Traumatic transdural spinal cord herniation and the nuclear trail sign: case report.

A woman with a history of spine injury in her remote past developed Brown-Sequard syndrome due to a thoracic transdural spinal cord herniation. A clue about the underlying mechanism was offered by the unexpected imaging feature of a nuclear trail sign just below the herniated cord. As suggested by Watters et al., who reported a similar case, this finding is consistent with the hypothesis that intrathecal rupture of disk material could have resulted in an acquired tear of the ventral dural, through which the cord herniated.