Spinal cord herniation: a misdiagnosed and treatable cause of thoracic myelopathy.

This study is a case report and review of the literature. Spinal cord herniation is a rare, although increasingly recognized, cause of spinal cord dysfunction. It is due to an anterior dural defect, through which the spinal cord herniates. The purpose of this article is to report the authors' experience and to provide insight on clinical presentation and radiological signs to make the reader aware of this entity and then to prevent misdiagnosis. The authors conducted a retrospective review of patients who underwent surgery for spinal cord herniation at their institution between 2000 and 2008. Three patients were treated (all women) and the interval between the onset of symptoms and surgery ranged from 24 to 48 months. All patients had progressive signs of thoracic myelopathy, and two of them were initially misdiagnosed. In all cases, the herniation was reduced and the defect repaired using different methods. The results and complications of our cases were compared with that of the reported literature. According to the results in these cases and the review of the literature, the authors believe that spinal cord herniation should be treated by using a dural patch to close the dural defect and to prevent retethering of the spinal cord.