Two types of neurogenic bladder can occur. If the neurological issue is located in the brain, or above T12-L1, an upper motor neuron bladder is diagnosed. This type of bladder is reflexive, meaning it has more tone (spasticity) which makes it prone to contract, expelling urine at a very low threshold but not always completely emptying. Neurological issues below T12-L1 result in a lower motor neuron bladder, which is areflexive, meaning a flaccid bladder (low to no tone) that fills with urine that is not released. The bladder continues to collect urine. Some may leak out in overflow, but most of the urine will remain within the bladder. For those with injury within the T12-L1 level, a mixed type of bladder function occurs, a combination of effects of the tone or spastic bladder and some effects of a flaccid bladder.
Individuals with issues from any neurological disease or injury can develop a neurogenic bladder. Although most often thought of with spinal cord injury, others with neurological issues may have a neurogenic bladder diagnosis. This includes individuals with diagnoses of brain injury, stroke, dementia, multiple sclerosis, spina bifida, hydrocephalus, tumors, and Parkinson’s disease, among others with neurological conditions. Individuals who have diabetes or alcoholism may have effects that result in damage to nerves, also leading to neurogenic bladder.
Not controlling the neurogenic bladder can lead to serious consequences. If urine is overfilling the bladder without expulsion, the urine can back up into the kidneys. Urine flows from the kidneys through long tubes in the body (called the ureters) to the bladder. The kidneys make urine but have no capacity for storing it. Therefore, if urine backs up into the kidneys, there is no place for it to go, so the pressure of the extra urine will push against delicate kidney tissue, destroying it. Protection of the kidneys by removal of urine from the bladder is critical for maintaining health and life.
Typically, urine is released from the body when the bladder (detrusor) contracts at the same time as the internal sphincter in the urethra relax or opens. Injury or disease in the brain above the pons (part of the brainstem that connects the brain to the spinal cord) can lead to incoordination of bladder (detrusor) contractions without sphincter relaxation. When the bladder contracts, the internal urethral sphincter should relax. This allows the bladder muscle to push urine out of the body through the urethra. When bladder contractions do not align with the internal sphincter opening, detrusor sphincter dyssynergia (DSD) is diagnosed. The pressure in the bladder becomes higher as the bladder muscle is contracting but the external sphincter does not open to release urine.
Individuals with injury to the upper spinal cord, between C1 to T11-L1 (basically in the neck or thorax) will develop an upper motor neuron bladder or reflexive bladder with uninhibited bladder contractions after spinal shock resolves (six to eight weeks after injury). This can lead to high voiding pressures as above which can lead to kidney destruction.
A reflexive bladder can lead to autonomic dysreflexia (AD), a symptom of the autonomic nervous system (ANS) responding to messages below the level of the injury of the spinal cord from disease or trauma. The body still works below the level of injury, but messages about discomfort or pleasure cannot reach the brain for processing. Still, the body is sending messages that something is amiss below the level of injury, but the messages are uninterpretable, so the ANS sends a massive response through the body to try to fix the issue. This results in an elevation of blood pressure 20mmHg over the individual’s normal blood pressure in adults and 15mmHg over the individual’s normal in children. Other symptoms such as slow or fast heartbeat, headache, flushing, goosebumps, visual disturbances, stuffy nose, and a feeling of apprehension may appear singly or with several symptoms. AD is a serious situation that can lead to stroke and death. More information about AD, symptoms, and how to treat it can be found here.
Individuals with injury to the lower spinal cord, sacral nerves, or nerve roots develop an areflexive bladder or one that has little to no contractile ability. The bladder fills but does not empty. Individuals with incomplete spinal cord injury in this area may have a bladder that fills with increases in bladder pressure. Usually, the issue with the contraction of the internal sphincter does not appear. Overfilling of the bladder without pressure buildup can result in the leaking of urine without emptying, back up into the kidneys, or rarely, rupture of the bladder. As long as the bladder remains overdistended, the elasticity of the bladder muscle can become lax, making the bladder flaccid and more difficult to contract.
Urinary tract infections (UTI) can become an issue with neurogenic bladder diagnosis. This can occur for a variety of reasons. Urine staying in the bladder for long periods of time can increase the risk of UTI. Urine may linger due to incomplete emptying or an inability to empty the bladder. The stagnant urine is more apt to house bacteria. Lack of movement in the body keeps the urine stagnant. Poor fluid choices (of fluids that contain sugar or alcohol) increase the risk of developing a UTI, as does bladder irritation from nicotine.
Another issue that affects UTI development is your body’s ability to fight pathogens that enter it. Usually, if a pathogen enters the body, the autonomic nervous system (ANS) will detect the pathogen and signal the brain to initiate the body’s natural immune response system to combat and destroy the pathogen. However, in neurological injury, the ANS is often affected, making the response to noticing the pathogen slow, response to the pathogen to destroy it slower, or even no response at all. This allows the pathogen to flourish in the body leading to symptoms of urinary tract infection.
The most often reported signs of UTI are pain with urination or pain over the bladder area. With changes in body sensation due to neurological disease or trauma, an individual may not feel these sensations. Instead, some of the other symptoms of UTI may be noticed, such as sudden urinary incontinence, increased tone (spasticity), episodes of AD, cloudy urine, urine odor, fever, or just a sense of apprehension that ‘something is not right’ in your body.
If you have a diagnosis of neurogenic bladder, more than likely, neurogenic bowel is also diagnosed. Some of the nerves that affect the bowel, especially in the lower bowel, exit the spinal cord at the same levels as the nerves for bladder function. Therefore, neurogenic bladder and neurogenic bowel function are seen together. A bowel program must be methodically maintained to keep the bowel empty and to avoid bowel incontinence. Movement of the lower body helps maintain a healthy bowel function as well as a healthy bladder. A consistent bowel program keeps pressure off the bladder and surrounding structures, giving the bladder more room to function. Management of the bowel with an effective program avoids bowel incontinence which can spread fecal material around to the urethra, which also promotes infection.
Hygiene must be carefully practiced, keeping the urethral area clean at all times to reduce the option of a pathogen entering your urethra. Even with an effective bowel program, the bowel releases gas and some fluids that can be transferred to the bladder. This is more so in women due to the anatomical placements of the rectum, vagina, and urethra. However, this spread of minimal rectal emissions also can affect men. Urine has an erosive effect on the skin. Maintaining hygiene after urinary incontinence will keep your skin healthy and eliminate odor.
Other issues that can occur with neurogenic bladder are bladder-related issues of stress, urge, overflow, and functional incontinence, as discussed last week. Even though these bladder-related issues develop from other issues than neurogenic bladder, they can occur in conjunction with it. There may be concerns about their development or may be temporary as a result of a response to an issue within the neurogenic bladder.
These are some of the concerns of neurogenic bladder. They are real issues but can be reduced or even avoided with treatment for neurogenic bladder. Next week, treatments of neurogenic bladder will be discussed.
Pediatric Considerations:
Often, individuals overlook the diagnosis and treatment of neurogenic bladder in infants because babies wear diapers and do not control their bladder. Some will use diapers up to or through school age. However, as neurogenic bladder is an issue with the communication of the nerves to and from the brain and bladder, treatment should be started immediately.
As soon as neurogenic bladder is diagnosed, you can begin to address the issue, which will avoid collecting many of the issues listed above. Starting to prevent the development of these issues will avoid lifelong health concerns due to bladder function.