対側下肢の不全麻痺を呈した硬膜管背側脱出腰椎椎間板ヘルニアに対し内視鏡下手術を行った1例

Microendoscopic Surgery for Posterior Epidural Migration of a Herniated Lumbar Disc Fragment Causing Contralateral Paralysis. Case Report

　硬膜管背側に脱出した稀な腰椎椎間板ヘルニアにより対側下肢の不全麻痺を呈した1例を経験したので報告する．症例は65歳の男性で，突然の腰臀部痛で発症し，疼痛が軽減するとともに左下肢の脱力が生じ歩行困難となった．MRIでL2/L3椎間板高位の硬膜管右背側に占拠性病変を認めた．麻痺発症の翌日に内視鏡下手術を行い，本病変が脱出ヘルニアであることを確認し，摘出した．術後，疼痛は軽快し麻痺も改善した．背側脱出ヘルニアは急性に発症し重篤な症状を呈することが多く，迅速に摘出術を行う必要がある．

　Posterior epidural migration of an extruded disc fragment is rare, and such a fragment causing contralateral paralysis and bilateral inguinal pain is extremely rare.　We report a case treated by microendoscopic surgery.　A 65-year-old man presented with sudden onset of bilateral inguinal pain, a gait disturbance, and decreased muscle strength in his left leg.　MRI revealed compression of the dural sac by an extradural mass located in the posterior epidural space on the right side at the L2-L3 level.　Urgent microendoscopic surgery was performed, and the extradural mass was found to be a massive extruded disc fragment.　The fragment was removed, and postoperative course was accompanied by an improvement of the muscle weakness but was otherwise uneventful.　Posterior migration of a disc fragment can be expected to cause significant neurologic symptoms.　Early surgery should be the treatment of first choice to prevent the development of severe neurologic deficits.