Vocal Cord Dysfunction

Often confused with asthma and treated as such, vocal cord dysfunction (VCD) pr paradoxic vocal fold movement disorder is a functional rather than a structural disorder. Normally, when inhaling, the vocal cords open and then narrow slightly during exhalation. However, in VCD the vocal cords close partially on inspiration and act as an obstruction in the airway.(1–4) It is this abnormal movement that causes wheezing which can be easily misdiagnosed as asthma. This paradoxical closure of the vocal cords can also be mistaken for anaphylaxis and be treated as such. It can also present as exercise-induced asthma.(3)

The symptoms of VCD include wheezing, cough, dyspnea, tachypnea, choking sensation, stridor, chest pain, voice changes, and difficulty in speaking.(5,6)

VCD may be triggered by exercise, a respiratory infection, emotional upset, fumes, strong odours, stress, tobacco smoke and even talking or singing. In about half the cases, the trigger for VCD is psychological.(7) Laryngeal irritants such as laryngopharyngeal reflux (LPR), allergic disease, sinusitis, gastroesophageal reflux (GER) and in some cases obstgructive sleep apnea can also be triggers.(8) VCD can also occur with exposure to water-damaged buildings.(9)

VCD differs from asthma in that it

  • does not cause nocturnal symptoms
  • occurs suddenly
  • is of variable duration
  • has unusual triggers
  • does not respond well to bronchodilators or to adequate asthma pharmacotherapy(8)

VCD is common in patients with asthma. It is usually diagnosed during adolescence and adolescents with VCD tend to have high levels of anxiety.(10) Groups at increased risk for developing VCD include young women with psychiatric issues, elite athletes, military recruits and individuals exposed to either inhaled or aspirated irritants.(11)

VCD can coexist with asthma, exertional dyspnea,(12) gastroesophageal reflux, anxiety, depression and even severe post nasal drainage. VCD most commonly presents as asthma and is often treated with oral steroids. Lack of response to asthma therapy is often the deciding factor to consideration of a differential diagnosis of VCD.

VCD is difficult to diagnose. Physical examinations will generally be negative. The usual reversibility test for asthma is not indicative of abnormality, unless it coexists with asthma. Pulmonary function tests are normal both after an episode and during asymptomatic periods.
Spirometry too will not always show any irregularity in either the inspiratory or expiratory flow volume loops unless it is done during a symptomatic episode. Some patients (about one in four) will have an abnormal inspiratory section in their flow volume loop.

VCD is diagnosed through a visual examination of the vocal cords during a symptomatic episode. Flexible fiberoptic rhinolaryngoscopy is considered the best method. This should be done by an experienced otolaryngologist.

This disorder can be managed successfully and requires both an otolaryngologist and a speech therapist. Patient education should include an emphasis on relaxation techniques, panting breathing, breath holding and slow relaxed expiration techniques, etc. Treatment of existing rhinitis. GER, LPR and upper airway cough syndrome (formerly known as post nasal drip) can also help improve VCD.

References

  1. Christopher KL, Wood RB, Eckert RC, Blager FB, Raney RA, Souhrada JF. Vocal cord dysfunction presenting as asthma. N Engl J Med 1983; 308(26): 1566–70
  2. Meltzer EO, Orgel HA, Kmp JP, Welch MJ Ostrom NK, Park SM, Kearns DB. Vocal cord dysfunction in a child with asthma. J Asthma 1991; 28(2): 141–145
  3. McFadden ER, Zawadski DK. Vocal cord dysfunction masquerading as exercise-induced asthma. A physiologic cause for choking during athletic activities. Am J Resp Crit Care Med 1996; 153: 942–947
  4. Newman KB, Mason UG, Schmaling KB. Clinical features of vocal cord dysfunction. Am J Resp Crit Care Med 1995; 152: 1382–1386
  5. Balfour-Lynn I. Difficult asthma: beyond the guidelines. Arch Dis Child 1999; 80: 201–206
  6. Tilles SA. Vocal cord dysfunction in children and adolescents. Curr Allergy Asthma Rep. 2003; 3(6): 467–72
  7. O’Connell MA, Sklarew PR, Goodman DL. Spectrum of presentation of paradoxical vocal cord motion in ambulatory patients. Ann Allergy Asthma Immunol 1995; 74(4): 341–44
  8. Matrka L. Paradoxic vocal fold movement disorder. Otolaryngol Clin North Am. 2014;47(1):135–46. doi: 10.1016/j.otc.2013.08.014. Epub 2013 Oct 23.
  9. Cummings KJ, Fink JN et al. Vocal cord dysfunction related to water-damaged buildings. J Allergy Clin Immunol Pract. 2013 Jan;1(1):46–50. doi: 10.1016/j.jaip.2012.10.001. Epub 2012 Dec 2. Abstract.
  10. Niggemann B. Functional symptoms confused with allergic disorders in children and adolescents. Pediatric Allergy Immunology 2002; 13(5): 312–18
  11. Balkissoon R, Kenn K. Asthma: vocal cord dysfunction (VCD) and other dysfunctional breathing disorders. Semin Respir Crit Care Med. 2012 Dec;33(6):595-605. doi: 10.1055/s-0032–1326959.
  12. Morris MJ, Deal LE, Bean DR, Grback VX, Morgan JA. Vocal cord dysfunction in patients with exertioal dyspnea. Chest 1999; 116: 1676–82