Vocal Cord Dysfunction

Michael Shreve, MD

Last updated 12/10/1997

Vocal Cord Dysfunction

Outline

• Definition
• Historical Perspective
• Epidemiology
• Clinical Presentation
• Diagnosis
  • History
  • Physical Exam
  • Laboratory Studies
• Vocal Cord Motion
• Laryngoscopy
• Psychologic Aspects
• Treatment
• Conclusion
• Bibliography

Definition:

• abnormal adduction of the vocal cords producing airflow obstruction at the larynx.

Historical perspective:

• 1842, Duglison - "hysteric croup"
• Osler - "hysterical cries"
• 1968, Rabin - "spasm of the vocal cords resulting in a choking sensation."

Epidemiology

• incidence/prevalence unclear
• at National Jewish Center, of patients referred for refractory asthma...
• 10% have VCD without any evidence of asthma
• 30% have VCD in addition to asthma
• age of onset 9+ years
• usually female
• often well educated, often employed in health-related field
• often history of high medical utilization and ER visits
• many reports of intubation and tracheostomy

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Clinical presentation

• often referred for intractable asthma
• steroid dependent, MTX, etc.
• wheezing spectrum of end-exp. to early exp. to insp. adduction
• stridor
• duration of symptoms = first episode Æ many years
• triggers = URI, exercise, stress, or no pattern evident
• may be present with other pulmonary disease

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Diagnosis

• history
  • throat tightness, voice changes during attack
  • little/no improvement with bronchodilators during attack
  • no night awakening secondary to an attack, no night cough
• physical exam
  • notoriously unreliable due to transmission of breath sounds
  • wheeze loudest at larynx
  • "clean wheeze"
  • ask patient to pant and breath hold
  • panting may improve sx's
  • patient with VCD can hold breath
  • asthmatic will not be able to perform the maneuvers during attack
• lab findings
  • asymptomatic VCD: normal PFT's with no bronchodilator response
  • 25% will have truncated insp. limb while asymptomatic
  • normal lung volumes (asthmatics may have high residual volumes)
  • spirometry during attack:
  • flattened insp. limb c/w variable extrathoracic obstruction or may be c/w fixed obstruction
  • relatively normal expiratory flows inconsistent with sx's
  • spirometry is only suggestive, NOT diagnostic
  • gold standard = vocal cord visualization during episode

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Vocal cord motion

• in normals, inspiratory VC movement is consistent among individuals
• expiratory VC movement varies among individuals, from 10 - 40% adduction
• in normals, VC's abduct during forced expiration
• if FEV1 < 60%, VC's may adduct during forced expiratory maneuvers, presumably to keep small airways patent (auto-peep)
• panting also causes glottic widening during expiration
• patients with VCD demonstrate exaggerated adduction of their VC's,with the timing of adduction responsible for either stridor or wheezing.

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Laryngoscopy

• highest yield is when patient is symptomatic
• 50% will have normal VC motion when asymptomatic
• may need to provoke sx's with exercise, methacholine, histamine
• classic appearance is early exp. adduction of ant. two-thirds of VC's
• normal laryngoscopy during sx's Þ VCD unlikely

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Psychologic aspects

• not conversion disorder because their are pathologic VC findings
• common themes: high stress, caretaking roles, highly motivated, difficulty expressing emotions, occasionally secondary gain
• one study: 36% of VCD patients had hx of childhood sexual abuse

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Treatment

• explanation of disorder and treatments
• success in treatment often hinges on this explanation
• relief vs. resentment vs. confusion
• describe VC function and the specifics of dysfunction
• show video of laryngoscopy if possible
• explain that stress may be a cause, just as in asthma
• refer to speech pathologist to teach relaxed breathing during attacks
• decrease laryngeal tone by concentrating on exp. rather than insp.
• abdominal breathing
• various other methods, including biofeedback
• occasionally panting can alleviate an attack
• if significant hypoxia that does not respond to conventional treatment:
• heliox for immediate relief
• tracheostomy
• unilateral laryngeal nerve sectioning
• botulinum toxin injection (experimental, requires repeated injections)

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Conclusion

• wheezing is not always asthma
• if it doesn't act like asthma and doesn't respond to aggressive asthma therapy, then it's probably not asthma.
• asthma and VCD can co-exist
• you will see VCD in your practice

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Bibliography

• McFadden and Zawadski. Vocal cord dysfunction masquerading asexercise-induced asthma. 1996. Am J Respir Crit Care Med 153:942-7.
• Newman and Dubester. Vocal cord dysfunction: masquerader of asthma. 1994. Seminars in Respir and Crit Care Med 15(2):161-167.

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Page last updated 12/10/97 for format only

This page is meant for teaching purposes only.