Overview. A neurogenic bladder is one that fails to function properly as a result of a disruption in the nerves associated with urination. In a normal bladder, sensory nerves send signals to the brain when the bladder is full and motor nerves signal the muscle movements that hold urine in or empty it from the bladder, depending on our desires. When the bladder is neurogenic, the nerves that carry these messages between the bladder and the brain are faulty, potentially affecting the internal and external sphincters as well as the bladder.
Types. The neurogenic bladder can be either overactive or underactive. When the neurogenic bladder is overactive, urination is frequent and uncontrolled, capacity is low and there is an inability to empty it completely. A person with an underactive neurogenic bladder, on the other hand, can hold unusually large amounts of urine but has a diminished sense of when the bladder is full and is not able to contract the muscles sufficiently, allowing urine to leak from the urethra as the bladder fills beyond its limits.
In either case, there can be complications, whether it’s urinary leakage – a major quality of life issue – or the potentially more serious medical problem of urinary retention, when the bladder muscles aren’t properly receiving the message that it’s time to release. The bladder or the ureters (the tubes that transport urine from the kidney to the bladder) can become infected from urine held too long, and the small blood vessels in the kidney can be damaged as a result of pressure from a bladder that is overflowing.
Causes, Symptoms and Diagnosis. A variety of conditions or injuries can precipitate a neurogenic bladder. Among the most common are diabetes, acute infections, neurological disorders including Parkinson’s disease and stroke, brain or spinal cord injuries, genetic nerve disorders, and heavy metal poisoning. When symptoms and a medical history and physical examination indicate the possibility of a neurogenic bladder, diagnostic tests include X-rays of the skull and spine, an EEG to measure electrical activity in the brain, imaging tests of the bladder and ureters, and tests of the bladder’s filling and emptying capacity. A cystoscopy is sometimes used to look inside the bladder and at the ureters that connect it with the kidneys.
Treatment. Several treatment approaches are used. Intermittent or continuous catheterization aims to reduce bladder stretching by emptying the urine several times a day at regular intervals; through intermittent self-catheterization, patients can avoid the risks that come with having an indwelling catheter. Preventive antibiotic therapy may be prescribed to reduce the risk of infection. Other drugs can control the symptoms of a neurogenic bladder, either by suppressing the contractions of the overactive bladder or by stimulating contractions when the underactive bladder fills. In the longer term, efforts are made to retrain the bladder to successfully void through methods such as the Credé maneuver (applying manual pressure over the lower abdomen) and the Valsava maneuver (increasing intra-abdominal pressure by simulating the mechanics of a strained bowel movement).