Therapeutic Effects Analysis of Pudendal Nerve Infiltrations After 3 Months, in Patients Suffering of Pudendal Neuralgia

Pudendal neuralgia is a recent identified pathology, extremely invalidating, related to chronic pelvic entrapment. Nowadays, pudendal neuralgia can be treated with: * neuropathic pains treatment * specific kinesitherapy * Alcock's canal and sacrospinal ligament infiltrations under scan * with diagnostic block * local steroids injections * and surgical decompression of pudendal nerve with transrectal approach. Only surgery was validated after a randomised protocol studying surgery versus abstention, performed and published by the CHU de Nantes. Many techniques have been proposed for realization of pudendal nerve infiltrations. The results of these infiltrations have never been published, and no randomised study had ever evaluated those results, even at short-run. Very few randomized studies have validated steroids infiltrations techniques in canal syndrome neuropathies. The primary objective of the investigators phase IV trial is to evaluate the efficacy of three different types of pudendal nerve infiltrations in Alcock's canal and sacrospinal ligament: * group A: only local anesthetic (control arm) * group B: local anesthetics associated with local steroids * group C: local anesthetics associated with local steroids and important volumes of physiological serum