Spontaneous spinal extradural hematoma.

Spontaneous spinal extradural hematoma is an uncommon but reversible cause of acute paraplegia. Only 44 cases have been reported in the English literature. This paper adds two cases and analyzes the data in previous case reports to identify prognostic factors. Patients with a history of trauma or an incomplete myelographic block have a good prognosis. In most patients no cause of bleeding is found at operation.