[Bilateral cyclic sciatica caused by endometriosis. Apropos of a case].

Introduction: Cyclical sciatica due to implantation of endometrial tissue in the sciatic nerve in the region of the sciatic notch is a very unusual cause of sciatica. It occurs in women of childbearing age, as episodes of pain in the distribution of the sciatic nerve, which present in a cyclic manner and coincide with menstruation. If it is not treated, a sensomotor mononeuropathy of the sciatic nerve develops.