Neurogenic Bladder

How nerves control the bladder

Bladder control relies on coordination between the brain (which decides when to urinate), the spinal cord (which carries signals) and the nerves to the bladder muscle (detrusor) and the urethral sphincter. During filling, the detrusor relaxes and the sphincter stays closed. During urination, the detrusor contracts and the sphincter opens. Damage at different levels disrupts this in predictable ways.

Types of neurogenic bladder

Many people, particularly with MS and spina bifida, have mixed patterns.

Symptoms

Overactive (spastic) bladder

• urgency, frequency and getting up at night
• urge incontinence, sometimes without warning
• small, frequent voids

Underactive (flaccid) bladder

• weak stream, straining, incomplete emptying
• reduced sensation of fullness
• constant dribbling (overflow incontinence)
• urinary retention

Common to both

• recurrent urinary tract infections
• bladder stones
• in spinal cord injury: muscle spasms, sweating or autonomic dysreflexia as signs of bladder problems

Causes

• spinal cord injury
• multiple sclerosis: bladder symptoms affect most people with MS at some point
• spina bifida and tethered cord
• stroke, Parkinson's disease, dementia and multiple system atrophy
• diabetes (diabetic cystopathy)
• cauda equina syndrome, disc disease and spinal stenosis
• pelvic surgery or radiation, such as for rectal or cervical cancer
• transverse myelitis, Guillain-Barre syndrome and HIV
• alcohol-related and B12-related nerve damage

Diagnosis

• history and bladder diary: fluid intake, voids, leaks and catheter volumes
• urinalysis and culture
• post-void residual measurement by bladder scan
• kidney function blood tests
• kidney and bladder ultrasound to check for hydronephrosis and stones
• urodynamic studies: the key test, measuring bladder pressure during filling and emptying, bladder capacity, compliance (stretchiness) and sphincter coordination. High storage pressure is the main threat to the kidneys
• cystoscopy for persistent blood, stones or catheter problems

Treatment

Goals: protect the kidneys, prevent infection, achieve continence and fit bladder management into daily life.

Bladder emptying

• clean intermittent self-catheterization (CIC): the preferred method for people who cannot empty, typically 4 to 6 times a day
• indwelling urethral or suprapubic catheter when intermittent catheterization is not possible
• timed voiding for milder problems

Medicines

• antimuscarinics (oxybutynin, solifenacin, trospium) and beta-3 agonists (mirabegron, vibegron) to calm an overactive bladder and lower pressure
• alpha-blockers to relax the bladder outlet in some people
• desmopressin for night-time urine production in selected people

Procedures

• onabotulinumtoxinA (Botox) injections into the bladder wall, lasting 6 to 12 months, often with intermittent catheterization afterward
• sacral neuromodulation or tibial nerve stimulation for some people
• bladder augmentation to enlarge a small, high-pressure bladder
• continent catheterizable channel (Mitrofanoff) through the belly button
• urinary diversion or artificial urinary sphincter in selected cases

Complications

• recurrent UTIs and kidney infections
• bladder and kidney stones
• hydronephrosis and kidney failure from high pressure
• skin breakdown from leaking
• autonomic dysreflexia in high spinal cord injury
• bladder cancer risk with long-term indwelling catheters

Living with neurogenic bladder

Regular follow-up with a urologist, kidney ultrasounds and periodic urodynamics catch silent problems early. Most people, including children and wheelchair users, learn self-catheterization quickly. Bowel management often needs attention too, since neurogenic bowel commonly coexists.

Frequently asked questions

What is a neurogenic bladder?

A neurogenic bladder is bladder dysfunction caused by damage to the nerves, spinal cord or brain that control urination. It can make the bladder overactive, causing urgency and leaking, or underactive, causing incomplete emptying and overflow.

What causes neurogenic bladder?

Common causes include spinal cord injury, multiple sclerosis, spina bifida, stroke, Parkinson's disease, diabetes, cauda equina syndrome and nerve damage from pelvic surgery or radiation. Anything that disrupts communication between the brain and bladder can cause it.

What is the difference between a spastic and a flaccid bladder?

A spastic bladder contracts involuntarily, causing urgency, frequency and leaking, often from damage above the lower spinal cord. A flaccid bladder contracts weakly or not at all, causing retention and overflow, usually from damage to the lower spinal cord or nerves.

How is neurogenic bladder treated?

Treatment often includes clean intermittent self-catheterization to empty the bladder, medicines or Botox injections to calm overactivity, and infection prevention. Nerve stimulation and surgery to enlarge the bladder or create a catheterizable channel are options for some people.

Can neurogenic bladder damage the kidneys?

Yes. High pressure in the bladder, especially when it contracts against a closed sphincter, can back urine up into the kidneys and cause damage. Regular monitoring with ultrasound and urodynamic testing, and treatments that lower bladder pressure, protect the kidneys.