A series of electrodes, both surface and subdermal, are attached to the body. Each patient may have different electrodes and arrangements based upon the individual’s surgery and condition. Nerve pathways are monitored by sending electrical impulses between stimulating and receiving electrodes and measuring the speed and intensity of the signals. If signal responses differ from established standards, the surgeon can quickly identify the problem (such as a compressed or stretched nerve). If needed, a correction can be made before damage becomes permanent.
There are different types of intraoperative monitoring.
1. Motor Evoked Potentials monitor signals sent from brain to specific muscle groups.
2. Somatosensory Evoked Potentials/Dermatome Evoked Potentials monitor signals from sensory areas to the brain.
3. Electromyography monitors signals within specific muscle groups during surgery to parts of the spine.