Detrusor Overactivity in Urology

Detrusor Overactivity (DO)

• DO is characterized by a rise in amplitude during pressure/flow cystometry, often with associated leakage and urgency.
• There are two types of DO: neurogenic detrusor overactivity (NDO) with a known neurological cause, and idiopathic detrusor overactivity (IDO) with an unknown cause.
• DO was previously known as detrusor instability, and NDO was previously known as detrusor hyperreflexia.
• During cystometry, the volume at which DO occurs and the rise in amplitude should be documented, as well as any associated leakage.
• It is also important to note if the DO was spontaneous or provoked.

Characteristics of DO

• Phasic contraction activity with increasingly frequent and higher amplitude contractions often occurs as the bladder continues to be filled.
• A large terminal contraction typically occurs, at which point the patient feels that they can no longer delay micturition and has reached maximum cystometric capacity.
• If voiding is delayed, the patient will frequently be incontinent.

Cough-Induced Incontinence

• Coughing can provoke urinary incontinence due to the abrupt change in intra-abdominal pressure.
• This is often confused with stress incontinence on the history alone, but during video urodynamics, DO is seen immediately following a cough with associated urinary leakage.
• Changing patient position, such as to the standing position, may similarly trigger DO.

Stress Urinary Incontinence (SUI)

• SUI is predominantly a female problem, affecting between 4% and 35% of the adult female population, with an apparent increase in prevalence with age.
• In men, SUI is most commonly seen in patients following a radical prostatectomy.
• The current International Continence Society definition of SUI is "the complaint of involuntary leakage on effort or exertion, or on sneezing or coughing".
• If involuntary leakage is observed during increased abdominal pressure, in the absence of a detrusor contraction during a urodynamic assessment, then the patient is described as having urodynamic stress incontinence.

Causes of Stress Incontinence

• SUI can affect females of any age and parity, but is particularly common in multiparous women who have had traumatic or prolonged vaginal deliveries.
• The causes of SUI include loss of pelvic floor support and/or damage to the sphincter mechanism, resulting in either:
  • Descent or hypermobility of the bladder neck and proximal urethra.
  • Intrinsic sphincter deficiency (ISD).

Treatment Options

• Initial therapy can be commenced empirically by the primary care physician.
• If this fails, the patient should be evaluated in secondary care for consideration of invasive management.
• Available treatment choices include:
  • Fluid intake advice.
  • Pelvic floor muscle training.
  • Devices (e.g. pads, adult nappies/diapers, cones, urethral plugs, electrical stimulation).
  • Bulking agents (to increase urethral resistance).
  • Sphincter cell injection therapies (currently at an investigative stage).

This quiz covers the concept of detrusor overactivity (DO) in urology, including its characteristics, types, and diagnosis. Learn about neurogenic detrusor overactivity (NDO) and idiopathic detrusor overactivity (IDO).