听性脑干反应和蜗神经直接动作电位联合听觉监护在侧颅底手术中的应用

目的:通过听性脑干反应(ABR)和蜗神经动作电位(CNAP)在侧颅底外科手术中的应用,分析造成听力损伤的原因,并对这两种听觉监测技术作出评价。方法:在手术过程中对14例保留听力的侧颅底手术的患者进行听觉监测。ABR在整个手术过程中监测,CNAP在打开脑膜、暴露蜗神经后进行监测。在患者出院后1个月左右随访听力。结果:所有患者在手术过程中都有不同程度的ABR变化,尤其是耳科电钻使用后[相对使用前延长(0.19±0.16)ms)]和颅内操作时[相对操作前延长(0.29±0.25)ms]。部分患者的波形潜伏期延长在术毕时有所恢复[10例,平均缩短(0.27±0.16)ms]。结论:侧颅底手术中应用听觉监护能防止听觉损伤。电钻使用造成的震动和噪声对听力有损伤,解除引起波形潜伏期延长的诱因后可恢复部分听力。术后的听力预后与术毕潜伏期的延长有相对应关系。术中监测的新趋势是联合应用ABR和CNAP,取长补短。

ABR and CNAP combined monitoring during the lateral skull base surgeries

OBJECTIVE: Through the application of ABRs and CNAPs monitoring during the lateral skull base surgeries, we intended to detect the causes of intraoperative hearing damage and estimate the value of the techniques. METHOD: Intraoperative auditory monitoring were performed in 14 lateral skull base surgeries in which hearing preservation were attempted. ABRs was recorded in all the steps of the procedure, while CNAPs was recorded after opening the dura. All patients' hearing levels were followed up. RESULT: All the patients had auditory evoked potentials (AEPs) change during the procedure, especially after the step of drilling [prolonged (0.26 +/- 0.19) ms] and during the encephalic manipulations [prolonged (0.68 +/- 0.38) ms]. Some patients' AEPs recruited in the end of procedure. CONCLUSION: The intraoperative auditory monitoring could play a role in preventing the hearing damage in the procedure. Drilling may cause the hearing damage. After relieving the manipulation inducement, the hearing damage would partially recruit. The prognosis of hearing is related to the prolongation of wave latencies in the procedure. A combination use of the ABR and CNAPs may be a better method of intraoperative auditory monitoring.