Current perception threshold evaluation of the female urethra.

The purpose of this study was to determine the feasibility of the current perception threshold (CPT) evaluation in the female urethra. Women without LUT dysfunction underwent CPT testing using a Neurometer (Neurotron, Inc., Baltimore, MD) connected to a ring electrode in the urethra. Testing was done in a standardized fashion at three frequencies, 2000, 250 and 5 Hz, to determine when subjects first perceived the stimuli and when perceived stimuli became painful. Current perception threshold testing was accomplished in all 10 subjects studied. The level at which subjects first perceived stimuli was significantly lower than that at which the stimuli became painful ( P<0.002). Mean perception thresholds at 2000, 250 and 5 Hz were 70 microA (range 14-230), 25 microA (4-80) and 17 microA (2-78), respectively, and mean pain thresholds were 229 microA (54-424), 91 microA (24-162) and 110 microA (25-200), respectively. There was no difference in subjects' perception thresholds at 250 and 5 Hz ( P=0.206). Perception thresholds and pain thresholds were significantly different at all other frequencies. Women without LUT dysfunction have lower perception thresholds than pain thresholds and can distinguish between most stimuli at different frequencies. Current perception threshold testing of the female urethra is technically feasible and may be useful for assessing the functional integrity of different afferent pathways.