Acute nontraumatic spinal subdural hematomas in three patients.

STUDY DESIGN: The clinical data, magnetic resonance imaging, intraoperative findings, and functional outcome were reviewed for three patients under anticoagulant therapy who experienced acute nontraumatic spinal subdural hematoma. OBJECTIVES: To draw attention to this rare complication of anticoagulant therapy and to assess the magnetic resonance findings and clinical outcome of patients with spinal subdural hematoma after surgical evacuation. SUMMARY OF BACKGROUND DATA: Among intraspinal hematomas, spinal subdural hematomas are by far the least common. Magnetic resonance findings have been demonstrated in only a few cases of spinal subdural hematomas. The timing of the operation and the anatomic location of the hematoma essentially determine the functional outcome. METHODS: Three case reports of spinal subdural hematomas in patients receiving anticoagulant therapy are presented. Particular interest was given to the clinical and magnetic resonance data, the intraoperative findings, and the functional outcome. RESULTS: The three patients each had a complete preoperative neurologic deficit. Sagittal T1- and T2-weighted magnetic resonance images of the spine proved to have high sensitivity for defining the type of bleeding and delineating the craniocaudal extension of the hematoma. Surgical evacuation was performed within 26 hours after the onset of symptoms. Intraoperative findings showed the hematoma to be confined between the dura and the arachnoid in two patients, and to be associated with rupture into the subarachnoid space in one patient. Postoperative recovery was incomplete in two patients, and did not improve in the remaining patient. CONCLUSIONS: Spinal subdural hematoma must be considered in patients under anticoagulant therapy with spontaneous signs of acute spinal cord or cauda equina compression. Magnetic resonance imaging with sagittal T1- and T2-weighted images were adequate and reliable for diagnosis of spinal subdural hematoma. On the basis of previous studies and the authors' intraoperative findings, spinal subdural hematomas could be viewed as spinal dural border hematomas. The level of preoperative neurologic deficit seemed to be critical for recovery despite prompt surgical evacuation.