An International Continence Society (ICS) report on the terminology for pelvic floor muscle assessment

INTRODUCTION

The terminology for female and male pelvic floor muscle (PFM) assessment has expanded considerably since the first PFM function and dysfunction standardization of terminology document in 2005. New terms have entered assessment reports, and new investigations to measure PFM function and dysfunction have been developed. An update of this terminology was required to comprehensively document the terms and their definitions, and to describe the assessment method and interpretation of the finding, to standardize assessment procedures and aid diagnostic decision making.

METHODS

This report combines the input of members of the Standardisation Committee of the International Continence Society (ICS) Working Group 16, with contributions from recognized experts in the field and external referees. A logical, sequential, clinically directed assessment framework was created against which the assessment process was mapped. Within categories and subclassifications, each term was assigned a numeric coding. A transparent process of 12 rounds of full working group and external review was undertaken to exhaustively examine each definition, plus additional extensive internal development, with decision making by collective opinion (consensus).

RESULTS

A Terminology Report for the symptoms, signs, investigations, and diagnoses associated with PFM function and dysfunction, encompassing 185 separate definitions/descriptors, has been developed. It is clinically based with the most common assessment processes defined. Clarity and user-friendliness have been key aims to make it interpretable by clinicians and researchers of different disciplines.

CONCLUSION

A consensus-based Terminology Report for assessment of PFM function and dysfunction has been produced to aid clinical practice and be a stimulus for research.

Fatigability of the external anal sphincter muscles using a novel strength training resistance exercise device

Exercises involving pelvic floor muscles including repetitive voluntary contractions of external anal sphincter (EAS) musculature have been used to improve fecal incontinence. Muscle fatigue is a prerequisite for successful strength training. However, muscle fatigue induced by these exercises has not been systematically studied. We aimed to assess the fatigability of EAS muscles during various exercise methods. Twelve nulliparous (21 ± 2.7 yr) women were studied. We evaluated fatigue during 40 repetitive 3-s contractions and 30-s long squeeze contractions both with and without an intra-anal compressible resistant load. The sequence of exercises was randomized. This load was provided by the continence muscles Resistance Exerciser Device. Anal canal pressures were recorded by high-resolution manometry. Exercise against a resistive load showed significant decrease in anal contractile integral (CI) and maximum squeeze pressure during repetitive short squeeze contractions compared with exercise without a load. Linear regression analysis showed a significant negative correlation between anal CI and successive contraction against load, suggesting "fatigue." Similar findings were observed for maximum squeeze pressure (slope with load = -4.2, P = 0.0003, vs. without load = -0.9, P = 0.3). Long squeeze contraction against a load was also more susceptible to fatigue than without a load (P < 0.0001). In conclusion, repetitive contractions against a compressible load induce fatigue and thus have the potential to strengthen the anal sphincter contractile function than contractions without a load. Fatigue rate in long squeeze contraction exercises with a load is significantly faster than that without a load, also indicating greater effectiveness in inducing muscle fatigue.NEW & NOTEWORTHY Fecal incontinence is a distressing disorder with a mainstay of treatment being pelvic floor muscle exercises. However, none of these exercises has proven occurrence of fatigability, which is an important prerequisite for successful muscle strengthening in rehabilitative exercises. In this study, we proved that we can fatigue the external anal sphincter muscles more efficiently by providing a resistive load during anal repetitive short squeeze contractions and long squeeze contraction exercise.

External Anal Sphincter Fatigability: An Electromyographic and Manometric Study in Patients With Anorectal Disorders

Background/Aims

External anal sphincter (EAS) plays an important role in fecal and gas voluntary continence. Like every muscle, it can be affected by repeated efforts due to fatigability (physiological response) and/or fatigue (pathological response). No standardized fatiguing protocol and measure method to assess EAS fatigability has existed. The aim is to test a simple, standardized protocol for fatiguing and measuring EAS fatigability and fatigue to understand better the part of EAS fatigability in the pathophysiology of fecal incontinence.

Methods

Patients with anorectal disorders evaluated with anorectal manometry were included. They had to perform 10 repetitions of maximum voluntary contraction (MVC) of 20 seconds. Measurement was made with an anorectal manometry catheter and a surface recording electromyography (EMG). The primary outcome was the difference in EMG root mean square between the first and the last MVC. Secondary outcomes were differences in other EMG and manometry parameters between the first and the last MVC. Difficulties and adverse effects were recorded.

Results

Nineteen patients underwent the fatiguing protocol. All patients completed the entire protocol and no complications were found. No difficulty was declared by the examiner. A significant decrease in root mean square was found between the first and last MVC (0.01020 ± 0.00834 mV vs 0.00661 ± 0.00587 mV; P = 0.002), in maximum anal pressure area under the curve of continuous recordings of anal pressure and mean and total EMG power (P < 0.05).

Conclusions

This protocol is simple and minimally invasive to measure EAS fatigue and fatigability. We highlighted a fatigue of EAS in many patients with anorectal disorders.

Novel insight into pressurization of the male and female urethra through application of a multi-channel fibre-optic pressure transducer: Proof of concept and validation

Purpose

To confirm feasibility of recording pressure along the length of the urethra using a multi-sensor fibre-optic pressure catheter; to identify the spatial and temporal features of changes in pressure along the urethra at sites related to specific striated pelvic floor muscles; and to investigate the relationship between urethral pressures and activation of individual pelvic floor muscles estimated from ultrasound imaging.

Materials and Methods

Proof-of-concept study including one male (47 years old) and one female (33 years old). A multi-sensor fibre optic pressure catheter (10 mm sensor separation) was inserted into the urethra. Pressure data were recorded simultaneously with trans-perineal ultrasound imaging measures of pelvic floor muscle activity during sub-maximal and maximal voluntary contractions and evoked coughs.

Results

Pressure changes along the urethra were recorded in all tasks in both participants. Face validity of interpretation of pressure measures with respect to individual muscles was supported by correlation with ultrasound-measured displacements induced by the relevant muscles. Onset of pressure increase occurred in a distal to proximal sequence in the urethra of the male but not the female during voluntary contraction. Peak urethral pressures varied in location, timing and amplitude between tasks. Evoked cough induced in the greatest urethral pressure increase across all tasks for both participants.

Conclusions

The high spatial resolution pressure catheter provide viable and valid recordings of urethral pressure in a male and female. Data provide preliminary evidence of sex differences in spatial and temporal distribution of urethral pressure changes.

Reconsideration of pelvic floor muscle training to prevent and treat incontinence after radical prostatectomy

Urinary incontinence is common after radical prostatectomy. Pelvic floor muscle training provides a plausible solution. Although early trials provided promising results, systematic reviews have questioned the efficacy of this intervention. A major consideration is that most clinical trials in men have applied principles developed for pelvic floor muscle training for stress urinary incontinence in women, despite differences in anatomy between sexes and differences in the mechanisms for continence/incontinence. Literature regarding continence control in men has been conflicting and often based on erroneous anatomy. New understanding of continence mechanisms in men, including the complex contribution of multiple layers of striated pelvic floor muscles, and detailed consideration of the impact of radical prostatectomy on continence anatomy and physiology, have provided foundations for a new approach to pelvic floor muscle training to prevent and treat incontinence after prostatectomy. An approach to training can be designed to target the pathophysiology of incontinence. This approach relies on principles of motor learning and exercise physiology, in a manner that is tailored to the individual patient. The aims of this review are to consider new understanding of continence control in men, the mechanisms for incontinence after radical prostatectomy, and to review the characteristics of a pelvic floor muscle training program designed to specifically target recovery of continence after prostatectomy.

Review of pelvic and perineal neuromuscular fatigue: Evaluation and impact on therapeutic strategies

BACKGROUND

Pelvic floor fatigue is known by its clinical consequences (fecal incontinence, stress urinary incontinence, pelvic organ prolapse), but there are still few studies on the subject.

OBJECTIVE

This article presents an overview of the current knowledge of pelvic and perineal fatigue, focusing on its assessment and consequences in terms of evaluation and therapeutic strategies, to propose an evaluation that could be routinely performed.

METHODS

We performed a systematic review of the literature in MEDLINE via PubMed and Cochrane Library databases by using the keywords pelvic floor, muscular fatigue, physiopathology, stress urinary incontinence, pelvic organ prolapse, fecal incontinence, physical activity, and pelvic rehabilitation. We included reports of systematic reviews and retrospective and prospective studies on adult humans and animals in English or French published up to April 2018 with no restriction on start date.

RESULTS

We selected 59 articles by keyword search, 18 by hand-search and 3 specific guidelines (including the 2009 International Continence Society recommendations); finally 45 articles were included; 14 are described in the Results section (2 reviews of 6 and 20 studies, and 12 prospective observational or cross-over studies of 5 to 317 patients including 1 of animals). Perineal fatigue can be assessed by direct assessment, electromyography and spectral analysis and during urodynamics. Because pelvic floor fatigue assessments are not evaluated routinely, this fatigability is not always identified and is often falsely considered an exclusive pelvic floor weakness, as suggested by some rehabilitation methods that also weaken the pelvic floor instead of enhancing it.

CONCLUSION

Pelvic floor fatigue is not evaluated enough on a routine basis and the assessment is heterogeneous. A better knowledge of pelvic floor fatigue by standardized routine evaluation could lead to targeted therapeutic strategies.

Postprostatectomy incontinence is related to pelvic floor displacements observed with trans-perineal ultrasound imaging

AIMS

To investigate the relationship between post-prostatectomy incontinence and dynamic features of activation of specific pelvic floor muscles in addition to anatomical parameters of the urethra.

METHODS

Forty-two men aged 66 (7) years (incontinent [N = 19] and continent [N = 23]) who had undergone prostatectomy participated. Transperineal ultrasound imaging was used to record sagittal images of pelvic structures during involuntary coughing and sustained maximal voluntary contractions. Imaging data were analyzed to calculate displacements of pelvic floor landmarks associated with activation of the puborectalis, striated urethral sphincter, and bulbocavernosus muscles. Anatomical features of functional urethral length and the resting position of the ano-rectal and urethra-vesical junctions were calculated. A principal component analysis and multiple logistic regression were used to consider which combinations of variables best distinguish between men with and without incontinence.

RESULTS

Five principal components were identified that together explained 72.0% of the data. Two principal components that represented (i) striated urethral sphincter activation and (ii) bulbocavernosus and puborectalis muscle activation were significantly different between participants with and without incontinence. Together these components correctly identified 88.1% of incontinent men, with a specificity and sensitivity of 91.3% and 84.2%, respectively. Poor function of the bulbocavernosus and puborectalis muscles could be compensated by good striated urethral sphincter function, but the bulbocavernosus and puborectalis muscles had less potential to compensate for poor striated urethral sphincter function.

CONCLUSIONS

Dynamic features of pelvic floor muscle activation, particularly shortening of the striated urethral sphincter during cough and voluntary contraction, are related to continence status after prostatectomy.

Bioelectrical activity of the pelvic floor muscles during synchronous whole-body vibration--a randomized controlled study

Background

More and more frequently stress urinary incontinence affects young healthy women. Hence, early implementation of effective preventive strategies in nulliparous continent women is essential, including pelvic floor muscle training. An initial evaluation based on the bioelectrical activity of the pelvic floor muscles (PFM) during whole-body vibration (WBV) would help to devise the best individualized training for prevention of stress urinary incontinence in woman. We hypothesized that synchronous WBV enhances bioelectrical activity of the PFM which depends on vibration frequency and peak-to-peak vibration displacement.

Methods

The sample consisted of 36 nulliparous continent women randomly allocated to three comparative groups. Group I and II subjects participated in synchronous whole-body vibrations on a vibration platform; the frequency and peak-to-peak displacement of vibration were set individually for each group. Control participants performed exercises similar to those used in the study groups but without the concurrent application of vibrations. Pelvic floor surface electromyography (sEMG) activity was recorded using a vaginal probe during three experimental trials limited to 30s, 60s and 90s. The mean amplitude and variability of the signal were normalized to the Maximal Voluntary Contraction – MVC.

Results

Friedman’s two-way ANOVA revealed a statistically significant difference in the mean normalized amplitudes (%MVC) of the sEMG signal from the PFM during 60s- and 90s-trials between the group exposed to high-intensity WBV and control participants (p < 0.05). Longer trial duration was associated with a statistically significant decrease in the variability of sEMG signal amplitude in the study and control groups (p < 0.05).

Conclusions

Synchronous high-intensity WBV (40 Hz, 4 mm) of long duration (60s, 90s) significantly enhances the activation of the PFM in young continent women. Prolonged maintenance of a static position significantly decreases the variability of sEMG signal amplitude independent of whole-body vibrations. Single whole-body vibrations in nulliparous continent women does not cause pelvic floor muscle fatigue.

Trial registration

The trial was registered in the Australian and New Zealand Clinical Trials Registry (no. ACTRN12615000966594); registration date: 15/09/2015.

Pattern of activation of pelvic floor muscles in men differs with verbal instructions

AIMS

To investigate the effect of instruction on activation of pelvic floor muscles (PFM) in men as quantified by transperineal ultrasound imaging (US) and to validate these measures with invasive EMG recordings.

METHODS

Displacement of pelvic floor landmarks on transperineal US, intra-abdominal pressure (IAP) recorded with a nasogastric transducer, and surface EMG of the abdominal muscles and anal sphincter were recorded in 15 healthy men during sub-maximal PFM contractions in response to different verbal instructions: "tighten around the anus," "elevate the bladder," "shorten the penis," and "stop the flow of urine." In three men, fine-wire EMG recordings were made from puborectalis and bulbocavernosus, and trans-urethral EMG recordings from the striated urethral sphincter (SUS). Displacement data were validated by analysis of relationship with invasive EMG. Displacement, IAP, and abdominal/anal EMG were compared between instructions.

RESULTS

Displacement of pelvic landmarks correlated with the EMG of the muscles predicted anatomically to affect their locations. Greatest dorsal displacement of the mid-urethra and SUS activity was achieved with the instruction "shorten the penis." Instruction to "elevate the bladder" induced the greatest increase in abdominal EMG and IAP. "Tighten around the anus" induced greatest anal sphincter activity.

CONCLUSIONS

The pattern of urethral movement measured from transperineal US is influenced by the instructions used to teach activation of the pelvic floor muscles in men. Efficacy of PFM training may depend on the instructions used to train activation. Instructions that optimize activation of muscles with a potential to increase urethral pressure without increasing abdominal EMG/IAP are likely ideal. Neurourol. Urodynam. 35:457-463, 2016. © 2015 Wiley Periodicals, Inc.