title: Improving the Utility of Laryngeal Adductor Reflex Testing: A Translational Tale of Mice and Men.
abstract: OBJECTIVE
  Evaluation of the laryngeal adductor reflex (LAR) entails delivering air through an endoscope positioned 1 to 2 mm from the arytenoid mucosa to elicit bilateral vocal fold (VF) closure. This short working distance limits visualization to only the ipsilateral arytenoid and results in quantification of a single LAR metric: threshold pressure that evokes the LAR. Our goal was to evolve the LAR procedure to optimize its utility in clinical practice and translational research.
  
  
  METHODS
  Prospective translational experiment.
  
  
  METHODS
  Academic institution.
  
  
  METHODS
  Young healthy human adults (n = 13) and 3 groups of mice: healthy, primary aging mice (n = 5), a transgenic mouse model of amyotrophic lateral sclerosis (ALS; n = 4), and young healthy controls (n = 10).
  
  
  METHODS
  The VFs were visualized bilaterally during supramaximal air stimulation through an endoscope. Responses were analyzed to quantify 4 novel metrics: VF adduction phase duration, complete glottic closure duration, VF abduction phase duration, and total LAR duration.
  
  
  RESULTS
  The 4 LAR metrics are remarkably similar between healthy young humans and mice. Compared to control mice, aging mice have shorter glottic closure durations, whereas ALS-affected mice have shorter VF abduction phase durations.
  
  
  CONCLUSIONS
  We have established a new LAR protocol that permits quantification of novel LAR metrics that are translatable between mice and humans. Using this protocol, we showed that VF adduction is impaired in primary aging mice, whereas VF abduction is impaired in ALS-affected mice. These preliminary findings highlight the enhanced diagnostic potential of LAR testing.
authors.affiliation: University of Missouri School of Medicine, Columbia, Missouri, USA.
authors.forename: Leslie A
authors.initials: LA
authors.lastname: Shock
authors.affiliation: University of Missouri School of Medicine, Columbia, Missouri, USA.
authors.forename: Brandon C
authors.initials: BC
authors.lastname: Gallemore
authors.affiliation: University of Missouri School of Medicine, Columbia, Missouri, USA.
authors.forename: Cameron J
authors.initials: CJ
authors.lastname: Hinkel
authors.affiliation: University of Missouri School of Medicine, Columbia, Missouri, USA.
authors.forename: Marlena M
authors.initials: MM
authors.lastname: Szewczyk
authors.affiliation: University of Missouri School of Medicine, Department of Otolaryngology-Head and Neck Surgery, Columbia, Missouri, USA.
authors.forename: Bridget L
authors.initials: BL
authors.lastname: Hopewell
authors.affiliation: University of Missouri School of Medicine, Department of Otolaryngology-Head and Neck Surgery, Columbia, Missouri, USA.
authors.forename: Mitchell J
authors.initials: MJ
authors.lastname: Allen
authors.affiliation: University of Missouri, Department of Statistics, Columbia, Missouri, USA.
authors.forename: Lori A
authors.initials: LA
authors.lastname: Thombs
authors.affiliation: University of Missouri School of Medicine, Department of Otolaryngology-Head and Neck Surgery, Columbia, Missouri, USA levert@health.missouri.edu.
authors.forename: Teresa E
authors.initials: TE
authors.lastname: Lever
mesh_terms: D000328:Adult; D000690:Amyotrophic Lateral Sclerosis / Q000503:physiopathology*; D000818:Animals; D004195:Disease Models, Animal; D005260:Female; D006801:Humans; D007821:Laryngeal Muscles / Q000503:physiopathology*; D007828:Laryngoscopy; D008297:Male; D051379:Mice; D008822:Mice, Transgenic; D010812:Physical Stimulation; D011930:Reaction Time / Q000502:physiology; D012016:Reference Values; D012018:Reflex / Q000502:physiology*; D015203:Reproducibility of Results; D014827:Vocal Cords / Q000503:physiopathology*; D055815:Young Adult
keywords: amyotrophic lateral sclerosis; aspiration; dysphagia; laryngeal adductor reflex; laryngeal reflex; laryngoscopy; mouse models; sensory testing