Category: For Allergy Fellows > Topics for Medical Professionals
Paradoxical Vocal Fold Motion, VCD
Vocal cord dysfunction is a broad term referring to a specific laryngeal disorder also known as paradoxical vocal fold motion disorder. For doctors who routinely treat asthma patients, it is something to consider in an atypical asthmatic.
If we think of the normal function of the vocal folds then we can better understand what vocal fold dysfunction is. The vocal folds have three main functions: Phonation, airway protection and as a valve during normal respiration. Therefore, vocal fold dysfunction may broadly be thought of as combination of dysphonia, aberrant hypersensitivity to stimuli and dyspnea/cough.
Classic vocal cord dysfunction is diagnosed by observation of glottic adduction during inspiration usually to the point that only a small posterior opening is visible. This paradoxical closure is also evident on pulmonary function testing in the form of a truncated flow volume loop. Most allergists know to look for VCD in asthmatics that are poorly responsive to therapy. Yet many asthma mimics do not meet the classic description of paradoxical vocal fold motion yet have respiratory symptoms of laryngeal origin.
There are a range of symptoms which may be confused with asthma or anaphylaxis that are in fact due to problems of the vocal folds. This includes occasional patients who have a marked expiratory closure of the glottis which on pulmonary function testing looks just like the obstructive pattern of asthma. Laryngeal findings that we have seen in chronic cough/asthma patients include asymmetric glottic closure or vocal fold palsies.
CASE 1: The following patient is representative of the difficulty in categorizing patients as VCD based on strict criteria. She is a 29 year old longstanding asthmatic who was for many years on high doses of prednisone for severe asthma without clear response. Her PFTs showed evidence of both mild asthma with response to bronchodilator and intermittent truncation of the inspiratory flow limb consistent with vocal cord dysfunction.
Video Nasolaryngoscopy showed true vocal fold edema, ventricular obliteration and posterior commissure edema consistent with laryngopharyngeal reflux. She also had some vocal fold asymmetry which might have contributed to her respiratory symptoms.
CASE 2: 68-year-old woman with chronic dyspnea, and intermittent coughing and wheezing. When she is sick she develops a severe barking cough which is quite disruptive and requires high doses of prednisone. She also has occasional throat pain and dysphagia. Her PFTs showed a bordeline obstructive pattern but she did not respond to bronchodilator or inhaled steroids.
Her endoscopy showed evidence of LPR and posterior kinking of the larynx with expiration (classic VCD has inspiratory kinking). Her proton pump inhibitor was increased to bid and she was referred to speech therapy. Expiratory VCD is rare and requires a high index of suspicion and cautious interpretation since it is difficult to rule out coinciding asthma. It has been described elsewhere (Echternach M, et al).
50 yo woman with history of asthma and “globus hystericus.” She has morning symptoms of coughing, choking, gagging and post nasal drip. Her PFTs showed a variably truncated inspiratory flow limb.
and this videolaryngoscopy shows the “floppy” vocal folds which seem to spasmodically adduct and abduct in asymmetric fashion. The significance of the vocal fold motion asymmetry is debatable since arytenoid asymmetries are extremely common (Bonilha et al). This may not classic VCD but the swollen vocal folds and reflux are the principal cause of her symptoms. Her inhaled steroids were tapered off and she responded well to PPI therapy.
Bonilha HS, O’Shields M, Gerlach TT, Deliyski DD. Arytenoid adduction asymmetries in persons with and without voice disorders. Logoped Phoniatr Vocol. 2009 Aug 26:1-7
Echternach M, Delb W, Verse T, Richter B. Does isolated expiratory vocal cord dysfunction exist? Otolaryngology-Head and Neck Surgery 138(6) 805-806
Holmes PW, Lau KK Crossett M. Diagnosis of vocal cord dysfunction in asthma with high resolution dynamic volume computerized tomography of the larynx. Respirology 2009
Tilles SA, Inglis AF. Masqueraders of exercise-induced vocal cord dysfunction. J Allergy Clin Immunol. 2009 Aug;124(2):377-8,