Wednesday, August 27, 2014

Neurogenic Bladder

Definition

This is a dysfunction of the urinary bladder caused by a problem of the nervous system. Types of neurogenic bladder are spastic bladder, reflex bladder, and flaccid bladder. It is also called neuropathic bladder.

Description

Neurogenic bladder is impaired bladder function resulting from damage to the nerves that govern the urinary tract. Various nerves converge in the area of the bladder and serve to control the muscles of the urinary tract, which includes the sphincter muscles that normally form a tight ring around the urethra to hold urine back until it is voluntarily released.

A variety of factors can damage these nerves and cause urinary incontinence. In some cases, spontaneous nerve impulses to the bladder trigger spastic unexpected bladder contractions, resulting in accidental voiding of sometimes large amounts of urine.

In other types of neurogenic bladder conditions, the bladder may become flaccid and distended and cease to contract fully, resulting in only partial emptying and continual dribbling of small amounts of urine. Rashes may erupt in areas of the skin irritated by urine.

Stagnant urine in the bladder also increases the risks of bladder stone formation and urinary tract infections. Such infections, when severe, can lead to life-threatening kidney failure. In some patients, there is a partial loss of anal sphincter control as well.

Causes

Neurogenic bladder can occur at any age, but it is especially common among the elderly.

Among the various causes are:

Symptoms

Symptoms include the following:

  • Urinary incontinence, characterized by either involuntary release of large volumes of urine or continuous dribbling of small amounts. Bed-wetting may occur
  • Frequent urination
  • Persistent urge to urinate despite recent voiding; a constant feeling that the bladder is not completely empty
  • Pain or burning on urination

Diagnosis

A thorough patient history is essential to record 24-hour urination patterns, including the actual volume of urine voided, how urgent the feeling is to urinate and any factors that aggravate incontinence.

Physical examination will likely include a rectal, genital, and abdominal exam to check for enlargement of the bladder or other abnormalities. A complete neurological examination is also essential. Tests to measure urine output are conducted.

To determine whether urine is retained after voiding, the doctor may use an ultrasound-like instrument that estimates the amount left in the bladder or insert a catheter into the bladder.

In order to detect whether leakage occurs, a full-bladder stress test may be necessary. The bladder is filled to capacity via a catheter and the patient is then asked to bend over, cough, or walk. Urine or blood samples may be taken to look for abnormalities including infection and underlying disorders that might be causing or aggravating the condition.

Treatment

Treatment is aimed at enabling the bladder to empty completely and regularly, preventing infection, controlling incontinence, and preserving kidney function.

A urinary catheter can be used continuously by patients who have sudden, unexpected bladder contractions. Women usually fare better with such therapy; men are more prone to develop urinary tract infections and complications, including abscess formation.

Patients suffering from bladder paralysis can be taught to insert a catheter several times a day to drain the bladder completely and so prevent urine retention that may led to bladder stones and infection. Various medications may help improve bladder muscle control and prevent involuntary muscle contractions. Muscle relaxants, antispasmodics and anticholinergic drugs are also helpful.

Bethanechol is the most commonly prescribed drug to help stimulate bladder contractions in patients who retain urine. Surgery may be performed to widen the sphincter to decrease resistance in the bladder outlet and thus maximize bladder emptying. In other cases, the sphincter or lower pelvic muscles may be surgically tightened to improve bladder control. In very severe cases, surgery may be done to reroute the flow of urine so that it empties into an externally worn receptacle.

Questions

What is causing the bladder dysfunction?

How extensive is the damage to the nerves?

Do you wish to do further diagnostic testing?

Is the bladder retaining urine? How much?

Would a muscle relaxant or antispasmodic help?

Is a catheter needed?

Under what circumstances would surgery be necessary?