Electromyography in urinary retention and obstructed voiding in women

Therapeutic Efficacy of Urethral Sphincteric Botulinum Toxin Injections for Female Sphincter Dysfunctions and a Search for Predictive Factors

External urethral sphincter (EUS) dysfunction is a common, bothersome female voiding dysfunction. This study aims to analyze the characteristics of different types of female EUS dysfunction, as well as to determine the outcome predictors of sphincteric botulinum toxin A (BoNT-A) injection. Women receiving sphincteric BoNT-A injections for refractory EUS dysfunction were retrospectively reviewed. A comparison of the baseline clinical, urodynamic parameters and the treatment responses were made for patients with different EUS dysfunctions. A total of 106 females were included. Significantly increased detrusor overactivity, detrusor contracting pressure and the bladder outlet obstruction index with decreased urge sensation were noted in patients diagnosed with dysfunctional voiding or detrusor sphincter dyssynergia comparing to those diagnosed with poor relaxation of the external urethral sphincter. The average subjective improvement rate was 67% for the injection. The therapeutic effect was not affected by the type of EUS dysfunction. The multivariate analysis revealed that bladder neck narrowing and catheterization history were predictive of negative outcomes. There is a distinct urodynamic presentation for each type of female EUS dysfunction. Sphincteric BoNT-A injection provides a good therapeutic outcome for refractory EUS dysfunction. A narrowing bladder neck and a history of catheterization suggest poor therapeutic outcomes.

International Continence Society best practice statement for use of sacral neuromodulation

AIMS

Sacral neuromodulation (SNM) is an accepted therapy for a variety of conditions. However, despite over 20 years of experience, it remains a specialized procedure with a number of subtleties. Here we present the recommendations issued from the International Continence Society (ICS) SNM Consensus Panel.

METHODS

Under the auspices of the ICS, eight urologists, three colorectal surgeons and two urogynecologists, covering a wide breadth of geographic and specialty interest representation, met in January 2017 to discuss best practices for neuromodulation. Suggestions for statements were submitted in advance and specific topics were assigned to committee members, who prepared and presented supporting data to the group, at which time each topic was discussed in depth. Best practice statements were formulated based on available data. This document was then circulated to multiple external reviewers after which final edits were made and approved by the group.

RESULTS

The present recommendations, based on the most relevant data available in the literature, as well as expert opinion, address a variety of specific and at times problematic issues associated with SNM. These include the use of SNM for a variety of underlying conditions, need for pre-procedural testing, use of staged versus single-stage procedures, screening for success during the trial phase, ideal anesthesia, device implantation, post-procedural management, trouble-shooting loss of device function, and future directions for research.

CONCLUSIONS

These guidelines undoubtedly constitute a reference document, which will help urologists, gynecologists, and colorectal surgeons optimize their use of SNM for refractory urinary urgency and frequency, UUI, NOR, and FI.

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

OBJECTIVE

To investigate by electromyography (EMG), the presence of complex repetitive discharges (CRDs) and decelerating bursts (DBs) in the striated external urethral sphincter during the menstrual cycle in female volunteers with no urinary symptoms and complete bladder emptying.

SUBJECTS AND METHODS

Healthy female volunteers aged 20-40 years, with regular menstrual cycles and no urinary symptoms were recruited. Volunteers completed a menstruation chart, urinary symptom questionnaires, pregnancy test, urine dipstick, urinary free flow and post-void ultrasound bladder scan. Exclusion criteria included current pregnancy, use of hormonal medication or contraception, body mass index of >35 kg/m(2) , incomplete voiding and a history of pelvic surgery. Eligible participants underwent an external urethral sphincter EMG, using a needle electrode in the early follicular phase and the mid-luteal phase of their menstrual cycles. Serum oestradiol and progesterone were measured at each EMG test.

RESULTS

In all, 119 women enquired about the research and following screening, 18 were eligible to enter the study phase. Complete results were obtained in 15 women. In all, 30 EMG tests were undertaken in the 15 asymptomatic women. Sphincter EMG was positive for CRDs and DBs at one or both phases of the menstrual cycle in eight (53%) of the women. Three had CRDs and DBs in both early follicular and mid-luteal phases. Five had normal EMG activity in the early follicular phase and CRDs and DBs in the mid-luteal phase. No woman had abnormal EMG activity in the early follicular phase and normal activity in the luteal phase. There was no relationship between EMG activity and age, parity or serum levels of oestradiol and progesterone.

CONCLUSIONS

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.

A functional magnetic resonance imaging study of the effect of sacral neuromodulation on brain responses in women with Fowler's syndrome

STUDY TYPE

Aetiology (case series).

LEVEL OF EVIDENCE

4.

OBJECTIVE

To examine brain responses to bladder filling in young women with Fowler's syndrome (FS, a sphincter abnormality manifested by impaired voiding and bladder sensation), treated with sacral neuromodulation (SNM).

PATIENTS AND METHODS

Six women, aged 18-39 years with FS underwent functional brain magnetic resonance imaging (fMRI) immediately after SNM and when untreated (baseline). Data were collected at four sessions: after SNM with an empty and a full bladder, and at baseline with an empty and a full bladder. In each session, 280 whole-brain scans were acquired while repeatedly infusing and withdrawing 50 mL of saline, using push-buttons to report changing desire to void. Data were analysed using Statistical Parametric Mapping.

RESULTS

At baseline with an empty bladder, extensive responses (contrast = infusion-withdrawal) were almost exclusively negative ('deactivations'), e.g. in the right insula, seat of visceral sensation. Increased bladder volume and/or SNM treatment reduced deactivations and strengthened normal (positive) responses, e.g. in the periaqueductal grey (PAG) terminus of ascending spinal afferents. At baseline, there was significant correlation of brain responses with maximum urethral closure pressure.

CONCLUSION

These data show that brain responses to bladder filling are abnormal in FS. The explanation for this that best explains the evidence is that the primary abnormality is an overactive urethra that generates abnormally strong inhibitory afferent signals, so effectively blocking bladder afferent activity at the sacral level and deactivating the PAG and higher centres, with consequent loss of bladder sensation and ability to void. Apparently, a normal mechanism for suppression of incontinence involving the striated urethral sphincter becomes exaggerated in FS and prevents voiding. SNM seems to act at the sacral level, by blocking inhibition by urethral afferents.