Dennis K. Ledford; Richard F. Lockey

Disclosures

Curr Opin Allergy Clin Immunol. 2013;13(1):78-86. 

In This Article

Paradoxical Vocal Fold Movement (Vocal Cord Dysfunction)

VCD is defined by the complete or partial adduction or closure of the vocal folds with inspiration and/or expiration. This maladaptive process is not usually volitional but seems to occur in response to irritation of the larynx or hypopharynx or secondary to emotional or physical stress. The symptoms of VCD include wheezing, usually more prominent with inspiration, hoarseness, dysphonia, cough, and globus pharyngeus. Affected individuals will frequently describe their 'chest tightness' as originating superior to the sternal notch. Symptoms are often episodic with rapid resolution, with or without therapy. The wheeze may be high pitched and musical or stridorous. The symptoms may be provoked by respiratory or laryngeal irritants, exercise, stress, or anxiety. Frequent use of inhalers may contribute as the larynx may be irritated by such therapies.

Prevalence is difficult to determine as VCD is a dynamic, episodic condition, which may not be evident or easily provoked at the time of the examination. There is one report using histamine inhalation challenge as a means of identifying 'hyperreactivity' of the larynx.[22] Exercise is a common trigger of VCD in extreme or elite athletes, often misdiagnosed as exercise-induced bronchospasm.

The appearance of the larynx during active symptoms shows the true or false vocal folds or both adducted during ventilation (Fig. 1). The most severe form of the adduction results in a small, diamond-shaped opening between the vocal folds, termed 'chink deformity'. Other suggestions of VCD are inflammation of the larynx or variable motion or quivering of the vocal folds during quiet ventilation or during forced inhalation or exhalation. The inflammation of the larynx can be associated with GERD or laryngopharyngeal reflux, another potential comorbidity with VCD. Treatment of GERD may improve VCD, but this has not been confirmed in prospective trials. Biofeedback therapy enables the affected individual to employ relaxation techniques to minimize muscle tension in the larynx, usually resulting in relief of symptoms and resolution of wheeze.

Figure 1.

This illustration is a diagram of paradoxical vocal cord closure during ventilation. Panel (a) shows the true and false vocal cords open during normal ventilation. With forced exhalation, individuals with paradoxical fold dysfunction may exhibit the appearance in (b). The true vocal cords have approximated, leaving only a diamondshaped opening for air passage. Other individuals will show less dramatic closure or will have the false vocal cords, superior to the true cords, in opposition as well. The narrow flow aperture will result in a sensation of difficulty breathing and frequently a wheeze. Relaxing of the vocal cords will immediately provide relief.

Relationship With Asthma

Patients may be misdiagnosed with asthma when VCD is responsible for their symptoms or have VCD and asthma simultaneously, a more common occurrence in the authors' opinion. Distinguishing the two conditions is challenging and may require direct visualization of the vocal folds during a symptomatic episode to be certain of the diagnosis.

Diagnostic or Therapeutic Considerations

Any patient with difficult-to-control asthma should be assessed for VCD. The use of the flow volume loop may be helpful in recognizing VCD.[23] The inspiratory loop typically exhibits decreased flow rate with variability in flow, resulting in a wavy, flattened curve instead of the typical smooth, oval appearance (Fig. 2). None of these findings is individually definitive but helpful if the diagnosis is suspected. The only method for confirmation is to visualize the vocal folds, usually with a flexible nasolaryngoscope, during symptoms. Psychological dysfunction is a significant contributor or predisposing factor in VCD and, thus, contributes to the association of asthma symptoms with anxiety and depression.[24]

Figure 2.

This is a diagram of a flow volume loop with the expiratory loop superior and the inspiratory loop inferior. Panel (a) is a normal flow volume loop and Panel (b) is representative of an individual with vocal cord dysfunction. The normal inspiratory loop should have a smooth, semicircular shape rather than the irregular shape. Comparing the flow rates of inspiration and expiration at various volume or flow rate points has been reported in the literature to quantify the probability of vocal cord dysfunction, with the figure showing comparison at the 50% flow rate point (forced expiratory flow rate 50%). The normal ratio of expiratory/inspiratory flow approximates, and this ratio is greatly increased with vocal cord dysfunction.

Factors associated with VCD are as follows:

  1. Anxiety disorders

  2. Family members of healthcare professionals

  3. History of psychiatric disease, particularly depression

  4. Perfectionists or obsessive/compulsive personalities

  5. Victims of remote sexual abuse or trauma.

  6. Clinical suspicion and careful evaluation are necessary as there is no single measurement or test to confirm the diagnosis other than direct visualization of the vocal cords during symptoms. A speech therapist or speech pathologist, knowledgeable about VCD can be very helpful in treating this disorder.

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