OBJECTIVE: To investigate the role of altered innervation of the urethral sphincter in the genesis of genuine stress incontinence. DESIGN: Prospective observational study. SETTING: Tertiary referral centre urodynamics unit. SUBJECTS: Sixty-eight women, 33 with urodynamically proven pure genuine stress incontinence and 35 controls without urinary symptoms. INTERVENTIONS: Concentric needle electromyography of the urethral striated sphincter. MAIN OUTCOME MEASURES: The means of motor unit potential duration, number of changes in polarity and the amplitude of individual motor unit potentials were compared between the two groups. RESULTS: There was no statistically significant difference in motor unit potential duration (P = 0.87) or in the number of changes in polarity (P = 0.85). There was a trend towards a higher amplitude of motor unit potentials in the control group (P = 0.07). CONCLUSIONS: Our findings suggest that denervation and re-innervation of the striated urethral sphincter following trauma to the pelvic floor, such as that occurring during childbirth, is not a major aetiological factor in the development of genuine stress incontinence.
OBJECTIVE: To investigate the role of altered innervation of the urethral sphincter in the genesis of genuine stress incontinence. DESIGN: Prospective observational study. SETTING: Tertiary referral centre urodynamics unit. SUBJECTS: Sixty-eight women, 33 with urodynamically proven pure genuine stress incontinence and 35 controls without urinary symptoms. INTERVENTIONS: Concentric needle electromyography of the urethral striated sphincter. MAIN OUTCOME MEASURES: The means of motor unit potential duration, number of changes in polarity and the amplitude of individual motor unit potentials were compared between the two groups. RESULTS: There was no statistically significant difference in motor unit potential duration (P = 0.87) or in the number of changes in polarity (P = 0.85). There was a trend towards a higher amplitude of motor unit potentials in the control group (P = 0.07). CONCLUSIONS: Our findings suggest that denervation and re-innervation of the striated urethral sphincter following trauma to the pelvic floor, such as that occurring during childbirth, is not a major aetiological factor in the development of genuine stress incontinence.
Authors: M A Rocha; M G F Sartori; M De Jesus Simões; V Herrmann; E C Baracat; G Rodrigues de Lima; M J B C Girão Journal: Int Urogynecol J Pelvic Floor Dysfunct Date: 2007-03-29