title: Use of botulinum toxin type A for chronic cough: a neuropathic model.
abstract: OBJECTIVE
  To review the experience and outcomes of a novel use of botulinum toxin type A (BtxA) in the treatment of chronic cough.
  
  
  METHODS
  Retrospective case series.
  
  
  METHODS
  Academic referral center.
  
  
  METHODS
  A total of 438 patients were diagnosed as having laryngeal spasm and chronic cough, and 6 were documented as having chronic cough treated with BtxA injections. Two patients were excluded from the study because of a history of tracheostomy or concurrent laryngeal and voice dysfunction.
  
  
  METHODS
  Electromyography-guided BtxA injections of the thyroarytenoid muscles.
  
  
  METHODS
  Patient demographics (age and sex), voice-related quality-of-life scores, postprocedure complications, number of BtxA units used, number and length of treatments, and voice outcomes are reviewed.
  
  
  RESULTS
  Three of the 4 patients (75%) were women, and the mean patient age was 55.6 years (range, 38-64 years). All patients had significant relief of cough after BtxA injection, with complete resolution after a median of 7 injections (range, 4-16), using a mean dose of 4.0 U (range, 1.0-10.0 U) per treatment session for a mean duration of 25.7 months (range, 7.2-42.9 months).
  
  
  CONCLUSIONS
  To our knowledge, this is the first reported series in the literature of the use of BtxA in the treatment of chronic cough in adults. In this small case series, we report a neuropathic model for chronic cough caused by neuroplastic changes and laryngeal hyperactivity as an explanation for the effectiveness of BtxA treatment. Further research and long-term follow-up are warranted, but BtxA is effective in directly decreasing laryngeal hypertonicity and possibly reducing neurogenic inflammation and neuropeptide-mediated cough. Botulinum toxin type A can be considered for the treatment of chronic cough refractory to other medical therapies.
authors.affiliation: Department of Otolaryngology-Head & Neck Surgery, Eastern Virginia Medical School, Norfolk, Virginia 23507, USA. chumw@evms.edu
authors.forename: Michael W
authors.initials: MW
authors.lastname: Chu
authors.forename: John D
authors.initials: JD
authors.lastname: Lieser
authors.forename: John T
authors.initials: JT
authors.lastname: Sinacori
mesh_terms: D000328:Adult; D019274:Botulinum Toxins, Type A / Q000008:administration & dosage / Q000627:therapeutic use*; D002908:Chronic Disease; D003371:Cough / Q000188:drug therapy* / Q000503:physiopathology; D004576:Electromyography; D005260:Female; D006801:Humans; D007267:Injections; D007826:Laryngismus / Q000188:drug therapy* / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D009465:Neuromuscular Agents / Q000008:administration & dosage / Q000627:therapeutic use*; D012189:Retrospective Studies; D016896:Treatment Outcome
chemical_list: D009465:Neuromuscular Agents; D019274:Botulinum Toxins, Type A