title: Botulinum toxin injection for dysphagia: a blinded retrospective videofluoroscopic swallowing study analysis.
abstract: OBJECTIVE
  To evaluate the effect of botulinum toxin type A injections on dysphagia accompanied by upper esophageal sphincter dysfunction.
  
  
  METHODS
  A preinjection and postinjection blinded retrospective review was performed using the videofluoroscopic swallowing study video clips of eight patients administered botulinum toxin type A because of dysphagia with accompanying upper esophageal sphincter dysfunction at a dysphagia clinic in a department of rehabilitation medicine at a university hospital. The outcome variables applied were a functional dysphagia scale that included assessments of food residues in vallecula and piriform sinuses, and bolus transit time, and physician's judgment regarding which videos (preinjection or postinjection) were functionally superior in terms of aspiration frequency and bolus transit time.
  
  
  RESULTS
  After botulinum toxin type A injection, residues in the piriform sinus significantly improved (P < 0.05), and the applied functional dysphagia scale showed a tendency toward improvement (P = 0.173). A blinded physician found postinjection to be superior to preinjection in terms of videofluoroscopic swallowing study results in six of eight cases.
  
  
  CONCLUSIONS
  Botulinum toxin type A injection to the upper esophageal sphincter was found to improve swallowing function in patients with upper esophageal sphincter dysfunction and seems to offer a possible therapeutic option in these patients.
authors.affiliation: Department of Rehabilitation Medicine, Seoul National University College of Medicine, Seoul National University Bundang Hospital, Seoul, South Korea.
authors.forename: Sang Yoon
authors.initials: SY
authors.lastname: Lee
authors.forename: Han-Gil
authors.initials: HG
authors.lastname: Seo
authors.forename: Nam-Jong
authors.initials: NJ
authors.lastname: Paik