Abstract
Spontaneous spinal extradural hematoma is uncommon. An early diagnosis and immediate surgical treatment are important to prevent severe neurological deficits such as paraplegia. The authors reported a case of thoracic level hematoma. Preoperative emergent magnetic resonance imaging (MRI) informed us of correct diagnosis and extension of extradural hematoma. Emergent operation relieved the patient's neurological deficits promptly. A healthy 52-year-old male developed severe back pain followed by progressive weakness in his legs. On admission, neurological examination revealed paraparesis, sensory disturbance below the Th5 dermatome and urinary and fecal disturbance. The myelogram showed blockage at Th3 and postomyelographic computed tomography disclosed an iso-density mass in the dorsal side of the spinal canal. MRI showed an extradural hematoma as a hyperintense mass extending over Th2 and Th3. Nineteen hours after the onset of symptoms, laminectomy from Th1 through Th3 and evacuation of hematoma was performed. A dilated vein was found attached to the hematoma between Th2 and Th3 on the left side. Histological examination of the hematoma revealed no other abnormal vessels. These findings suggested the extradural bleeding was venous in origin. The patient had a good postoperative recovery. He regained muscle strength enough to walk and urinary and fecal function within two weeks after the surgery. Sensory disturbance became minimal within a month. In the literature, MRI findings of 18 cases of spontaneous spinal extradural hematoma have been reported, including our case. According to them, hematomas within a day from onset were iso- or hyperintense on T1 weighted image and hyperintense or heterogenous on T2 weighted image. In addition, most of those between a day and a week were hyperintense on both images. In conclusion, MRI proved to be an accurate, efficient method of localizing and characterizing spinal extradural hematoma.
