Bladder Issues in NMO

Incontinence can have a huge impact on a person’s life. The embarrassment and stigma attached to continence has the potential to significantly change lifestyle and mood. A thorough assessment from a specialist can identify problems and strategies to manage these problems. This article is aimed to help you understand why things go wrong and how these difficulties can be managed.

Until there are problems, bladder control is something we all tend to take for granted. In health, we have the ability to inhibit the bladder (‘hold on’) and to activate it at will. A warning system operates between brain and bladder to alert us when the bladder needs emptying and that we should take the next convenient chance to pass urine. Or, we can empty even when the bladder is not full if that’s what we judge best – before going on a journey for example.

 

Urinary Continence

Continence is defined as the ability to store urine in the urinary bladder and pass at an appropriate time.

Therefore incontinence refers to problems with either

♦  Ability to store urine

♦  Ability to pass urine

An area in the brain called the “pontine micturition centre” senses that the bladder needs emptying and relays a message down the spinal cord to the nerves supplying the bladder. This stimulates the bladder wall (which is made of muscle) to contract, at the same time the small valve at the head of the bladder is relaxed and urine is passed.

Difficulty in bladder control is very common in patients who have a disease of the spinal cord, such as NMO. If somebody has had a “demyelinating” attack in the spinal cord above the level of the Bowel and Bladder, the electrical messages that would normally control continence are unlikely to get through.

The nerves that control the bowel and bladder are at a similar level to the nerves that control the lower limbs. This can mean that people who have difficulties with continence can also have mobility issues, which make it increasingly difficult to respond to an “urgency” to get to the bathroom.

There are two distinct types of bladder disorders in NMO. Some patients may experience both simultaneously which presents its own set of treatment issues, described later.

 

Bladder Overactivity

This is a common occurrence for NMO patients and causes the “bladder symptoms” that can cause huge disruptions to people’s lives. Fortunately, there are many ways of managing an overactive bladder.

It is important to think of the bladder like a “balloon” of muscle, but unlike a balloon, it has the remarkable property of being able to keep the pressure inside at a constant, despite the volume of urine constantly changing. The loss of this function is due to the lack of correct messages being able to get through the spinal cord. This causes the bladder wall to have vigorous contractions despite the amount of urine being very low (a bladder with normal nerve supply has a capacity of 300-500mls compared to a damaged nerve supply being as small as 100mls).

This leads to a sensation known as “urgency” where the person feels they need to get to a toilet with all haste. If the contractions are particularly strong or prolonged and the bladder pressure becomes too high, the muscles that control the release “valve” may be forced open and the person may be incontinent.

Another common issue is “frequency” of passing urine. This is classed as needing to visit the toilet more than 8 times in a 24 hour period, but may be as bad as needing to go hourly.

A combination of these two symptoms can be hugely disabling. People become nervous of leaving areas where there isn’t an obvious toilet facility and have to plan all trips to coincide with regular toilet stops which can be difficult when travelling abroad.

 

Incomplete Emptying

The inability of the bladder to be completely emptied is known as “retention” of urine. Some people will be able to feel that they are not emptying their bladder completely, others are unaware. For many, the need to void again soon after doing so is a good indicator of retention.

Incomplete bladder emptying is the result of two faults in the spinal cord

♦   The muscle controlling the “valve” out of the bladder (known as a sphincter) is unable to relax when the bladder contracts. This causes an interrupted flow of urine

♦   The neural impulses which keep the bladder muscle contracting until it is completely empty are unable to pass the area of damage on the spinal cord. This causes weak and poorly sustained contractions of the bladder.

If your specialist suspects that you are retaining urine, they may request a bladder ultrasound for you. This is a painless technique, which involves placing a scanner over the area of the bladder after you have attempted to empty your bladder. The volume in a bladder with healthy nerve supply should be under 100mls. Therefore a scan of over 100mls may require treatment.

It is worth understanding the implication of retaining urine. The most important factor is reducing the accumulation of urine, which can build up and stagnate. The risk of a bladder infection is greatly increased with this stagnating urine. A bladder infection can subtly raise the body’s core temperature (a normal response to infection).

 

Treatments

Anticholinergic medication

As the bladder is effectively a bag of smooth muscle, the treatments used for over activity are based on relaxing the muscle. These are known as anticholinergic medication. Unfortunately, all of these medications have the likelihood of causing a dry mouth as the chemical messages that the body uses to cause the bladder to contract also activates the salivary gland and therefore both are reduced by the drugs action. However a dry mouth can be a good indicator that the medication is at a therapeutic level. Adjusting the medication to ensure good relief of bladder symptoms without a significantly dry mouth can take some time, but is worth pursuing. 

For patients who have issues emptying, treatments are limited in terms of medication. By far the best treatment is manually emptying the bladder using intermittent self catheterisation (ISC). This term conjures up images of rubber tubes and bags hanging from the leg. The reality is that modern equipment allows for a catheter which is 10-20cm long and fits into a holder about the same size and shape of a ballpoint pen to be used. This will be discussed further in the next section.

For people who do not empty completely and also have an overactive bladder, treatment becomes more complicated. By its effective action of reducing activity of the bladder, an anticholinergic medication may compound incomplete emptying. This means it is essential to treat incomplete emptying first with ISC, followed with an anticholinergic to reduce symptoms.

It is also worth remembering that an anticholinergic medication may cause a bladder which normally empties completely to go into retention. Therefore a bladder scan three months after beginning treatment can be essential to rule this phenomena out.

 

Intermittent Self Catheterisation

As mentioned before, many peoples’ initial reaction to being told they may need ISC is one of fear and horror, which is borne of long held understanding of “in dwelling urethral catheters” which are kept in the urethra indefinitely. However, most people are willing to try the technique once they have seen the small intermittent catheters, know the simple technique and have been reassured that the technique should be painless. Some continence advisors suggest talking to another person who uses ISC for reassurance.

For most people, ISC is fairly straightforward, however those with mobility problems or hand dexterity issues may find ISC too intricate to perform regularly. In this situation, an indwelling catheter may be the best option.

Anxiety about ISC causing infections is common. Providing the correct minimal touch technique and single use of disposable catheters is observed, the risk will be reduced. If recurrent infections become a problem, it is better to use a full course of antibiotics rather than a long term course of low dose antibiotics to reduce the chance of resistance.

 

Botulinum Toxin Therapy

For those patients who find that anticholinergic medication has no positive effect on their symptoms, treatments are limited. This is usually due to the bladder being overactive; it is unable to store any useful volume of urine, leading to an uncontrollable frequency of urination, or on occasions leaking of urine.
In this instance, it is viable to completely paralyse the bladder as whatever function is occurring is not useful. This can be done by injecting Botulinum Toxin directly into the muscular bladder wall and sphincter controlling the release of urine. The procedure can be done under local anaesthetic and lasts for a number of months between injections. This procedure nearly always requires the patient to learn ISC to empty the bladder.

 

Quick access

A RADAR key, obtained from http://www.radar.org.uk/ or 0207 250 3222, gives access to locked public toilets around the UK. An urgency flash card can be obtained from the Bladder & Bowel Foundation at http://www.bladderandbowelfoundation.org.uk/ or 01536 533255.

Incontinence Living A great site that has all the information for people struggling with incontinence

http://www.incontinenceliving.co.uk/incontinence-products-buying-guide/i69 

If you have any tips that you have found beneficial, please let us know as it may help others nmo.advice@thewaltoncentre.nhs.uk