Cranial nerves can be injured during surgical procedures performed in the middle and posterior cranial fossae as well as in the head and neck region. Damage results from compression, stretch, abrasion, or ischemia of the nerve. If axonal disruption occurs, recovery is limited, resulting in significant clinical deficits. Cranial nerve function can be monitored during anesthesia by recording spontaneous or stimulus-evoked electrical activity directly from the nerve or the cranial muscles. Activity in other pathways in the brain stem can be monitored by following changes in evoked potentials of sensory and motor pathways. These methods can detect damage to either the intra-axial or the extra-axial portion of cranial nerves and can localize cranial nerves during an operation when normal anatomy is altered, making accurate identification of nerves difficult. Finally, information from intraoperative cranial nerve monitoring may lead to an altered surgical plan to preserve neurological function.
Cranial nerve monitoring in endoscopic endonasal surgery of skull base tumors (observing of 23 cases)
