2 DIFFERENT FORMS OF DYSFUNCTIONAL VOIDIN G IN WOMEN - PREDOMINANCE OF THE PELVIC FLOOR OR PSEUDOMYOTONIA IN THE EXTERNAL URETHRAL SPHINCTER

X-ray and ultrasound studies as well as pressure measurements are not able to determine the etiology of dysfunctional voiding in women becau se these techniques are not able to differentiate between the various muscular structures surrounding the urethra. For this reason it is nec essary to combine different EMC; techniques. 12 women with unexplained , severe symptoms of urinary outlet obstruction, with a mean age of 41 .7 years (range 18 - 61) and an average follow-up of 30.5 months were examined. Urodynamic evaluation included kinesiologic EMC recordings o f the right and left pubococcygeus muscle (the most prominent part of the levator ani) and the external urethral sphincter. For the kinesiol ogic EMG recordings, unipolar wire electrodes were inserted percutaneo usly. The concentric needle EMG examination of the external urethral s phincter was performed as a separate study. All women showed prolonged , intermittent flow in the primarily performed uroflow examination dia gnosed in general as detrusor-sphincter externus-dyssynergia. Kinesiol ogic EMC recordings revealed differences between the activity patterns of the two muscle groups (the external urethral sphincter and the pub ococcygeus m.) during bladder filling, different maneuvers and micturi tion. In 9 women, dysfunctional voiding was due to the pubococcygeal m uscles only. In these women, the concentric needle EMG examination of the urethral sphincter showed no evidence of spontaneous activity oder denervation/reinnervation. In three women, abnormal pseudomyotonic-li ke EMG activity could be demonstrated by concentric needle examination of the external urethral sphincter. The kinesiologic EMG examination of this muscle revealed no modulation of activity during voluntary or reflex maneuvers, and bursts of activity during voiding decreasing the uroflow. In our patients we were able to differentiate two groups of women, one group with dysfunctional voiding due to the pelvic floor (a change of the motor program of the muscle) and one group with dysfunc tion of the external urethral sphincter (bizarre high frequency discha rges). The described EMG recordings are considered relevant for therap eutic decisions.