[Value of somatosensory evoked potentials in spinal surgery monitoring in children and adolescents: 110 cases].

This study shows the results obtained in 110 patients, children and adolescents by monitoring somatosensory evoked potentials during spinal surgery: Cotrel-Dubousset instrumention, surgical anterior correction by plating, spondylolisthesis and hemivertebra surgery. The recordings were made in preoperative, peroperative and postoperative period; the anaesthetic and electrophysiological conditions allowed us to obtain reliable recordings. In the peroperative period, the recordings were made: after induction of anesthesia and exposure of the spine, after instrumentation, after maximum traction and at the end of the operation. Analysis of the peroperative somatosensory evoked potentials (PESEP) showed significant differences in latencies, but also in amplitudes and morphology during distraction in scoliosis or spondylolisthesis. These impairments gradually improved and recovered their normal values at the end of the operation. The impairments were, with equal correction, 4 times more important in Cotrel-Dubousset instrumentation than in surgical anterior correction by plating. During instrumentation and in two cases, the impairments observed led the surgeon to change his operative behavior, certainly avoiding a postoperative neurological disorder, the "wake-up test" was made in one case. The correlation between the neurological problems, and the impairments of the potentials allowed us to define alarm criteria, and if they persist the "wake-up test" becomes necessary.