Objective:To explore the value of high resolution computed tomography（HRCT） combined with Magnetic Resonance Imaging（MRI） in the diagnosis of inner ear malformation. Methods:HRCT and MRI data of 82 patients with inner ear malformations were analyzed retrospectively. HRCT MPR and CPR reconstruction of the inner ear structure, facial nerve canal and oblique sagittal MRI reconstruction of the internal auditory canal were performed. The inner ear malformations were classified, the conditions of facial nerve canal and cochlear nerve were evaluated. The association between inner ear malformation and cochlear nerve dysplasia were analyzed by Chi-square test with continuity correction. Results:Among the 82 patients with inner ear malformations,there were 49 cases of bilateral symmetry, 11 cases of bilateral asymmetry and 22 cases of unilateral inner ear malformations. Respectively, the most prevalent types were IP-Ⅱ（42.96%）, dilatation of atrium aqueduct（18.31%） and malformations of atrium and semicircular canal 19.72%. Out of 50 cases of cochlear malformations,only 3 were isolated cochlear malformations, and the rest were accompanied by other malformations of varying degrees. In the 67 ears examined by MRI, 26（38.81%） had cochlear nerve deficiency（CND）, and the incidence of CND varied with different types of inner ear malformations. Out of 142 ears, 28（19.72%） had abnormalities of the facial nerve canal. Conclusion:HRCT combined with MRI can accurately distinguish the types of inner ear malformation and effectively evaluate the facial nerve canal and cochlear nerve, and further provides the important finger and Guide value for the clinician to formulate the reasonable treatment and the operation plan.
Humans ; Ear, Inner/diagnostic imaging* ; Magnetic Resonance Imaging/methods* ; Retrospective Studies ; Female ; Male ; Tomography, X-Ray Computed/methods* ; Child ; Adolescent ; Adult ; Child, Preschool ; Cochlear Nerve/diagnostic imaging* ; Facial Nerve/abnormalities* ; Cochlea/abnormalities* ; Infant ; Young Adult

Objective:The aim of this study was to present an institution's experience with cochlear reimplantation（CRI）, to assess surgical challenges and post-operative outcomes and to increase the success rate of CRI. Methods:We retrospectively evaluated data from 76 reimplantation cases treated in a tertiary center between 2001 and 2022. Clinical features include caused of CRI, type of failure, surgical issues, and auditory speech performance were analyzed. Categorical Auditory Performance （CAP） and Speech Intelligibility Rating （SIR） scores were used to evaluate pre-and post-CRI outcomes. Our center's consecutive cohort of 1 126 patients had seven patients, while 69 patients were from other cochlear implant centers. Device failure was the most common cause of CRI（68/76）, with the remaining cases including flap complications（3/76）, magnet displacement（3/76）, secondary meningitis（1/76）, and foreign bodies around the implant（1/76）. Postoperative auditory and speech outcome improved in 31.6%（24/76） of patients, remained unchanged in 63.2%（48/76）, and decreased in CAP and SIR scores in 5.2%（4/76） of patients. Postoperatively, the seven patients with cochlear ossification and fibrosis scored lower on the overall CAP and SIR scale than non-ossification individuals, which is a significant factor in surgical success rates and auditory-speech outcomes. Conclusion:CRI surgery is a challenging but relatively safe procedure, and most reimplanted patients experience favorable postoperative outcomes. Medical complications and intracochlear damage are the main causes of poor postoperative results. Therefore, minimally invasive CI has a positive significance for reducing the difficulty of CRI surgery and improving the CI performance.
Humans ; Cochlear Implantation/methods* ; Retrospective Studies ; Cochlear Implants ; Male ; Female ; Postoperative Period ; Treatment Outcome ; Adult ; Speech ; Middle Aged ; Postoperative Complications ; Replantation ; Cochlea/surgery*

Objective:To investigate the application value of intraoperative sliding rail computed tomography （CT） in complicated and difficult cochlear implantation by analyzing the cases of complicated and difficult cochlear implantation. Methods:The clinical data of patients with complicated and difficult cochlear implantation assisted by sliding rail CT were retrospectively analyzed, the intraoperative complications and the number of electrode adjustments were summarized, and the patients were followed up. Results:A total of 51 subjects were included in this study, including 46 patients with inner ear malformation, 2 patients with cochlear ossification, there were 7 patients underwent secondary scanning to adjust the electrode and achieved satisfactory implantation position. Conclusion:Intraoperative CT scanning is a reliable adjunctive tool for determining the placement of complex cochlear implantation, and it improves the accuracy of difficult cochlear implantation surgeries.
Humans ; Cochlear Implantation/methods* ; Retrospective Studies ; Tomography, X-Ray Computed ; Cochlear Implants ; Male ; Female ; Child, Preschool ; Child ; Cochlea ; Electrodes, Implanted ; Infant

Objective:This study aims to investigate the mechanism and potential effects of two exposures to 100 dB sound pressure level（SPL） broadband white noise, with a 14-days interval, on the myelin sheath of the cochlear auditory nerve in mice. The research provides experimental evidence for understanding the pathophysiological processes of noise-induced hearing loss and hidden hearing loss. Methods:Fifteen 6-week-old male C57BL/6J mice with normal hearing thresholds were randomly divided into three groups: a control group（no noise exposure）, a single noise exposure group, and a double noise exposure group. The single noise exposure group was exposed to 100 dB SPL white noise for 2 hours, and ABR thresholds were measured 1 day（P1） and 14 days（P14） after the exposure. The double noise exposure group was exposed to the same conditions of 100 dB SPL white noise for 2 hours, followed by a second identical exposure 14 days later. ABR thresholds were measured 1 day（P15） and 14 days（P28） after the second exposure. The cochleae of all three groups were then collected for immunofluorescence observation of the basilar membrane and transmission electron microscopy to observe changes in the structure of the auditory nerve myelin sheath. Results:In the single noise exposure group, ABR thresholds at all frequencies were significantly elevated compared to the control group at P1. There were no significant changes in ABR thresholds at any frequency at P14. In the double noise exposure group, ABR thresholds at all frequencies were significantly elevated compared to the control group at P15 and P28（P<0.001）. After the first noise exposure, immunofluorescence observation revealed no significant weakening of the auditory nerve myelin sheath signal; transmission electron microscopy showed no significant changes in myelin sheath morphology. However, after the second noise exposure, immunofluorescence observation revealed a weakening of the myelin sheath signal, and transmission electron microscopy showed thinning of the myelin sheath, disruption of the lamellar structure, and separation from the axon, indicating demyelination. Conclusion:Two exposures to 100 dB SPL broadband white noise can lead to damage to the auditory nerve myelin sheath in mice, whereas a single exposure does not cause significant changes.
Animals ; Male ; Myelin Sheath/pathology* ; Mice ; Cochlear Nerve/pathology* ; Mice, Inbred C57BL ; Noise/adverse effects* ; Hearing Loss, Noise-Induced/physiopathology* ; Cochlea ; Evoked Potentials, Auditory, Brain Stem

The extracellular matrix（ECM）is a complex network structure composed of collagen，glycoproteins，and proteoglycans.It not only provides structural support and viscoelasticity to tissues but also participates in cell signaling，responding to environmental forces and signals to mediate tissue remodeling in response to environmental cues. Due to the intricate and precise functions of the inner ear，the perception and transmission of sound rely on the complex interactions between cochlear cell structures and the ECM. In the inner ear，the ECM not only constitutes key structures such as the basilar membranes（BM）and tectorial membranes（TM），which are essential for sound perception，but also regulates cell shape，adhesion，and migration.Certain ECM components interact with cell surface receptors to activate signaling pathways that regulate gene expression.Additionally，the ECM modulates the storage and diffusion of ions and secreted factors, creating concentration gradients.These functions are critical for inner ear development，repair，and function.Thus，the ECM plays a vital role in auditory processes，and abnormalities in ECM are a cause of certain hereditary hearing loss.This review primarily summarizes the ECM genes that lead to hearing loss.
Humans ; Extracellular Matrix/genetics* ; Hearing Loss/genetics* ; Mutation ; Cochlea ; Extracellular Matrix Proteins/genetics*

Objective: To investigate the application of cochlear nerve action potential (CNAP) monitoring in the resection of vestibular schwannoma, especially evaluating its significance for hearing preservation. Methods: From April 2018 to December 2021, 54 patients with vestibular schwannoma who underwent resection via retrosigmoid approach were collected in Chinese PLA General Hospital. Before surgery, all patients had effective hearing (AAO-HNS grade C or above). Brainstem auditory evoked potential (BAEP) combined with CNAP monitoring was performed during surgery. The CNAP monitoring was combined with continuous monitoring and cochlear nerve mapping. And patients were divided into hearing preservation group and non-preserved group according to postoperative AAO-HNS grade. SPSS 23.0 software was used to analyze the differences of CNAP and BEAP parameters between the two groups. Results: A total of 54 patients completed intraoperative monitoring and data collection, including 25 males (46.3%) and 29 females (53.7%), aged 27-71 years with an average age of 46.2 years. The maximum tumor diameter were (18.1±5.9) mm (range 10-34 mm). All tumors were totally removed with preserved facial nerve function (House-Brackmann grade I-II). The hearing preservation rate of 54 patients was 51.9% (28/54). During surgery, the V wave extraction rate of BAEP waveform was 85.2% (46/54) before tumor resection, 71.4% (20/28) in the hearing preservation group after tumor resection, and disappeared in the hearing preservation group (0/26). CNAP waveform was elicited in 54 patients during operation. Differences were found in the distribution of CNAP waveforms after tumor resection. The waveforms of the hearing-preserving group were triphasic and biphasic, while those in the non-preserving group were low-level and positive. For hearing preservation group, the amplitude of N1 wave after tumor resection was significantly higher than that before tumor resection[14.45(7.54, 33.85)μV vs 9.13(4.88, 23.35)μV, P=0.022]; However, for the non-preserved group, the amplitude of N1 wave after tumor resection was significantly lower than that before tumor resection [3.07(1.96, 4.60)μV vs 6.55(4.54, 9.71)μV, P=0.007]; After tumor resection, the amplitude was significantly higher than that of the unreserved group [14.45(7.54, 33.85)μV vs 3.07(1.96, 4.60)μV, P<0.001]. Conclusions: BAEP combined with CNAP monitoring is conducive to intraoperative hearing protection, and the application of cochlear nerve mapping can prompt the surgeon to avoid nerve injury. The waveform and N1 amplitude of CNAP after tumor resection have a certain value in predicting postoperative hearing preservation status.
Female ; Male ; Humans ; Middle Aged ; Neuroma, Acoustic/surgery* ; Action Potentials ; Evoked Potentials, Auditory, Brain Stem ; Cochlea ; Cochlear Nerve

Mice ; Animals ; Spiral Ganglion/physiology* ; Cochlea/physiology* ; Neurons

The cochlear auditory epithelium contains two types of sound receptors, inner hair cells (IHCs) and outer hair cells (OHCs). Mouse models for labelling juvenile and adult IHCs or OHCs exist; however, labelling for embryonic and perinatal IHCs or OHCs are lacking. Here, we generated a new knock-in Fgf8^P2A-3×GFP/+ (Fgf8^GFP/+) strain, in which the expression of a series of three GFP fragments is controlled by endogenous Fgf8 cis-regulatory elements. After confirming that GFP expression accurately reflects the expression of Fgf8, we successfully obtained both embryonic and neonatal IHCs with high purity, highlighting the power of Fgf8^GFP/+. Furthermore, our fate-mapping analysis revealed, unexpectedly, that IHCs are also derived from inner ear progenitors expressing Insm1, which is currently regarded as an OHC marker. Thus, besides serving as a highly favorable tool for sorting early IHCs, Fgf8^GFP/+ will facilitate the isolation of pure early OHCs by excluding IHCs from the entire hair cell pool.
Animals ; Mice ; Hair Cells, Auditory, Inner ; Cochlea/metabolism* ; Hair Cells, Auditory, Outer/metabolism* ; Disease Models, Animal ; Fibroblast Growth Factor 8/metabolism*

Progressive functional deterioration in the cochlea is associated with age-related hearing loss (ARHL). However, the cellular and molecular basis underlying cochlear aging remains largely unknown. Here, we established a dynamic single-cell transcriptomic landscape of mouse cochlear aging, in which we characterized aging-associated transcriptomic changes in 27 different cochlear cell types across five different time points. Overall, our analysis pinpoints loss of proteostasis and elevated apoptosis as the hallmark features of cochlear aging, highlights unexpected age-related transcriptional fluctuations in intermediate cells localized in the stria vascularis (SV) and demonstrates that upregulation of endoplasmic reticulum (ER) chaperon protein HSP90AA1 mitigates ER stress-induced damages associated with aging. Our work suggests that targeting unfolded protein response pathways may help alleviate aging-related SV atrophy and hence delay the progression of ARHL.
Mice ; Animals ; Transcriptome ; Aging/metabolism* ; Cochlea ; Stria Vascularis ; Presbycusis

Electrode array misplacement is a rare complication of cochlear implant. This article reports an 11-year-old boy who was mistakenly implanted the cochlear electrode array into the superior semicircular canal during the initial cochlear implant. After the diagnosis was confirmed, he underwent a second cochlear implant and the electrode array were successfully implanted into the cochlea. This article conducted a systematic review of the literature on electrode array misplacement, and the causes of electrode array misplacement were analyzed from different implantation position.
Male ; Humans ; Child ; Electrodes, Implanted ; Reoperation ; Cochlea ; Cochlear Implantation ; Cochlear Implants/adverse effects* ; Semicircular Canals/surgery*