The Application Of Intraoperative Electrophysiologic Monitoring Of The Facial Nerve In The Operation Of Acoustic Neurilemoma

Objective： By27cases of acoustic neurilemoma with intraoperativeelectrophysiologic monitoring and supplying intraoperatively bad information aboutthe facial nerve to operator and changing the operating way immediately to avoidinjurying the facial nerve, to investigate the significance of protecting and evaluatingthe function of the facial nerve in the operation of acoustic neurilemoma withintraoperative electrophysiologic monitoring and to increase the completely-resectedrate of acoustic neurilemoma and the anatomical and functional preservation rate ofthe facial nerve so as to improve the life quality after the operation.Methods：Electrophysiologic examination was performed in the operation of27cases of acoustic neurilemoma and the intraoperatively free electromyography wasobserved and the preoperative and postoperative transcranial electrical motor evokedpotentials of the facial nerve were recorded. The relationship between theelectrophysiologic chang and the postoperative function of the facial nerve wasinvestigated.Results：24cases(88.9%) were completely resected and3cases(11.1%) weresubtotally resected.The facial nerve was anatomically preserved in26cases(96.3%)and functionally preserved in17cases(63.0%) without operative mortality. All thecomplications included3obviously intraoperative cerebelumm swelling,2intracranialinfection,severe injury of the facial function（House-Brackmann grade IV2cases andgrade V2cases）,Varying degrees injury of rear cranial nerve2cases.Less than60%of the postoperative-to-preoperative transcranial electrical motor evoked potentialsof the facial nerve was possibly related to the poorly facial function after theoperation.Conclusion:Intraoperative electrophysiologic monitoring could timely detectdangerous action during the operation of acoustic neurilemoma and avoid injurying the cranial nerves at the functional level.So intraoperative electrophysiologicmonitoring had an importent value for safely resecting the tumors and protecting andevaluating the function of the facial nerve to most extent. Less than60%of thepostoperative-to-preoperative transcranial electrical motor evoked potentials of thefacial nerve is an alarm for a possibly severe injury of the facial nerve function.