A spinal epidural hematoma is a well known, though uncommon, condition associated with spinal fractures and invasive intraspinal procedures such as epidural anesthesia and it can also occur spontaneously9)
. A spontaneous SEH can occur by the following mechanism: local pooling within the valves of thin walled epidural veins, and brief increases in intravenous pressure due to raised intrathoracic and intraabdominal pressure may lead to their rupture2)
Kummell's disease is a spinal disorder characterized as delayed post-traumatic collapse of vertebral body. Generally, it is thought to be a pseudoarthrosis, and intravertebral clefts represent fracture nonunion with dynamic mobility. The presence of a vacuum cleft within the vertebral fracture represents focal bone ischemia associated with non-healing vertebral collapse and it is indicative of bone changes with position or respiration11)
. SEH usually results from osteoporotic compression fractures, however, there are rare reports associated with Kummell's disease. In fact, Kummell's disease is not thought to cause SEH because it is not diagnosed during the acute phase of compression fractures6)
. However, in this case, Kummell's disease was likely responsible for the development of SEH. The pathophysiology seemed neither traumatic nor spontaneous. Kerslake et al.7)
reported that a SEH resulting from spinal trauma is usually resolved within three weeks in most cases. The current case presented with an epidural hematoma seven weeks after the injury. This is based on a connection between the intravertebral cleft and epidural space. The integrity of the posterior cortex is an important consideration for the development of a SEH. The defect of posterior cortex may increase the chance of a SEH under weight bearing by nonunion with dynamic mobility. Oda et al.10)
suggested the possibility that the fluid including the hemorrhage inside of the intravertebral cleft may be under pressure, and be pushed out into the epidural space during daily motion, and cause a subacute or chronic SEH.
MRI is considered the initial diagnostic imaging method for a SEH. The variability of the signal intensity can make the diagnosis difficult, but this phenomenon can also be helpful in determining the phase of the hematoma. In the acute phase, the hematoma appears isointense when compared with the spinal cord on T1-weighted images, and hyperintense on T2-weighted images. In the subacute stage, hematomas show characteristic high signal intensity on T1-weighted images, whereas they tend to be slightly hypointense or hyperintense on T2-weighted images. In the chronic stage, hematomas appear hyperintense on both T1- and T2-weighted images1)
The prognosis of SEH appears to be related to the severity of the preoperative neurological deficits and the time to intervention; early surgical treatment is crucial for good outcomes8)
. For this reason, urgent decompression is the treatment of choice for SEH5)
. However, in the case of a neurologically intact patient with SEH related to Kummell's disease, vertebroplasty alone may be effective treatment for the hematoma. A cleft or cavity completely filled with bone cement can block the connection between the intravertebral cleft and epidural space and aid in the spontaneous resolution of the hematoma over time.