neurogenic bladder

Neurogenic bladder Dr,mohamed fawzi alshahwani

The urinary bladder is probably the only visceral smooth muscle that is under complete voluntary control from cerebral cortexIt has both somatic & autonomic innervationsThe functional features include:A normal capacity of 400 – 500 mlSensation of fullnessVolume change without change in intraluminal pressureInitiation & maintenance of contraction until bladder is emptyVoluntary initiation or inhibition of voiding

The sphincteric unit

In both male & females : two sphinctersInternal involuntary SM sph. at bladder neckExternal voluntary striated M. sph. from the prostate to membranous urethra in males & at mid urethra in femalesInnervationParasympathetic : S 2 – 4Symp. : T10 – L 2Somatic motor innervation :S 2 – 3 though the pudendal N.

The micturition reflex

Intact pathway via the spinal cord & pons required for normal micturition Disruption of pontine control as in upper spinal cord injury lead to contraction of the bladder without sph. Relaxation ( detrusor-sphincter dyssynergia) Urodynamic studies Tech. used to obtain graphic recording of activity in UB, urethral sph., & pelvic musculature

Classification of neurogenic bladder

Upper motor neuron , spastic , uninhibited : injury above spinal cord micturition center Lower motor neuron, flaccid , atonic, areflexic : injury in the pelvic nerves or spinal micturition center


N.B. Spinal shock Immediately after injury, regardless of the level, there is a stage of flaccid paralysis with numbness below the level of the injury that lead to bladder overfilling to the point of overflow incontinence & rectal impaction. It last few weak up to 6 months during this ti;e bladder should be drained by a catheter

Clinical picture

UMNL : reduced capacity , involuntary detrusor contraction , high intravesical detrusor pressure , spasticity of pelvic striated M. , autonomic dysreflexia in cervical cord lesions LMNL : large bladder capacity, lack of voluntary detrusor contraction, low intravesical pressure, deceased tone in external sph. N.B.: full neurologic exam. Is required for those patients

Investigations

Urinalysis Renal function test Imaging study Instrumental exam. Cystoscopy Urodynamic studies


UDS



Differential diagnosis


Cystitis Chronic urethritis Vesical irritation 2ry to psychic disturbance Interstitial cystitis Cystocele Infravesical obstruction

Treatment

:The treatment is guided by the need to restore low pressure activity to the bladder in order to preserve renal function, continence, & control infection-Spinal shock bladder drainage is required by intermittent catheterisation , indwelling catheter or suprapubic cystostomy Increase fluid intake to 2 – 3 l/day

- Spastic neuropathic bladder

Voiding by trigger tech. Anticholinergic medications (parasympatholytic drugs) like oxybutynin(ditropan) 5mg 2-3 times /day Indwelling catheter or CIC Condom catheter & leg bag Sphincterotomy Sacral rhizotomy at S 3-4 Neurostimulation Urinary diversion

Flaccid neuropathic bladder

-Crede maneuver ( manual suprapubic pressure) accompanied by strainingBladder training & care , voiding every 2hrCSIC every 3-6 hrTUR in hypertrophied bladder neck or BPHparasympathmimetic drugs like bethanecol chloride( Urecholine) 5 – 50 mg every 6-8hr

complications

Infection : cystitis, periurethritis, prostatitis, epididymoorchitis, pyelonephritis Hydronephrosis Calculus Renal imperment Autonomic dysreflexia: , dramatic elevation in systolic &/or diastolic pressure, increase pulse pressure, bradycardia, headache, piloerection. brought by over distention of the bladder in patients with cord lesion above T1


Treatment of autonomic dysreflexia immediate catheterisation oral nifedipine (20mg) 30 min before cystoscopy as prophylaxis alpha adrenergic blockers

prognosis

The greater threat to those pt is progressive renal damage caused by pyelonephritis , calculosis, hydronephrosis