CE/CME

Vocal Cord Dysfunction: Unmasking the Asthma Pretender

Clinician Reviews. 2014 December;24(12):18-24

References

1. Hoyte FCL. Vocal cord dysfunction. Immunol Allergy Clin N Am. 2013;33:1-22.

2. Ibrahim WH, Gheriani HA, Almohamed AA, Raza T. Paradoxical vocal cord motion disorder: past, present and future. Postgrad Med J. 2007;83:164-172.

3. Powell DM, Karanfilov BI, Beechler KB, et al. Paradoxical vocal cord dysfunction in juveniles. Arch Otolaryngol Head Neck Surg. 2000;126(1):29-34.

4. Husein OF, Husein TN, Gardner R, et al. Formal psychological testing in patients with paradoxical vocal fold dysfunction. Laryngoscope. 2008; 118(4):740-747.

5. Dunglison RD. The Practice of Medicine. Philadelphia, PA: Lea and Blanchard; 1842:257-258.

6. MacKenzie M. Use of Laryngoscopy in Diseases of the Throat. Philadelphia, PA: Lindsey and Blackeston; 1869:246-250.

7. Osler W. Hysteria. In: The Principles and Practice of Medicine. 4th ed. New York, NY: Appleton; 1902:1111-1112.

8. Patterson R, Schatz M, Horton M. Munchausen’s stridor: non-organic laryngeal obstruction. Clin Allergy. 1974;4:307-310.

9. Christopher KL, Wood RP 2nd, Eckert RC, et al. Vocal cord dysfunction presenting as asthma. N Engl J Med. 1983;308(26):1566-1570.

10. Christopher KL. Understanding vocal cord dysfunction: a step in the right direction with a long road ahead. Chest. 2006;129(4):842-843.

11. Christopher KL, Morris MJ. Vocal cord dysfunction, paradoxic vocal fold motion, or laryngomalacia? Our understanding requires an interdisciplinary approach. Otolaryngol Clin N Am. 2010;43:43-66.

12. Sasaki CT, Weaver EM. Physiology of the larynx. Am J Med. 1997;103:9S-18S.

13. Balkissoon R. Occupational upper airway disease. Clin Chest Med. 2002;23:717-725.

14. Murakami Y, Kirschner JA. Mechanical and physiological properties of reflex laryngeal closure. Ann Otol Rhinol Laryngol. 1972;81(1):59-71.

15. Forrest LA, Husein T, Husein O. Paradoxical vocal cord motion disorder: classification and treatment. Laryngoscope. 2012;122:844-853.

16. Altman KW, Simpson CB, Amin MR, et al. Cough and paradoxical vocal fold motion. Otolaryngol Head Neck Surg. 2002;127(6):501-511.

17. Freedman MR, Rosenberg SJ, Schmaling KB. Childhood sexual abuse in patients with paradoxical vocal cord dysfunction. J Nerv Ment Dis. 1991;179(5):295-298.

18. Buddiga P. Vocal cord dysfunction. Medscape. http://emedicine.medscape.com/article/137782-overview. Accessed November 12, 2014.

19. Chiang T, Marcinow AM, deSilva BW, et al. Exercise-induced paradoxical vocal fold motion disorder: diagnosis and management. Laryngoscope. 2013;123:727-731.

20. Morris MJ, Deal LE, Bean DR, et al. Vocal cord dysfunction in patients with exertional dyspnea. Chest. 1999;116(6):1676-1682.

21. Hicks M, Brugman SM, Katial R. Vocal cord dysfunction/paradoxical vocal fold motion. Prim Care. 2008;35(1):81-103.

22. Maschka DA, Bauman NM, McCray PB, et al. A classification scheme for paradoxical vocal fold motion. Laryngoscope. 1997;107(11):1429-1435.

23. Uloza V, Vegiene A, Pribuisiene R, Saferis V. Quantitative evaluation of video laryngostroboscopy: reliability of the basic parameters. J Voice. 2013;27(3):361-368.

24. Pitchenik AF. Functional laryngeal obstruction relieved by panting. Chest. 1991;100(5):1465-1467.

25. Deckert J, Deckert L. Vocal cord dysfunction. Am Fam Physician. 2010;81(2):156-160.

26. Carding PN, Horsley IA, Docherty GJ. A study of the effectiveness of voice therapy in the treatment of 45 patients with nonorganic dysphonia. J Voice. 1999;13(1):72-104.

VOCAL CORD PHYSIOLOGY AND FUNCTIONS
The vocal cords are located within the larynx. Abduction, or opening, of the cords is controlled by the posterior cricoarytenoid muscle; adduction, or closing, occurs via contraction of the lateral cricoarytenoid muscle. These muscles are innervated by the recurrent laryngeal nerve to control the width of the space—the rima glottidis—between the cords. During inspiration, the glottis opens; during expiration, it narrows but remains open.¹²

The vocal cords are involved in three main functions: protection of the airway, respiration, and phonation (vocal production). These functions are at least partially controlled involuntarily by brain stem reflexes; however, only airway protection—the most important of these functions—is reflexive and involuntary.¹²Respiration may be controlled voluntarily, and phonation is primarily voluntary. Closure of the vocal cords is under the control of the laryngeal nerve branches of the vagal nerve.^12,13

The vocal cords normally abduct during inspiration to allow air to pass through them into the trachea and the lungs. Sniffing, puffing, snuffling, and panting also cause the vocal cords to abduct. The vocal cords adduct with phonation (talking, singing), coughing, clearing the throat, performing the Valsalva maneuver, and swallowing. During expiration, 10% to 40% adduction is considered normal.¹⁴

VOCAL CORD DYSFUNCTION
Pathogenesis and etiology
VCD is a nonspecific term, and a number of factors may be involved in its development.¹⁵ Although the precise cause of VCD is unknown, it is believed to result from laryngeal hyperresponsiveness. This exaggerated responsiveness may be prompted by irritant and nonirritant triggers of the sensory receptors in the larynx, trachea, and large airways that mediate cough and glottis closure reflexes.¹⁶

VCD may be among a group of airway disorders triggered by occupational exposures, including irritants and psychologic stressors. For example, occupationally triggered VCD was diagnosed in rescue, recovery, and cleanup workers at the World Trade Center disaster site.⁴

A history of childhood sexual abuse has also been associated by some researchers with the development of VCD. For example, Freedman et al reported that, of 47 patients with VCD, 14 identified such a history and five were suspected of having been sexually abused as children.¹⁷

Paradoxical movement of the vocal cords causes them to close when they should open. (Click here for a video on normal and abnormal vocal cord movement.) VCD generally occurs during inspiration, causing obstruction of the incoming air through the larynx. Symptoms of VCD frequently include dyspnea, coughing, wheezing, hoarseness, and tightness or pain in the throat.

Examination of the flow-volume loops recorded when a patient experiences “wheezing” during spirometry testing reveals a flattened inspiratory loop, indicating a decrease of airflow into the lungs (see Figure 1).^13,16 “Wheezing” is actually a misnomer in this situation because the term typically refers to sounds that occur during expiration.

Triggers
Physiologic, psychologic, and neurologic factors may all contribute to VCD.^1,15Conditions that can trigger VCD include
• Asthma
• Postnasal drip
• Recent upper respiratory illness (URI)
• Talking, singing
• Exercise
• Cough
• Voice strain
• Stress, anxiety, tension, elevated emotions
• Common irritants (eg, strong smells)
• Airborne irritants
• Rhinosinusitis
• GERD
• Use of certain medications
Identification of a particular patient’s triggers is key to successful management of VCD.

PATIENT PRESENTATION
Although there is no “typical” patient with VCD, the condition occurs more frequently in women, with the most common age at onset between 20 and 40 years. However, VCD has been seen in very young children and in adults as old as 83, and its diagnosis in the pediatric population is increasing.¹⁸

The patient may present with complaints of atypical chest pain, throat tightness, stridor, choking, difficult vocalization, cough and sometimes dysphagia, GERD, or rhinosinusitis (see Table 1). These signs and symptoms may occur without provocation, or patients may relate a history of triggers such as anxiety, irritant exposure, or exercise. In fact, about 14% of VCD is associated with exercise, particularly in young female athletes who experience shortness of breath and even stridor with exercise.¹⁹

A characteristic finding on physical examination is inspiratory stridor, along with respiratory distress.²⁰ The stridor is best auscultated not over the anterior chest wall but over the tracheal area of the anterior neck.

Continue for differential diagnosis >>