Differential Staged Sacral Reflexes: Methodology and Normal Values from 51 Healthy Subjects and 134 Patients with Pudendal Neuralgia

Objective: to develop a reproducible method for electrophysiological study of pudendal nerves which can explore the different risk areas: sacral spinal, infrapiriformis area and ischiorectal fossa. This method is called differential staged sacral reflexes (DSSR) . 51 patients not suffering from pudendal neuralgia and 134 patients with pudendal neuralgia have been selected. The sacral reflexes (SR) are made at the ventral and dorsal quadrants of the anal sphincter and at the pubococcygeus muscle. Considering the values of the DSSR obtained on healthy subjects and on patients with pudendal neuralgia, maximum threshold values have been established: a significant difference between ventral and dorsal quadrant of the anal sphincter: damage orientation at the level of the ischiorectal fossa; significant difference between dorsal quadrant of the anal sphincter and pubococcygeus muscle: damage orientation at the level of the infrapiriformis area. SR delayed uniformly at the three afore-mentioned muscles: damage orientation at the level of the sacral spinal. The DSSR allow in a reproducible way to investigate the pudendal nerve in all areas suitable to entrap this nerve, which is impossible with the method of pudendal nerve terminal motor latency (PNTML).