External urethral sphincter electromyography in asymptomatic women and the influence of the menstrual cycle

Abstract

CRDs and DB activity in the external striated urethral sphincter is present in a high proportion of asymptomatic young women. This abnormal EMG activity has been shown for the first time to change during the menstrual cycle in individual women. CRDs and DBs are more commonly found in the luteal phase of the menstrual cycle. The importance of CRDs and DBs in the aetiology of urinary retention in young women remains uncertain. The distribution and or quantity of abnormal EMG activity in the external urethral sphincter may be important. In a woman with urinary retention the finding of CRDs and DBs by needle EMG does not automatically establish Fowler's syndrome as the explanation for the bladder dysfunction. Urethral pressure profilometry may be helpful in establishing a diagnosis. Opiate use and psychological stress should be considered in young women with urinary retention.

Fowler's syndrome: a primary disorder of urethral sphincter relaxation

“…Variability in the quantity of abnormal EMG activity has been reported between the proliferative and luteal phases of the menstrual cycle in apparently asymptomatic women, providing yet further evidence for a hormonal link to the condition. 7 A similar type of sphincter disturbance has not been found in men with urinary retention. The distal urethra has been shown to be a constituent part of the clitoris, forming the 'clitorourethrovaginal complex', and hence clearly the distal urethra has major sex-determined attributes.…”

“…This association is now no better understood than when the observation was first made, and although the coincidence of PCOS and retention is by no means inevitable, a hormonal basis for the EMG abnormality seems likely. Variability in the quantity of abnormal EMG activity has been reported between the proliferative and luteal phases of the menstrual cycle in apparently asymptomatic women, providing yet further evidence for a hormonal link to the condition . A similar type of sphincter disturbance has not been found in men with urinary retention.…”

“…Thus retention is a secondary effect of the abnormal sphincter contraction and only when the strength of the inhibitory signal is sufficient will retention occur. Therefore, the finding of complex repetitive discharges and decelerating burst activity in apparently asymptomatic young women does not invalidate the significance of the finding of the EMG activity in the context of urinary retention in a young woman …”

New Frontiers in Molecular and Imaging Research on Evaluation and Diagnosis of Bladder Outlet Obstruction in Women

“…However, the presence of CRDs and DBs do not absolutely correlate with the diagnosis of BOO, as these phenomenon were not uncommon in women with no retentive symptoms or in patients who underwent anti-incontinence procedures (15). A recent study also showed CRDs and DBs were present in a high proportion (53%) of asymptomatic women, were shown to change during the menstrual cycle in individual women, and occurred most commonly in the luteal phase (16). …”

Do ‘whale noises’ help in the diagnosis of Fowler's syndrome?

“… found the presence of CRD in 30% of healthy women and Tawadros et al. also found this in 53% of healthy female volunteers. These authors showed that CRD and DB are mostly present during the luteal phase of the menstrual cycle.…”