Single Best Answer (SBA) · Urinary Incontinence in Women
Which statement correctly defines genuine (urodynamic) stress urinary incontinence?
Show answer and explanation
Answer: D. Involuntary loss of urine when intravesical pressure exceeds urethral pressure in the absence of a detrusor contraction, without a desire to void
Defining stress urinary incontinence
Genuine (urodynamic) stress incontinence / urethral sphincter incontinence is the involuntary loss of urine when the intravesical pressure exceeds the urethral pressure in the ABSENCE of a detrusor contraction, and is not associated with a desire to void.
Underlying mechanisms
- Urethral hypermobility - excessive descent of the bladder neck, so a rise in intra-abdominal pressure is poorly transmitted to the proximal urethra.
- Intrinsic sphincter deficiency - poor urethral closure from scarring (surgery, childbirth) or neurological injury.
Contrast
| Type | Definition cue |
|---|---|
| Stress | Leak when bladder pressure > urethral pressure, no detrusor contraction, no urge |
| Urge (OAB) | Involuntary detrusor contractions + strong desire to void |
| Overflow | Over-distended bladder, obstruction/impaired detrusor |
Why the others are wrong
Options A, B, C and E describe urge, fistula (extra-urethral), overflow and functional incontinence respectively - not stress incontinence.
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