clinical study of cauda equina action potentials in lunbar disorders

In orede to evaluate the degree and the level of lesions of lumber nerve root and cauda equia, elecrtophysiological measurements have been carried on. The monoplolar catheter electrode was inserted into the epidural space at the levels of L3-4, L4-5 and L5-S for recording the cauda equina action potentials (CEAP). Stimuli to the tibial or pernoeal nerve were given at the polotieal forssae. CEAP were recorded in 82 cases with various linds of lumber disorders, including lumber disk herniation, lumber canal stenosis, chronic low back pain. The control was taken in cases with cervical or thoracic spinal disorders without any lumber problem. In 77% of cases with lumber disk herniation, the voltage decrease rate of the affected side was more than 30%. In 83% of cases with lumber canal stenosis, the voltage decrease rate of the affected level to the caudal level was more than 30%. The results suggest that CEAP is useful for diagnosis of the affected level. To obtain more accurate evaluation and more research will be necessary.