[Neuralgia of the pudendal nerve. Anatomo-clinical considerations and therapeutical approach].

The anatomic study of the pudendal nerve and its relation allows an approach of the mechanisms of compression likely to engender perineal neuralgia. Two conflictual zones are isolated: the first is linked to the clamp which is produced by the insertion of the sacro-epinous ligament on the ischial spine and the sacro-tuberal ligament; the second is linked to the falciform process of the sacrotuberal which threatens the nerve by its sharp upper edge. This conflict is particularly acute in a sitting position. The relation between the trunk of the nerve, its branches and these zones of conflict may explain the clinical observations. The electrophysiological investigations (detection of neurogenic muscles of the perineal floor. Increased sacral latency, pudendal nerve terminal motor latency) confirm the diagnosis. The anesthetic blocks of the pudendal nerve on the ischial spine only have a complimentary diagnostic value. The peridural blocks may also have an interesting therapeutic action (60% of good results 3 months later). In some persistent cases, the nerve has been decompressed firstly by perineal approach, but latterly by transguteal approach.