Editing Functional: Pathophysiology and Classification of LUT Dysfunction (section)

== Classification Systems ==

* Storage vs. Voiding phase classification system proposed by the ICS is an extension of a urodynamic classification system
* '''Normal bladder function during filling/storage implies no significant increases in detrusor pressure''' (stability)'''.'''
* '''Overactive detrusor function indicates the presence of “involuntary detrusor contractions during the filling phase, which may be spontaneous or provoked.”'''
** '''If the condition is caused by:'''
*** '''Neurologic disease, the term neurogenic detrusor overactivity''' (previously, detrusor hyperreflexia) '''is used'''
*** '''Non-neurologic disease, the term idiopathic detrusor overactivity''' (previously, detrusor instability) '''is used.'''
* Bladder sensation can be categorized only in qualitative terms.
* Bladder capacity and compliance (Δ volume/ Δ pressure) are cystometric measurements.
** Bladder capacity can refer to cystometric capacity, maximum cystometric capacity, or maximum anesthetic cystometric capacity.
* '''Normal urethral function'''
** '''During filling/storage, uretheral closure pressure should be positive (urethral pressure minus bladder pressure) even with increases in intra-abdominal pressure, although it may be overcome by DO.'''
*** Incompetent urethral function during filling/storage implies urine leakage in the absence of a detrusor contraction. This leakage may be due to genuine stress incontinence, intrinsic sphincter dysfunction, a combination, or an involuntary decrease in urethral pressure in the absence of detrusor contraction.
** During voiding, the urethra opens and is continuously relaxed to allow bladder emptying at a normal pressure.
*** Abnormal urethral function during voiding may be due to either mechanical obstruction or urethral overactivity.
* During the voiding/emptying phase of micturition, normal detrusor activity implies voiding by a voluntarily initiated sustained contraction that leads to complete bladder emptying within a normal time span.
** An underactive detrusor defines a contraction of inadequate magnitude or duration, or both, to empty the bladder within a normal time span.
** An acontractile detrusor is one that cannot be demonstrated to contract during urodynamic testing.
** Areflexia is defined as acontractility secondary to an abnormality of neural control, implying the complete absence of centrally coordinated contraction.
* Dysfunctional voiding describes an intermittent or fluctuating flow rate secondary to involuntary intermittent contractions of the periurethral striated muscle in neurologically normal individuals.
* '''Detrusor sphincter dyssynergia defines a detrusor contraction concurrent with an involuntary contraction of the urethral or periurethral striated muscle, or both.'''
* Non-relaxing urethral sphincter obstruction usually occurs in individuals with a neurologic lesion and is characterized by a nonrelaxing obstructing urethra resulting in reduced urine flow.