To assess the efficacy, defined as improvement of flow rates by more than 50%, improvement in residual volume and scores on the IPSS questionnaire, and safety of urethral sphincter injections of onabotulinumtoxinA in women with a primary disorder of urethral sphincter relaxation, characterised by an elevated urethral pressure profile and specific findings in the urethral sphincter EMG (Fowler's Syndrome).