Intraoperative motor evoked potentials monitoring in spinal neurosurgery

Neurological damage may follow even a technically accurate spinal surgery. The intraoperative monitoring of neurological functions put at risk by the operation is a method utilized to correctly identify the topography of neural structures and to avoid surgical insults. SEPs monitoring is 20 year old, and only recently direct motor tract monitoring has become possible. Transcranial electrical motor cortex stimulation with single pulses or with short trains of stimuli and recording of the evoked responses from the spinal epidural space (D-waves) and from limb muscles is a reliable and safe technique for monitoring corticospinal tract activity even under general anesthesia. The method has a solid theoretical experimental background. Its clinical application has demonstrated high sensitivity and specificity. Intraoperative MEPs monitoring is nowadays considered indispensable during spinal neurosurgery.