Most patients with MS (up to 90 percent) experience some type of bladder difficulty during the course of their disease. MS-related bladder dysfunction is sometimes called "neurogenic bladder."

The bladder is a muscular bag that expands as it collects urine. At the junction of the bladder and the urethra (the tube that takes urine outside the body), there is a sphincter muscle. The sphincter stays contracted between times of urination, keeping urine in the bladder. When to 200 to 500 milliliters of urine (about 1-2 cups) collects in the bladder, a signal is sent to the brain. The brain returns a signal that permits the bladder to contract and the sphincter muscle to open and release urine. This process of normal urination is under the voluntary control of an individual.

In MS, plaques (scar tissue) on the nerves of the brain and spinal cord interrupt the messages between the bladder and the brain. The bladder and sphincter are no longer able to coordinate their functions properly, creating problems for the patient. The type of problem a person has depends on the exact location of the plaques.

Failure to store syndrome, also known as a "spastic" or "small" bladder, is the most common bladder problem. The bladder involuntarily contracts as if it were full when only a small amount of urine is present, and the person feels a strong need to urinate. The bladder tends to empty automatically, resulting in frequent urination, incontinence or dribbling. Nocturnal incontinence can be a problem as well. People with a reduced capacity for bladder sensation do not experience as strong an urge to void.

Treatment focuses on relaxing the bladder so that it will hold a normal amount of urine before contracting to void. Anticholinergic drugs are most effective for this. Patients with a spastic bladder should avoid diuretics (substances that create an increase in urine), such as alcohol, caffeine and aspartame. Behavior modification techniques such as timed voiding or scheduled voiding may be recommended and taught to patients.

Failure to Store - Symptoms

Urgency (the feeling that urination cannot be delayed)

Incontinence (the inability to control urination)

Nocturia (the need to urinate several times during the night)

Failure to empty syndrome, or a "flaccid" or "big" bladder, occurs when bladder fullness is not correctly perceived. The bladder also may not completely empty because the sphincter muscle is tight and spastic and does not open properly. It contracts when it should relax to release urine. Usually some, but not all, urine is released from the bladder. Retained urine can encourage bacteria growth, which can lead to a urinary tract infection. Urine can also back up in the ureters, causing kidney damage or stones in the bladder or kidneys.

If failure to empty is due to a spastic sphincter, symptoms may respond to treatment with the drug Baclofen (Lioresal®). The most successful way to manage failure to empty syndrome is with intermittent self-catheterization. At intervals throughout the day the patient inserts a thin catheter through the urinary opening and into the bladder. Urine drains out through the tube, completely emptying the bladder. Self-catheterization is a relatively simple procedure that most people can learn. Indwelling catheters can be used when self-catheterization is not practical. Catheterization may only be needed for a short period of time, since normal bladder function often returns after a period of weeks or months.

Failure to Empty - Symptoms

Hesitancy (difficulty starting the flow of urine)

Urgency (frequent urination; a sensation of incomplete emptying)

Incontinence (leaking or dribbling from an overfull bladder)

Urinary tract infections

The conflicting bladder, or "combined dysfunction," has both storing and emptying problems. The condition is "conflicting" because the bladder muscle works in conflict with the sphincter muscle. This lack of coordination can mean either that the bladder is contracting to empty but the sphincter will not allow urine to pass, or that the sphincter relaxes to release urine when the bladder is not contracted. This condition is also known as "dyssynergic bladder" or "mixed failure to store and failure to empty."

A conflicting bladder is treated in the same way as the two conditions it combines.

The Conflicting Bladder - Symptoms:

Urgency to urinate; incontinence

Hesitancy (a sensation of incomplete emptying)

Kidney or bladder stones; kidney damage

Nocturia

Urinary tract infections

Diagnosing Bladder Problems

An accurate diagnosis of bladder problems must be based upon test results.

The first step is usually to rule out a urinary tract infection. A urine sample will be examined under a microscope to see if bacteria or white blood cells are present. If bacteria are found, they will be grown in a laboratory culture for three days and then tested for sensitivity to various antibiotics. If symptoms persist after successfully treating any infection, other tests can be done.

A post-void residual test is usually done next because it is simple and inexpensive. This test measures whether there is urine left in the bladder after voiding. The patient is asked to drink a quantity of water. After voiding, a bladder scanner (ultrasound machine) is used to measure the amount of urine left in the bladder. This machine is just held on the surface of the skin over the bladder for less than a minute. The ultrasound can also determine the shape and size of the bladder, kidneys and prostate. Alternatively, a catheter can be inserted into the bladder to drain any remaining urine. If the amount of urine in the bladder measures greater than 100 cc, the patient is retaining urine and may have a flaccid bladder, or more likely, dyssynergic bladder. If the amount is smaller than 100 cc, the patient may have a spastic bladder.

Cystoscopy is a procedure that uses a thin, telescope-like instrument called a cystoscope to perform a visual check inside the bladder.

Urodynamic tests allow the physician to discover whether bladder sensations are normal and whether it fills and empties normally. These tests look for obstructions to urinary flow, examine the bladder wall to determine its stability, and study sphincter muscle activity.

First published October 1, 1999
Last updated September 12, 2003
Copyright © 1999 Accordant Health Services, Inc. All Rights Reserved.

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