Vocal cord dysfunction is a condition in which the vocal cords close when they should be opening, particularly during inspiration. This can be more severe and impair breathing or, more commonly, less severe and impact the patient's voice. This article is a brief summary and review of the best available evidence for the presentation, diagnosis, and management of vocal cord dysfunction.

Epidemiology

• Vocal cord dysfunction predominantly occurs in females (prevalence is two to three times greater in females than in males).^1,2

• It occurs at any age but is more commonly diagnosed in patients 30 to 40 years of age.¹

• It may coexist with asthma (25% to 30%),^3,4 gastroesophageal reflux disease, or anxiety disorders.^1,4–7

• Vocal cord dysfunction is categorized as inducible laryngeal obstruction and is known by many other names,^2,8–10 which are listed in Table 1.⁸

Diagnosis

• Vocal cord dysfunction should be considered in patients with poor response to optimal medical management of asthma or in those who have sudden, severe dyspnea without hypoxia, tachypnea, or increased work of breathing.^{1,4–7,11–13}

• The differential diagnosis includes poorly controlled asthma, anatomic defects, laryngeal edema, nerve injury, and neurologic disorders¹¹ (Table 2).

• A suggested approach to the diagnosis of vocal cord dysfunction includes obtaining a clinical history focusing on triggers (Table 3) and symptoms, physical examination focusing on location and timing of stridor or wheezing, pulmonary function testing, and direct nasolaryngoscopy performed during an episode.^1,4–7

SIGNS AND SYMPTOMS

• Many symptoms are a result of difficulty with breathing in air due to inappropriate closure of the vocal cords during inspiration. These symptoms include:

  Inspiratory stridor¹¹

  Wheezing, predominantly over the upper airway¹¹

  Severe, sudden dyspnea without oxygen desaturation, tachypnea, or increased work of breathing; often associated with anxiety^11–13

  Chest or throat tightness¹²

  Chronic cough may be an associated condition, although it typically does not occur during symptoms related to vocal cord dysfunction¹⁴

  Onset with exposure to known triggers (Table 3)

• When the vocal cord closure is less severe (from abnormal laryngeal muscle spasm), it impacts the voice, but not breathing, causing dysphonia or aphonia.¹⁵

DIAGNOSTIC TESTING

• The diagnostic standard is direct visualization of vocal cord adduction during inspiration using nasolaryngoscopy.⁷ Diagnostic yield of nasolaryngoscopy is improved when the patient is experiencing symptoms and with provocation, such as exercise or use of methacholine.^{3–5,11–15} Based on expert opinion, nasolaryngoscopy should be performed when signs and symptoms suggest vocal cord dysfunction.

• In patients with vocal cord dysfunction, pulmonary function testing may show a flattened inspiratory flow loop or FEF₅₀/FIF₅₀ (ratio of expiratory flow to inspiratory flow at 50% of forced vital capacity) of 1 or greater.^6,7,11 Yield is higher when the patient is experiencing symptoms.⁶ Use of methacholine during pulmonary function testing helps evaluate for asthma as an alternative diagnosis.^7,16–20

• Pulmonary function testing should be performed when signs and symptoms suggest vocal cord dysfunction or when asthma is considered as a possible etiology.

• If asthma is being considered, initial pulmonary function testing should be ordered before flexible nasolaryngoscopy. However, if asthma is unlikely, flexible nasolaryngoscopy should be used for the initial evaluation based on expert opinion.

• Chest radiography may be considered to evaluate for other etiologies, such as a compressive mass, although vocal cord dysfunction tends to cause more intermittent symptoms.

• Reviewing a patient-generated video of an acute, symptomatic episode can be helpful to assess signs and symptoms.