Spontaneous spinal epidural hematoma: Case report

We report a case of spontaneous spinal epidural hematoma (SSEH) at the upper thoracic level which accompanied an epidural vascular lesion demonstrated by histological examination. A 62-year-old male was referred to our department, because of sudden onslaught of back pain, progressive paraparesis, and sensory disturbance below the dermatome of Th8. He had no history of a tendency to bleed, anticoagulant therapy, or trauma. There was no abnormality in the laboratory data. MRI revealed that an epidural mass at the level of dorsal T1 and T2 was compressing the spinal cord. Multilevel spondylotic change and thickened yellow ligament were also noted. Sixteen hours after the onset, we performed laminectomy at T1 and T2 and evacuated the epidural hematoma. An unusual vascular-net like tissue was found on the dura mater after removal of the hematoma. Postoperatively, neurological symptoms disappeared within three weeks. Histological appearance of the vasuclar tissue was a cluster of vessels containing a dilated vein with partially thin wall due to lack of elastic and collagen fibers. In reviewing the literature, there are several reports describing vascular lesions, such as cavernous angioma and AVM, as possbile etiologies of SSEH. In the present case, long lasting compression of the posterior epidural venous plexus by the thick yellow ligament might have resulted in formation of an abnormal vein which ultimately caused bleeding.