Pelvic Floor Muscle Activity During Coughing: Altered Pattern in Women with Stress Urinary Incontinence

ObjectivesTo assess the relationship between bladder pressure (BP) and pelvic floor muscle activity during coughing in women with stress urinary incontinence (SUI).MethodsExternal anal sphincter integrated electromyographic activity (EAS-EMGi) was recorded in 21 women using pregelled surface electrodes. The relationship between BP and EAS-EMGi activity was assessed during four successive coughs at 0, 200, and 400 mL of filling. We also compared this relationship in 6 women presenting with SUI and 4 continent women.ResultsAmong the considered models, a sigmoid relationship between EAS-EMGi and BP best described the data: EMGi = exp[a × (BP − b)]/(1 + exp[a × (BP − b)]). This relationship between EAS-EMGi and BP was significantly altered in women presenting with SUI (P <0.0001).ConclusionsWomen with SUI exhibited an altered pattern of the pelvic floor muscle response during successive coughing efforts. The lack of this modulation of pelvic floor muscle response to stress might be one of the pathophysiologic factors of SUI.