Urge incontinence

Urge incontinence is a form of urinary incontinence characterized by a sudden urge to urinate, resulting in involuntary leakage of urine. The condition is caused by sensory or motor dysfunction. It is typically idiopathic but can also result from neurologic conditions such as spinal cord injury and stroke. The prevalence of urge incontinence increases with age, with more women affected than men. The condition is usually diagnosed via a detailed medical history and urodynamic studies. Treatment is conservative and involves the administration of anticholinergics. Surgical options should be considered only as a last resort.

• Sensory urge incontinence: pathologically increased bladder sensitivity, which results in the reflex action of bladder emptying
• Motor urge incontinence: autonomous detrusor overactivity

References:^[1]

• Prevalence increases with age
• Sex: ♀ > ♂

References:^[2]

Epidemiological data refers to the US, unless otherwise specified.

• Idiopathic (most common)
• Neurological conditions: lesions above the brain stem, spinal cord injury, stroke, Parkinson disease, dementia, and multiple sclerosis
• Genitourinary conditions: bladder cancer, inflammation, or renal stones
• Risk factors include:
  • Recurrent urinary tract infections
  • Bladder symptoms (e.g., bed wetting) in childhood
  • Constipation
• See also “Etiology” of urinary incontinence.

References:^[3][4]

• Urinary urgency: sudden urge to urinate
• Loss of urine without exertion, with urinary tenesmus; → frequent episodes, with variable volumes of urine voided each time

See diagnosis of urinary incontinence for general diagnostic measures.

• Urinary stress test
  • Used to rule out concomitant stress incontinence
  • Negative in individuals who only have urge incontinence (no leakage of urine)
• Pad test
  • Used to quantify urine leakage over a 1–24-hour period
  • Patients are asked to wear a preweighed sanitary pad, perform certain activities, and drink a certain volume of liquid. The pad is then weighed again to measure urinary leakage.

References:^[5]

• Stress incontinence
• Mixed urinary incontinence
• Overflow incontinence
• Total incontinence
• Overactive bladder: a condition characterized by urinary urgency, with or without incontinence, nocturia, and urinary frequency.

The differential diagnoses listed here are not exhaustive.

Conservative measures

Conservative measures should first be attempted before considering medical treatment.

• Nonpharmacological treatment: behavioral therapies, exercises, lifestyle modifications (see general principles of treatment of urinary incontinence)
• Medical treatment
  • First-line are anticholinergics, including oxybutynin, tolterodine, solifenacin, trospium, and darifenacin
    • Effect: competitive blockage of acetylcholine at the muscarinic acetylcholine receptors → parasympathetic effect is impaired → decreased overactivity of the detrusor muscle → reduced voiding
    • Adverse effects: dry mouth, tachycardia, glaucoma
  • Alternatives or combined administration
    • Alpha blockers: e.g., tamsulosin
    • Additional spasmolytic agents: e.g., scopolamine (hyoscine) hydrobromide, flavoxate
    • Tricyclic antidepressants (anticholinergic): e.g., imipramine
    • Beta-3 agonists: e.g., mirabegron

Oxybutynin treats Overactive bladder.

Second-line treatment

• Endoscopic injection of botulinum toxin at different points in the bladder wall
• Sacral nerve stimulation
• Augmentation cystoplasty

References:^[2][4]