Intraoperative EMG monitoring for protection of the posterior cranial nerves nucleus

Objective In order to protect the posterior cranial nerves nucleus,the intraoperative EMG monintoring was used during the surgical resection of brain tumors related to the forth ventrical floor.Method 23 brain tumors were surgically removed in our hospital from February 2007 to April 2008, which including 8 case of medulloblastoms, 7 enpendymomas, 3 brain stem gliomas.All the tumors were microsurgical removed and intraoperative EMG monitoring was applied during the operation. The dates of the posterior cranial nerves function,the surgical procedure and EMG monitor changes were analyzed in order to find their relationship.Results 17 tumors were totally removed and 6 subtotally removed.The patients posterior cranial nerves function were protected well in 6 cases, 13 cases of slight dysfunction and 4 cases of moderate dysfunction.There was no serious damage in our group.The myoelectricity induced by the posterior cranial nerve nucleus stimulation could be recorded successfully under normal anesthesia condition.Conclusion The intraoperative EMG monitoring could avoid posterior cranial nerves nucleus damage and provide objective judgment for resection strategy of tumors related to the forth ventrical floor. Key words: Brain stem neoplasms;  Microsurgery;  Intraoperative EMG monitor