Extraspinal causes of lumbosacral radiculopathy.

Twelve of 12,125 patients who had been referred during a seven-year period to a specialist in spinal disorders were found to have an extraspinal cause of radiculopathy or neuropathy of the lower extremity. The records of these twelve patients were reviewed retrospectively. The average age of the twelve patients was sixty-five years (range, forty-two to seventy-seven years). The cause of the symptoms was an occult malignant tumor in nine patients and a hematoma, an aneurysm of the obturator artery, or a neurilemoma of the sciatic nerve in the others. The average time from the onset of symptoms to the final diagnosis was eight months (range, one month to two years). The most useful test for determination of the correct diagnosis was computed tomography or magnetic resonance imaging of the abdomen and pelvis. Computed tomography or magnetic resonance imaging of the spine and bone-scanning of the whole body were of little help in localizing the disease. In four of the twelve patients, an operation was performed on the basis of an incorrect diagnosis. In dealing with elderly patients who have radiculopathy, one should be suspicious that the cause is outside the spine.