Basic Science Viva
Surgical • Intraoperatively during a surgical procedure to identify the nerve, preserve
function, and prevent intraoperative injury.
Several neurosurgical procedures warrant routine monitoring of cranial nerves depending on the position and extent of surgery. All cranial nerves except CN I can be monitored. As most cranial nerves are motor, placing the EMG electrodes on muscles supplied by the nerve tests their function. CN VIII, being a sensory nerve, is tested by brainstem evoked auditory potential (BAEP). CN II is rarely monitored.