Diagnosis and significance of idiopathic overactive bladder.

OBJECTIVES: To offer a critical overview of the basis for the International Continence Society (ICS) classification of detrusor instability, to summarize current diagnostic methodologies, and to outline the etiologic factors that should be excluded in the diagnosis of idiopathic overactive bladder.
METHODS: The current ICS definitions of overactive bladder are discussed. Issues related to the diagnosis of detrusor instability (DI) are addressed through a review of the literature.
RESULTS: The term idiopathic overactive bladder reflects the present lack of knowledge concerning vesicourethral function and dysfunction. The term is used to apply to a wide spectrum of different conditions that may have a common final pathophysiologic pathway. This heterogeneous group of conditions could be subdivided on the basis of presumptive etiopathogenesis, urodynamic patterns, and response to treatment. The diagnosis of DI, its rate of detection, and its urodynamic patterns depend on the type of urodynamic test used and the way the test is performed. The ICS definitions of DI have been called into question by the results of studies using urodynamic tests in addition to, or instead of, provocative cystometry--for instance, ambulatory urodynamics, urethrocystometry, the ice-water test, and evaluation of the voiding phase. The literature supports a broadening of the ICS criteria for excluding all known causes of DI when establishing the diagnosis of idiopathic overactive bladder.
CONCLUSIONS: Appropriate longitudinal studies, using contemporary urodynamic tests and knowledge, are needed to improve the identification of subsets of patients with overactive bladder who have different prognoses and outcomes. The ICS definitions and classification should be updated.