The effect of optimizing EABR parameters in artificial cochlear implantation for auditory rehabilitation.

OBJECTIVE The objective of the present study was to observe the relationship between V extraction rate and threshold value of electrically evoked auditory brainstem response (EABR) waves in artificial cochlear implantation, in order to optimize EABR parameters for improving auditory rehabilitation. PATIENTS AND METHODS Thirty patients without residual hearing and treated with artificial cochlear implants were selected. The experimental group included 17 cases with normal cochlear morphology, four with large vestibular aqueduct syndrome (LVAS), six with Mondini malformation, and three with internal auditory canal stenosis. Thirty patients with residual hearing and approximate conditions, treated with artificial cochlear implantation to conduct matching were taken as the control group. For artificial cochlear implantation, Remolded Cochlear Freedom artificial cochleas and platinum-iridium alloy spheroid electrodes were used to provide electric stimulation of different pulse widths (50 μs, 100 μs and 200 μs) to patients in the two groups. A Bio-logic Navigator Pro auditory evoked potentiometer was used to record V extraction rate and threshold value of EABR waves under the different pulse widths. RESULTS There were no significant differences in V extraction rates of EABR waves at pulse widths of 50 μs, 100 μs and 200 μs (p >0.05). All EABR threshold values in the experimental group were higher than those in the control group, and the differences were statistically significant (p <0.05). CONCLUSIONS The monopole stimulation within the cochlea can induce good EABR waves and EABR threshold values of patients without residual hearing were significantly higher than those of patients with residual hearing (p <0.05). Waveform differentiation of pulse width 100 μs was better, dynamic range was broader and it was necessary to increase stimulation when the malformation was serious.