LOWER URINARY TRACT SYMPTOMS

Standardization

What follows is based on the International Continence Society (ICS) Standardization Report, except where specifically stated to be otherwise.¹ The ICS divides lower urinary tract symptoms into three groups: storage, voiding, and postmicturition. However, the ICS also recognizes a number of pain syndromes that are poorly defined and cannot be easily classified. Storage symptoms include daytime frequency, urgency, incontinence, nocturia, and pain. Voiding symptoms are experienced during the voiding phase and include slow stream, splitting or spraying of the stream, intermittent stream, hesitancy, straining to void, and terminal dribble. Postmicturition symptoms are experienced immediately after micturition and include a feeling of incomplete emptying, postmicturition dribble, or pain.

Storage Symptoms

Urinary frequency (i.e., pollakisuria) is defined as eight or more voids per 24 hours. Urinary urgency is defined by the ICS as “the complaint of a sudden, compelling desire to pass urine, which is difficult to defer.” We think this definition is too restrictive. Many patients feel a “compelling desire to void” that is not sudden, and others feel uncomfortable, annoying feelings in their bladder that make them think they should void frequently, but the desire is really not compelling. There are currently no single other words or phrases to capture these symptoms.

Urinary incontinence is the involuntary loss of urine. It denotes a symptom, a sign, and a condition. It indicates the patient’s (or caregiver’s) statement of involuntary urine loss. The sign is the objective demonstration of urine loss. The condition is the pathophysiology underlying incontinence as demonstrated by clinical, cystoscopic, or urodynamic techniques. The symptoms of incontinence include stress, urge, mixed, unaware, continuous, and nocturnal enuresis.^1,²

Stress urinary incontinence is the complaint of involuntary leakage on effort or exertion or on sneezing or coughing, and urge incontinence is the complaint of involuntary leakage accompanied by or immediately preceded by urgency. Mixed urinary incontinence is the complaint of involuntary leakage associated with urgency and with exertion, effort, sneezing, or coughing. Enuresis means any involuntary loss of urine, and nocturnal enuresis is the complaint of loss of urine occurring during sleep. Continuous urinary incontinence is the complaint of continuous leakage. Other types of urinary incontinence may be situational, such as the report of incontinence during sexual intercourse or giggle incontinence.

CAUSES OF URINARY INCONTINENCE

Urinary incontinence can be further divided into urethral and extraurethral incontinence. Extraurethral causes of incontinence include an ectopic ureter opening into the vagina and urinary fistula. Urethral incontinence is caused by bladder abnormalities, sphincter abnormalities, or combinations of both. Cognitive abnormalities and physical immobility, although not the proximate causes of incontinence, are important cofactors that should be taken into account for the diagnosis and treatment. For example, a woman with mild urgency and severe Parkinson’s disease may develop disabling incontinence because it takes her too long to get to the bathroom.

The conditions causing urinary incontinence may be presumed or definite.² Definite conditions are documented by urodynamic or other objective techniques. Presumed conditions are documented clinically. For example, a neurologically normal woman who complains of urge incontinence despite a normal cystometrogram is considered to have presumed detrusor overactivity provided that sphincter abnormalities and overflow incontinence have been excluded. If the cystometrogram documents involuntary detrusor contractions, the diagnosis is definite detrusor overactivity.

Urethral Incontinence

Bladder abnormalities causing urinary incontinence include detrusor overactivity and low bladder compliance. Detrusor overactivity is a generic term for involuntary detrusor contractions, defined by the ICS as a “urodynamic observation characterized by involuntary detrusor contractions during the filling phase which may be spontaneous or provoked.” The ICS subdivides detrusor overactivity into idiopathic (i.e., non-neurogenic) and neurogenic detrusor overactivity. We have modified this classification as follows:

Idiopathic detrusor overactivity denotes involuntary detrusor contractions that are not associated with neurologic disorders or other conditions known to be associated with involuntary detrusor contractions.

Neurogenic detrusor overactivity denotes involuntary detrusor contractions that are caused by neurologic conditions.

Non-neurogenic detrusor overactivity denotes involuntary detrusor contractions that are associated with conditions thought to be related to detrusor overactivity, such as urethral obstruction and stress incontinence.^3,^28,²⁹ The causes of detrusor overactivity are depicted in Table 7-1.

Low bladder compliance denotes an abnormal (decreased) volume-pressure relationship during bladder filling. Low bladder compliance is recognized by a steep rise in detrusor pressure during bladder filling. Causes of low bladder compliance are provided in Table 7-2.

Table 7-1 Detrusor Overactivity: Causes and Associated Conditions

Table 7-2 Causes of Low Bladder Compliance

Sphincter Abnormalities Causing Urinary Incontinence

It has long been thought that sphincter abnormalities that cause urinary incontinence were of two generic types—urethral hypermobility and intrinsic sphincter deficiency—and many clinicians still adhere to this concept.⁴^–⁶ According to this classification, urethral hypermobility is characterized by rotational descent of the vesical neck and proximal urethra during increases in abdominal pressure.⁴^–¹¹ If the urethra opens concomitantly, stress urinary incontinence ensues. The basic abnormality causing urethral hypermobility is a weakness of the pelvic floor. Intrinsic sphincteric deficiency denotes an intrinsic malfunction of the urethral sphincter itself.^4,¹² Clinically, intrinsic sphincter deficiency manifests by a low leak point pressure and is most commonly seen in three circumstances: after surgery on the urethra, vagina, or bladder neck; as a consequence of a neurologic lesion that involves the nerves to the vesical neck and proximal urethra; and in the elderly.^4,^12,¹³ It had also been accepted that urethral hypermobility and intrinsic sphincter deficiency often coexist in the same patient.¹⁴

The validity of the concept of urethral hypermobility as a sole cause of urinary incontinence has been challenged, and several investigators have shown that there is no relationship between vesical leak point pressure and urethral mobility.^15,¹⁶ For that reason, we no longer use the term intrinsic sphincter deficiency, but instead characterize sphincteric incontinence by two parameters, vesical leak point pressure and urethral mobility, as measured by the Q-tip test.^7,¹⁷

Overflow Incontinence

Overflow incontinence is the leakage of urine associated with incomplete bladder emptying caused by impaired detrusor contractility or bladder outlet obstruction. The pathophysiology of overflow incontinence has not been studied very well. Conceptually, the leakage must be caused by an overactive detrusor or a relative sphincter deficiency.

SYMPTOMS, SIGNS, AND CONDITIONS CAUSING INCONTINENCE

The symptoms of incontinence are elicited by the patient’s history, questionnaires, voiding diaries, and pad test. Symptoms can and should be reproduced during urodynamic studies. The signs are assessed by examination and urodynamic studies. The conditions are the underlying pathophysiologies. Table 7-3 lists symptoms and conditions that cause urinary incontinence.

Table 7-3 Storage Symptoms and the Conditions That Cause Urinary Incontinence

Symptom	Conditions
Urinary frequency	Polyuria
	Sensory urgency
	Detrusor overactivity
	Low bladder compliance
	Acquired behavior (e.g., defensive voiding)
Urgency or urge incontinence	Sensory urgency
	Detrusor overactivity
	Low bladder compliance
Stress incontinence	Urethral hypermobility
	Intrinsic sphincter deficiency
	Stress hyperreflexia
Unaware incontinence^*	Detrusor overactivity
	Sphincter weakness
	Extra-urethral incontinence
Continuous leakage	Sphincter weakness
Continuous leakage	Extra-urethral incontinence
Nocturnal enuresis	Detrusor overactivity
	Sphincter weakness
	Extra-urethral incontinence
Postvoid dribble	Urethral diverticulum
	Urethral obstruction
	Vaginal voiding
Extra-urethral incontinence	Urinary fistula
Extra-urethral incontinence	Ectopic ureter