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

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Epidemiology

Association with Asthma

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

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Etiology

Psychiatric Disease

• Anxiety (see Anxiety)
• Depression (see Depression)
• History of Childhood Sexual Abuse
• Personality Disorders
• Post-Traumatic Stress Disorder (PTSD) (see Post-Traumatic Stress Disorder)
• Separation Anxiety

Neurologic Disease

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

Other

• 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]])

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Physiology

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

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Diagnosis

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

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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

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Treatment

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

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References

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