Spinal epidural hematoma and ankylosing spondylitis.

Spinal epidural hematoma is an unusual condition requiring urgent neurosurgical intervention. Imaging plays an important role in the preoperative work-up. Although MR imaging is the examination of choice, a myelogram and CT myelogram are often performed in an emergency situation. The association with ankylosing spondylitis has been described and is considered a risk factor for developing a hematoma.