[Urethral instability].

This study was carried out on 121 sets of records of uretrocystomanometry and 25 records of uretrocystomanometry combined with dynamic sphincterometry. The patients consulted us either for stress incontinenceor urgency incontinence. The mean age was 41 years. The urethra was considered to be unstable when variations in pressure reached 20 cm of water or higher. There are four different types of instability described and these correspond to different urodynamic pictures. The treatments that have been proposed resulted from the different aetiologies that we have been proposed resulted from the different aetiologies that we have worked out. Some of these cases are due to an inadequate perineal floor. This has been shown by changes in striated urethral sphincter behaviour and in the improvement that can be brought about by re-education of the levator and muscles.