During surgeries, physicians will often utilize intraoperative nerve monitoring to assess the condition of the patient’s nervous system and ensure that no damage is being done to the spinal cord, brain or nerves during the procedure. In essence, intraoperative nerve monitoring—sometimes known as intraoperative neurophysiological monitoring or intraoperative neuromonitoring—helps reduce the risks of surgeries on the spine and brain, surgeries in which complications can have serious consequences.

Before a surgical procedure, electrodes will be placed on and under the skins along nerve pathways and connected to central computer that will monitor nerve activity. Once connected, the electrodes will send electrical impulses through the nerves to assess the level of activity occurring (based on the speed of the impulses between electrodes).

If, during surgery, the computer detects that the speed at which the impulses are traveling is slowing, physicians will know a problem with a nerve exists and they will be able to take actions to prevent damage to that nerve and alleviate any compression occurring.

Different forms of intraoperative nerve monitoring are available to surgeons. Motor evokes potentials watches signals between the brain and specific muscle groups; somatosensory evoked potentials/dermatome evoked potentials monitors signals from the brain to a particularly sensory areas; and electromyography is used to view signals within certain muscle groups, for instance in the arms during neck (cervical) surgeries or in the legs during lower back (lumbar) procedures.