Spinal arteriovenous malformations and neurogenic claudication. Report of two cases

Spinal arteriovenous malformations (AVM's) can present with symptoms of neurogenic claudication indistinguishable from those of lumbar spondylosis. Spinal AVM's occur most frequently in males of middle age or older; lumbar spondylosis is often also present in these patients. The myelographic appearance of the abnormal vessels may resemble that of the dilated veins or redundant nerve roots sometimes seen adjacent to regions of spinal block, obscuring the diagnosis. Two patients are described who presented with clinical histories and myelographic findings that led to laminectomies for presumed spinal stenosis; ultimately, both were found to have an AVM. Treatment of the AVM arrested the neurological decline in one patient, and resulted in dramatic improvement in the other. A hypothesis related to hemodynamic consequences of venous hypertension is presented in an attempt to link the pathophysiology of the two conditions.