Thoracic intradural disc herniation.

Intradural disc herniation is a well-recognized entity in the lumbar region, where over 90% of all intradural herniations are seen.1 By contrast, fewer than 5% occur in either the cervical or thoracic regions.1 We describe a case of a sudden onset neurological deficit caused by an intradural thoracic disc herniation at the T11-T12 level, the intradural nature of which was not diagnosed on preoperative MRI. To the best of our knowledge this is the first description of an intradural disc herniation at this level.