Towards a better understanding of involuntary detrusor activity

There is a wide spectrum of topics covered in this section. The ever-present problem of nocturia is further explored by authors from Sweden, with interesting conclusions. In addition, several papers describe various issues relating to the surgical correction of stress urinary incontinence. Finally, authors from Switzerland describe their use of sacral magnetic stimulation in non-inflammatory chronic pelvic pain syndrome.

To compare the measured variables of involuntary detrusor activity (IDA) during ambulatory cystometry (AC) in women with and with no overactive bladder symptoms, and to evaluate the correlation between these variables and symptom severity.

In all, 61 symptomatic and 39 asymptomatic women completed the Bristol Female Lower Urinary Tract Symptoms Questionnaire (BFLUTS-Q) and underwent AC. Measured variables of IDA (amplitude, duration, bladder volume and symptoms) were compared in the two cohorts.

IDA was detected in 47 of 61 symptomatic women (77%) and in 17 of 36 (47%) controls (P < or = 0.01). The maximum IDA (defined as the highest amplitude contraction in any fill-void cycle) occurred at significantly lower volumes (328 vs 450 mL, P < or = 0.05), was of higher amplitude (26 vs 12 cm H(2)O, P = 0.14) and longer duration (83 vs 14 s, P < or = 0.05) in symptomatic women than in controls. There was coincident incontinence in 22 (36%) symptomatic women and no controls (P < or = 0.01). Discriminatory levels for clinically relevant IDA were established, and when applied retrospectively, classified 35 of 61 symptomatic women (55%) and one control (3%) as having such IDA. The correlation between symptom severity (measured by the BFLUTS-Q) and urodynamics was higher when these criteria were applied (r = 0.52 vs 0.38, P < or = 0.01).

There are quantifiable differences between IDA found during AC in symptomatic and asymptomatic women. The measured variables of IDA may be useful to determine its clinical relevance, which may be indicated by contractions associated with leakage or contractions of >30 s occurring at bladder volumes of <300 mL.