope 2004;114:372-375). The authors hypothesized that insufficient opening of the glottis during inspiration generates strong negative pressure in the trachea and that this negative pressure triggers an airway reflex that activates the adductor.

STUDY DESIGN

Experimental study of the mechanism of laryngeal obstruction using an animal model of restricted abduction of the vocal cords.

METHODS

To identify such an airway reflex, the authors recorded the adductor electromyogram in anesthetized cats whose vocal cords were mechanically adducted by stitching both cords together. To determine whether this reflex modulation of adductor activity is induced through afferents from the larynx or from the lower airway, the authors applied negative pressure to the subglottic space and lower airway separately.

RESULTS

The adductor was activated during inspiration with powerful negative pressure in the trachea. Negative pressure in the subglottic space had a more marked effect on the adductor activity than did pressure in the lower airway. The adductor inspiratory activity was virtually abolished by laryngeal deafferentation.

CONCLUSION

Glottal narrowing during inspiration reflexly activates the vocal cord adductor. This paradoxical inspiratory-related adductor activation is induced by an airway reflex triggered mainly through afferents from the larynx and probably contributes to stridor and dyspnea in patients with laryngeal obstruction.

Inspiratory Activation of the Vocal Cord Adductor, Part I: Human Study in Patients With Restricted Abduction of the Vocal Cords

OBJECTIVES/HYPOTHESIS

In patients with restricted abduction of the vocal cords, it has generally been accepted that glottis narrowing with laryngeal stridor during inspiration is attributed to static and passive obstruction of the glottis. However, active glottis narrowing can also be contributory. We tested the hypothesis that the vocal cord adductor is activated during inspiration in patients with restricted abduction of the vocal cords.

STUDY DESIGN

Electromyographic evaluation of vocal cord adductor activity in patients with restricted abduction of the vocal cords.

METHODS

Five patients with restricted abduction of the vocal cords who had stridor with mild to severe dyspnea during wakefulness were anesthetized with propofol. We recorded the adductor muscle electromyogram during breathing through a laryngeal mask airway while observing the vocal cord movement endoscopically. In three patients who had undergone tracheostomy, we also recorded adductor firing patterns not only while closing but also while opening the tracheostoma.

RESULTS

The adductor was activated during inspiration, and the glottis was narrowed in accordance with inspiratory stridor. This adductor inspiratory activity was abolished by opening the tracheostoma in the tracheostomized patients.

CONCLUSION

Not only static or passive glottis narrowing but also active narrowing may contribute to inspiratory flow limitation in patients with restricted abduction of the vocal cords. This active glottis narrowing is probably induced by an airway reflex.

Oscillometric assessment of airway obstruction in a mechanical model of vocal cord dysfunction

Vocal cord dysfunction (VCD) is characterized by inappropriate adduction of the vocal cords, particularly during inspiration, resulting in obstruction and airflow limitation. Direct visualization of the vocal cords with laryngoscopy is the 'gold standard' for diagnosing VCD. However, it is an invasive technique that may induce airway irritation. The aim of this study was to determine whether the forced oscillation technique (FOT) is useful to estimate the degree of closure of a non-linear orifice under conditions mimicking those found in VCD. The FOT (5 Hz, +/-1 cm H(2)O) was applied to an airway model simultaneously with constant levels of flow in the normal breathing range (0-0.8l/s). Pressure-flow (P(0)-V'(0)) curves, quasi-static resistance (R(eff)) and oscillatory resistance (R(FOT)) were measured in orifices with different areas (0.15-1.12 cm2) and shapes and in an orifice with variable area. Their pressure-flow relationship followed a quadratic model. Changes in R(FOT) normalized by flow (DeltaR(FOT)/V'(0)) were related to changes in the area of the vocal cord model (1/A(VC2)(2)-1/A(VC1)(2)) from maximum aperture (A(VC1)) to different degrees of closure (A(VC2)): DeltaR(FOT)/V'(0)=1.93(1/A(VC2)(2)-1/A(VC1)(2))+2.08 cm H(2)Os(2)/l(2); r(2)=0.99. We conclude that FOT could be a useful tool for non-invasively assessing glottic closure in VCD diagnosis, obviating the need for other invasive techniques.

Vocal cord dysfunction in children and adolescents

Vocal cord dysfunction (VCD) is a nonorganic disorder of the larynx that involves unintentional paradoxical adduction of the vocal cords while breathing. The resultant symptoms can include dyspnea, chest tightness, cough, throat tightness, wheezing, or voice change. Most patients with VCD are female, and among adolescents and children, VCD tends to be triggered by exercise and is typically confused with exercise-induced asthma. Both gastroesophageal reflux disease (GERD) and psychiatric illness have been reported as having strong associations with VCD, although, to date, there is no evidence that either causes VCD. VCD often coexists with asthma, and should be suspected in any patient in whom asthma treatment fails. Confirming the diagnosis involves direct visualization of abnormal vocal cord motion, and this usually only occurs during symptoms. Adolescent athletes often require free running exercise challenge to reproduce their symptoms and confirm abnormal vocal cord motion laryngoscopically. The primary treatment for VCD involves a combination of patient education and speech therapy, and, in most cases, patients may resume their activities without significant limitation.

Psychiatric symptoms in patients with asthma causality, comorbidity, or shared genetic etiology

Despite the range of diverse studies that attempt to understand the comorbidity of asthma and psychiatric diagnoses, it is still not possible to provide a reliable quantitative estimate of the increased risk for anxiety and mood disorders in children with asthma. A new hypothesis for this comorbidity has evolved, however. It is likely that the stress of having a chronic illness increases the likelihood of the development of anxiety and depressive symptoms. If this were a sufficient etiologic explanation, however, increased comorbidities of psychiatric illnesses would be found in all chronic pediatric illnesses. More precise prevalence estimates of these comorbidities require the completion of large studies that use a longitudinal design and reliable and well-validated assessment instruments. The most promising direction for future research is the definition of underlying genetic vulnerabilities that reflect autonomic regulation, may contribute to the onset of some forms of asthma, and are associated with increased risk for anxiety and mood disorders.

Psychophysiologic treatment of vocal cord dysfunction

BACKGROUND

Vocal cord dysfunction (VCD) is an obstructive upper airway syndrome that frequently mimics asthma and for which there is no empirical treatment of choice.

OBJECTIVE

To describe two military service members experiencing VCD who were treated with psychophysiologic self-regulation training.

METHODS

Both cases were active-duty military members with VCD confirmed by laryngoscopy They each received biofeedback self-regulation training to decrease tension in the extrinsic laryngeal musculature.

RESULTS

Both patients responded to the treatment, denied the presence of dsypnea, and had resumed military physical training.

CONCLUSIONS

Psychophysiologic self-regulation strategies both with and without concurrent speech therapy positively impacted VCD symptoms.

Inspiratory stridor in elite athletes

STUDY OBJECTIVES

Diagnosis and medical intervention for exercise-induced bronchospasm (EIB) are often based on self-reported symptoms, without spirometric confirmation. Inspiratory stridor (IS), a symptom of vocal cord dysfunction (VCD), is frequently mistaken for EIB wheeze. Athletes with exercise IS that spontaneously resolves on activity cessation are suspect for VCD and may not have EIB. This study estimated IS prevalence in elite athletes and determined its relationship to EIB.

SUBJECTS/METHODS

Three hundred seventy athletes (174 female and 196 male subjects) provided a medical history, and underwent spirometry before and after exercise challenge. Exercise challenges were conducted in cold, dry ambient conditions. EIB positive (EIB +) was defined as a > or = 10% postexercise fall in FEV(1). Athletes were monitored for IS during exercise; 78.4% of the athletes in this study (n = 290) were tested on multiple occasions.

RESULTS

EIB was identified in 30% of 370 athletes tested (58 female and 53 male subjects). IS was observed in 5.1% (18 female and 1 male subjects) during exercise and spontaneously resolved in these subjects within 5 min after exercise cessation. Ten IS-positive (IS +) athletes (52.6%) were EIB +, and 8 of these athletes had a previous EIB diagnosis; however, beta(2)-agonist treatment resolved IS in only 2 subjects. Eight of nine IS +/EIB-negative (EIB -) athletes had a previous EIB diagnosis; seven subjects received beta(2)-agonist treatment with no IS resolution. Resting spirometric measurements did not distinguish IS, but postexercise mid-flow (FEF(50)/FIF(50)) ratio > 1.5 was more frequent (33%, p < 0.05) among IS + athletes. The FEF(50)/FIF(50) ratio was higher for IS +/EIB + athletes than for IS -/EIB + athletes (1.97 +/- 1.69 vs 0.81 +/- 0.39, p < 0.05). The postexercise fall in FVC was greater (p < 0.05) for IS +/EIB - athletes (9.2 +/- 5.0%) than for IS-negative (IS -) /EIB - athletes (5.3 +/- 4.3%). No difference in postexercise FEV(1) was identified between IS + and IS - athletes (within EIB + or EIB - groups).

CONCLUSIONS

Five percent of athletes were IS +, with EIB comorbidity observed in 53% of these subjects. Misdiagnosis of IS as EIB is common. The lack of a beta(2)-agonist response in combination with postexercise serial spirometry can be useful in excluding solitary IS and confirming EIB diagnosis.

Idiopathic Environmental Intolerance

Toxicogenic and psychogenic theories have been proposed to explain idiopathic environmental intolerance (IEI). Part 2 of this article is an evidence-based causality analysis of the psychogenic theory using an extended version of Bradford Hill's criteria. The psychogenic theory meets all of the criteria directly or indirectly and is characterised by a progressive research programme including double-blind, placebo-controlled provocation challenge studies. We conclude that IEI is a belief characterised by an overvalued idea of toxic attribution of symptoms and disability, fulfilling criteria for a somatoform disorder and a functional somatic syndrome. A neurobiological diathesis similar to anxiety, specifically panic disorder, is a neurobiologically plausible mechanism to explain triggered reactions to ambient doses of environmental agents, real or perceived. In addition, there is a cognitively mediated fear response mechanism characterised by vigilance for perceived exposures and bodily sensations that are subsequently amplified in the process of learned sensitivity. Implications for the assessment and treatment of patients are presented.

Hysterical Stridor: A Report of Two Cases

Stridor as an initial symptom of a conversion reaction (hysteria) is rare. We report cases of hysterical stridor in two older women, unrelated and unacquainted, from the same rural community in Oman. Once the diagnosis was made, both patients were successfully treated with a single dose of an anxiolytic. We also review the literature on hysterical stridor and discuss the diagnostic dilemmas and therapeutic options.