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.