Pudendal nerve terminal sensitive latency: technique and normal values.

Abstract

We evaluated a new technique to study the terminal sensory branches of the pudendal nerve in 30 normal men. To elicit response endorectal stimulation of the pudendal nerve was delivered just to the left then right of the ischiatic spine using an electrode. The sensory potential was recorded in the balanopreputial zone with ring contact electrodes wrapped around the shaft of the penis. From 5 to 40 responses were averaged to obtain the sensory potential. The pudendal nerve terminal sensory response was obtained for each normal subject. Mean latency value plus or minus standard deviation was 5.35+/-0.97 milliseconds for the left side with a mean amplitude of 4.24 microV. and 5.33-/+0.77 milliseconds for the right side with a mean amplitude of 3.77 microV. This method allows comparative study of the right and left terminal sensory branches of the pudendal nerve, and may be helpful in the diagnosis of different perineal disorders, such as sexual dysfunction, perineal pain and fecal incontinence, but further experience is necessary.