title: Continent women have better urethral neuromuscular function than those with stress incontinence.
abstract: OBJECTIVE
  The objective of this study is to describe urethral neuromuscular function using concentric needle electromyography (EMG) in stress incontinent (SUI) and asymptomatic women.
  
  
  METHODS
  Following Institutional Review Board approval, we recruited SUI and asymptomatic women without urinary incontinence. Participants underwent quantitative urethral EMG and urodynamic testing.
  
  
  RESULTS
  Sixty-seven women (37 SUI, 30 continent) with mean ± SD age of 44 ± 12 years participated. Nearly all EMG parameters showed significant differences between continent and SUI women consistent with better motor unit recruitment in continent women. Continent women had larger-amplitude, longer-duration motor unit action potentials (MUP) with increased turns and better MUP recruitment during bladder filling (P < .05). Increasing age was inversely correlated with nearly all MUP parameters (P < .05), suggesting MUP to be consistent with neuropathy.
  
  
  CONCLUSIONS
  We found significant differences in multiple MUP parameters in urethral sphincter between continent and stress incontinent women, suggesting continent women have better urethral innervation. We also found significant neuropathic MUP changes with advancing age, regardless of continence status.
authors: Division of Female Pelvic Medicine & Reconstructive Surgery, Department of Obstetrics & Gynecology, Loyola University Stritch School of Medicine, 2160 South First Avenue, Maywood, IL 60153, USA. kkenton@lumc.edu
authors: Kimberly
authors: K
authors: Kenton
authors: Elizabeth
authors: E
authors: Mueller
authors: Linda
authors: L
authors: Brubaker
mesh_terms: D000200:Action Potentials / Q000502:physiology; D000328:Adult; D000375:Aging / Q000502:physiology; D016022:Case-Control Studies; D004566:Electrodes; D004576:Electromyography / Q000295:instrumentation / Q000379:methods; D005260:Female; D006801:Humans; D008875:Middle Aged; D009132:Muscles / Q000294:innervation / Q000502:physiology / Q000503:physiopathology*; D009469:Neuromuscular Junction / Q000502:physiology / Q000503:physiopathology*; D014521:Urethra / Q000294:innervation* / Q000502:physiology / Q000503:physiopathology*; D014550:Urinary Incontinence, Stress / Q000503:physiopathology*; D014563:Urodynamics / Q000502:physiology