Neurogenic Bladder

Etiology of neurogenic bladder

Brain and spinal cord related:

Cerebral palsy

Parkinson’s disease

Multiple sclerosis, amyotrophic lateral sclerosis

Encephalitis

Stroke

Congenital defects of spinal cord

Brain or spinal cord tumors

Spinal cord injury

Peripheral nerve related:

Diabetic neuropathy

Chronic alcohol use

Vitamin B₁₂ deficiency

Herniated disk

Nerve damage from pelvic surgery

Syphilis, poliomyelitis

Childhood urological problems such as enuresis, recurrent urinary tract infections, vesicoureteral reflux and congenital spinal problems are relevant. Medical and surgical history focusing on conditions such as diabetes, multiple sclerosis, Parkinsonism, spinal cord injuries and pelvic surgeries is essential, along with the use of alcohol and medications that are likely to affect bladder function. Since the parity, duration of labor, mode of delivery, and menopausal status influence the bladder function, a thorough obstetric and gynecological history is of use. Pelvic floor disorders commonly being interrelated, bowel function needs to be elicited, as neurogenic bowel is likely to coexist with neurogenic bladder, presenting with constipation. In addition, previous treatments and their effect on symptoms can guide subsequent management.

Of significance to the clinician is the identification of an “unsafe” neurogenic bladder. The indications of which could be the presence of hematuria, pain, urinary infections, deranged renal function, or hydronephrosis. Further evaluation should focus on the possibilities of stone or growth.

In spinal cord injury patients with injury level above T6, it is important to get a history or be wary of autonomic dysreflexia, a medical emergency that needs to be treated rapidly and adequately. This results from exaggerated sympathetic activity in response to stimuli below the level of injury. Bladder or rectal distension or lower urinary tract instrumentation can result in severe headache, hypertension, flushing and sweating above the level of lesion accompanied usually by bradycardia but occasionally with arrhythmias and tachycardia [4].

The physical examination in these patients is focused on identifying evidence of voiding problem and a probable causative factor. An abdominal and pelvic examination can identify a palpable or tense bladder and pelvic organ prolapse, a digital rectal examination assesses anal/perianal sensation and sphincter tone and a bulbocavernosus reflex checks integrity of S2–S4 neurons.

The focused neurological evaluation should be supplemented by a general neurological assessment starting with the gait and mobility of the patient, presence of intentional tremors (Parkinsonism) and gross neurological deficits in spinal cord injuries, depending on the level involved.

Investigations

A bladder diary for a minimum of 3 days, with voided volumes, can provide very useful information. It is important to assess renal function and rule out urinary infection as initial part of investigation. In suspected spinal lesions, an X-ray or more commonly magnetic resonance imaging (MRI) is employed in the identification of the site and type of lesion. Other imaging techniques such as ultrasound helps in estimating post-void residual (PVR) urine volume and ruling out hydronephrosis or hydroureter and calculi. CT urogram may be needed in select patients with hematuria, abnormal urinary tract, and spinal dysraphism and in those with reconstructed lower urinary tract to rule out vesicoureteral reflux. Cystoscopy may be needed in those with irritative symptoms, to rule out stone or growth.

Urodynamics, however, is the gold standard evaluation in patients with neurogenic bladder. Uroflow (free flow study) with PVR measurement and cystometrogram (CMG; pressure flow study) will guide the initial management in majority of these patients. Complex testing (videocystometrogram, VCMG; electromyography, EMG; urethral pressure profilometry, UPP) is reserved for those where simple initial evaluation is inconclusive or in those who are at risk of renal compromise and therefore may need surgical intervention. In other cases, such as in patients with complex symptom profile associated with multiple sclerosis, Parkinson’s disease, diabetes mellitus, spinal dysraphism, or following radical pelvic surgery, this may be indicated to establish the underlying urodynamic profile. And if symptoms change in the future, further urodynamic evaluation may have to be repeated to guide therapy.

While a detailed elucidation on invasive urodynamic testing is beyond the scope of this chapter, it is important to understand some key determinants such as bladder compliance, detrusor leak point pressure, and abdominal leak point pressure that underpin management of these patients. In patients with suspected neurogenic pathology, slow filling rate is recommended.

Compliance describes the relationship between bladder pressure and volume. It is easy to remember the concept of compliance if one imagines a balloon being blown. Initially, it is difficult to overcome the resistance of the balloon as it is “stiff” or poorly compliant. As one continues to blow the balloon, it becomes easier (one is able to increase the volume of the balloon with little effort), highly compliant, or accommodative. The bladder’s viscoelastic property allows it to behave in a similar fashion. Therefore, a compliant bladder allows storage of increasing volumes of urine without proportionate increase in its pressure.

Detrusor leak point pressure (DLPP) helps in identification of patients at risk of upper tract damage in neurogenic bladder. DLPP is the lowest detrusor pressure (Pdet) at which urine leakage occurs in the absence of either a detrusor contraction or increased abdominal pressure. The bladder is filled to the point when leakage occurs without increase in abdominal pressure and this detrusor pressure is the DLPP. It measures resistance of the urethra to bladder storage pressure. In the presence of an outlet resistance, high bladder pressure is needed for leakage to occur. When the DLPP is >40 cm H₂O, ureteral peristalsis is hindered and leads to hydroureters, hydronephrosis, and vesicoureteral reflux resulting in renal deterioration [5]. In a poorly compliant bladder with a low DLPP, the patient can be incontinent, but their upper tract is not damaged, as the urethra opens with low pressure. Hence, the “safe” bladder should have a resting pressure of less than 40 cm H₂O.

Valsalva leak point pressure (VLPP), or abdominal LPP (ALPP) as it is often called, is the intravesical pressure (Pves) at which urine leakage occurs due to increased abdominal pressure in the absence of a detrusor contraction. This is used as an indirect measure of the competence of the sphincter. McGuire showed that 76 % of those with intrinsic sphincter deficiency had an ALPP of <60 cm H₂O [6]. Pelvic organ prolapse can interfere with ALPP assessment and has to be carried out with the anatomy restored (e.g., using a pessary).

It is worth mentioning that urodynamic testing needs to be an interactive session between the patient and investigator and it should ideally reproduce the patient’s symptoms. Recognition of associated factors like vesicoureteral reflux and pelvic organ prolapse and their impact on bladder and outlet function is paramount in the management of some of these complex cases.

It is essential to categorize the neurogenic bladder dysfunction following urodynamic testing, into obstructed or non-obstructed and also as due to bladder or outlet problem and the presence or absence of detrusor-external sphincter dyssynergia (DESD).

Management

Medical Goals

Aim for a low-pressure compliant bladder.
Protect renal function.
Maintain continence.
Address patient’s symptom.
Voiding ideally without the need for catheterization.

Psychosocial Goals

Patient’s desires and suitability for a specific treatment option:
- Physical ability to deal with treatment option, e.g., can the person perform clean intermittent self-catheterization (CISC)?
- Cognition, e.g., does the patient understand the complexity of the underlying issues?
- Mental ability, e.g., the ability to cope with any planned intervention.
- Social ability, e.g., does the person have any caregivers/support?
Improve or maintain good quality of life.

It is important that the patient is fully aware of the underlying problem and the progressive ladder of management that may be used in difficult cases. For some, nonmedical management may suffice for life without significant morbidity, while others may require invasive therapies. The treatment plan needs to be individualized for the patient’s needs and abilities. Patient involvement is crucial for the success of any management plan.

Treatment of Urgency and Urgency Incontinence

The aim is to improve quality of life by reducing the urgency and urgency incontinence episodes and could be achieved with nonmedical or medical management or a combination of both.

Conservative Management

Provided the upper tract is not at risk, those with minimal symptoms are likely to do well with coping strategies for urgency combined with pelvic floor exercises. The voiding diary would have indicated about their fluid intake and the intake of bladder irritants like caffeine. Switching to decaffeinated beverages and reducing intake before key activities should be part of any successful management plan. A strategy that is commonly taught in practice involves asking the patients to sit down at the first sensation of “urgency.” The patient is taught that this is uncoordinated contraction of the bladder muscle, which if ignored is likely to pass. The patient is then asked to count to about 50 very slowly. During this time they are instructed to perform pelvic floor exercise intermittently (Kegel exercise). Once the sensation of urgency passes away completely, they can then resume their activity and pass urine the next time there is a natural call. If they are able to do this, the next step is to start voiding by the clock, i.e., timed voiding. If the patient’s urgency incontinence episodes are minimal and there is improvement of their quality of life, then these measures would suffice.

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