Cauda equina syndrome with normal lumbar myelography.

The consequences of signs of emergency compression of cauda equina in combination with a normal lumbar myelography are reported in 19 patients. Two of them had a tumor and a herniated disc, respectively, in the thoracic spine discovered by a second myelography. One patient was considered to have a hysterical paresis. In 3 patients the symptoms were attributed to diseases not related to the spine. Thirteen patients recovered spontaneously. We conclude that the prognosis for patients with signs of compression of the cauda equina is favorable provided the myelography is normal; surgical exploration is then not indicated. However, if severe unexplained symptoms persist and computed tomography is normal, myelography of the thoracic spine should be considered.