title: Sacral neuromodulation effects on periurethral sensation and urethral sphincter activity.
abstract: OBJECTIVE
  To characterize the effect of sacral neuromodulation (SNM) on urethral neuromuscular function.
  
  
  METHODS
  Following IRB approval, women with refractory overactive bladder (OAB) underwent standardized urethral testing prior to and after Stage 1 SNM implantation. Periurethral sensation was measured using current perception thresholds (CPT). Striated urethral sphincter activity was quantified using concentric needle electromyography (CNE) and Multi-Motor Unit Action Potential (MUP) analysis software. Nonparametric analyses were used to characterize pre/post changes with intervention. Baseline CPT and CNE findings were compared between SNM responders and non-responders.
  
  
  RESULTS
  Twenty-seven women were enrolled in this pilot study with a mean age of 61 ± 13 years. Twenty of 26 women (76.9%) responded to SNM and went to Stage 2 permanent implantation. Four (14.8%) withdrew after Stage 1 implantation; three of the four withdrawals had not had therapeutic responses to SNM. CPT and CNE parameters did not significantly differ from baseline 2 weeks after SNM. Pre-SNM urethral sensation was not significantly different between responders and non-responders. However, responders had larger amplitude, longer duration and more turns and phases at baseline approaching significance, reflecting more successful urethral reinnervation, than non-responders.
  
  
  CONCLUSIONS
  SNM does not alter urethral neuromuscular function 2 weeks post Stage 1 implantation.
authors.affiliation: Division of Urogynecology and Reconstructive Pelvic Surgery, University of Alabama at Birmingham, Birmingham, AL, USA. gleasj@gmail.com
authors.forename: Jonathan L
authors.initials: JL
authors.lastname: Gleason
authors.forename: Kimberly
authors.initials: K
authors.lastname: Kenton
authors.forename: W Jerod
authors.initials: WJ
authors.lastname: Greer
authors.forename: Olga
authors.initials: O
authors.lastname: Ramm
authors.forename: Jeff M
authors.initials: JM
authors.lastname: Szychowski
authors.forename: Tracey
authors.initials: T
authors.lastname: Wilson
authors.forename: Holly E
authors.initials: HE
authors.lastname: Richter
mesh_terms: D000200:Action Potentials; D000368:Aged; D004599:Electric Stimulation Therapy / Q000009:adverse effects / Q000295:instrumentation*; D004576:Electromyography; D004867:Equipment Design; D005260:Female; D006801:Humans; D058542:Implantable Neurostimulators; D008160:Lumbosacral Plexus; D008875:Middle Aged; D010465:Perception; D010865:Pilot Projects; D011446:Prospective Studies; D020127:Recovery of Function; D012677:Sensation; D012684:Sensory Thresholds; D013997:Time Factors; D016896:Treatment Outcome; D014521:Urethra / Q000294:innervation*; D001743:Urinary Bladder / Q000294:innervation*; D053201:Urinary Bladder, Overactive / Q000175:diagnosis / Q000503:physiopathology / Q000628:therapy*