Increase / Decrease article text size:
You are here:
Your bladder and spinal cord injury Tools

Your bladder after a spinal cord injury

After a spinal cord injury (SCI), your bladder changes. It is unable to store urine in the same fashion and you no longer have the ability to voluntarily empty it. A bladder whose function has been disrupted by changes in the nervous system is called a neurogenic bladder.

 

What causes a neurogenic bladder?

 

Nervous system changes can occur as the result of:

  • spinal cord injury
  • spinal cord disease
  • damage to the nerves leading to and from the bladder
  • brain trauma

How will my bladder function after my injury?

There are two types of post-spinal injury bladder, depending on what sort of spinal cord injury you have:

  • reflex or upper motor neuron bladder
  • flaccid or lower motor neuron bladder

What is the reflex, or upper motor neuron (UMN) bladder?

Spinal cord injuries that occur above the conus medullaris leave the S2-S4 levels of the spinal cord spinal intact. This means that all the spinal and autonomic nerves located in these levels can still function in a reflex (unconscious) way. This means that your nerves still feel, and are able to control, the stretch muscles of the bladder and both your urethral sphincters.

If you have a reflex bladder

If you have a reflex bladder, you will find that:

  • The stretch (detrusor) muscles are more sensitive. This means that your bladder is likely to signal your brain that it needs to be emptied more frequently, and with smaller amounts of urine.
  • There is an increase in the muscle tone in your external urethral sphincter.
  • There may be misjudged timing between your bladder muscles and the external sphincter. This can mean the bladder and the external sphincter contract at the same time. This is called detrusor sphincter dysynergia. When this happens, pressure in your bladder rises dramatically, which can lead to the development of outpouchings of the bladder wall called diverticulae, and reflux (urine being pushed back up into the ureters and kidneys). This can cause infection and harm your kidneys.

What is the flaccid or lower motor neuron (LMN) bladder?

Spinal cord injuries that occur at or below the conus medullaris damage the nerves that are involved with your bladder function. Whole spinal cord damage (for example, when an aortic aneurysm bursts) can also result in this nerve damage. These injuries damage nerves in the S2-S4 levels of your spinal cord (the cauda equine).

This type of injury means that all reflex nerve activity in the bladder no longer functions. Your detrusor muscles in your bladder and your internal and external urethral sphincters have neither unconscious or conscious control.

If you have a flaccid bladder

If you have a flaccid bladder, you will find that

  • Your detrusor, or stretch muscle no longer function, and your bladder remains in a flaccid state.
  • No nerve reflexes are activated as your bladder fills.
  • There is no muscle tone in your external urethral sphincter. This means that when the volume in your bladder reaches 400-500 ml, your bladder neck, internal and external sphincters are stretched, allowing urine to pass.