Electrophysiological and urodynamic studies to monitor surgical outcome in children with tethered spinal cords

Children with myelodysplasia often develop tethering of their spinal cord within 2–3 years after correction of their initial birth defect, leading to either neurological or urological dysfunction. Surveillance of these children includes electrophysiologic/urodynamic (EMG/UDS) studies to monitor improvement or deterioration of their neurourological function. We reviewed 39 patients who underwent surgical untethering from 1979 to 1994 to determine whether postoperative EMG/UDS studies were useful in assessing outcome after surgery. All patients had a complete neurologic examination and an EMG/UDS prior to and 3 months after surgery. Twenty patients (51%) showed improvement in their EMG/UDS study after untethering, 15 (39%) demonstrated no significant change, and 4 (10%) showed deterioration. Improvement consisted of either return of previously absent motor units, return of sacral reflexes, or improved bladder dynamics. In a further 3 patients, subsequent deterioration on serial postoperative EMG/UDS testing was the first indication of recurrent tethering. We conclude that serial EMG/UDS evaluation in patients at risk for tethering of the spinal cord may serve as a useful adjunct to close clinical observation. © 1995 John Wiley & Sons, Inc.