Letters to the Editor
Vocal Cord Dysfunction
FREE PREVIEW Log in or buy this issue to read the full article. AAFP members and paid subscribers get free access to all articles. Subscribe now.
FREE PREVIEW Subscribe or buy this issue. AAFP members and paid subscribers get free access to all articles.
Am Fam Physician. 2004 Mar 1;69(5):1045-1046.
to the editor: I was pleased that the article “The ‘Crashing Asthmatic’”1 included a differential diagnosis of vocal cord dysfunction (VCD). I would like to further discuss this puzzling condition.
VCD is a paradoxic adduction (closure) of the vocal cords during inspiration or expiration, when they should normally remain open. Unfortunately, misdiagnosis of VCD as asthma has led to several unnecessary intubations and iatrogenic side effects from unnecessary medications. The incidence of VCD is unknown and probably underreported, but an estimated 2 to 3 percent of the general population is affected. The majority of cases reported are in adolescent females. One study2 found that almost 10 percent of elite winter athletes had VCD.
The etiology of VCD is unknown, but there are several triggers, including exercise, gastro-esophageal reflux disease (GERD), postnasal drip, allergic rhinitis, and inhaled irritants.3 VCD is most commonly misdiagnosed as exercise-induced bronchospasm. There also seems to be a large psychologic component. A recent case report4 proposed focal dystonia as an etiology, suggesting that neurologic causes may at times need to be considered.4 The typical clinical presentation is acute onset of an inability to catch one's breath, inspiratory stridor, and choking or full sensation in the throat. The “so-called” classic history is an adolescent female who appears with inspiratory stridor just before a major sporting competition. The attack usually abates as quickly as it began. Most patients will appear very anxious, but are almost never hypoxemic, which differentiates VCD from an acute asthma attack. Patients also will have poor to no response from bronchodilators, except for the 30 percent of patients who have VCD and coexistent asthma and may be suffering from a simultaneous attack.
Diagnosis rests with a high clinical suspicion and direct observation of paradoxic vocal cord function. The diagnosis can be strongly suggested by abnormal flow volume loops during an acute or provoked attack showing truncation or irregularity of the inspiratory or expiratory limbs of the flow volume loop (see the accompanying figure).5 VCD may be either an inspiratory (most common), expiratory, or combined phenomenon. During pulmonary function testing (PFT), methacholine can be used to induce reactive airway disease, and negative results almost certainly rule out any asthmatic component. Unfortunately, methacholine can act as an irritant and provoke VCD, but the flow volume loops will not reveal the characteristic obstructive pattern. If VCD is considered during PFT, direct laryngoscopy should be available to visually confirm the paradoxic vocal cord motion if induced. The real role of PFT is determining if there is a reversible bronchoconstrictive process. Fluoroscopy has been demonstrated as a reliable and noninvasive technique to confirm the diagnosis of VCD.6
Initial management depends on the severity of the attack. For mild episodes, coughing or panting may break the cycle. Acute, severe episodes of VCD can be managed with oxygen, Heliox (80 percent helium/20 percent oxygen), or sedation. Intermittent, positive pressure also can resolve an attack. Topical lidocaine applied to the larynx and discontinuing unnecessary asthma medication may be useful. Treatment of patients with GERD, allergic rhinitis, or postnasal drip are contributory; treatment of these conditions can greatly decrease the number of attacks. Behavior modification and speech therapy also are necessary. Anxiolytics have a role in the chronic management, because there is a large psychologic component to VCD.
1. Higgins JC. The ‘crashing asthmatic’. Am Fam Physician. 2003;67:997–1004.
2. Rundell KW, Spiering BA. Inspiratory stridor in elite athletes. Chest. 2003;123:468–74.
3. Balkissoon R. Occupational upper airway disease. Clin Chest Med. 2002;23:717–25.
4. Vlahakis NE, Patel AM, Maragos NE, Beck KC. Diagnosis of vocal cord dysfunction: the utility of spirometry and plethysmography. Chest. 2002;122:2246–9.
5. Brugman SM, Simons SM. Vocal cord dysfunction: don't mistake it for asthma. Phys Sportsmed. 1998; 26:63–74.
6. Mistry DJ, Kramer CM. Imaging of cardiopulmonary diseases. Clin Sports Med. 2003;22:197–212.
Send letters to Kenneth W. Lin, MD, MPH, Associate Deputy Editor for AFP Online, e-mail: firstname.lastname@example.org, or 11400 Tomahawk Creek Pkwy., Leawood, KS 66211-2680.
Please include your complete address, e-mail address, and telephone number. Letters should be fewer than 400 words and limited to six references, one table or figure, and three authors.
Letters submitted for publication in AFP must not be submitted to any other publication. Possible conflicts of interest must be disclosed at time of submission. Submission of a letter will be construed as granting the American Academy of Family Physicians permission to publish the letter in any of its publications in any form. The editors may edit letters to meet style and space requirements.
Copyright © 2004 by the American Academy of Family Physicians.
This content is owned by the AAFP. A person viewing it online may make one printout of the material and may use that printout only for his or her personal, non-commercial reference. This material may not otherwise be downloaded, copied, printed, stored, transmitted or reproduced in any medium, whether now known or later invented, except as authorized in writing by the AAFP. Contact email@example.com for copyright questions and/or permission requests.
Want to use this article elsewhere? Get Permissions