Vocal Cord Dysfunction

Michael Shreve, MD

University of Minnesota - Division of Pulmonary and Critical Care Medicine, Department of Pediatrics

Vocal Cord Dysfunction

• Vocal cord dysfunction = 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
• 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
• 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
• 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.
• 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
• 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
• 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)
• 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

Back to Michael Shreve's page

Back to the U of MN: Peds PCCM home page

Page last updated 5/21/97