Vocal Cord Dysfunction Often Misdiagnosed and Treated Inappropriately
Print PDF Version
 |
Ronald C. Balkissoon, MD, DIH, MSc Associate Professor,
Pulmonary Division,
Department of Medicine,
National Jewish Medical and Research Center.
Assistant Professor
Departments of Medicine and Department of Biometrics and Preventive Medicine,
University of Colorado Health Sciences Center.
|
 |
Florence B. Blager, PhD
Professor Emeritus,
Department of Medicine,
National Jewish Medical and Research Center.
The Department of Otolaryngology,
University of Colorado Denver.
|
Introduction
Vocal cord dysfunction (VCD) refers to the paradoxical adduction of vocal cords that typically occurs during inspiration but may also be noted during early to mid-expiration. The closure of the vocal cords obstructs airflow, producing wheezing, cough, shortness of breath, and chest tightness. [1]
VCD is frequently misdiagnosed as asthma, anaphylaxis, or angioedema; this misdiagnosis may lead to frequent emergency room visits, hospitalization, inappropriate treatment with systemic steroids, and, on occasion, intubation, or tracheostomy. [1, 2 ]The prevalence of VCD is unknown, but it may occur in up to 40% of patients who present with apparent treatment-resistant asthma. [1] VCD can also masquerade as exercise-induced asthma, [3] appear after exposure to inhalational irritants, [4] or co-exist with asthma, further complicating its timely diagnosis.
Presentation
Case Discussion
A 52-year-old male carpet cleaner presented with a one-year history of progressive respiratory symptoms including cough, shortness of breath, audible wheeze, nighttime cough, and central chest pain. These symptoms developed after the patient started a carpet cleaning company with his son. He had been diagnosed with asthma by his primary care physician and was on prednisone, with a 30-pound weight gain over the previous 12 months. He had had numerous emergency room visits during this time. He was a lifelong nonsmoker with no upper or lower respiratory or allergy history and no family history of asthma. He denied any problems with heartburn or indigestion but did have episodic hoarseness and throat clearing. He was being treated with fluticasone propionate (220 mg/actuation, 4 puffs BID), salmeterol (2 puffs BID), albuterol (prn), and montelukast (10 mg QD). His symptoms had become so bothersome that he was considering selling his business.
Patients with VCD commonly complain of throat tightness, voice change, and difficulty "getting air in more than out." [1] The attacks occur during the day more than at night, and, for a subset of patients, their symptoms may be temporarily relieved if they are momentarily distracted. Inspiratory wheezing may be heard during acute episodes and does not typically worsen with cough or panting; it is generally loudest over the larynx. Patients can typically hold their breath despite symptoms. Many patients with primarily VCD without an asthma component report that inhalers worsen their symptoms rather than improve them. Many end up on regular nebulized bronchodilators because they tolerate them better than typical MDI inhalers.
The typical characteristics and clinical features of VCD patients were described in a retrospective study of patients diagnosed with VCD at the National Jewish Medical and Research Center between 1984 and 1991. [5] Newman et al. identified 95 patients with VCD demonstrated by laryngoscopy. Of these, 44% had pure VCD without asthma, while the others were diagnosed with a combination of VCD and asthma. These two groups were compared to each other and to a control group of patients with asthma but no VCD. The group with VCD only was younger and more predominately female than the other two groups (Table 1). All groups were significantly overweight. Among those whose occupations were listed, the VCD only group had the highest proportion of health care workers, but the differences among groups were not statistically significant. Smoking history (pack-years) and race did not differ significantly among the groups.
The group with VCD only had been misdiagnosed with asthma for an average of nearly five years, and these patients were being treated with the same medications as the groups with asthma alone or VCD with asthma. Almost all of the patients were taking prednisone, and the group with pure VCD had been taking the drug regularly for more than four years prior to admission, with an average dose of 30 mg/d at the time of the study. The VCD only group also had a higher medical utilization rate, averaging ten emergency room visits and six hospital admissions during the year prior to the study. This was approximately double the number of emergency room visits averaged by the VCD plus asthma group and the asthma alone group.
Differential Diagnosis
The differential diagnosis for VCD includes a wide variety of conditions with wheezing and/or stridor as a dominant presenting feature (Table 2), including a number of conditions that present with sudden obstruction of the airway. Clinical history and additional studies can exclude most of these; for example, a foreign body in the trachea or esophagus, traumatic injury, hereditary angioedema, infections such as epiglottitis or croup, or an underlying anatomic defect. [1] It can be more difficult to distinguish VCD from asthma, exercise-induced asthma, and gastroesophageal reflux disease (GERD).
While VCD has frequently been misdiagnosed as asthma, patients with VCD are more likely (but not always) to report difficulty on inspiration more than on expiration, unlike patients with asthma. [6] Nocturnal symptoms are less likely in patients with VCD than asthma unless they have GERD or postnasal drip. In addition, patients with VCD who do not have associated postnasal drip lack sputum production. In Newman's comparison of VCD, VCD plus asthma, and pure asthma, the three groups were similar in the number of reports of wheeze, cough, and dyspnea, but the group with VCD had more reports of stridor than the asthma group. [5] The pure asthma group had more complaints of choking sensation, chest pain, and sputum production than the group with pure VCD and was more likely to have symptoms improve with bronchodilators. [5] Asthma will typically respond to beta2-adrenergic agonists with regard to improvements in objective measures of airway function (improved spirometry), but VCD will not; this is one of the best means of discriminating between the two conditions. [5]
VCD may also closely mimic exercise-induced asthma. [3,6,7] Athletes may present with a history of acute dyspnea during sporting competitions [3] or high-pitched wheezing during exertion. [7] Stridor that is mostly inspiratory, an abrupt onset and resolution of symptoms, an unpredictable symptom pattern, and failure of asthma medications to help resolve the symptoms are suggestive of VCD triggered by exercise rather than exercise-induced asthma. [7]
Symptoms of GERD include hoarseness, persistent non-productive cough, a sensation of pressure in the throat, and a constant need to clear the throat. These symptoms overlap those reported in VCD, and GERD should be considered in the differential diagnosis of VCD. [4] GERD may also accompany VCD, however. Perkner et al. describe a high frequency of GERD in patients with irritant-induced VCD (IVCD) (70%) and a control VCD (59%) group, frequencies that are much higher than the 7% incidence reported in US adults. [4] The authors suggest that refluxing gastric contents may directly irritate the vocal cords and play a role in the pathogenesis of VCD.
Case Discussion , continued
The patient's pulmonary function test results included reduced FEV1 and FVC, but no bronchodilator response. The methacholine challenge result indicated a PC20 FEV1 greater than 25 mg/mL. CT scans of the sinuses were negative, and the pH probe had an index value of 242 (normal < 22). Laryngoscopy revealed mid-inspiratory vocal cord adduction with posterior chinking.
Several testing options exist to sort out the differential diagnosis of VCD [1,8] including:
- Spirometry
- Laryngoscopy
- pH probe to identify GERD
- CT scan to look for rhinosinusitis
- Spirometry of patients with symptomatic asthma demonstrates airflow obstruction, while spirometry in patients with symptomatic VCD may show reduced FEV1 and FVC but a relatively well preserved FEV1/FVC, and it is more likely to show blunting or truncation of the inspiratory and/or expiratory portion of the flow-volume loop (Figure 1 ). [1]
However, during asymptomatic periods the flow-volume loop may be normal in patients with VCD.
The definitive diagnostic tool for VCD is flexible fiberoptic rhinolaryngoscopy of the patient while symptomatic;1 this can be photographed or videotaped for inclusion in the medical record. In the classic picture of VCD, the anterior portion of the vocal cords adduct during inspiration, and the posterior glottis remains open ("posterior chink"). In normal subjects, the vocal cords are abducted during inspiration and expiration or may be slightly adducted at the end of the expiratory phase (Figure 2). [1]
One problem that can arise during laryngoscopy is the misinterpretation of closure of vocal cords caused by the gag reflex upon insertion of the laryngoscope, which may lead to an erroneous diagnosis of VCD. [1] A suggested procedure is outlined in Table 3.
A normal laryngoscopy in the absence of symptoms does not exclude the diagnosis of VCD. In the series of patients described by Newman, laryngoscopy was diagnostic in all patients with VCD who had the procedure while they were symptomatic. [5] Laryngoscopy was diagnostic in 60% of patients with VCD who were examined when they were not having symptoms. To increase the likelihood of diagnostic results, common challenge procedures (including methacholine, histamine, exercise, or exposure to a specific irritant suspected as a triggering factor) have been employed to provoke symptoms prior to laryngoscopy.
Laboratory evaluation also may help to differentiate VCD from asthma; arterial blood gases will demonstrate normal blood oxygen, normal alveolar-arterial oxygen gradient, and normal or low PCO2 in patients with VCD. [6] Eosinophils may be elevated in the blood of patients with asthma, but are not elevated in patients with VCD unless they have a concomitant allergic condition. [6] In the series summarized by Newman,
pulmonary function tests indicated airway obstruction and bronchodilator response in the group with asthma, but not in the group with VCD. Patients with VCD were more likely to have normal chest and sinus radiographs. [5]
A computed tomography (CT) scan may be ordered to determine the presence of sinusitis. The percentages of patients with chronic rhinosinusitis in the IVCD (73%) and VCD (91%) groups in Perkner's series were higher than those seen in the general population (20 to 40%), suggesting that chronic rhinosinusitis may, in fact, contribute to VCD. The majority of these individuals had primarily rhinitis with postnasal drip without objective evidence of sinusitis. [4]
VCD and Irritant Exposure
Irritant-associated VCD (IVCD) is characterized by onset of symptoms within 24 hours of exposure to an irritating gas, smoke, fume, vapor, mist, or dust. Perkner et al. compared 11 cases of IVCD to 33 age-matched control VCD subjects. [4] The researchers found no statistically significant differences between the groups in gender, smoking status, pulmonary function parameters, or symptoms, except patients with IVCD, who were more likely to present with chest pain or tightness. Most of the IVCD exposures occurred at work; irritants included ammonia, flux fumes, cleaning chemicals, pungent odors, organic solvents, smoke, ceiling tile dust, and machining fluid. Because of the temporal association between irritant exposure and onset of IVCD symptoms in this series, the authors hypothesize that the irritants provoking the VCD have a direct injury and resultant inflammatory effect on the larynx. [4]
Case Discussion, continued
The carpet cleaner was diagnosed with VCD and GERD. He was treated with a proton pump inhibitor plus instruction on anti-reflux lifestyle changes and taught techniques of throat clearing suppression and cough suppression by our voice rehabilitation specialists. On followup two months later, the patient showed significant improvement. He was off all medications and had decided to keep his carpet cleaning business.
This patient noted the onset of his symptoms with the use of the carpet cleaning agents. The onset of his symptoms was relatively gradual, and there was no history of an extraordinary high-level exposure. Further, he was able to continue on in his business once his GERD was maximally treated with proton pump inhibitor anti-reflux medication. The progressive onset and the ability to tolerate the environment with treatment of his reflux suggests that the carpet cleaning agents simply aggravated or triggered symptoms without being the major cause. As such, this would be regarded as VCD with aggravation from carpet cleaning chemicals rather than IVCD.
Treatment
Short-Term Treatment
Several options may be tried in the emergency room to interrupt the acute symptoms of VCD (Table 4). Panting may abort the VCD attack; it helps to abduct the vocal cord, which widens the glottic aperture, relieving symptoms. [2] Coughing and breathing against pressure on the abdomen may also help. [2] Breathing a mixture of helium and oxygen can resolve an acute attack of VCD. [2,9] Heliox, which is available as a 20:80, 30:70, or 40:60 mixture of oxygen in helium, has different laminar flow characteristics than room air or pure oxygen. Heliox is less dense than room air and reduces airflow turbulence, which, in turn, reduces wheezing and dyspnea in patients with VCD. [9] The patients will most often improve rapidly once heliox is provided by non-rebreather facemask, with a partial or complete resolution of symptoms and reduction in attendant anxiety. The immediate relief from heliox, should not, however, be relied upon as the sole treatment; followup with speech therapy is recommended. [9]
Other options for short-term treatment in the emergency room setting include topical lidocaine spray, oxygen via nasal cannula or facemask, and use of a special portable mask device designed to adjust resistance to inspiratory airflow while maintaining minimal resistance to expiratory airflow. [10] The patient can use this apparatus to increase airflow resistance during inspiration, which, it is hypothesized, likely slows the rate of airflow such that the vocal cords are not stimulated to adduct abnormally. [10] This device has been described for use both in the emergency room and by the patient at home.
Various other therapies have been tried in the treatment of pure VCD in the emergency room setting, but they have poor risk-benefit profiles and should be avoided. [9] These include tracheostomy, botulinum toxin injection, and intubation and mechanical ventilation. Inhaled corticosteroids and beta agonists will not relieve the symptoms of VCD and should not be used in the absence of asthma. Systemic corticosteroids are not indicated in pure VCD; these will not improve VCD and may lead to complications from chronic use.
Long-Term Treatment
Speech therapy is the definitive long-term treatment for VCD. [8,9,11] Improvement may be seen with as few as two sessions. [12] Speech therapy focuses on breathing exercises that train the patient to avoid or reduce paradoxical vocal cord adduction. Techniques that have been used successfully with the patients were adapted from techniques used with other functional voice disorders where the goal is a reduction of tension in the extrinsic laryngeal musculature. [8] Patients learn to focus attention away from the larynx and to concentrate on active exhalation rather on inspiration. They are taught to relax the oropharyngeal muscle groups and the neck, shoulder, and chest muscles. Patients can then combine these techniques at the first indication of throat tightness or stridor to abort VCD attacks.
The first step in the process is to acknowledge the patient's fear and sense of helplessness that often accompany VCD, while explaining that the laryngeal stridor can come under voluntary control (Table 5). [8] Then, patients are provided with specific exercises to practice during periods of normal breathing so that they can be prepared to deal with attacks of VCD. [8,11] Diaphragmatic breathing is used to divert attention away from the larynx and avoid laryngeal tension. Wide-open throat breathing develops a sense of openness and relaxation in the area of the larynx and helps the patient avoid the tension of pushing from the laryngeal, neck, shoulder, or chest areas.
In the next step, the patient learns to focus on exhalation, which interrupts the tendency to hold onto the breath in the neck, shoulder and chest by giving the patient a place to direct conscious attention. The speech therapist trains the patient to count silently during an exhalation, increasing the number slowly to a reasonable level, and using this approach to control exhalation during an attack to avoid breathing in shallow gasps of air. The patient is next taught to experience each stage of inhalation and exhalation with increased self-awareness and to identify correct breathing technique. Finally, patients learn to interrupt breathing that has become effortful and substitute correct, relaxed breathing.
Older patients may present with somewhat different needs than younger patients during speech therapy. [13] The older patient may have had more time to habituate to illness and may have voluntarily reduced daily activity levels to "avoid attack," often under a physician's directions. The older patient may have been on asthma medications, particularly systemic steroids for some time and may have significant side effects including weight gain, cushingoid facies, hyperglycemia, osteopenia, hypercholesterolemia, skin changes, cataracts, etc. An older patient may also have secondary gains from the VCD attacks, such as family support and extra attention. Finally, an older patient may be particularly concerned that the physician or speech therapist is trying to say VCD is the patient's "fault" or that it is "all in their head."
A younger patient, on the other hand, may have had less time to habituate to the illness, will likely have higher energy level, and may have maintained kinesthetic awareness. A younger person may also have secondary gains from the disorder, and may also fear that he or she somehow "causes" the problem upon learning he/she will be responsible for the treatment.
Speech therapy should also be tailored to specific subgroups. [13] Patients with exercise-induced VCD, for example, should incorporate gradually increased levels of exertion (for example, slow walk, fast walk, slow jog, fast jog) with the breath training exercises. The patients should become sensitive to the first indications of constriction and learn to stop before VCD begins, then recover and continue with exercise. In this way, they should gradually increase the level of exertion that can be tolerated without provoking the symptoms of VCD.
Patients with VCD and asthma should learn to start with relaxed breathing for several minutes, but if the symptoms do not resolve, they should use an inhaler with just the mouthpiece and no medication and repeat the relaxed breathing. If symptoms still do not resolve after an additional fifteen minutes, they should use the inhaler with medication. Nebulized saline is often as effective as nebulized albuterol in those with pure VCD without asthma. The moisture applied to the pharynx is soothing and may alleviate and/or abort significant symptoms.
Referral for psychological evaluation may be indicated for some patients with VCD; psychological issues or diagnoses contributing to VCD have frequently been described in the literature. [1,5,8,9] According to Martin et al., psychiatric conditions associated with VCD may include depression, obsessive-compulsive personality, borderline personality, passive dependent personality, adjustment reaction, or somatization disorder. [8] However, patients do not consciously control VCD; it is not a fictitious or malingering disorder. [8]
When VCD and asthma co-exist, both must be treated acutely and chronically. [9] The asthma may require both immediate reliever medication (beta agonist) and long-term anti-inflammatory controller medication. [8]
There are many challenges in treating irritant associated or work-related VCD patients. Many have been misdiagnosed as having asthma for several years and been on asthma medications for many years despite only modest to no response. It is often difficult for them to let go of this diagnosis, particularly when it has major workers' compensation or medicolegal implications. Patients need to be reassured that this is not a factitious or malingering type of problem and that there is indeed a valid relationship between their problem and workplace exposures. They must understand that they need treatment but that it is different from asthma treatment (assuming that a true asthmatic component has been ruled out). Critical for this group is the evaluation and treatment of underlying or co-existing GERD and/or postnasal drip, as these are chronic irritants to the larynx that will prime it for reacting to irritant exposures.These individuals may need to be removed from irritant exposure until they have learned the techniques to control reflex laryngeal closure that has become a conditioned response to a wide variety of irritants beyond the initial inciting agent.
Summary
VCD is often misdiagnosed, especially as treatment-resistant asthma, and patients may be treated inappropriately with asthma medications, including prednisone. Because these medications are ineffective, patients with unrecognized VCD have a high utilization of medical resources, including emergency room visits. The most definitive approach to diagnosing VCD is flexible fiberoptic rhinolaryngoscopy of the patient while symptomatic, which, in the classic case, reveals the vocal cords adducting anteriorly during inspiration while the posterior glottic chink remains open. Having the patient breathe heliox may interrupt an acute episode of VCD in the emergency room setting, but speech therapy is recommended to train the patient to avoid or reduce inappropriate vocal cord adduction long term.
Acknowledgment
The authors wish to thank Mary E. King, PhD, for assistance in the preparation of this manuscript.
References
- Wood RP, Milgrom H. Vocal cord dysfunction. J Allergy Clin Immunol. 1996;98:481-485.
- Bahrainwala AH, Simon MR. Wheezing and vocal cord dysfunction mimicking asthma. Curr Opin Pulm Med. 2001;7:8-13.
- McFadden ER, Zawadski DK. Vocal cord dysfunction masquerading as exercise-induced asthma: a physiologic cause for "choking" during athletic activities. Am J Respir Crit Care Med. 1996;153:942-947.
- Perkner JJ, Fennelly KP, Balkissoon R, et al. Irritant-associated vocal cord dysfunction. J Occup Environ Med. 1998;40:136-143.
- Newman KB, Mason UG, Schmaling KB. Clinical features of vocal cord dysfunction. Am J Respir Crit Care Med. 1995;152:1382-1386.
- Bacharier LB, Strunck RC. Vocal cord dysfunction: a practical approach to diagnosis. J Respir Dis. 2001;22:93-103.
- Brugman SM, Simons ST. Vocal cord dysfunction: don't mistake it for asthma. Physician Sportsmed. 1998;26:63ff.
- Martin RJ, Blager FB, Gay ML, Wood RP. Paradoxical vocal cord motion in presumed asthmatics. Semin Respir Med. 1987;8:332-337.
- Weir M. Vocal cord dysfunction mimics asthma and may respond to heliox. Clin Ped. 2002;41:37-41.
- Archer GJ, Hoyle JL, McCluskey A, Macdonald J. Inspiratory vocal cord dysfunction, a new approach in treatment. Eur Respir J. 2000;15:617-618.
- Blager FB. Paradoxical vocal cord movement: diagnosis and management. Curr Opin Otolaryngol Head Neck Surg. 2000;8:180-183.
- Blager FB, Brugman SM, Howell JH, Mahler JL, Rosenberg DM. Vocal cord dysfunction. Presented at the American Thoracic Society meeting, Toronto, Canada, May 5-10, 2000.
- Blager FB. Diagnostic models and treatment of vocal cord dysfunction. Presented at the American Speech-Language-Hearing Association. San Francisco, CA, November 18-21, 1999. Milgrom H. Vocal cord dysfunction. J Allergy Clin Immunol . 1996;98:481-485.
- Bahrainwala AH, Simon MR. Wheezing and vocal cord dysfunction mimicking asthma. Curr Opin Pulm Med. 2001;7:8-13.
- McFadden ER, Zawadski DK. Vocal cord dysfunction masquerading as exercise-induced asthma: a physiologic cause for "choking" during athletic activities. Am J Respir Crit Care Med. 1996;153:942-947.
- Perkner JJ, Fennelly KP, Balkissoon R, et al. Irritant-associated vocal cord dysfunction. J Occup Environ Med. 1998;40:136-143.
- Newman KB, Mason UG, Schmaling KB. Clinical features of vocal cord dysfunction. Am J Respir Crit Care Med. 1995;152:1382-1386.
- Bacharier LB, Strunck RC. Vocal cord dysfunction: a practical approach to diagnosis. J Respir Dis. 2001;22:93-103.
- Brugman SM, Simons ST. Vocal cord dysfunction: don't mistake it for asthma. Physician Sportsmed. 1998;26:63ff.
- Martin RJ, Blager FB, Gay ML, Wood RP. Paradoxical vocal cord motion in presumed asthmatics. Semin Respir Med. 1987;8:332-337.
- Weir M. Vocal cord dysfunction mimics asthma and may respond to heliox. Clin Ped. 2002;41:37-41.
- Archer GJ, Hoyle JL, McCluskey A, Macdonald J. Inspiratory vocal cord dysfunction, a new approach in treatment. Eur Respir J. 2000;15:617-618.
- Blager FB. Paradoxical vocal cord movement: diagnosis and management. Curr Opin Otolaryngol Head Neck Surg. 2000;8:180-183.
- Blager FB, Brugman SM, Howell JH, Mahler JL, Rosenberg DM. Vocal cord dysfunction. Presented at the American Thoracic Society meeting, Toronto, Canada, May 5-10, 2000.
- Blager FB. Diagnostic models and treatment of vocal cord dysfunction. Presented at the American Speech-Language-Hearing Association. San Francisco, CA, November 18-21, 1999.
