Paradoxical Vocal Fold Motion

Other Alternative Nomenclature

  • Emotional Laryngeal Wheezing
  • Episodic Paroxysmal Laryngospasm
  • Factitious Asthma
  • Functional Stridor
  • Hysterical Croup
  • Inspiratory Vocal Cord Adduction
  • Irritable Larynx Syndrome
  • Laryngeal Dyskinesia
  • Munchausen’s Stridor
  • Paradoxical Vocal Cord Motion
  • Periodic Occurrence of Laryngeal Obstruction
  • Pseudoasthma
  • Psychogenic Stridor


Association with Asthma

  • Epidemiology: up to 75% of asthmatics have co-existent vocal cord dysfunction


Psychiatric Disease

Neurologic Disease

  • Herpes Simplex Virus-Associated Polycranial Neuropathy
  • Post-Cervical Spine Surgery
  • Post-Thyroid Surgery


  • Asthma (see Asthma, [[Asthma]])
    • While paradoxical vocal fold motion may be misdiagnosed as asthma, it may occur concomitantly with asthma [MEDLINE]
  • Exercise: exercise is a precipitant of paradoxical vocal fold motion in 14% of cases
    • Occurs mainly in young, female athletes
  • Irritants: onset is usually within 24 hrs of exposure to irritant
    • Aerosolized Machining Fluids
    • Ammonia (see Ammonia, [[Ammonia]])
    • Cleaning Chemicals
    • Construction Dust
    • Smoke (see Smoke Inhalation, [[Smoke Inhalation]])
    • Soldering Fumes
  • Laryngopharyngeal Reflux (see Gastroesophageal Reflux Disease, [[Gastroesophageal Reflux Disease]])
  • Post-Extubation: paradoxical vocal fold motion may occur shortly after extubation
    • Post-operative dyspnea/stridor is more commonly caused by laryngospasm than by paradoxical vocal fold motion
      • Laryngospasm is usually a brief, acute onset episode of sustained vocal fold adduction which occurs on emergence from general anesthesia (see Laryngospasm, [[Laryngospasm]])


  • Paradoxic medial motion of vocal cords during inspiration: unclear etiology


Arterial Blood Gas (ABG) (see Arterial Blood Gas, [[Arterial Blood Gas]])

  • Normal A-a-Gradient

Pulmonary Function Tests (PFT’s) (see Pulmonary Function Tests, [[Pulmonary Function Tests]])

  • Spriometry/Lung Volumes: usually normal (although restriction may be seen in some cases)
  • Flow-Volume Loop: during episode, extrathoracic obstruction on flow-volume loop (flattened inspiratory limb) is seen
    • If paradoxical vocal fold motion occurs during expiration, expiratory flow limitation will be seen
  • Methacholine Challenge: may trigger paradoxical vocal fold motion (likely via an irritant mechanism)
    • Normal methacholine challenge (with normal flow-volume loop) does not exclude paradoxical vocal fold motion

Bronchoscopy (see Bronchoscopy, [[Bronchoscopy]])

  • Paradoxic Medial Motion (Adduction) of Vocal Cords DuringIinspiration

Flexible Laryngoscopy (see Flexible Laryngoscopy, [[Flexible Laryngoscopy]])

  • Paradoxic Medial Motion (Adduction) of Vocal Cords DuringIinspiration

Exercise Testing (see Exercise Test, [[Exercise Test]])

  • xxx

Clinical Manifestations

General Comments

  • Duration of Episodes: episodes requiring emergency department evaluation have been shown to last several hours-several days
    • In Contrast, Laryngospasm Usually Lasts Seconds-Minutes (see Laryngospasm, [[Laryngospasm]])

Gastrointestinal Manifestations

  • Dysphagia (see xxxx, [[xxxx]]): less common
  • Reflux Symptoms (see xxxx, [[xxxx]]): less common

Otolaryngologic Manifestations

  • Choking Sensation
  • Dysphonia (see xxxx, [[xxxx]])
  • Acute Rhinosinusitis (see Acute Rhinosinusitis, [[Acute Rhinosinusitis]]): less common
  • Stridor (see xxxx, [[xxxx]]): may be inspiratory, expiratory, or both
  • Throat Tightness

Pulmonary Manifestations

  • Acute Respiratory Failure (see Respiratory Failure, [[Respiratory Failure]])
  • Cough (see xxxx, [[xxxx]])
  • Dyspnea (see xxxx, [[xxxx]])
  • Obstructive Symptoms (see Obstructive Lung Disease, [[Obstructive Lung Disease]]): may mimic asthma
    • Lack of Responsiveness to Bronchodilators: characteristic


  • Intubation: leads to prompt resolution of dyspnea (with normal static and dynamic compliance observed during mechanical ventilation)


  • Paradoxical vocal fold motion dysfunction in asthma patients. Respirology. 2009 Jul;14(5):729-33 [MEDLINE]