Types of bladder impairment

The most common types of bladder impairment in SCI are:

  • a loss of reflex control (reflexic or spastic bladder)
  • a loss of the ability to contract, leading to overfill (areflexic or flaccid bladder), and
  • abnormal growths in the bladder organ or tissue (mixed lesion bladder).

Reflexic bladder

The reflexic bladder is caused by an upper motor neurone (UMN) injury and may have the following outcomes:

  • Loss of sensation of a full bladder or the ability to know when the bladder has emptied.
  • Loss of control over the ability to void or prevent leaking.
  • Pelvic floor dysfunction, secondary to muscle paralysis, as well as hypertonicity.
  • Intact spinal reflexes coupled with the loss of descending inhibition. This causes the detrusor to reflexively contract spontaneously, or with small bladder volumes. An overactive (hyperreflexic) detrusor results in reduced bladder capacity.
  • Increased risk of Detrusor Sphincter Dyssynergia (DSD), where the detrusor muscle and urethral sphincter simultaneously contract, due to loss of coordination between the central and peripheral nervous systems. DSD results in an increase in pressure within the bladder, which puts the upper renal tracts at risk of long-term complications.

The risks of an overactive bladder are:

  • Incomplete emptying
  • Ureteric reflux
  • Reduced capacity
  • Increased frequency
  • Incontinence
  • Increased risk of urinary tract infections
  • High pressures within the upper renal tract

Areflexic bladder

An areflexic bladder is caused by a lower motor neurone (LMN) or cauda equina syndrome and may have the following outcomes:

  • Loss of sensation of a full bladder or the ability to know when the bladder has emptied.
  • Loss of control over the ability to void or to prevent leaking.
  • Pelvic floor dysfunction, secondary to muscle paralysis.
  • Detrusor underactivity, compromising bladder emptying.
  • Potential loss of sphincter muscle tone, causing urinary leakage.

The risks of the underactive bladder are:

  • Incomplete emptying
  • Bladder distension
  • Increased frequency
  • Incontinence
  • Increased risk of urinary tract infections

Manoeuvres that increase intraabdominal pressure – such as a Valsalva manoeuvre (straining to empty the bladder and/or bowel), application of external pressure to the bladder (Credé manoeuvre), coughing and sneezing – can increase the risk of:

  • Urinary and/or faecal leakage
  • Vaginal and/or rectal prolapse or haemorrhoids

Mixed lesion bladder

  • Mixed-level injuries around the conus medullaris (T10-L1) can show both signs of a reflexic and areflexic bladder.
  • An individualised plan is required in these cases.

References

Hsieh JTC, McIntyre A, Loh E, Ethans K, Mehta S, Wolfe D, Teasell R. (2019). Epidemiology of Paediatric Spinal Cord Injury. In Eng JJ, Teasell RW, Miller WC, Wolfe DL, Townson AF, Hsieh JTC, Connolly SJ, Noonan VK, Loh E, Sproule S, McIntyre A, Querée M, editors. Spinal Cord Injury Rehabilitation Evidence. Version 7.0. Vancouver: p 1-274 bladder-management_final_v7-1.pdf