Patients
This study included 78 children (41 females and 37 males) who underwent CI at the Department of Otorhinolaryngology Head and Neck Surgery at Beijing Tongren Hospital between January 2021 and February 2022. The children’s mean age at implantation was 5.7±4.1 years (range, 0.7–17.8 years). All participants met the dignosis criterion for bilateral profound or severe hearing loss and met the CI implanted criterion. In order to eliminate residual hearing or impact of crossover from the normal ear ,single-sided deafness was excluded here. Besides, patients aged >18 years, with cognitive and psychological impairments, and unable to participate in follow-up examinations were excluded from this study.
The type and degree of IEMs were classified according to the work of Sennaroglu et al. in 2017[11]. The IEM group classification is listed in Table 1. All patients were divided into two groups based on the presence (IEM group) or absence of IEMs (control group). Each group had 39 patients.
Before surgery, inner ear computed tomography (CT) and magnetic resonance imaging (MRI) scans, audiological assessments (including standard pure tone audiometry, auditory brainstem response evaluation, auditory steady-state response assessment, distortion product otoacoustic emission, cochlear microphonics evaluation), and cVEMP test, were performed. Electronic ear endoscope or tympanograms performs prior to VEMP testing to ensure there was no middle ear fluid or an ongoing hemotympanum. The O-VEMP was performed on patients who were able to cooperate. This study was approved by the Institutional Review Board of Beijing Tongren Hospital.