Dysfunctional voiding in women: which muscles are responsible?

Objective To analyse the striated external urethral sphincter (EUS) and pel vic floor muscles using two different electromyography (EMG) techniques in women with dysfunctional voiding and/or urinary retention. Patients and methods Fifteen women (mean age 38.2 years, range 18-61) with dysfunctional voiding and/or unexplained voiding dysfunction associated wit h urinary retention were examined neurologically and urologically; urodynam ics and kinesiological EMG of the bilateral pubococcygeal and external uret hral striated sphincter muscles were obtained. In an additional neurophysio logical session. concentric-needle EMG of the external urethral sphincter w as performed. Results Kinesiological EMG recordings revealed inappropriate pelvic floor m uscle activation during voiding in 11 and EUS activation in four women. Con centric needle EMG of the EUS revealed complex repetitive discharges in the four women with inappropriate urethral sphincter activation recorded by ki nesiological EMG during voiding. Biofeedback training led to improvement in women with inappropriate pubococcygeal activation but not in those with ur ethral sphincter complex repetitive discharges. Conclusion Urodynamic examinations in combination with kinesiological EMC e xamination of the pubococcygeal and external urethral sphincter muscles rev ealed two groups of women with dysfunctional voiding, Further diagnostic ev aluation of such patients with concentric-needle EMG is mandatory. The diff erentiation of the two groups is therapeutically relevant.