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.