Effects of cochlear implantation on VEMPs
VEMP changes before and after surgery were recorded, but only the CI ear was analyzed. The postoperative VEMP test was performed 25–39 days after surgery, and 64 CI ears were retested under the condition of CI-off. 50% of the implanted ear cVEMP waveform and 39.1% of the oVEMP waveforms disappeared after CI, the difference in the lost rate was not statistically significant between the implanted ear cVEMP and oVEMP. Moreover, we compare the p13 and n23 latency ,peak amplitude and corrected amplitude, there was no statistically significant difference in above the parameters before and after surgery. In the group of 25 patients with preoperatively present VEMPs, 40% and 31.75% lost their cVEMP and oVEMP, respectively, after implantation. The variation between cVEMP and oVEMP results before and after surgery of the IEM and control groups are shown in Fig. 2. The independent sample T-test showed that the abnormal cVEMP rate after surgery was increased in the control group (p< 0.001). The abnormal oVEMP rate after surgery of all patients together and the control group significantly increased, but decreased in the IEM group (Fig. 2).