Cauda equina syndrome secondary to posterior epidural migration of a lumbar disc fragment: a rare phenomenon

Most symptomatic lumbar disc herniations occur in a postero-lateral direction. Disc fragments also commonly migrate both caudally and rostrally. The extrusion of lumbar discs is usually limited by the posterior longitudinal ligament and its attachments. Migration of disc tissue around the dural sac to the posterior epidural space is a rare occurrence. There have been even fewer reports, in the published literature, of cauda equina syndrome resulting from posterior epidural migration of lumbar disc fragments. We present a case of cauda equina syndrome due to compression of the neural elements by a large fragment of sequestered lumbar disc tissue, which had migrated to the posterior epidural space.