title: Bilateral vocal fold immobility: a 13 year review of etiologies, management and the utility of the Empey index.
abstract: BACKGROUND
  Bilateral vocal fold immobility (BVFI) is a rare diagnosis causing dyspnea, dysphonia and dysphagia. Management depends on respiratory performance, airway patency, vocal ability, and quality-of-life priorities. The authors review the presentation, management and outcome in patients diagnosed with BVFI. The utility and efficacy of the Empey index (EI) and the Expiratory Disproportion Index (EDI) are evaluated as an objective monitoring tools for BVFI patients.
  
  
  METHODS
  A 13-year retrospective review was performed of BVFI patients at St. Michael's Hospital, University of Toronto, a tertiary referral centre for laryngology.
  
  
  RESULTS
  Forty-eight patients were included; 46 presented with airway obstruction symptoms. Tracheotomy was required for airway management in 40% of patients throughout the course of their treatment, which was reduced to 19% at the end of the study period. Twenty-one patients underwent endoscopic arytenoidectomy/cordotomy. Non-operative management included continuous positive airway pressure devices. Pulmonary function testing was carried out in 29 patients. Only a portion of the BVFI patients met the defined upper airway obstruction criteria (45% EI and 52% EDI). Seven patients had complete pre- and post-operative PFTs for comparison and all seven had ratios that significantly improved post-operatively which correlated clinically.
  
  
  CONCLUSIONS
  The EI and EDI have limited use in evaluating patients with who have variable upper airway obstruction, but may be helpful in monitoring within subject airway function changes.
authors.affiliation: Department of Otolaryngology - Head and Neck Surgery, University of Toronto, Ontario, Canada. drmariabrake@gmail.com.
authors.forename: Maria K
authors.initials: MK
authors.lastname: Brake
authors.affiliation: St. Michael's Hospital, Department of Otolaryngology - Head and Neck Surgery, University of Toronto, 30 Bond St. 8C-129, ON, M5B 1 W8, Toronto, Canada. andersonj@smh.ca.
authors.forename: Jennifer
authors.initials: J
authors.lastname: Anderson
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000402:Airway Obstruction / Q000175:diagnosis / Q000209:etiology / Q000628:therapy; D015331:Cohort Studies; D045422:Continuous Positive Airway Pressure; D005260:Female; D006801:Humans; D007821:Laryngeal Muscles / Q000601:surgery; D008297:Male; D008875:Middle Aged; D009864:Ontario; D012189:Retrospective Studies; D012307:Risk Factors; D014140:Tracheotomy; D014826:Vocal Cord Paralysis / Q000145:classification / Q000209:etiology* / Q000628:therapy*; D014827:Vocal Cords / Q000601:surgery; D055815:Young Adult