title: Acute lumbosacral nerve stimulation does not affect anorectal motor function in a rodent model.
abstract: BACKGROUND
  Sacral nerve stimulation has become a first line treatment for fecal incontinence, however, its effect on the motor function of the anorectum is uncertain. The aim of this study was to apply acute lumbosacral nerve stimulation in an animal model and to determine its effect on the external and internal anal sphincter forces, the rectoanal inhibitory and excitatory reflexes, and the slow wave frequency of the internal anal sphincter.
  
  
  METHODS
  Lumbosacral nerve stimulation was applied to 16 nulliparous female rats. A novel in vivo preparation was designed to allow simultaneous monitoring of external and internal anal sphincter forces. The effect of rectal distension on the two anal sphincters was also studied.
  
  
  RESULTS
  Lumbosacral nerve stimulation delivered at either S1 or L6 in rodents did not affect sphincter forces, rectoanal reflexes or slow wave frequency of anal canal smooth muscle.
  
  
  CONCLUSIONS
  The absence of effect on the motor pathways of continence suggests that the mechanism of action is predominantly on sensory feedback mechanisms from the anorectum, thereby increasing cortical awareness of the pelvic floor.
authors.affiliation: School of Medicine and Medical Science, University College Dublin, Dublin, Ireland.
authors.forename: L A
authors.initials: LA
authors.lastname: Devane
authors.affiliation: School of Medicine and Medical Science, University College Dublin, Dublin, Ireland.
authors.forename: J
authors.initials: J
authors.lastname: Evers
authors.affiliation: National Centre for Bowel Research and Surgical Innovation and GI Physiology Unit, Queen Mary College, University of London, London, UK.
authors.forename: M S
authors.initials: MS
authors.lastname: Scott
authors.affiliation: National Centre for Bowel Research and Surgical Innovation and GI Physiology Unit, Queen Mary College, University of London, London, UK.
authors.forename: C H
authors.initials: CH
authors.lastname: Knowles
authors.affiliation: School of Medicine and Medical Science, University College Dublin, Dublin, Ireland.|Centre for Colorectal Disease, St Vincent's University Hospital, Dublin, Ireland.
authors.forename: P
authors.initials: P
authors.lastname: O'Connell
authors.affiliation: School of Medicine and Medical Science, University College Dublin, Dublin, Ireland.
authors.forename: J F X
authors.initials: JF
authors.lastname: Jones
mesh_terms: D001003:Anal Canal / Q000294:innervation* / Q000503:physiopathology; D000818:Animals; D004195:Disease Models, Animal; D004558:Electric Stimulation; D005242:Fecal Incontinence / Q000503:physiopathology*; D005260:Female; D008160:Lumbosacral Plexus / Q000502:physiology*; D051381:Rats; D012007:Rectum / Q000294:innervation* / Q000503:physiopathology
keywords: anorectal function; fecal incontinence; rat; rectoanal reflex; sacral nerve stimulation; sacral neuromodulation; slow wave