Intra-Operative Monitoring (IOM) is the evaluation of the function of the spinal cord and nerves during spine surgery. Its role is to provide the surgeon with immediate feedback and warning before permanent nerve injury has occurred. This has been shown to increase safety and improve outcomes in complex spine surgery.

IOM is carried out by the use of Somatosensory Evoked Potentials (SSEP), Transcranial Electrical Motor Evoked Potential (TcMEP or MEP) and for lower spine operations Free-Run Electromyography (frEMG) may also be used. This combined monitoring of SSEP, MEP and frEMG is known as Multi-Modal Monitoring

While SSEP may be influenced by motor damage it cannot provide reliable information on the functional integrity of the motor system. MEP techniques, which monitor motor pathways of the spinal cord, have been increasingly used. The cerebral cortex is electrically stimulated transcranially, using surface or needle electrodes. The MEP produced is recorded directly from muscles. Loss of motor potential may be associated with motor deficit after the operation, and motor deficits are generally considered to be more functionally devastating to the patient than sensory deficits.

In contrast to SSEP monitoring, MEP monitoring is virtually instantaneous and extremely sensitive to any ischaemic events, thus reducing reaction time for the surgical team.

Multi-Modal Monitoring is routinely carried out for all spinal cord monitoring cases by Bespoke Healthcare.