A fatal illness presenting as an S1 radiculopathy. Vascular causes of lumbar radicular pain.

Lower extremity radiculopathy usually originates from abnormal changes in the spinal canal, such as herniated nucleus pulposus, degenerative spinal stenosis, or spondylolisthesis. Multiple cases have been reported in which lower extremity neurologic symptoms were associated with a vascular abnormality in the abdomen or pelvis. Femoral and obturator neuropathies and lumbosacral radiculopathies have been described as presenting signs of complicated aortic and iliac aneurysms. We present an unusual case of a nonruptured aortoiliac aneurysm with erosion into the spinal canal and neuroforamina which presented as a lumbosacral radiculopathy secondary to direct compression of nerve roots. The unsuspected presence of a major vascular structure in an atypical location could have catastrophic consequences in the fact of instrumentation. In patients with known or suspected aortoiliac aneurysms, CT or MRI evaluation of the spine should be performed as the initial diagnostic evaluation of new radicular pain.