[Somatosensory evoked potentials during surgery of scoliosis: significance of epidural recording].

PURPOSE OF THE STUDY: To evaluate the usefulness of the epidural recording in scoliosis surgery in children or young adults.

MATERIAL AND METHOD: We used somatosensory-evoked potentials in 60 children or young adults in surgical treatment of scoliosis. Somatosensory-evoked potentials were elicited and recorded using a standard method recording of cortical P40 and subcortical P27, simultaneously with the monitoring of spinal cord function using epidural electrode to record the ascending somatosensory volley (by tibial nerve stimulation) at a high thoracic level.

RESULTS

The use of subcortical and epidural recording sites for the somatosensory-evoked potentials indicated that a reliable response could be obtained in 96 p. 100 of the patients. Cortical somatosensory-evoked demonstrated a 48 p. 100 false positive rate.

DISCUSSION: Epidural recording in scoliosis surgery is safe and reliable. Combined subcortical and epidural recordings are especially useful in patients with neuromuscular scoliosis or with cerebral palsy that may not have reliable cortical potentials.