Editing Neurogenic LUT Dysfunction (section)

== Diseases at or above the brainstem ==

* '''Examples: CVA, dementia, TBI, brain tumour, cerebellar ataxia, NPH, cerebral palsy, Parkinson’s, MSA'''

=== Cerebrovascular accident ===

* '''After an initial acute CVA, urinary retention from detrusor areflexia often occurs'''
* '''The most common long-term expression of LUT dysfunction after CVA is phasic detrusor overactivity'''
** '''Urinary incontinence within 7 days of a stroke is a more powerful prognostic indicator for poor survival and functional dependence than a depressed level of consciousness'''
* '''Sensation is variable but most typically intact''', and thus the patient has urinary urgency and frequency with detrusor overactivity.
** '''The appropriate response to detrusor overactivity is to try to inhibit the involuntary bladder contraction by voluntarily and forcefully contracting the striated sphincter. If this can be accomplished, only urgency and frequency result; if not, the result is urgency urinary incontinence'''
*** Patients with lesions in only the basal ganglia or thalamus have normal sphincter function.
*** The majority of patients with involvement of the cerebral cortex and/or internal capsule are unable to forcefully contract the striated sphincter under these circumstances, and may therefore have incontinence
* Possible mechanisms for the incontinence associated with involuntary bladder contractions in patients who have sustained a CVA (2):
*# Impaired striated sphincter control
*# Lack of appreciation of bladder filling and impending bladder contraction
* '''In general, the smooth sphincter is unaffected after CVA and remains synergic;''' true detrusor striated sphincter dyssynergia does not occur in this situation, '''although pseudodyssynergia (electromyographic sphincter “flare” during filling cystometry that is secondary to attempted inhibition of an involuntary bladder contraction by voluntary contraction of the striated sphincter) has been found to occur'''
* '''The guarding reflex in these patients usually remains intact'''
* Detrusor hypocontractility or areflexia may rarely persist after CVA; poor flow rates and high residual urine volumes in a man with LUTS before CVA usually indicate prostatic obstruction. However, a full urodynamic evaluation to exclude detrusor overactivity with impaired contractility as a cause of symptoms is advisable before committing such a patient to surgical reduction of bladder outlet obstruction.
* In the functional system of classification (see Pathophysiology and Classification of LUT Dysfunction Chapter Notes), the most common type of LUT dysfunction after CVA would be characterized as a failure to store secondary to detrusor overactivity, specifically involuntary bladder contractions. In the International Continence Society classification system, '''the dysfunction would most likely be classified as overactive neurogenic detrusor function, normal sensation, low capacity, normal compliance, and normal urethral closure function during storage; regarding voiding, the description would be normal detrusor activity and normal urethral function''', assuming that no anatomic obstruction existed.
* '''Management'''
** '''In the absence of coexisting significant bladder obstruction or significantly impaired contractility, is directed at decreasing bladder contractility and increasing bladder capacity'''

=== Dementia ===

* Urinary dysfunction does not consistently accompany dementia; when voiding dysfunction occurs the result is typically '''incontinence'''. It is difficult to ascertain whether the pathophysiology and considerations are similar to those in the stroke patient or whether the incontinence reflects a situation in which the individual has simply lost the awareness of the desirability of voluntary urinary control.
* Therapy that inhibits muscarinic brain receptors may be contraindicated in Alzheimer disease if current theories about its cause are valid (cortical cholinergic loss).

=== Traumatic brain injury ===

* There may be an initial period of detrusor areflexia when LUT dysfunction occurs.
* With lesions above the PMC, detrusor overactivity and coordinated sphincter function are the most frequent manifestations of chronic LUT dysfunction.
* In patients who have more isolated brainstem injuries with involvement below the PMC, additional findings may include detrusor striated sphincter dyssynergia.

=== Brain tumour ===

* When LUT dysfunction occurs, it usually consists of detrusor overactivity and urinary incontinence
** Urinary retention has also been described in patients with space-occupying lesions of the frontal cortex, in the absence of other associated remarkable neurologic deficits.
** Posterior fossa tumors is usually associated with retention or difficulty voiding is the rule; incontinence rarely reported.
* In general, smooth and striated sphincters are synergic

=== Cerebellar ataxia ===

* LUT dysfunction typically manifests with incontinence, usually detrusor overactivity and sphincter synergy.
* Retention or high postvoid residual urine volume may occur as well. When present, impaired emptying is most commonly caused by detrusor areflexia, but it may also be associated with detrusor striated sphincter dyssynergia, presumably a result of spinal cord involvement

=== Normal-pressure hydrocephalus ===

* A condition of progressive dementia and ataxia occurring in patients with normal cerebrospinal fluid pressure and distended cerebral ventricles, but with no passage of air over the cerebral convexities on pneumoencephalography.
* When voiding dysfunction occurs, it is usually incontinence secondary to detrusor overactivity with synergic sphincters

=== Cerebral palsy ===

* A nonprogressive injury of the brain that typically occurs during the first year of life (but potentially up to 3 years of age) and produces neuromuscular disability and/or specific symptom complexes of cerebral dysfunction. In general, the cause is infection or a period of hypoxia. Affected children exhibit delayed gross motor development, abnormal motor performance, altered muscle tone, abnormal posture, and exaggerated reflexes.
* '''Most children and adults with only CP have urinary control and what seems to be normal storage and emptying.'''
* Some individuals with CP exhibit significant phasic detrusor overactivity and coordinated sphincters dysfunction

=== Parkinson disease ===

* A neurodegenerative disorder of unknown cause that affects primarily the dopaminergic neurons of the substantia nigra
** Classic symptoms include tremor, skeletal rigidity, and bradykinesia
** The gold standard for the diagnosis of PD is the neuropathologic examination
* LUT dysfunction occurs in 35-70% of patients with PD
** It has been hypothesized that dopamine modulates the normal micturition reflex, and therefore neurogenic degeneration in the nigrostriatal pathway leads to the significant LUT dysfunction associated with PD
** '''When LUT dysfunction does occur:'''
*** '''Symptoms usually consist of urgency, frequency, nocturia, and urgency incontinence.'''
*** '''The most common urodynamic finding is detrusor overactivity'''
*** '''The smooth sphincter is synergic'''
*** '''Pseudodyssynergia may occur, as well as a delay in striated sphincter relaxation (bradykinesia) at the onset of voluntary micturition, both of which can be urodynamically misinterpreted as true dyssynergia'''
*** '''Impaired detrusor contractility may also occur, either in the form of low amplitude or poorly sustained contractions or a combination. Detrusor areflexia is relatively uncommon in PD.'''
** PET scanning shows brain responses with bladder filling.
** '''The time from onset of PD to initiation of LUTS is ≈5 years'''
* '''TURP should not be contraindicated in patients with PD, because external sphincter acontractility is extremely rare in such patients. However, one must be cautious with such patients, and a complete urodynamic or video-urodynamic evaluation is advisable.''' Poorly sustained bladder contractions, sometimes with slow sphincter relaxation, should make one less optimistic regarding the results of outlet reduction in the male.

=== Multiple system atrophy ===

* A progressive neurodegenerative disease of unknown cause; results from glial α-synucleinopathy
* Symptoms encompass parkinsonism and cerebellar, autonomic (including urinary and erectile problems), and pyramidal cortical dysfunction in a multitude of combinations
* The neurologic lesions of MSA consist of cell loss and gliosis in widespread areas and occur to a significantly greater degree than with PD. This more diffuse nature of cell loss probably explains why '''bladder symptoms may occur earlier and be more severe than in PD, and why erectile function may be affected as well'''
* '''The initial urinary symptoms of MSA are urgency, frequency, and urgency incontinence, occurring up to 4 years before the diagnosis is made.'''
** As would be expected from the central nervous system (CNS) areas affected, '''detrusor overactivity is frequently found'''
** Decreased compliance may also occur, reflecting distal spinal involvement of the locations of the cell bodies of autonomic neurons innervating the LUT.
** As the disease progresses, difficulty in initiating and maintaining voiding may occur, probably from pontine and sacral cord lesions, and this usually is associated with a poor prognosis.
** Cystourethrography or video-urodynamic studies may reveal an '''open bladder neck''' (different than PD), and many patients exhibit evidence of '''striated sphincter denervation on motor unit electromyography.'''
* '''Management'''
** The treatment of LUTS caused by MSA is difficult
** Treatment of detrusor overactivity during filling may worsen problems initiating voluntary micturition or worsen impaired contractility during emptying.
** '''Patients usually have smooth and striated sphincter insufficiency predisposing females to sphincteric incontinence and making outlet-reducing procedures (prostatectomy) hazardous in males''' (different than PD)
** Conversely, drug treatment for sphincteric incontinence may further worsen emptying problems.
** In general, the goal in these patients is to facilitate storage, and CIC would often be desirable. Unfortunately, patients with advanced disease often are not candidates for CIC.
** Some patients do respond well to desmopressin administration for predominant nocturia; however, the majority of the patients do not respond well to antimuscarinic or other types of therapy