术中视觉诱发电位监测对视觉通路保护的研究

Study on intraoperative VEP monitoring to protect the optical path

目的对累及视路的肿瘤,术中应用视觉诱发电位(VEP)监测技术,监测视路的传导功能,为保护术后视觉功能提供实时的电生理传导依据。方法对16例累及视路的颅内肿瘤及颅骨病变,术中监测视觉诱发电位,比较术中视觉诱发电位变化和术后视力改变的关系。结果(1)12例引出稳定、可重复的VEP电位。其中3例术中VEP波幅上升50%以上,潜伏期缩短10%,术后视力均较术前明显提高;5例术中VEP波幅下降小于50%,潜伏期延长10%以内,术后视力轻度下降3例,明显下降1例,基本同前1例;4例VEP波幅下降大于50%,潜伏期延长10%以上,术后视力明显下降3例,轻度下降1例。(2)4例术中未引出VEP,术后视力均明显下降。(3)术中VEP波幅下降大于和小于50%的两组,术后视力明显下降率经X2检验,P<0.05,差异有统计学意义。结论视觉诱发电位监测可以术中及时发现视路的传导功能,为术者判断视觉功能提供了客观、实时的电生理传导依据。VEP波幅下降50%可以作为视路传导功能严重受损、术后视力可能严重下降的警戒参考点。

Objective In order to find the relationship between the optical pathway electrophysiological conductive changes and the postoperative visual deficit, the flash-Visual evoked potential （F-VEP） were monitored before and after tumor removal which have close contact with the optical pathway. Methods 16 patients with tumor close contact to the optical pathway were involved in our study, and their VEP changes and the visual function postoperative were analyzed in order to find their relationship. Results （1） 12 patients had recorded the stable and reproducible VEP, which 3 patients VEP amplitude increased more than 50% following obvious visual function improvement postoperatively; 5 case＇s VEP amplitude decreased less than 50% with VEP latency shortened in 10% , following 3 cases severe visual deterioration, 1 cases no change and l case severe visual deterioration postoperatively. 4 case＇s VEP amplitude decreased more than 50% following 3 severe visual deterioration and 1 slight visual damage. （2） While the other 4 cases cannot be recorded the VEP, all of them had obvious visual deficit postoperatively. （3） The different patients with different loss of the VEP amplitude had significant different clinical outcomes （ P 〈 0.05 ）. Conclusion F-VEP can provide the stable and on-time electrophysiological conductive evidence to judge the optical pathway function. 75% loss of the amplitude of VEP should lead to severe visual disability.