Urinary incontinence: Differential Diagnosis

Stress incontinence

24 to 45% in women > 30 yo.

Sphincter weakness (urethral sphincter and/or pelvic floor weakness)

Patient loses a small amount of urine w/ physical activity/exertion or anything that increases the intra-abdominal pressure ( eg. exercise, lifting, jumping, coughing, and sneezing). It may even occur w/ very little activity such as simply walking or rising from a chair.  The patient can usually predict which activities will cause leakage.

Common causes are Childbirth and obesity in women. Men may have it after a prostatectomy.

Urge incontinence (UI)
-incidence Increases w/ age.

Overactive bladder and urge incontinence exist in a continuum. 

With Overactive bladder, urgency occurs without urinary loss. But if urine loss occurs, it becomes urge incontinence.

Detrusor overactivity. I.e the detrusor muscle contracts when it shouldn’t. When the patient is not ready to urinate.  These uninhibited bladder contractions can be caused by:
1) Irritation within the bladder, or
2) Loss of inhibitory neurologic control of bladder contractions

-Inability to reach the toilet, urgency, associated with unintentional urine loss. Patients usually lose urine on the way to the toilet.
-Loss of urine preceded by a sudden and severe desire/urge to urinate. 
-UI is often associated w/ frequency and nocturia. So query patients.

“Bladder contractions may also be stimulated by a change in body position (i.e., from supine to upright) or with sensory stimulation (e.g., running water, hand washing, cold weather, arriving at the front door)”

The amount of urine loss varies depending on how full the bladder is. It can go from small (if the bladder is empty) to flooding (if the bladder was full).

Causes:
1) Bladder irritation caused by cystitis, prostatitis, atrophic vaginitis, bladder diverticula, prior pelvic radiation therapy. OR
2) Loss of neurologic control caused by stroke, dementia, spinal cord injury, Parkinson disease

Mixed Incontinence
-Combination of urge + stress symptoms.
– Occurs in 20 to 30 % of patients with chronic incontinence

Combination of stress and urge incontinence

Patient has both sx of stress & urge incontinence.

Incontinence associated with chronic urinary retention (formerly called Overflow incontinence.)

Occurs in 5% of patients with chronic incontinence

Overdistention of the bladder caused by impaired detrusor contractility or bladder outlet obstruction; leads to urine leakage by overflow

Patients have urinary retention. Are unable to empty their bladder. There would have urinary hesitancy and dribble urine. Finally, they will experience urine loss without a recognizable urge or sensation of fullness/pressure in the lower abdomen.

Does not usually occur unless bladder emptying is poor (postvoid residual volumes > 200 to 300 mL).

Common causes: Anticholinergic meds, BPH, pelvic organ prolapse, DM, multiple sclerosis, spinal cord injuries.

Functional Incontinence.

Variable leakage of urine, usually caused by environmental or physical barriers to toileting

-Caused by non-genitourinary factors, such as cognitive or physical impairments that result in the patient’s inability to void independently.
-Impaired physical function (immobility) and/or impaired cognition.
–the absence of cognitive impairment usually rules out a functional component to the incontinence.

Possible lower urinary tract deficits.

Common causes: Severe dementia, physical frailty or inability to ambulate, mental health disorder (e.g., depression)