Intraoperative somatosensory evoked potentials. A localizing technique in the DREZ operation.

The localization of neural pathology by the evoked potential technique through the use of the Nicolet compact four-signal averager is reviewed. Stimulating electrode application on facial nerves and peripheral nerves of the limbs is described, as well as spinal cord and medullary recording electrode type and placement. Several pathological lesions causing pain are presented and the intraoperative evoked potentials prior to and after lesion production are examined and analyzed.