Anatomy of the Urinary System
The urinary system, removes impurities from the blood and eliminates them, together with the body's excess fluid, as urine. Urine is formed in the kidneys, which lie on either side of the spinal column. Urine flows from the kidneys to the bladder through two connecting tubes called ureters. Finally the bladder expels urine from the body through the urethra.
The bladder, is a muscular bag which slowly expands as urine collects, similar to a balloon gradually enlarging as air enters it. The muscular part of the bladder is called the detrusor. At the opening of the bladder, where it meets the urethra, there is a muscle called the sphincter which remains contracted and closed between times of urination. The bladder and sphincter are normally under voluntary control, which means that the individual has control over urination.
Voluntary control of urination is managed by the brain. When the bladder is full, it signals this to the brain via impulses up the spinal cord. Impulses from the brain are then transrnitted to the bladder causing the bladder to contract and the sphincter to open, resulting in urination.
MS plaques in the brain and spinal cord interrupt the transmission of signals which may result in storage problems, emptying problems or combined dysfunction.
Urine collects in the bladder until 300 to 500 milliliters (1 or 2 cups) have accumulated. The bladder gradually stretches as this amount accumulates. For urination to occur, two events must take place simultaneously: the bladder detrusor muscle must contract to expel the urine at the same time that the sphincter relaxes and opens to permit free flow of urine out of the body
In summary, normal urination is under voluntary control. When the bladder has collected 1 to 2 cups of urine, the person will experience the urge to urinate. The bladder contracts to push out the urine, while the sphincter opens to provide clear exit.
A storage problem occurs when the bladder is unable to contain urine as it accumulates.In this type, the detrusor muscle of the bladder is overly active. Contractions of the bladder are initiated involuntarily when only a small amount of urine has collected. The sphincter opens in a normal way, resulting in frequent and urgent urination and, in severe cases, involuntary loss of urine.
Storage Dysfunction Symptoms
The symptoms most commonly associated with storage dysfunction may include:
Urinary urgency: a very strong sensation that urination is imminent and cannot be postponed.
Urinary frequency: having the need to urinate more frequently than every three to four hours.
Incontinence: loss of urinary control before reaching the toilet.
Nocturia: having the need to urinate one or more times during the night.
Management of Storage Dysfunction
Management of the most common type of storage dysfunction is aimed at relaxing the bladder detrusor muscle so that a normal amount of urine may accumulate before the urge to urinate is experienced. This may be achieved by medications such as propantheline bromide [Probanthin&], oxybutynin chloride [Ditropan), or imipramine [Tofranil®].
Emptying dysfunction is the inability of the bladder to completely eliminate stored urine. In this case the urethra is blocked by a spastic or tight sphincter which prevents the bladder from emptying completely. More specifically, the urinary sphinc ter contracts instead of relaxing when the bladder (detrusor) contracts to push the urine out. Usually some urine is eliminated, but a significant amount may remain in the bladder.
There is another form in which the detrusor is weakened and cannot expel all of the urine, but this occurs infrequently in MS.
Both types of emptying dysfunction cause urine to be retained. The residual urine (urine left in the bladder) may contribute to urinary tract infection since bacteria multiply freely in stagnant urine. Kidney damage can occur from frequent upper urinary infections caused by infected urine backing up" in the ureters when the exit is blocked by a contracted or tight sphincter. Another complication is bladder or kidney stones. Small mineral particles are normally expelled in the urine but may clump together to form stones which cannot be passed through urination.
Emptying Dysfunction Symptoms
The symptoms associated with "failure to empty" may include:
Sensation of incomplete emptying:
Weak urinary system
Urgency frequency and nocturnia:
Management of Emptying Dysfunction
For some individuals with a mild emptying problem (low amount of urine retained) prescribed medication such as baclofen (Lioresal] may be successful.
The most successful mechanism for bladder emptying is intermittent catherization (IC) by which urine is periodically drained by insertion of a thin tube into the bladder through the urinary opening. Intermittent catheterization is a simple, painless procedure performed either by the person with MS alone or with assistance when needed. Minimal instruction and a few practice sessions with a nurse are all that are required. Females are generally more receptive than men to IC, because of familiarity with the process of tampon insertion. Males tend to be more psychologically resistant, but once they overcome this and realize the benefits, they have an easier time with catheterization because of the accessibility of the urinary opening. The procedure is most conveniently performed at the toilet. The initial relief of symptoms and long-term avoidance of serious complications usually encourage continued practice. For some people with MS, the need to practice IC is only necessary for several weeks to several months, since the bladder often returns to normal or near-normal function.
A third category of bladder dysfunction, is a combination of retention and emptying problems. Symptoms result from both an excesisively active bladder and a sphincter blockage due to spasms and may include any combination of the following:
Combination of Stoage a Emptying Dysfunetion
Management of combined dysfunction includes methods previously described to control both storage and emptying dysfunction tailored to an individual's specific problems.
Consultation with your physician is essential to establish an accurate diagnosis
Consultation Consultation with one's physician is essential to establish an accurate bladder diagnosis. Relying on symptoms alone may be misleading and bladder function tests may be necessary to determine the course of proper medical management. Tests of Bladder Function Tests of bladder function may include one or more of the following:
The goals of bladder management are:
It is important to emphasize that there is variability in each individual's response to management interventions. A trial-and-error period may ~be needed to identify which measures are most effective. In most instances, successful management of urinary problems can be achieved.
Since bladder dysfunction is common in multiple sclerosis, it is important to have a good understanding of the kinds of problems which may occur. Control of symptoms is more easily accomplished with early treatment; therefore, consultation with the physician should take place at the first sign of urinary dysfunction.
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