Spina Bifida - Neurogenic Bladder

Damage to the main, spinal cord and/or the sacral nerves may lead to neurologically impaired bladder, genital and bowel function. This may be congenital in origin such as in spina bifida, sacral agenesis and cerebral palsy or acquired such as in trauma. near drowning, viral or bacterial infections of the brain and/or spinal cord tumors of the central nervous systern or the surgery to remove those tumors. Those with a non-neurogenic neurogenic bladder do not have a definable neurologic lesion.

Neurogenic bladder dysfunction may take one of several forms and these forms usually affect both the detrusor (bladder muscle) and the sphincter mechanisms of bladder function (storage and control) in varying degrees.

In some cases the bladder may be hyperactive or hypoactive while the sphincter mechanism may be affected in the same or a different manner. For example, the bladder may be relatively inactive while the external sphincter may be hyperactive leading to urinary retention and possible infections, hydronephrosis and possibly renal failure.

No type of neurogenic bladder dysfuntion is likely to remain the same over time and the age and speed at which bladder deterioration can occur is very variable. Furthermore. the severity of the neurologic lesion, as well as the site of the lesion does not appear to correlate with the degree of neurogenic bladder dysfunction.

DIAGNOSIS

Patients may complain of frequency/urgency and incontinence. They may also present with urinary tract infections, hemorrhagic cystitis, pyelonephritis, epididymitis or stone disease. These stones can be in the kidney, ureter, or bladder.

Bowel symptoms may include soiling, constipation or obstipation. Genital function with impaired or absent erections may be seen in males. Autonomic dysreflexia may be seen in patients with spinal cord lesions above T1. Symptoms in those affected by autonomic dysreflexia may be brought on by urinary retention or constipation and can lead to elevated blood pressure, sweating, headaches and slow pulse. It is relieved through emptying the bladder and/or rectum.

At birth a clinically obvious spina bifida (myelomeningocele) may be present. A clinically less obvious lumbo-sacral skin defect may indicate a spina bifida occulta and/or possibly spinal dysraphism.

Rectal examination can evaluate anal tone and reflexes. Abdominal palpation can detect a distended bladder.

INVESTIGATIONS

The neurologic cause of neurogenic bladder dysfunction may be recognized by examination and magnetic resonance imaging (MRI) of the spinal tract. MRI’s of the spinal tract and especially the limbosacral spine can be very useful to diagnose a tethered cord. If the spinal cord is tethered, neurosurgery may be necessary to release it.

Urinary tract radiological examination focuses on two aspects: 1)on bladder morphology and function through cystograms or voiding cysto urethrograms involving either contrast or isotope and 2)evaluation of the kidneys and ureters or upper tracts.

Studies of the upper tracts with ultrasounds, intravenous pyelograms (IVP), DMSA scans, and Mag 3 lasix renal scans may be useful.

Urodynamic or video urodynamic studies can be very useful. Cystoscopy is seldom needed.

MANAGEMENT

The goals here are to relieve incontinence with regular emptying of the bladder and to preserve the kidneys, as well as prevent urinary tract infections.

1) Non Surgical Options

a) Intermittent catheterization

Many patients can be kept dry by performing clean sell-intermittent catheterization which can be performed at 3-4 hourly intervals during waking hours. Most catheterizations do not have to be done using a sterile technique.

b) Medications

These may be employed to influence bladder function, sphincteric function or both.

c) Crede

Crede is bladder expression, by pressing over the bladder. This can only work in patients with an adequate bladder capacity without reflux and hydronephrosis and with minimal outflow obstruction (enough to stop dribbling, but not enough to impair emptying.)

Various medications and prophylactic antibiotics may he used in conjunction with the catheteriztion program. Continuous catheterization, with an indwelling foley catheter, or suprapubic catheter changed every 4 weeks is usually not recommended. Similarily, a condom catheter in males is associated with risks.

Bowel Control

This can be manipulated through diet or suppositories and enemas as necessary. The continent cecostomy procedures to allow antegrade enemas may be useful in some patients.

2) Surgical Options

Botulinim Toxin

Botulinim toxin (Botox) may be injected about the sphincter and or bladder to enhance emptying and storage aspects of some neurogenic bladders.

External sphincter surgery

External sphincterotomy may be indicated in some males with neurogenic bladder dysfunction to relieve external sphincter obstruction.

Either sphincter resection or reconstruction may have a place in some select patients.

Endoscopic collagen

Continence may be improved in some patients with neurogenic bladder dysfunction by injecting collagen (Deflux) about the bladder neck and sphincter. Collagen may also be injected about the ureteral orifices to cure vesicoureteral reflex if this is present.

Urethral Compression
These may be external or implanted.
a) Cunningham Clamp as a penile clamp.
b) In-Vance Sling can be performed in men that have had sphincter resection or damage.
c} Artificial sphincters in the form of an implantable compressible balloon system such as the AMS [American Medical Systems) devices may help to control continence.

Sacral Rhizotomy
This may be performed chemically or surgically.

Implanted Stimulators
Nerve root stimulators such as the Interstim may have a place.

Bladder Augmentation
This procedure usually requires the patient committed to clean intermittent catheterization post operatively.

Urinary diversion
Cutaneous urinary diversion is rarely performed these days. A vesicostomy may be performed for tempoary diversion.