A spinal cord injury may interrupt communication between the nerves in the spinal cord that control bladder and bowel function and the brain, causing incontinence. This results in bladder or bowel dysfunction that is termed "neurogenic bladder" or "neurogenic bowel."
If you have a spinal cord injury, look for these signs of a neurogenic bladder:
- Loss of bladder control (urinary incontinence)
- Inability to empty the bladder
- Urinary frequency
- The lowest part of the spinal cord is the sacral spinal cord. Bladder function, bladder, and bowel external sphincters, sexual functions (including erections and ejaculation in men and responsiveness in women), and some leg muscles are the domain of the sacral spinal cord.
- A very important part of voiding involves the sacral spinal cord. There is a part of the sacral spinal cord known as the sacral voiding, or micturition, center. This center receives and sends signals directly to and from the bladder. When the bladder becomes filled with urine, it sends signals to the sacral spinal cord. If this communication is disrupted, through disease or injury, the message is delayed or not received. The result is incontinence.
- A spinal cord injury above the sacral centre may prevent signals from going from the sacral voiding center up to the brain. The spinal cord injury may also block signals going from the brain back down the cord to the sacral voiding center. Since the brain is unable to have any control of the sacral center, the sacral center works on its own.
- Urinary tract infections.
- A bladder that has involuntary or uninhibited contractions is known as an overactive bladder, or overactive detrusor (the bladder is also known as the detrusor). Since voiding occurs as a reflex, with signals coming in and out of the sacral voiding center, this is type of voiding is known as reflex voiding.
- Between the brain and spinal cord is an area called the brainstem. Within the brainstem is the brain micturition, or “voiding”, center. This center is responsible for sending signals down the spinal cord to the sphincter to tell it to relax when a person’s bladder contracts. The spinal cord injury blocks signals from the brain micturition centre to the sphincters. When the bladder, or detrusor, has an uninhibited (involuntary) contraction, the sphincters may not relax. This is known as detrusor sphincter dyssynergia (DSD).
- There are two main types of neurogenic bowel, depending on the level of injury: an injury above the conus medullaris (at L1) results in upper motor neuron (UMN) bowel syndrome; a DSD can cause high pressures to develop in the bladder. High bladder pressure over time can cause kidney damage.
- Another problem that can occur in those with spinal cord injury at or above thoracic level 6 (T-6) is autonomic dysreflexia. The most dramatic effect is a sudden severe rise in blood pressure. One or more common symptoms that often occur with high blood pressure are severe headaches, sweating, flushing, goosebumps, chills, a feeling of anxiety, and a slower pulse rate.
However, about 30 to 40% of people have elevated blood pressures with few, if any, other symptoms (silent dysreflexia). Therefore, it is important to check your blood pressure when you have a full bladder or are voiding.
In addition to bladder issues, there is a lower motor neuron (LMN) bowel syndrome that occurs in injuries below L1. The position and effect of the spinal cord injury are similar to those causing neurogenic bladder.
Management of urinary incontinence
- Clean technique intermittent catheterization. In clean technique intermittent catheterization (CIC), you or a healthcare professional inserts a thin tube (catheter) through the urethra and into your bladder several times during the day to empty your bladder.
- Continuous catheter drainage. A healthcare professional may insert a catheter through your urethra or abdominal wall and into your bladder to continuously empty your bladder.