Female urinary incontinence: The incidence, identification, and characteristics of detrusor instabiiity

One hundred thirty‐three women with urinary incontinence, including 51 patients who had undergone unsuccessful surgical treatment, were evaluated urodynamically. A high incidence (55%) of bladder instability was noted, and several patterns of instability were recognized. In 52% of the cases, provocation by erect fast fill and other provocative maneuvers were necessary to unmask the abnormal detrusor activity, and it was also noted that the patient's history did not accurately predict instability. A high incidence (33%) of seemingly inapproprate sphincter electrical silence occurred in those with an unstable bladder and appeared to be the precipitating event of the bladder contraction.