[Pudendo-anal reflex in normal women]

The pudendo-anal reflex was studied in a sample of 31 normal women. Responses were obtained after bilateral independent stimulation of the clitoris, with surface recordings from both sides of the external anal sphincter. Responses were elicited with double-pulses of 0.2 ms duration with a interstimulus interval of 5 ms, frequency of stimulation was lower than 0.5 Hz. A minimal of four responses were recorded after supramaximal stimulation. In one volunteer no response was recorded after unilateral stimulation. Latencies of the responses from the right and left sides of the anal sfincter after right and left stimulation were 36.35+/-6.37, 36.28+/-6.23, 35.88+/-4.68, 36.44+/-4.45 ms, respectively. No relation was detected between latencies and age, body mass index and parity (considering either total parity or vaginal delivery only). In 12% of the recordings uncertainty was introduced in the latency measurements related to a poor signal-noise ratio.