title: Reversal of sensory deficit through sacral neuromodulation in an animal model of fecal incontinence.
abstract: Sacral neuromodulation (SNM) is a treatment option for intractable fecal incontinence. The mechanism of action is unclear, however, increasing evidence for afferent somatosensory effects exists. This study's aim was to elucidate effects of acute SNM on the cerebral cortex in a rodent model of pudendal nerve injury.
  
  
  
  The effects of 14 Hz and 2 Hz SNM on sensory cortical activation were studied. In 32 anesthetized rats, anal canal evoked potentials (EPs) were recorded over the primary somatosensory cortex. Pudendal nerve injury was produced by 1-hour inflation of two intra-pelvic balloons. Four groups were studied: balloon injury, balloon injury plus either 14 Hz or 2 Hz SNM, sham operation. Immunohistochemistry for the neural plasticity marker polysialylated neural cell adhesion molecule (PSA-NCAM) positive cells (numerical density and location) in the somatosensory cortex was performed.
  
  
  
  Anal EP amplitudes diminished during balloon inflation; 14 Hz SNM restored diminished anal EPs to initial levels and 2 Hz SNM to above initial levels. Evoked potential latencies were prolonged during balloon inflation. The numerical density of PSA-NCAM positive cells increased in the SNM groups, but not in sham or balloon injury without SNM. Stimulated cortices showed clusters of PSA-NCAM positive cells in layers II, IV, and V. Post SNM changes were similar in both SNM groups.
  
  
  
  Sacral neuromodulation augments anal representation in the sensory cortex and restores afferent pathways following injury. PSA-NCAM positive cell density is increased in stimulated cortices and positive cells are clustered in layers II, IV, and V.
authors.affiliation: School of Medicine and Medical Science, University College Dublin, Dublin, Ireland.
authors.forename: J
authors.initials: J
authors.lastname: Evers
authors.affiliation: School of Medicine and Medical Science, University College Dublin, Dublin, Ireland.
authors.forename: L
authors.initials: L
authors.lastname: Devane
authors.affiliation: School of Medicine and Medical Science, University College Dublin, Dublin, Ireland.|National Centre for Bowel Research and Surgical Innovation and GI Physiology Unit, Queen Mary College, University of London, London, UK.
authors.forename: E V
authors.initials: EV
authors.lastname: Carrington
authors.affiliation: National Centre for Bowel Research and Surgical Innovation and GI Physiology Unit, Queen Mary College, University of London, London, UK.
authors.forename: S M
authors.initials: SM
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 R
authors.initials: PR
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: D000818:Animals; D004195:Disease Models, Animal; D004599:Electric Stimulation Therapy / Q000379:methods*; D005073:Evoked Potentials, Somatosensory / Q000502:physiology*; D005242:Fecal Incontinence / Q000503:physiopathology* / Q000628:therapy; D005260:Female; D051381:Rats; D017208:Rats, Wistar; D012447:Sacrum / Q000502:physiology*; D013003:Somatosensory Cortex / Q000502:physiology*
keywords: PSA-NCAM/polysialylated neural cell adhesion molecule; cortical evoked potentials; mechanism of action; sacral nerve stimulation