Introduction

Urinary Incontinence is a common condition that often goes under treated. Estimates of prevalence vary depending on the population studied, the measurement period (e.g., daily or weekly) and the instruments used to assess severity. It is estimated to affect about 50% of adult women and 3% to 11% in adult men, however, only 25% to 61% of those women seek care. This may be due to embarrassment, lack of knowledge about treatment options, or a belief that urinary incontinence is a normal inevitable part of aging.

• Urinary incontinence (symptom): Complaint of involuntary loss of urine.
• Stress urinary incontinence: Complaint of involuntary loss of urine on effort or physical exertion (e.g. sporting activities), or on sneezing or coughing.
• Urgency urinary incontinence: Complaint of involuntary loss of urine associated with urgency.
• Mixed urinary incontinence: Complaint of involuntary loss of urine associated with urgency and also effort or physical exertion or on sneezing or coughing.
• Urgency: Complaint of a sudden, compelling desire to pass urine which is difficult to defer.
• Overactive bladder (OAB, Urgency) syndrome: Urinary urgency, usually accompanied by frequency and nocturia, with or without urgency urinary incontinence, in the absence of urinary tract infection or other obvious pathology.

Epidemiology

Urinary incontinence remains a worldwide problem, affecting both males and females, across different cultures and races. As mentioned above, the world wide prevalence is difficult to determine due to differences in definitions used, population surveyed, survey type, response rate, age, gender, availability and efficacy of health‐care, and other factors.

Clinically Relevant Anatomy: Pelvic Floor

The pelvic floor is made up of the muscles, ligaments, and fascial structures that act together to support the pelvic organs and to provide compressive forces to the urethra during increased intra-abdominal pressure.

The pelvic floor muscles refer to the muscular layer of the pelvic floor. It includes the levator ani, striated urogenital sphincter, external anal sphincter, ischiocavernosus, and bulbospongiosus.

The urethra, vagina, and rectum pass through the pelvic floor and are surrounded by the pelvic floor muscles. During increased intra-abdominal pressure, the pelvic floor muscles must contract to provide support. When the pelvic floor muscles contract the urethra, anus, and vagina close. The contraction is important in preventing involuntary loss of urine or rectal contents. The pelvic floor muscles must also relax in order to void.

Etiology

Stress urinary incontinence:

1. Urethral hypermobility: increases in intra-abdominal pressure (e.g., from coughing or sneezing) with insufficient support of the pelvic floor musculature and vaginal connective tissue to the urethra and bladder neck can lead to incontinence.
2. Pregnancy and vaginal birth, post-partum, obesity, chronic cough, chronic heavy lifting and constipation: if there is an increase in abdominal pressure that is greater than the opposing force of the pelvic floor muscles, it can result in stress incontinence.
3. Intrinsic sphincteric deficiency (ISD): this results from a loss of intrinsic urethral mucosal and muscular tone that normally keeps the urethra closed, it can occur in presence or absence of urethral hypermobility and with minimal abdominal pressure.

Urgency urinary incontinence:

This may be secondary to neurologic disorders (e.g., spinal cord injury), bladder abnormalities, increased or altered bladder microbiome, or may be idiopathic.

Overactive bladder:

This could be due to neuropathic, an infection (i.e. urinary tract infection), weak pelvic floor muscles, diet (i.e. consumption of diuretics), medications, excess weight.

Mixed Incontinence:

Individuals can present with more than one type of incontinence. For example stress incontinence and/or urge incontinence might be “masked” by an overactive bladder (frequenting the washroom often to avoid leakage).

Risk Factors

Risk factors for urinary incontinence (UI)             

• Age: The prevalence and severity of UI increases with age. Age may not be an independent risk factor, when studies have controlled for co-morbidities.
• Obesity : This is a strong risk factor for UI. Additionally, weight reduction is associated with improvement or resolution of symptoms, particularly with stress urinary incontinence.
• Parity: Increasing parity is a risk factor for UI, however, nulliparous women also report bothersome UI.
• Mode of delivery: Women who have had a vaginal delivery have an increased risk of UI, however, caesarean delivery does not protect women from UI.
• Family history: This may be a risk factor for UI, particularly with urge incontinence and overactive bladder.
• Other conditions such as diabetes, stroke, and depression are associated with an increased risk of UI.  

Clinical Presentation

• Urine Leaking
• Urinary Frequency
• Urinary Urgency
• Nocturia
• Prolapse

Diagnostic Procedures

A large portion of women with urinary stress incontinence can be diagnosed from clinical history alone. In a systematic review performed in 2006, little evidence was found to support the use of urinary diaries, and pad-tests although these measures are common diagnostic assessments used in physical therapy.

1. Clinical history

Clinical history taking compared with multi-channel urodynamic was found to have 0.92 sensitivity and 0.56 specificity for the diagnosis of urinary stress incontinence based on the presence of stress incontinence symptoms.

• Pelvic Floor Muscle Function and Strength

Modified Oxford grading system:

0 – no contraction

1 – flicker

2 – weak squeeze, no lift

3 – fair squeeze, definite lift

4 – good squeeze with lift

5 – strong squeeze with a lift

• Palpation

Palpation of the pelvic floor muscles per the vagina in females and per the rectum in male patients.

• PERFECT mnemonic assessment:

P – power, may use the Modified Oxford grading scale

E – endurance, the time (in seconds) that a maximum contraction can be sustained

R – repetition, the number of repetitions of a maximum voluntary contraction

F – fast contractions, the number of fast (one second) maximum contractions

ECT – every contraction timed, reminds the therapist to continually overload the muscle activity for strengthening

• Pad Test

The 1 hour pad test was found to have 0.94 sensitivity and 0.44 specificity for diagnosing any leakage compared with multi-channel urodynamic. The 48 hour pad-test was found to have 0.92 sensitivity and 0.72 specificity for the diagnosis of urinary stress incontinence.

While the 48 hour pad test is better used in clinical research due to its high reproducibility, the 1-hour pad test is the standardized method in a clinical setting.

The test involves the patient wearing a pre-weighed pad, next the patient drinks 500 ml of sodium-free liquid in < 15 minutes, resting, after which he/she exercises for 30 minutes. The exercise would include activities such as walking, climbing up and down a flight of stairs, standing up from sitting, coughing vigorously, running on the spot for 1 minute. The pad is then re-weighed and the resulting measurement given in grams of urine lost.

• Urinary (Voiding) Diary

One study found a scale derived from a 7 day diary was 0.88 sensitive and 0.83 specific for the diagnosis of detrusor over activity in women. The National Institute for Diabetes and Digestive and Kidney Diseases provides clinicians with an easy to use Bladder Diary pdf that may be used in clinical practice.

Physiotherapy management

The pelvic floor muscles are known as the levator ani, made up of the pubococcygeus – puborectalis complex. Those muscles form a sling around the anorectal junction. They are made up of both Type I (slow-twitch) and Type II (fast-twitch) fibres. The majority are Type I (about 70%) which provide sustained support and are fatigue resistant. The remaining Type II fibres provide the quick compressive forces necessary to oppose leakage during increased abdominal pressure. A contraction of the pelvic floor muscles also causes a reflex inhibition of the detrusor muscle.

Patient specific training is necessary to ensure a proper contraction of the pelvic floor muscle group. It is also essential to train both the fast and slow-twitch muscle fibres. Also, training must include instruction in volitional contractions before and during an activity that may cause incontinence, such as coughing, sneezing, and lifting. Patients are typically recommended to perform exercises four to five times daily.

A non-controlled trial studying the effects of a home-based pelvic floor muscle training and bladder training in women with urinary incontinence showed that combined pelvic floor muscle training and bladder training decreased the symptoms and improved the quality of life.

PFMT for the prevention of postpartum incontinence

Pelvic floor muscle training (PFMT) performed during pregnancy helps to decrease the short-term risk of urinary incontinence in women without prior incontinence. A meta-analysis that included randomised or quasi-randomised trials on pregnant or postnatal women, found that women assigned to antenatal PFMT had a significant decrease in the rate of urinary incontinence at up to three months postpartum.

A systematic review including randomised or quasi-randomised trials on primiparous or multiparous pregnant or postpartum women found that PFMT during pregnancy and after delivery can prevent and treat urinary incontinence. The authors recommended a supervised training protocol following strength-training principles, emphasizing close to maximum contractions and lasting at least 8 weeks.

PFMT for stress urinary incontinence

Similarly to the findings stated above, PFMT has been found to be effective for treating stress urinary incontinence as well. A systematic review looking at the effects of PFMT by comparing the effects of this training with no treatment, or with any inactive treatment (for example, advice on management with pads). The authors found women with stress urinary incontinence in the PFMT group were, on average, eight times more likely to report being cured. In addition the participants reported an improved QoL. A recent review suggested that integrating PFMT with self-management strategies-lifestyle changes to maintain a healthy weight and quit smoking had a good outcome in mild-to-moderate stress urinary incontinence.

A Randomized Controlled Trial in women with stress urinary incontinence suggests that the Pelvic floor Muscle Training and Extracorporeal Magnetic Innervation are effective in improving the stress urinary incontinence and quality of life in women. Another randomized control study suggested better outcomes with a combined training of PFMT and Transversus Abdominis muscle than with PFMT alone in patients with stress urinary incontinence. However, the training was more effective in the group of women who had lesser than three vaginal births.

A study examining the training parameter for strengthening the pelvic floor found the most effective protocol to consist of digital palpation combined with biofeedback monitoring and vaginal cones, including 12 week training parameters, and ten repetitions per series in different positions.

PFMT for urgency incontinence

PFMT has been shown to improve or cure symptoms of urge urinary incontinence. In addition to PFMT, behavioural therapies and bladder training (described below) may be beneficial in this population.

Behavioural Therapy

The focus of behavioural therapy is on lifestyle changes such as fluid or diet management, weight control, and bowel regulation. Education about bladder irritants, like caffeine, is an important consideration. Also, discussing bowel habits to determine if constipation is an issue as it is important to educate the patient about avoiding straining. Education and explanation about normal lower urinary tract function is also included. Patients should understand the role of the bladder and the pelvic floor muscles. A randomized clinical trial examined the effects of a group-administered behavioural therapy for urinary incontinence in older women and found it to be a modestly effective treatment for reducing symptoms of urinary incontinence. The group behavioural therapy included a one-time, two hour bladder health class, including written material and an audio CD.

Bladder Training

The information gathered from the bladder diary is used to guide decision making for bladder re-training, including a voiding schedule if necessary to increase the capacity of the bladder for people with frequency issues. Bladder training attempts to break the cycle by teaching patients to void on a schedule, rather than in response to urgency. Urge suppression techniques are taught, such as distraction and relaxation. It is also important to teach the patient to contract the pelvic floor to cause detrusor inhibition. A voluntary contraction of the pelvic floor muscles helps increase pressure in the urethra, inhibit detrusor contractions, and control urinary leakage.

Source: Physiopedia