Acute non-traumatic idiopathic spinal subdural hematoma: radiographic findings and surgical results with a literature review

Intraspinal hematoma is a serious condition, and early diagnosis is necessary to permit emergency treatment. Among such hematomas, non-traumatic spinal subdural hematoma is a rare occurrence. We have experienced three patients with surgically proven subdural spinal hematoma, and here we report these cases with a review of their clinical and imaging characteristics. All three cases were idiopathic with no history of disease, no coagulopathy, and no trauma. All had acute onset that brought about paralysis of the lower limbs with severe pain. Early surgery was performed, based on a relatively early diagnosis using thoracolumbar MRI and CT. Since the epidural fat is not affected by bleeding, the normal structure remains and the boundary between hematoma and fat is a significant feature in MRI and CT. Partial Gd enhancement in MRI and ring enhancement in contrast CT were also apparent. Two of the cases had subarachnoid hematomas. Preoperative diagnosis of spinal subarachnoid hematoma is difficult because there are no specific radiological findings and confirmation can only occur intraoperatively. In particular, one case had a massive hematoma causing canal stenosis, and it was difficult to distinguish between intradural and extradural hematoma. In all cases of subarachnoid or subdural hematoma, decompression was performed within 24 h after onset, and consequently, the patients had relatively good outcomes.