Ventral thoracic spinal cord herniation: frequently misdiagnosed entity.

Study Design: Case report with review of the literature.

Objective: Symptomatic spinal cord herniation through ventral aspect of dura is frequently misdiagnosed because this condition is rare. The most frequent misdiagnosis was that of dorsal arachnoid cyst. The purpose of this article is to provide insight on clinical presentation, diagnosis, and surgical treatment of this entity. Results of our cases were compared with that of the reported literature.

Summary Of Background Data: Eighty-six cases reported in the literature were reviewed and data are presented in this article.

Methods: We had 3 patients diagnosed with spinal cord herniation through the ventral aspect of the dural sac. All 3 cases were misdiagnosed initially and later successfully operated. The dura was repaired primarily with suture in 1 case and with surgical graft in the other 2 cases.

Results: Reduction of spinal cord herniation reverses some of the signs and symptoms that have been present for years. Two of our patients had remarkable recovery in motor strength and bladder function. The third patient improved but remained with residual myelopathy.

Conclusion: Ventral herniation of the thoracic spinal cord is a partially treatable cause of myelopathy, when recognized promptly and treated surgically. Recognizing this infrequent cause of myelopathy prevents misdiagnosis. Delay in diagnosis may impair recovery at a later date.