CONTENTS

• Overview
• Epidemiology
• Clinical presentation
• Bedside evaluation
• Differential diagnosis
• Acute evaluation – Diagnostics & approach
• Other diagnostic tests
• Treatment
• Podcast
• Questions & discussion
• Pitfalls

---

overview

(back to contents)

---

• Vocal Cord Dysfunction (VCD) is known by a variety of names, including:
  • Paradoxical vocal fold motion.
  • Inducible laryngeal obstruction.
  • Functional upper airway obstruction.
  • Functional dysphonia.
  • Psychogenic upper airway obstruction.
  • Spasmodic dysphonia.
  • Psychsomatic stridor.
  • Irritable larynx syndrome.
  • Episodic laryngeal dyskinesia.
• VCD is a disorder marked by intermittent episodes of vocal cord contraction, particularly during inspiration. This causes episodic dyspnea with stridor, which is classically confused with asthma.
• This is a functional disorder that is often associated with psychiatric comorbidities.
  • Patients are not malingering (not doing this intentionally).
  • There is actual airway obstruction (in severe cases, hypercapnia can occur).

---

epidemiology

(back to contents)

---

• VCD tends to occur in younger patients, with female predominance.
• VCD is associated with various conditions, including:
  • Psychiatric comorbidities.
  • Asthma (this is discussed in the section below).
  • Gastroesophageal reflux disease.
  • Rhinosinusitis.

---

clinical presentation

(back to contents)

---

pattern: repeated episodes

• VCD may be triggered by various factors listed below:
  • Stress.
  • Inhaled irritants.
  • Exercise.
  • Viral upper respiratory tract infection, rhinosinusitis.
  • Gastroesophageal reflux.
  • Psychiatric disorders (e.g., anxiety, depression).
• The pattern of repeated exacerbations may mimic asthma or angioedema.

clinical manifestations

• Stridor:
  • Stridor is audible to other people in the room (this really isn't a feature of asthma).
  • Inspiratory stridor is generally seen, but it is possible to have both inspiratory and expiratory stridor.
• Subjective features which may point towards VCD (rather than asthma):
  • Throat tightness is a primary complaint (rather than chest tightness).
  • Dysphonia (if present).
  • Dysphagia, globus sensation.

relationship to asthma

• Roughly 40% of patients with VCD also have asthma, which may create a diagnostically confusing situation. (de Moraes 2024) However, in other patients, pure VCD may be misdiagnosed as asthma.  
• Some clues that may support a diagnosis of VCD include:
  • [1] Evaluation in the pulmonary clinic for “asthma” with a negative workup (especially if asthma is excluded using a methacholine challenge test).
  • [2] A failure to respond to treatment for “asthma.”  (29517494)
  • [3] Occasionally, a patient with VCD will be misdiagnosed with asthma and intubated. Following intubation, airway pressures are normal, and there is no auto-PEEP, which essentially excludes severe asthma. A history of multiple intubations for “asthma” with extubation the following day suggests VCD.

---

bedside evaluation

(back to contents)

---

#1: differentiate asthma from upper airway obstruction

• Patients with VCD (or other upper airway problems) often present with easily audible stridor and/or expiratory wheeze. This is often very dramatic and scary. Alternatively, this shouldn't be audible from across the room in patients with severe asthma. In fact, patients with severe asthma may have a quiet chest (even with a stethoscope).
• Listen over the patient's throat and also the lung bases:
  • VCD will often cause harsh, loud stridor, which is louder over the throat.
  • Asthma tends to cause more musical diffuse wheezing, which is distributed more broadly throughout the chest.

#2: look for characteristics of vocal cord dysfunction

• Patients with VCD may be able to pant or sing normally. If present, this “sign” localizes the problem to the brain (specifically, this argues against angioedema or neck infections, which may cause hoarseness).
  • Ask the patient to sing “Row Row Row Your Boat.”
  • Instruct the patient to open their mouth, stick out their tongue, and “pant like a dog.” (27522309)
• Use therapeutic breathing maneuvers (box below).
  • These may be both diagnostic and therapeutic. Sustained improvement following these maneuvers would argue against ongoing structural pathology.

---

differential diagnosis

(back to contents)

---

• Vocal cord dysfunction:
  • Bilateral vocal cord paralysis.
  • Recurrent laryngeal nerve injury.
  • Vocal cord polyps.
  • Laryngospasm.
• Laryngeal edema:
  • Epiglottitis.
  • Angioedema, Anaphylaxis.
• Other upper airway obstruction:
  • Neck hematoma.
  • Deep neck space infection.
  • Subglottic stenosis.
  • Tracheal mass.
  • Foreign body aspiration.
• Asthma.

---

acute evaluation – diagnostics & approach

(back to contents)

---

laryngoscopy during an episode

• If logistically feasible, this is the ideal diagnostic test. A major advantage is that it usually secures the diagnosis, which may clarify future management.
• Normal findings:
  • During inspiration, vocal cords abduct (open)
  • During expiration, vocal cords may adduct somewhat
• Findings in VCD:
  • Abnormal adduction of the vocal cords, especially during inspiration.
  • Adduction typically involves the anterior vocal cords (which may leave only a tiny opening in the posterior portion of the glottis during inspiration).
  • Adduction coincides with audible stridor (alternatively, if you are hearing stridor with the vocal cords open, the obstruction is more distal in the airway).
• Differential diagnosis – can look a lot like:
  • Vocal cord paralysis
  • Laryngospasm
• Laryngoscopy is typically performed by ENT surgery (using a dedicated flexible laryngoscope). Another option is bronchoscopy via the nares, but the bronchoscope is larger than a fiberoptic laryngoscope and thus less comfortable. Anyone can be trained in these skills, so emergency physicians may also perform this if a nasolaryngoscope is in the department.

neck & chest CT scan

• This may be considered in some situations:
  • i) The patient is adequately stable to undergo a CT scan.
  • ii) Nasolaryngoscopy isn't readily available.
• CT scan is predominantly useful for excluding other causes of upper airway obstruction, such as:
  • Tracheal disease, including tumors or stenosis (which will be missed with nasolaryngoscopy).
  • Extra-tracheal compression (e.g., thyroid mass or goiter, peritonsillar abscess, or other space-occupying lesions in the neck).
  • Epiglottitis.

diagnostic/therapeutic trial of non-dissociating sedation

• 🛑 This is not supported by high-quality evidence and should only be performed selectively by physicians with experience in airway management.
• This may be considered for moderate-severity cases (see flowsheet above).
• Reasonable options could be low-dose, rapid-acting benzodiazepine (e.g., IV midazolam) or IV haloperidol. (Karaman et al. 2009)

diagnostic/therapeutic trial of ketamine

• 🛑 This is not supported by high-quality evidence and should only be performed very selectively by physicians with experience in airway management. (27522309)
• Situations where this could be considered:
  • A diagnosis of VCD is strongly suspected.
  • The patient is unable to tolerate therapeutic breathing maneuvers (box above).
  • The patient cannot tolerate laryngoscopy, or this option isn't available.
  • The patient appears very distressed, and immediate intubation is the alternative course of action.
• Preparations should be made for intubation, with staff prepared to immediately intubate if necessary.
• Give a dissociating dose of ketamine (~1.5 mg/kg) slowly over 2-3 minutes.
  • Slow administration of ketamine avoids inducing apnea (which generally isn't dangerous but may confuse matters).
• One of two things should happen:
  • (a) If stridor/wheeze disappears immediately, this is diagnostic and therapeutic for VCD. The patient should continue breathing and eventually wake up like any patient sedated with ketamine.
  • (b) If the patient continues to have stridor/wheeze, then
    • The patient probably doesn't have VCD.
    • The patient probably has a life-threatening upper airway obstruction!
    • Do not paralyze the patient to facilitate intubation.
    • Consider an awake/fiberoptic intubation with a double setup.

---

other diagnostic tests

(back to contents)

---

flow-volume loop

• Flattening of the inspiratory loop may occur due to paradoxical closure during inspiration.
• The expiratory curve is generally normal or near-normal (since inspiration is primarily affected).
• The sensitivity of flow-volume loops is often low if evaluated in between episodes. However, this finding may occasionally be elicited during methacholine bronchoprovocation testing. (de Moraes 2024)
• Other causes of inspiratory loop flattening include causes of variable extrathoracic obstruction (e.g., upper airway tumors, vocal cord paralysis). (de Moraes 2024)

---

treatment

(back to contents)

---

acute management

• Reassurance.
• Anxiolysis may be helpful in the short term (e.g., using benzodiazepines).
• Breathing exercises, such as nasal inspiration & pursed-lip expiration (bow below).
• Heliox may provide some symptomatic relief.

chronic management

• Treatment and/or avoidance of any triggers (e.g., allergic rhinitis, gastroesophageal reflux).
• Therapy with a speech-language pathologist.
• Treatment of any underlying psychiatric comorbidities.

---

podcast

(back to contents)

---

Follow us on iTunes

---

questions & discussion

(back to contents)

---

To keep this page small and fast, questions & discussion about this post can be found on another page here.

• Many patients have both VCD and asthma. Therefore, a history of either of these disorders doesn't eliminate the possibility that the patient will present with the other. A thoughtful evaluation must occur every time the patient presents with dyspnea.
• A common pitfall is failing to consider VCD, leading to unnecessary intubation for the management of “asthma.”
• If a patient is presumptively diagnosed with VCD but fails to respond to therapeutic sedation, re-consider whether the patient could have an alternative, life-threatening cause of upper airway obstruction.

Guide to emoji hyperlinks

• = Link to online calculator.
• = Link to Medscape monograph about a drug.
• = Link to IBCC section about a drug.
• = Link to IBCC section covering that topic.
• = Link to FOAMed site with related information.
• = Link to supplemental media.