Define incontinence
Involuntary leakage of urine
When does incontinence occur?
When bladder pressure > urethral pressure
Who is most likely to suffer from incontinence?
<2 years old
Unable to suppress reflex bladder emptying
What are the types of incontinence?
- stress incontinence
- urge incontinence
- overflow incontinence
What is stress incontinence due to?
- intrinsic sphincter deficiency
- damage to external sphincters and/or pelvic floor
- increased abdominal pressure = lifting/sneezing/coughing
What is urge incontinence due to?
- overactive bladder
- instability of bladder reflexes = sudden bladder contractions
What is overflow incontinence due to?
- bladder doesn’t contract as amount of urine exceeds capacity
- frequent voiding of small volumes
- after dribble
- caused by poor bladder emptying
- due to obstruction or detrusor muscle/nerve damage
What are some causes of urinary incontinence?
- trauma to pelvic floor
- spinal cord injury
- stroke/brain injury
- MS
- prostate enlargement
- bladder cancer
- urethral strictures
How can trauma to the pelvic floor occur?
- child birth & post-prostectomy
- stress incontinence
- pelvic floor exercises
Treatment for pelvic floor trauma incontinence
- AUS (artificial urinary sphincter)
- bulking materials
- slings
- mesh implants
What are the sections of the spinal cord?
8 paired cervical 12 paired thoracic nerves 5 paired lumbar nerves 5 paired sacral nerves 1 pair of coccygeal nerves
What is the role of the cerebral cortex?
- interprets messages as full or empty bladder
What is the role of the pontine micturition centre?
Switches between filling/storage and voiding
What is the role of the hypogastric nerve?
Sympathetic
Inhibits detrusor contraction during filling mode and contract muscles in urethra and bladder neck
What is the role of the pelvic nerve?
Parasympathetic
Unopposed impulses result in detrusor contraction
What is the role of the pudendal nerve?
Somatic
Under voluntary control
What are the roots of the hypogastric nerve?
T10-L2
What are the roots of the sacral micturition centre?
S2-S4
How does a spinal cord injury above T10 present?
- reflexes are intact but no suppression = abberant reflexes
- no co-ordination of bladder and external sphincter contraction
What are the result of abberrant reflexes?
- bladder reflex contractions at low volumes
- hyper-reflexia, urge incontinence
What are the result of no co-ordination of bladder & external sphincter contraction?
- DSD
- high bladder pressure
- reflux, damage to ureters + kidneys
- kidney failure
What is DSD?
Detrusor sphincter dyssynergia
What is the treatment for incontinence due to spinal cord injury above T10?
- anticholinergic drugs (botox)
- intermittent catheters
- electrical stimulator implants (neuromodulation)
How does incontinence due to spinal cord injury below T10 present?
- areflexic
- no contraction of detrusor or sphincter
- overflow incontinence
- little chance of reflux or kidney damage
- some patients can void by raising abdominal pressure -> incomplete emptying + UTI risk
