Electrophysiologic evaluation and monitoring of spinal cord and root function.

The spinal cord can be monitored intraoperatively with somatosensory evoked potentials. Although this is only a posterior column test, it is sensitive to most acute cord impairment. Techniques have become standardized and include monitoring from scalp or around the spinal cord itself. Motor evoked responses are currently under investigation for possible OR use, and they may someday supersede somatosensory testing as the monitoring tool of choice.