Abstract
Various electrophysiological monitoring techniques are available for localizing and protecting cranial nerves and the brain stem during skull-base procedures. Separate neural pathways are used with each method, allowing for the simultaneous monitoring of different cranial nerves and brain stem tracts. Although monitoring of the facial nerve during resection of an acoustic neuroma is considered to be a standard of care, other monitoring techniques, such as tracking motor evoked potentials and visual evoked potentials, have not yet gained wide acceptance with neurosurgeons. This situation is in part attributable to technical factors that create difficulties in interpreting intraoperative changes in these responses. The use of individual techniques is usually based on the surgeon's level of comfort in attacking a given lesion and in his or her perception of the sensitivity and specificity of each type of electrophysiological monitoring.