Neurophysiological monitoring in spinal cord surgery

Intraoperative neurophysiological monitoring (IOM) during spine surgery consists of several functional tests including somatosensory evoked potentials (SSEPs), motor evoked potentials (MEPs), dermatomal potentials (DPs) and EMG (electromyography). Permanent neurological damage after spine surgery performed without intraoperative neurophysiological monitoring is frequent and often very costly. The main goal of IOM is the immediate detection, prevention and correction of neurological damage during surgery, which may go unnoticed without using these tests.

A total of 351 clinical files of patients with spinal surgery and continuous neurophysiological monitoring were transversally and descriptively reviewed from 2007 to 2008.

There were 135 male patients (38.46%) and 216 female patients (61.54%); 82% of the cases were osteodiscal pathology with or without medullar involvement, 12% were patients with traumatic injuries, 4% with scoliosis and 2% had medullary tumors. Regarding localization, 62.1% were lumbar, 33% cervical, 4.3% thoracic and 0.5% sacral involvement; 12.4% of our cases showed significant improvement of the basal responses on SSEPs, and 56.8% showed no significant change during the procedure. In 28.4% of the cases, the surgical team had to be advised of potential neurological damage and in 2.4% there was absence of neurophysiological responses. No patient showed complete loss of any neurophysiological response. All patients reported clinical improvement after hospital discharge.

Intraoperative neurophysiological monitoring may help avoid certain neurological risks during spine surgery, which may go unnoticed without the use of this technique.