title: Can PFTS Differentiate PVFMD From Subglottic Stenosis?
abstract: OBJECTIVE
  To determine if the results of routine spirometry and flow volume loops (Pulmonary Function Tests (PFTs)) can be used to distinguish Paradoxic Vocal Fold Movement Disorder (PVFMD) from Subglottic Stenosis (SGS).
  
  
  METHODS
  PFT records and medical history of 49 patients with diagnosis of PVFMD and 39 patients with SGS were compared. Groups were then subdivided to compare PFTs in patients with and without smoking history or lung disease.
  
  
  RESULTS
  Peak expiratory flow rate (PEFR) and Expiratory Disproportion Index (ratio of forced expiratory volume in 1 second (FEV1) over PEFR (FEV1/PEFR)) were both significantly different between patients with SGS and those with PVFMD (p<0.02). FEV1 was also significantly different, but only in the patients with no smoking history or lung disease (p<0.02).
  
  
  CONCLUSIONS
  The findings suggest that spirometry can be a valuable tool in distinguishing SGS from PVFMD. Previous studies have shown the utility of PFTs for distinguishing SGS from pulmonary pathology, but this is the first study to exploit PFTs for distinction of SGS from PVFMD. Given that the flexible laryngoscopic exam used to diagnose PVFMD does not always visualize the subglottis completely, PFTs can be used to increase suspicion of SGS and direct further work-up.
authors.affiliation: Department of Otorhinolaryngology-Head and Neck Surgery, Hospital of the University of Pennsylvania, Philadelphia, PA, USA.
authors.forename: Liuba
authors.initials: L
authors.lastname: Soldatova
authors.affiliation: Department of Otolaryngology-Head and Neck Surgery, The Ohio State University Wexner Medical Center, Columbus, OH, USA.
authors.forename: Candace
authors.initials: C
authors.lastname: Hrelec
authors.affiliation: Department of Otolaryngology-Head and Neck Surgery, The Ohio State University Wexner Medical Center, Columbus, OH, USA Laura.Matrka@osumc.edu.
authors.forename: Laura
authors.initials: L
authors.lastname: Matrka
mesh_terms: D000328:Adult; D000368:Aged; D001249:Asthma / Q000453:epidemiology; D016022:Case-Control Studies; D015897:Comorbidity; D005260:Female; D005541:Forced Expiratory Volume; D005764:Gastroesophageal Reflux / Q000453:epidemiology; D006801:Humans; D057045:Laryngopharyngeal Reflux / Q000453:epidemiology; D007829:Laryngostenosis / Q000175:diagnosis* / Q000453:epidemiology / Q000503:physiopathology; D008171:Lung Diseases / Q000453:epidemiology / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D010366:Peak Expiratory Flow Rate; D029424:Pulmonary Disease, Chronic Obstructive / Q000453:epidemiology; D012129:Respiratory Function Tests; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D012907:Smoking / Q000453:epidemiology / Q000503:physiopathology; D013147:Spirometry; D064706:Vocal Cord Dysfunction / Q000175:diagnosis* / Q000453:epidemiology / Q000503:physiopathology
keywords: expiratory disproportion index; paradoxic vocal fold motion disorder; paradoxic vocal fold movement disorder; pulmonary function test; subglottic stenosis; vocal cord dysfunction