[Cyclic sciatica and extrauterine endometriosis].

Cyclic sciatica caused by ectopic endometriosis is an unusual cause of compression of a lumbar root, of the sciatic nerve or its plexus. A 38-year-old patient is presented with a history of menstruation associated with right-sided sciatica, which gradually developed over a 2 1/2-year period into disabling constant pain and a lumboradicular syndrome with signs of S1-root involvement. Suggested compression of the sciatic nerve by ectopic endometriosis in the sciatic notch region could be confirmed by CT and MR, by prompt response to hormonal suppression of ovarian function and by regression of the radiological findings. If the history of cyclic pain, local tenderness on deep palpation and the onset of referred pain in the buttock had been observed at the beginning, unnecessary and costly medico-technical procedures delaying diagnosis and treatment (including unnecessary physiotherapy) could have been avoided. Cyclic sciatica is discussed in a review of literature, and possibilities of treatment are discussed.