Functional urology and neurourology: symptoms, urodynamics and pressure control
What the exam tests
Classification of incontinence and lower urinary tract dysfunction, the stepwise treatment ladder, urodynamic interpretation, and the renal risks of the neurogenic bladder.
Core rules
- Overactive bladder is urgency, frequency and nocturia with or without urgency incontinence. Before treatment exclude infection, haematuria, incomplete emptying and pelvic pathology. Start with bladder training and fluid advice, then an antimuscarinic or beta-3 agonist, then intradetrusor onabotulinumtoxin A, percutaneous tibial nerve stimulation or sacral neuromodulation.
- Stress urinary incontinence is leakage on effort without urgency. Pelvic floor muscle training is first-line for at least three months; a midurethral sling is the standard surgical option.
- Check post-void residual before starting antimuscarinics; a high residual means the drug may precipitate retention.
- Neurogenic bladder: spinal cord injury above the conus gives detrusor overactivity with detrusor-sphincter dyssynergia; cauda equina and lower lesions give an acontractile bladder. The priority is protecting the upper tracts by keeping storage pressure low, usually with clean intermittent self-catheterisation plus antimuscarinic therapy.
- Cauda equina syndrome, with bilateral sciatica, saddle anaesthesia and retention with overflow, requires emergency MRI.
Worked example
A man with a T6 spinal cord injury has a leak point pressure of 60 cmH2O on video-urodynamics. Reasoning: sustained storage pressures above 40 cmH2O risk vesicoureteric reflux and renal scarring. He needs antimuscarinic therapy and a timed intermittent catheter regimen, with repeat urodynamics to confirm pressures have fallen.
Traps
Prescribing anticholinergics without a residual; assuming a long-term indwelling catheter protects a neurogenic bladder; diagnosing detrusor overactivity from symptoms alone; missing cauda equina syndrome.