Redundant lumbar nerve root syndrome: myelographic features.

Nine patients with redundant lumbar nerve root syndrome were identified using positive-contrast myelography, seven with metrizamide and two with iophendylate. Serpiginous intradural filling defects occurred in conjunction with a complete or partial extradural block and spinal stenosis. These redundant nerve roots were seen on the cephalic side of the block. Eight of the nine patients had pseudoclaudication. One case was found incidentally during a cervical myelogram. This series is presented to demonstrate the characteristic myelographic pattern that should be recognized and differentiated from tortuous intradural blood vessels. Possible causes are discussed.