TRANSCRANIAL MAGNETIC EVOKED-POTENTIALS USED TO MONITOR THE SPINAL-CORD DURING NEURORADIOLOGIC ANGIOGRAPHY OF THE SPINE

A current topic in intraoperative monitoring of the spinal cord is the inability of the somatosensory evoked potentials (SSEP) to adequately document anterior spinal cord function. Transcranial magnetic stimula tion (TMS) of the cortex for assessing corticospinal (efferent) pathwa ys is a developing modality. The authors demonstrate a potential appli cation of TMS as a monitoring medium for use in the neuroradiology sui te. Limitations of intraoperative applications of cortical magnetic st imulation associated with cortical suppression are caused by anestheti cs and neuromuscular blockers. These limitations generally are not an issue in the neuroradiology suite. In this report, motor improvement w as correctly predicted by magnetic evoked potential amplitudes, wherea s an SSEP remained unchanged during neuroradiologic angiography.