The main 2 functions of urinary bladder are (1) storage of urine till it is time to empty and (2) Evacuation by passing urine periodically at appropriate times.

These 2 functions are achieved by finely co-ordinated processes of contraction and relaxation of detrusor muscle and urethral sphincters of bladder under control of centers of micturition in brain stem with inhibitory influence of cerebral cortex which occurs around 3-4 years. By 3-4 years majority of children stop daytime wetting. This fine balance of detrusor contraction and relaxations of sphincter are controlled by innervation of detrusor and sphincter muscles by sympathetic (T10, L1 spinal segment) parasympathetic (S2-S4 spinal segments) and motor/sensory nerves.

Disorders of voiding develop as incontinence or urinary retention if spinal segments of nerves are affected.

The clinical conditions commonly causing disorders of voiding are a variety of congenital and acquired conditions affecting spinal cord segments of dorsal lumbar, sacral regions including cauda equina and Conus medullaris ex. Meningomyelocele, lipomeningocele, diastematomyelia, spina bifida and sacral agenesis. Traumatic injuries and tumors of spinal cord are rare but important causes of neurogenic bladder.

Approach to neurogenic bladder consists of:

Detailed history of age of bladder and bowel control, type of voiding problems. Daytime and nighttime enuresis should be noted. Incontinence or enuresis denotes hyperactive bladder contraction or small capacity bladder. Incontinence may occur during daytime,whilst giggling, laughing etc. Urinary retention may be due to increased tone of sphincter with poor relaxation ex. Detrusor - sphincter dyssynergia (DSD). Continuous dribbling is due to continuous relaxation of sphincters, usually caused by spinal cord lesions affecting cauda equina. Daytime incontinence in children above 8 years of age without obvious neurologic cause needs complete work up of neurogenic bladder. Family history of incontinence may be present.

Detailed examination of back to detect nevus, hair, lump, dimple which indicates abnormalities of spine like spina bifida, lipomeningocele, sacral agenesis which can be diagnosed by simple x-ray of spine followed by MRI to detect spinal cord compression and/or tethering  requiring surgery. Examination of genitals, neurological examination for paraplegia, hydrocephalus and tone of anal sphincters are  important points.

Urine examination- routine and culture to detect UTI which is a common clinical presentation of neurogenic bladder with functional obstruction, incomplete voiding and residual urine. Longterm chemotherapy is useful to prevent recurrent UTI.

Ultrasonography of kidneys, ureters and bladder to detect upper tract dilatation like hydronephrosis, hydroureter, hypertrophy of bladder wall in DSD. Due to backpressure transmitted from bladder contractions against a non-relaxing sphincter in DSD; secondary VUR and  reflux nephropathy with multiple renal scars occur, chronic renal failure is a consequence of poorly managed neurogenic bladder.

Kidney function tests to detect azotemia, metabolic acidosis, calcium / phosphorus abnormality, urinary concentrating defects which are due to tubular dysfunction are common metabolic problems.

Urodynamic studies, which measure the activity of detrusor muscle and urethral sphincter, bladder capacity, sensory and motor functions of bladder are important in evaluation of type and severity of bladder dysfunction. This special test helps in diagnosis of type of neurogenic  bladder so that drug therapy can be decided to control inappropriate detrusor contraction and relaxation of sphincter. Indication of UDS are  (1) wetting with neurologic lesions (2) day and night time enuresis after age of 10 years.

Management of neurogenic bladder is complex and needs a team approach. In a common situation such as meningomyelocele pediatric urologist, nephrologist neurophysician, physiotherapist, radiologist with dedication are required for the comprehensive treatment.

Management includes:

• Prevention and control of urinary tract infection with appropriate long term drug therapy.
 
• Clean intermittent catheterization to evacuate bladder completely is advocated to reduce backpressure and prevent residual urine. Parents can be trained to perform CIC 3-4 times a day at home.
 
• Use of drugs to relax hypercontractile detrusor muscle ex. Oxybutynin or to increase contraction of hypocontractile bladder muscles use of cholinergic agents like Bethanachol can help to certain extent. Relaxation of urethral sphincter may be different and alpha blockers like prazosin may be useful. These drugs should be used after urodynamic evaluation by experts.

Rarely in selected cases surgery is indicated to augment the bladder capacity and or tighten the urethral sphincter.

Bladder training programs using biofeed methods should be tried.

Last created on 06-03-2002
Last updated on 01-07-2006