{"paper_id":"9477ac08-7eb1-45ee-8951-5a4fca21d1a8","body_text":"Arq Neuropsiquiatr 2011;69(6)\n 995\nLetters\nEndometriosis of the sciatic nerve\nAlice Becker Teixeira1, William A. Martins1, Rui d’Ávila1, Luciele Stochero1, \nLuciele Alberton1, Sofia Bezerra1, Alicia C.B. Romero 2, Paulo E. Freitas2, Carlos Eduardo da Silva3\nEndometriosis is a common disease, which affects \n5-10% of women in fertile age1. It can affect multiple or-\ngans, such as ovaries, lungs, colon, nasal mucosa and \nbrain2. Endometriosis of the sciatic nerve is a rare presen-\ntation3, manifesting as cyclic sciatica, parestesis and pa -\nresis with loss of deep tendon reflex. We cite a case of sci-\natica endometriosis and make a review of the literature.\nCASE\nA 26-year-old Caucasian woman exhibits intense \npain and weakness in the lower left limb, which had pro-\ngressed over the past nine years. She had no previous \npregnancy and symptoms were worse during the men -\nstrual period. \nDuring examination, a dorsiflexion paresis of the left \nfoot was notable. Magnetic resonance imagining (MRI) \nrevealed an expansive process in the left sciatic nerve to-\npography at gluteal topography.\nThe patient was referred for microsurgery, pro -\nceeding exeresis of a cystic lesion in the left sciatic nerve. \nNeuropathology analysis showed an endometrioma \n(Figure). The patient had no complications during the \npost-operative period.\nDuring initial follow-up, dorsiflexion paresis in the \nleft foot persisted. Post-operative MRI showed a cica -\ntricial process, with no residual tumor. The eletroneu -\nromiography (ENMG) displayed signs of a subacute de -\nnervatory process.\nDISCUSSION\nEndometriosis is a chronic recurrent pathology, char-\nacterized by proliferation of endometrial tissue outside \nthe uterine cavity\n4. Typical locations include the ova -\nries, uterosacral ligaments, pelvic peritoneum, vagina 2. \nCommon clinical presentations are dysmenorrhea, in -\nfertility, dyspareunia, dysuria, or it can be asymptomatic.\nThe occurrence of endometrial tissue in the nerve \nroot is a rare location, which was related for the first time \nin 1946 by Schlicke\n5. Cyclic sciatic is a rare symptom of \nendometriosis. Salazar-Grueso and Roos describe a mean \nFigure. Hemorrhagic stroma with endometrial epithelium.\n\nArq Neuropsiquiatr 2011;69(6)\n996\nLetters\ninterval of 3.7 years between the onset of symptoms and \ndiagnosis. The typical symptom is cyclic sciatica related \nto the menstrual period, with painless intervals that be -\ncome shorter each time until the pain becomes constant. \nOther symptoms are sensory loss, muscle weakness, re -\nflex alterations, and a positive Lasègue’s sign.\nPresumably, endometriosis causes nerve damage by \ncyclical inflammation 4. The ectopic uterine tissue once \nimplanted in the nerve, advances aggressively the epineu-\nrium and perineurium.\nDiagnosis can be made by an association of the symp-\ntoms to menstrual periods, and MRI findings. In the MRI \nit can be presented as a hiperintense solid or cystic mass. \nThe signal intensity is due to the quantity and time of \nthe bleeding. Further, the MRI can be useful in the dif -\nferential diagnosis between a benign neurogenic tumor \nand the endometrioma. ENMG can demonstrate signs \nof denervation and a diminished conduction time, being \nuseful to follow nerve recovery. However, a definitive di-\nagnosis only can be made by the anatomopathological.\nEndometriosis treatment involves pain control, hor -\nmone therapy and, for severe cases, surgical resection \nof the lesions1.\nEndometriosis invading the sciatic nerve is a rare \nmanifestation of a common disease. Early diagnosis \nand treatment is very important to minimize the nerve \ndamage caused by recurrent cycles of bleeding and fi -\nbrosis, which are characteristics of endometriosis. \nREFERENCES \n1. Fraser IS. Recognising, understanding and managing endometriosis. J \nHum Reprod Sci 2008;1:56-64.\n2. Zager EL, Pfeifer SM, Brown MJ, et al. Catamenial mononeuropathy and  \nradiculopathy: a treatable neuropathic disorder. J Neurosurg 1998; 88:  \n827-830.\n3. Baker GS, Parsons WR, Welch JS. Endometriosis within the sheath of the \nsciatic nerve. J Neurosurg 1966;25:652-656.\n4. Lu PY, Ory SJ. Endometriosis: current management. Mayo Clin Proc 1995; \n70:453-463.\n5. Schlicke CP. Ectopic endometrial tissue in the thigh. JAMA 1946;132:445.\nENDOMETRIOSE DO NERVO CIÁTICO\nDepartment of Neurosurgery and Skull Base Surgery, Hospital Ernesto Dornelles; \nPorto Alegre RS, Brazil: 1Medical Student; 2PhD; 3MD.\nCorrespondence: Alice Becker Teixeira - Av. Protásio Alves 3563 / apto 23 - \n90410-003 Porto Alegre RS - Brasil. E-mail: likabt@gmail.com\nReceived 29 May 2011. Received in final form 8 July 2011. Accepted 15 July 2011.","source_license":"CC0","license_restricted":false}