Editing Neurogenic LUT Dysfunction (section)

== Diseases distal to the spinal cord ==

=== Disk disease ===
* '''Spinal Cord Anatomy'''
** '''In the adult, the sacral spinal cord begins at spinal column (vertebral bodies) levels T12 to L1 and terminates in the cauda equina at spinal column level L2'''
*** In this distal end of the spinal cord (conus medullaris), the spinal cord segments are named for the vertebral body at which the nerve roots exit the spinal canal.
*** Thus, although the sacral spinal cord segment is located at vertebral segment L1, its nerve roots run in the subarachnoid space posterior to the L2 to L5 vertebral bodies until reaching the S1 vertebral body, at which point they exit the canal.
*** Therefore, '''all of the sacral nerves that originate at the L1 and L2 spinal column levels run posterior to the lumbar vertebral bodies until they reach their appropriate site of exit from the spinal canal.''' '''This group of nerve roots running at the distal end of the spinal cord is commonly referred to as the cauda equina.'''
*** Conus medullaris vs. cauda equina
**** The most distal bulbous part of the spinal cord is called the '''conus medullaris''', and its tapering end continues as the filum terminale. Distal to this end of the spinal cord is a collection of nerve roots, which are horsetail-like in appearance and hence called the '''cauda equina''' (Latin for horse's tail)§
* '''Usually, disk prolapse is in a posterolateral direction, which does not affect the majority of the cauda equina. However, in 15% of cases, central disk prolapse occurs and compression of the cauda equina may result.'''
** '''Thus, disk prolapse anywhere in the lumbar spine could interfere with the parasympathetic and somatic innervation of the LUT, striated sphincter, and other pelvic floor musculature, and afferent activity from the bladder and affected somatic segments to the spinal cord.'''
** '''Most disk protrusions compress the spinal roots in the L4 to L5 or L5 to S1 vertebral interspaces.'''
*** '''DESD does not occur as the injury is infrasacral'''
* '''When LUT dysfunction is present, it typically occurs with the usual clinical manifestations of low back pain radiating in a girdle-like fashion along the involved spinal root areas. The most characteristic findings on physical examination are sensory loss in the perineum or perianal area (S2 to S4 dermatomes), sensory loss on the lateral foot (S1 to S2 dermatomes), or both.'''
* '''Detrusor areflexia occurs in 27% of patients with lumbar disk disease'''
* '''The most consistent urodynamic findings are:'''
** '''Normal compliance'''
** '''Areflexic bladder associated with normal innervation or findings of incomplete denervation of the perineal floor musculature.'''
** Occasionally, patients may show detrusor overactivity, attributed to irritation of the nerve roots
* '''Laminectomy may not improve LUT function in many cases''', and prelaminectomy urodynamic evaluation is prudent because it may be difficult postoperatively to separate causation of voiding dysfunction resulting from the disk sequelae from changes secondary to the surgery.
* Cauda equina syndrome is a term applied to the clinical picture of perineal sensory loss with loss of voluntary control of both anal and urethral sphincter and of sexual responsiveness. Patients undergoing surgery are found to have an acontractile bladder and no bladder sensation. This can occur not only secondary to disk disease (severe central posterior disk protrusion) but also to other pathologic processes affecting the spinal canal.

=== Spinal stenosis ===
* May occur without disk prolapse
* Urodynamic findings are dependent on the level and the amount of spinal cord or nerve root compression
* Because there is no consistent pattern of dysfunction with any type of spinal stenosis, urodynamic studies again should serve as the cornerstone of therapy

=== Radial pelvic surgery ===
* '''LUT dysfunction after pelvic plexus injury occurs most commonly after abdominoperineal resection (APR) and radical hysterectomy'''
**'''The inferior hypogastric plexus (pelvic plexus) which innervates the viscera of the pelvic cavity is a paired structure located on the side of the rectum in males and at the sides of the rectum and vagina in females.'''
** Injury may occur from denervation or neurologic decentralization, tethering of the nerves or encasement in scar, direct bladder or urethral trauma, or bladder devascularization.
** Adjuvant treatment, such as chemotherapy or irradiation, may compound the damage.
** Other dysfunctions commonly associated with APR related to sexual activity include
***Ejaculatory dysfunction in males
***Vaginal dryness and dyspareunia in females
**Uncertainty  whether nonradical pelvic surgery such as simple hysterectomy can be ultimately responsible for storage or emptying abnormalities on the basis of neurologic damage
* ≈1/3 of patients have some element of urinary tract dysfunction (urinary frequency, urgency, and/or poor detrusor contraction resulting in retention and incomplete emptying). 
**The type of LUT dysfunction that occurs is dependent on the specific nerves involved, the degree of injury, and any pattern of reinnervation or altered innervation that occurs over time
**Patients often experience leakage across the distal sphincter area and are unable to empty the bladder, because, although intravesical pressure may be increased, they cannot mount a true bladder contraction. The patient often has urinary incontinence that is characteristically and most commonly initiated with increases in intra-abdominal pressure. This is usually most obvious in females, because the prostatic bulk in males often masks an equivalent deficit in urethral closure function. Alternatively, patients may have variable degrees of urinary retention.
* '''<span style="color:#ff0000">When permanent LUT dysfunction occurs after radical pelvic surgery, usually pattern of impaired bladder contractility or a failure of the bladder to voluntarily contract.</span>'''
** '''UDS may show'''
*** '''Residual fixed striated sphincter tone, which is not subject to voluntarily induced relaxation, and may result in obstruction'''
*** '''Often, the smooth sphincter is open and nonfunctional.'''
*** '''<span style="color:#ff0000">Decreased compliance is common</span>, and, with the “obstruction” caused by fixed residual striated sphincter tone, may result in both storage and emptying failure.'''
* '''<span style="color:#ff0000">Management</span>'''
** '''<span style="color:#ff0000">Upper tract risk factors are related to intravesical pressure and the detrusor leak point pressure, and the therapeutic goal is always low-pressure storage with periodic emptying.</span>'''
** '''<span style="color:#ff0000">Most of these dysfunctions will be transient, and patients can be discharged on CIC with full urodynamic evaluation at a later date.</span>'''
*** '''<span style="color:#ff0000">Frequently, 6-12 months may elapse before detrusor function returns to an acceptable level</span>'''
**'''In males, prostatectomy should be avoided unless a clear bladder outlet obstruction is demonstrated at this level. Otherwise, prostatectomy simply decreases urethral sphincter function and thereby may result in the occurrence or worsening of sphincteric urinary incontinence.'''
'''Simple and radical hysterectomy'''
* '''Women who undergo hysterectomy by the vaginal approach may be more likely to have micturition symptoms as compared with abdominal approach patients'''
* As compared with simple hysterectomy, radical hysterectomy may have more debilitating effects on bladder and bowel function

=== Diabetes ===
* Most common cause of peripheral neuropathy in Europe and North America.
* 5-59% of patients with diabetes report symptoms of LUT dysfunction
* '''Diabetic cystopathy'''
** Term to describe the involvement of the LUT by this disease.
** '''Current evidence points to both a sensory and a motor neuropathy as being involved in the pathogenesis, with the motor aspect contributing to the impaired detrusor contractility'''
*** '''The classic description is that of a peripheral and autonomic neuropathy that first affects sensory afferent pathways, causing the insidious onset of impaired bladder sensation'''.
*** As the classic description continues, a gradual increase in the time interval between voiding results, which may progress to the point at which the patient voids only once or twice a day without ever sensing any real urgency. If this continues, detrusor distention, overdistention, and decompensation ultimately occur. '''Detrusor contractility, therefore, is classically described as being decreased in the end-stage diabetic bladder'''.
* '''Urodynamics'''
** '''More recently, detrusor overactivity has been cited as the most frequent urodynamic finding'''.
*** This could be a result of a difference in the time of diagnosis with reference to the natural history of the effects of diabetes on the LUT.
** '''Other classic urodynamic findings include impaired bladder sensation, increased cystometric bladder capacity, decreased bladder contractility, decreased flow, and, later, increased residual urine volume'''
** At least in men, the main differential diagnosis is bladder outlet obstruction, because both conditions commonly produce a low urinary flow rate; however, pressure-flow urodynamic studies easily differentiate the two.
** '''Smooth or striated sphincter dyssynergia usually is not seen in classic diabetic cystopathy'''
* '''Early institution of timed voiding will avoid some of the impaired detrusor contractility from chronic distention and detrusor decompensation. intensive therapy for diabetes can slow its progression and slow the development of abnormal autonomic tests.'''

=== Guillain-Barre syndrome ===
* An inflammatory demyelinating disorder of the peripheral somatic and autonomic nervous system
* '''Triggered by a preceding bacterial or viral infection''', with the immune responses directed toward the infecting organisms cross-reacting with neural tissues.
* Characterized by potentially life-threatening rapidly evolving ascending paralysis, symmetrical limb weakness, loss of tendon reflexes, absent or mild sensory signs, and variable autonomic dysfunctions
* Autonomic neuropathy is a common complication. Cardiac arrhythmia, hypertension and hypotension, and bowel, bladder, and sexual dysfunction may occur. The prevalence of LUT dysfunction ranges from 25% to over 80%
* '''The most common urinary findings include increased postvoid residual volume, followed by decreased bladder sensation, detrusor overactivity, diminished bladder compliance, and underactive detrusor contraction, as well as sphincteric dyssynergia.''' These findings underscore the difficulty in prediction of LUTS based on condition diagnosis only
* Management
** Voiding dysfunction is usually reversible with resolution of the disorder and should therefore be managed by reversible therapy (e.g., CIC, anticholinergic therapy) pending resolution

=== Herpesvirus infections ===
* Invasion of the sacral dorsal root ganglia and posterior nerve roots with herpes zoster virus '''may produce''' '''urinary''' '''retention and detrusor areflexia''' days to weeks after the other primary viral manifestations
* Urinary incontinence secondary to detrusor overactivity may also occur, but the pathophysiology is unclear.
* Cystoscopy may reveal vesicles in the bladder mucosa similar to those seen on the skin. Spontaneous resolution usually occurs in 1 to 2 months.
* Urinary retention has also been reported to occur in association with anogenital herpes simplex virus infection.