title: Value of the pudendal nerves terminal motor latency measurements in the diagnosis of occult stress urinary incontinence.
abstract: BACKGROUND
  Occult stress urinary incontinence may lead to de novo stress urinary incontinence after pelvic floor repair surgery. A measurement of pudendal nerve terminal motor latency can reflect the integrity of the nerves. We aimed to explore the value of pudendal nerve terminal motor latency in the diagnosis of occult stress urinary incontinence in pelvic organ prolapse patients.
  
  
  METHODS
  Ten patients with stress urinary incontinence (SUI group), 10 with SUI and uterine or vaginal prolapse (POP + SUI group) and 10 with uncomplicated uterine or vaginal prolapse (POP group) were evaluated for their pudendal nerve terminal motor latency using a keypoint electromyogram.
  
  
  RESULTS
  The amplitude of positive waves was between 0.1 and 0.2 mV. The nerve terminal motor latency was between 1.44 and 2.38 ms. There was no significant difference in the wave amplitudes of pudendal nerve evoked action potential among the three different groups (P > 0.05). The pudendal nerve latency of the SUI group, POP + SUI group and POP group were (2.9 ± 0.7) seconds, (2.8 ± 0.7) seconds and (1.9 ± 0.5) seconds respectively. The difference between the SUI group and POP + SUI group was not statistically significant (P > 0.05), whereas the difference between the SUI and POP groups and between the POP + SUI and POP groups were statistically significant (P < 0.05). There was a positive correlation between pudendal nerve latency and the severity of SUI; the correlation coefficient was 0.720 (P < 0.01).
  
  
  CONCLUSIONS
  Patients with SUI may have some nerve demyelination injuries in the pudendal nerve but the damage might not involve the nerve axons. The measurement of pudendal nerve latency may be useful for the diagnosis of SUI in POP patients.
authors.affiliation: Department of Obsterics and Gynecology, Peking Union Medical College Hospital, Peking Union Medical College, Beijing 100730, China. zhu_julie@sina.com
authors.forename: Lan
authors.initials: L
authors.lastname: Zhu
authors.forename: Ning
authors.initials: N
authors.lastname: Hai
authors.forename: Jing-He
authors.initials: JH
authors.lastname: Lang
authors.forename: Shi-Yun
authors.initials: SY
authors.lastname: Yu
authors.forename: Bin
authors.initials: B
authors.lastname: Li
authors.forename: Felix
authors.initials: F
authors.lastname: Wong
mesh_terms: D005071:Evoked Potentials / Q000502:physiology; D005260:Female; D006801:Humans; D008875:Middle Aged; D056887:Pelvic Organ Prolapse / Q000503:physiopathology; D060525:Pudendal Nerve / Q000503:physiopathology; D014550:Urinary Incontinence, Stress / Q000175:diagnosis* / Q000503:physiopathology; D014596:Uterine Prolapse / Q000503:physiopathology