What is a Neurogenic Bladder?
A neurogenic bladder is a bladder with an abnormal nerve supply. Abnormalities of nerve supply can affect both the bladder and the urinary sphincter (the urinary control mechanism or valve located in the urethra). Abnormalities at any level of the nervous system (i.e. the brain, spinal cord, peripheral nerves) can affect the function of the lower urinary tract.
What are the causes of a Neurogenic Bladder?
Some of the many potential causes of a neurogenic bladder include:
- Cerebral (brain) conditions
- Cerebrovascular accidents – “strokes”
- Intracerebral haemorrhage
- Head injuries
- Brain tumours
- Spinal cord conditions
- Spinal cord injury
- Spina bifida
- Transverse myelitis
- Spinal cord tumours
- Peripheral nerve problems
- Pelvic surgery
- Pelvic radiation
- Peripheral neuropathy
- Prolapsed spinal disc
- General conditions that can affect nerve function at multiple levels
- Multiple Sclerosis
- Parkinson’s disease
- Vitamin B12 deficiency
Nerve control of the Bladder
The bladder and urethra require a normal nerve supply in order to function properly. Any abnormality in the nerve supply to the bladder can result in abnormal bladder function. Good bladder function depends on normal nerve signals at all neurological levels from the brain, spinal cord and in the peripheral nerves. Any interruption in these complex nerve pathways transmitting messages to and from the bladder and urethra may result in a neurogenic bladder.
Classification of Neurogenic Bladder
One of the classification systems used for neurological bladder disorders looks separately at the abnormality of the bladder and the urethral sphincter (on/ off valve that sits below the bladder in the urethra and prevents urine leakage).
The classification system divides function of the bladder (or detrusor muscle) and the sphincter into overactive, underactive or “normo-active” (i.e. functioning normally).
The EAU (European Association of Urology) - Madersbacher classification system classifies neurogenic bladder issues as follows:
- Overactive detrusor with overactive urethral sphincter
- Overactive detrusor with underactive urethral sphincter
- Overactive detrusor with normal urethral sphincter
- Underactive detrusor with overactive urethral sphincter
- Underactive detrusor with underactive urethral sphincter
- Underactive detrusor with normal urethral sphincter
- Normal detrusor with overactive urethral sphincter
- Normal detrusor with underactive urethral sphincter
Another way of looking at neurological problems affecting the urinary tract is that they affect the ability of the bladder to store the urine as well as to empty the urine. Treatment is then directed at issues of urinary storage and of urinary emptying.
What symptoms can a Neurogenic Bladder cause?
The symptoms of neurological problems affecting the urinary tract are highly variable and do not necessarily correlate with a specific neurological problem. Each neurological condition can also cause marked variation in the “type “ of neurogenic bladder that occurs. Symptoms of different patterns of bladder abnormality also overlap. Additionally the effects of a neurological condition can result in changes in bladder and urethral function over time.
“The bladder is an unreliable witness” is an expression used to indicate that bladder symptoms do not give a specific diagnosis especially when it comes to the complex abnormalities of bladder function and malfunction that occur with neurological conditions. This is the reason why a urodynamic study is crucial in providing information about the specific type of neurogenic bladder present in an individual patient’s neurological condition.
Problems with detrusor overactivity can cause symptoms of:
- Urinary urgency
- Frequency of urination
- Nocturia – going often to pass urine at night
- Urge urinary incontinence – leakage of urine on the way to the toilet usually associated with a feeling of urgency
Symptoms of detrusor underactivity (or an underactive bladder), include:
- Needing to wait for the flow to start
- Needing to push and strain to empty the bladder
- Poor or slow urinary stream
- Stop and start urinary stream
- Prolonged time required to pass urine
- Feeling like the bladder has not emptied completely
- Needing to go back a second time shortly after passing urine to pass more urine
- Reduced sensation of bladder fullness
- Frequent urination
- Urge urinary incontinence
- Overflow urinary incontinence
Some patients can present with the complications of a neurological problem in the urinary tract such as:
- Recurrent urinary tract infections
- Stones within the urinary tract
- Impaired kidney function – in late stages of severe bladder dysfunction
- Haematuria (blood in the urine)
Complications Of Neurological Bladder problems
Neurological disorders of the urinary tract can cause a variety of long term complications the most serious of which is kidney damage resulting in renal (kidney) failure. Early diagnosis and management of neurological urinary tract problems can prevent irreversible deterioration in the function of the kidneys as well as bladder and urinary sphincter.
Potential complications from neurological urinary tract problems include:
- Reduced quality of life
- Urinary incontinence and problems with urinary control
- Recurrent urinary tract infections including
- Bladder infections
- Kidney infections (pyelonephritis)
- Urinary tract stones – in the bladder and kidneys
- Kidney failure due to the transmission of abnormally high bladder pressures to the kidneys
- Autonomic dysreflexia (hyperreflexia)
- This is a potentially life-threatening condition associated with high spinal cord injury (in the cervical and high thoracic spinal cord) which cases marked elevation in blood pressure with abnormalities in heart rate and headache due to an abnormality of the regulation of the autonomic nervous system.
- Autonomic dysreflexia (or hyperreflexia) can be triggered by acute bladder distension as well as other causes.
Investigations of Neurological Bladder problems
Initial assessment includes a full clinical assessment with:
- Including other indirect problems related to the neurological condition such as problems with bowel and sexual function
- Physical examination
- Bladder diary
- Testing of kidney function with blood tests and urine testing
- Imaging of the urinary tract – initially with a renal tract ultrasound
- Assessment of urinary flow rate and bladder emptying (residual volume)
Urodynamic studies are a crucial part of assessing neurological bladder disorders to determine:
- The exact type of neurological problem affecting the bladder
- Its severity
- The potential risk to kidney function
- Treatment options
- The effectiveness of treatment
Video-urodynamics (i.e. a Urodynamic study combined with fluoroscopic X-ray imaging) is regarded as the gold standard Urodynamic study in patients with neuro-urological disorders.
Urodynamic studies are often combined with cystoscopy for a full assessment of the lower urinary tract.
Aims of treatment in Neurological Bladder problems
The key aims of treatment in patients with neurological problems affecting the urinary tract are:
- Protection and preservation of kidney function
- Improvement of urinary continence or control
- Improvement in lower urinary tract (i.e. bladder and urethral) function
- Improvement in the patient’s quality of life
Treatment options for Neurological Bladder problems
Treatment for neurological problems affecting the bladder is highly individualised to the specific patient. Many factors have to be taken into consideration when determining the best treatment for the individual including:
- The patient’s quality of life and aims for treatment
- The specific neurological condition and its prognosis or likelihood of progressive disability
- The patient’s mobility and level of independence and self-care
- The patient’s hand and eye function and potential ability to perform intermittent self catheterisation
- The patient’s cognitive function
- Carer support and assistance in continence management
- The severity of the neurological abnormality affecting the bladder and its potential to cause deterioration in kidney function and bladder function
Combinations of treatment are very commonly used in management of neurological problems affecting the urinary tract due to the combinations of problems affecting both the bladder and the urinary sphincter.
Bladder drainage can be performed with:
- Intermittent self-catheterisation
- Intermittent self-catheterisation (or ISC also known as CIC or clean intermittent catheterisation) is a technique whereby the patient or carer is taught to empty the bladder by passing a catheter into the bladder. This drains out urine and the catheter is then immediately removed.
- The procedure is taught to the patient or carer by a specialist Urology or Continence nurse using disposable catheters.
- The frequency of performing intermittent self-catheterisation varies according to the neurological problem affecting the bladder and may be performed once or more per day.
- Intermittent self-catheterisation is the preferred non-surgical treatment for an underactive bladder.
- Indwelling catheters (or permanent catheters)
- Ideally a permanent indwelling catheter should be avoided except in cases in which intermittent catheterisation cannot be performed by the patient or a caregiver as indwelling catheters are associated with more infections and long term problems than intermittent catheterisation.
- A long-term suprapubic indwelling catheter (i.e. entering the bladder through the abdomen rather than through the urethra or water pipe) is a better long-term option than an urethral catheter (i.e. a catheter exiting the urethra or urinary drainage pipe) as it prevents complications affecting the urethra.
- Neuromodulation with the InterStim® neuromodulation device
Bladder storage can be improved by:
- Anticholinergic medication
- Botulinum toxin injections into the bladder
- Bladder surgery such as:
- augmentation cystoplasty
- urinary diversion surgery with either continent or incontinent urinary diversion surgery
Overactivity of the urethral sphincter can be treated by:
- Intermittent self-catheterisation
- Botulinum toxin injections into the urethral sphincter
- Urethral sphincterotomy (performed in men) to surgically open a neurologically abnormal sphincter
Underactivity of the urethral sphincter can be treated by:
- Sling surgery
- Natural tissue or autologous fascial slings – are preferred in patients with neurological problems
- Artificial urinary sphincter insertion surgery
- Urinary diversion surgery
- Urinary diversion surgery with either continent or incontinent urinary diversion
- Long-term suprapubic catheters with surgical closure of the urinary sphincter or bladder neck
Monitoring and follow up in Neurogenic Urinary Tract Abnormalities
Neurological abnormalities of the bladder and urethra are often unstable and the symptoms can vary significantly even over a relatively short time period.
All patients with neurological abnormalities which affect the urinary tract require ongoing follow up because of the potential for silent deterioration in kidney function which can occur without a significant change in urinary symptoms.
The risk to kidney function can be determined by the type of neurological problem (e.g. high spinal cord injury), the results of the urodynamic study and type of neurogenic bladder and urethral dysfunction. In high-risk patients, regular urinary tract imaging with renal ultrasound (performed at least every 6 months) as well as monitoring of kidney function with blood tests is performed. Urodynamic testing may need to be repeated at intervals in high-risk patients to determine changes from baseline.
Low-risk patients also require regular follow up at less frequent intervals with imaging and a check of renal function.