A case of anterior spinal cord syndrome in a patient with unruptured thoracic aortic aneurysm with a mural thrombus.

Background: Spinal cord infarction is an uncommon condition. Anterior cord syndrome present with paraparesis or quadriparesis with sparing of vibration and proprioceptive senses. The common causes of anterior cord syndrome are aortic dissection and aortic surgical interventions. Spontaneous unruptured nondissected aortic aneurysms with intramural thrombus can rarely cause anterior cord infarctions.

Case Presentation: We report a case of anterior spinal cord syndrome due to aneurysm of the thoracic aorta with a mural thrombus. A 64 year old male presented with sudden onset paraparesis with a sensory level at T1 with preserved sense of proprioception and vibration. The MRI panspine revealed increased T2 intensity in the anterior portion of the spinal cord from C5 to T10 level with characteristic 'owl eye' appearance on axial imaging. The CT aortogram detected aneurysmal dilatation of the ascending aortic, arch and descending thoracic aorta with significant intimal irregularities, calcified atherosclerotic plaques and a small mural thrombus.

Conclusion: The possible mechanisms postulated are occlusion of ostia of radicular arteries by the atherosclerotic plaques and mural thrombus or thromboembolism to the anterior spinal artery. Nondissected atherosclerotic aortic aneurysms should be considered in patients presenting with spinal cord infarctions especially in the presence of vascular risk factors and smoking.