Vocal Cord Dysfunction (VCD) is Often Misdiagnosed and Improperly Treated
Vocal cord dysfunction is characterized by closure of the vocal cords, obstructing airflow and causing wheezing, cough, shortness of breath, and chest tightness.
VCD is frequently misdiagnosed as asthma, anaphylaxis, or angioedema; this misdiagnosis may lead to frequent emergency room visits, hospitalization, inappropriate treatment with systemic steroids, and, on occasion, intubation, or tracheostomy.
The prevalence of VCD is unknown, but it may occur in up to 40% of patients who present with apparent treatment-resistant asthma. VCD can also masquerade as exercise-induced asthma, appear after exposure to inhalational irritants, or coexist with asthma, further complicating its timely diagnosis.
Patients with VCD commonly complain of throat tightness, voice change, and difficulty “getting air in more than out.” The attacks occur during the day more than at night, and, for a subset of patients, their symptoms may be temporarily relieved if they are momentarily distracted. Inspiratory stridor may be heard during acute episodes and does not typically worsen with cough or panting; it is generally loudest over the larynx. Patients can typically hold their breath despite symptoms. Many patients with primarily VCD without an asthma component report that inhalers worsen their symptoms rather than improve them. Many end up on regular nebulized bronchodilators because they tolerate them better than typical MDI inhalers.
The definitive diagnostic tool for VCD is flexible fiberoptic rhinolaryngoscopy of the patient while symptomatic; this can be photographed or videotaped for inclusion in the medical record. In the classic picture of VCD, the anterior portion of the vocal cords adduct during inspiration, and the posterior glottis remains open (“posterior chink”). In normal subjects, the vocal cords are abducted during inspiration and expiration or may be slightly adducted at the end of the expiratory phase. It should be noted that a normal laryngoscopy in the absence of symptoms does not exclude the diagnosis of VCD.
Speech therapy is the definitive treatment for VCD. Improvements may be seen with as few as two sessions. Speech therapy focuses on breathing exercises that train the patient to avoid or reduce paradoxical vocal cord adduction. Techniques that have been used successfully with the patients were adapted from techniques used with other functional voice disorders where the goal is a reduction of tension in the extrinsic laryngeal musculature. Patients learn to focus attention away from the larynx and to concentrate on active exhalation rather on inspiration. They are taught to relax the oropharyngeal muscle groups and the neck, shoulder, and chest muscles. Patients can then combine these techniques at the first indication of throat tightness or stridor to abort VCD attacks.