title: Laryngeal response patterns influence the efficacy of mechanical assisted cough in amyotrophic lateral sclerosis.
abstract: Most patients with amyotrophic lateral sclerosis (ALS) are treated with mechanical insufflation-exsufflation (MI-E) in order to improve cough. This method often fails in ALS with bulbar involvement, allegedly due to upper-airway malfunction. We have studied this phenomenon in detail with laryngoscopy to unravel information that could lead to better treatment.
  
  
  
  We conducted a cross-sectional study of 20 patients with ALS and 20 healthy age-matched and sex-matched volunteers. We used video-recorded flexible transnasal fibre-optic laryngoscopy during MI-E undertaken according to a standardised protocol, applying pressures of ±20 to ±50 cm H2O. Laryngeal movements were assessed from video files. ALS type and characteristics of upper and lower motor neuron symptoms were determined.
  
  
  
  At the supraglottic level, all patients with ALS and bulbar symptoms (n=14) adducted their laryngeal structures during insufflation. At the glottic level, initial abduction followed by subsequent adduction was observed in all patients with ALS during insufflation and exsufflation. Hypopharyngeal constriction during exsufflation was observed in all subjects, most prominently in patients with ALS and bulbar symptoms. Healthy subjects and patients with ALS and no bulbar symptoms (n=6) coordinated their cough well during MI-E.
  
  
  
  Laryngoscopy during ongoing MI-E in patients with ALS and bulbar symptoms revealed laryngeal adduction especially during insufflation but also during exsufflation, thereby severely compromising the size of the laryngeal inlet in some patients. Individually customised settings can prevent this and thereby improve and extend the use of non-invasive MI-E.
authors.affiliation: Thoracic Department, Norwegian Centre of Excellence for Home Mechanical Ventilation, Bergen, Norway.|Department of Physiotherapy, Haukeland University Hospital, Bergen, Norway.|Institute of Clinical Medicine, University of Bergen, Bergen, Norway.
authors.forename: Tiina
authors.initials: T
authors.lastname: Andersen
authors.affiliation: Institute of Clinical Medicine, University of Bergen, Bergen, Norway.
authors.forename: Astrid
authors.initials: A
authors.lastname: Sandnes
authors.affiliation: Bergen University College, Bergen, Norway.
authors.forename: Anne Kristine
authors.initials: AK
authors.lastname: Brekka
authors.affiliation: Department of Otolaryngology/Head and Neck Surgery, Haukeland University Hospital, Bergen, Norway.
authors.forename: Magnus
authors.initials: M
authors.lastname: Hilland
authors.affiliation: Institute of Clinical Medicine, University of Bergen, Bergen, Norway.|Department of Pediatrics, Haukeland University Hospital, Bergen, Norway.
authors.forename: Hege
authors.initials: H
authors.lastname: Clemm
authors.affiliation: Thoracic Department, Norwegian Centre of Excellence for Home Mechanical Ventilation, Bergen, Norway.
authors.forename: Ove
authors.initials: O
authors.lastname: Fondenes
authors.affiliation: Department of Neurology, Haukeland University Hospital, Bergen, Norway.|Institute of Surgical Science, University of Bergen, Bergen, Norway.
authors.forename: Ole-Bjørn
authors.initials: OB
authors.lastname: Tysnes
authors.affiliation: Department of Otolaryngology/Head and Neck Surgery, Haukeland University Hospital, Bergen, Norway.|Institute of Surgical Science, University of Bergen, Bergen, Norway.
authors.forename: John-Helge
authors.initials: JH
authors.lastname: Heimdal
authors.affiliation: Institute of Clinical Medicine, University of Bergen, Bergen, Norway.|Department of Pediatrics, Haukeland University Hospital, Bergen, Norway.
authors.forename: Thomas
authors.initials: T
authors.lastname: Halvorsen
authors.affiliation: Thoracic Department, Norwegian Centre of Excellence for Home Mechanical Ventilation, Bergen, Norway.|Institute of Clinical Medicine, University of Bergen, Bergen, Norway.|Department of Pediatrics, Haukeland University Hospital, Bergen, Norway.
authors.forename: Maria
authors.initials: M
authors.lastname: Vollsæter
authors.affiliation: Bergen University College, Bergen, Norway.|Department of Pediatrics, Haukeland University Hospital, Bergen, Norway.
authors.forename: Ola Drange
authors.initials: OD
authors.lastname: Røksund
mesh_terms: D000368:Aged; D000690:Amyotrophic Lateral Sclerosis / Q000503:physiopathology*; D003371:Cough; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D007327:Insufflation; D007828:Laryngoscopy; D008297:Male; D009664:Norway; D012129:Respiratory Function Tests; D012138:Respiratory Therapy / Q000379:methods*; D014741:Video Recording
keywords: Cough/Mechanisms/Pharmacology; Non invasive ventilation