Urodynamic assessment of voiding dysfunction and dysfunctional voiding in girls and women.

Voiding dysfunction is defined as impaired bladder emptying, and presents with a mixture of lower urinary tract symptoms. Dysfunctional voiding is a condition in which there is a lack of coordination between the sphincter and detrusor during emptying in a patient without overt uropathy or neuropathy. Assessment of voiding dysfunction is important in women and girls in the prevention and treatment of urinary incontinence, retention, urinary tract infection and subsequent kidney damage. Accurate diagnosis is essential in order to select the correct treatment. Screening can be done by history-taking: symptom scores can help to guide the screening. More objective measures are uroflowmetry, ultrasonography and video-urodynamics. The latter is the gold standard for the diagnosis of voiding dysfunction and consists of simultaneous registration of pressure in the bladder and rectum and external sphincter behavior, either by electromyographic recording of pelvic floor activity or by pressure recording at the external sphincter, during the whole bladder cycle of filling and emptying. On fluoroscopy the bladder can be visualized throughout the filling and emptying phase. In dysfunctional voiding, hypertonicity and instability of the external urethral sphincter during filling cystometry and impaired external sphincter relaxation during emptying are pathognomonic findings. Pressure-flow analysis reveals no obstruction and the detrusor contractility is low.