Editing Neurogenic LUT Dysfunction (section)

=== 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'''