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Item does not contain fulltext IMPORTANCE: The cost of bilateral cochlear implantation (BCI) is usually not reimbursed by insurance companies because of a lack of well-designed studies reporting the benefits of a second cochlear implant. OBJECTIVE: To determine the benefits of simultaneous BCI compared with unilateral cochlear implantation (UCI) in adults with postlingual deafness. DESIGN, SETTING, AND PARTICIPANTS: A multicenter randomized clinical trial was performed. The study took place in 5 Dutch tertiary referral centers: the University Medical Centers of Utrecht, Maastricht, Groningen, Leiden, and Nijmegen. Forty patients eligible for cochlear implantation met the study criteria and were included from January 12, 2010, through November 2, 2012. The main inclusion criteria were postlingual onset of hearing loss, age of 18 to 70 years, duration of hearing loss of less than 20 years, and a marginal hearing aid benefit. Two participants withdrew from the study before implantation. Nineteen participants were randomized to undergo UCI and 19 to undergo BCI. INTERVENTIONS: The BCI group received 2 cochlear implants during 1 surgery. The UCI group received 1 cochlear implant. MAIN OUTCOMES AND MEASURES: The primary outcome was the Utrecht Sentence Test with Adaptive Randomized Roving levels (speech in noise, both presented from straight ahead). Secondary outcomes were consonant-vowel-consonant words in silence, speech-intelligibility test with spatially separated sources (speech in noise from different directions), sound localization, and quality of hearing questionnaires. Before any data were collected, the hypothesis was that the BCI group would perform better on the objective and subjective tests that concerned speech intelligibility in noise and spatial hearing. RESULTS: Thirty-eight patients were included in the study. Fifteen patients in the BCI group used hearing aids before implantation compared with 19 in the UCI group. Otherwise, there were no significant differences between the groups' baseline characteristics. At 1-year follow-up, there were no significant differences between groups on the Utrecht Sentence Test with Adaptive Randomized Roving levels (9.1 dB, UCI group; 8.2 dB, BCI group; P = .39) or the consonant-vowel-consonant test (median percentage correct score 85.0% in the UCI group and 86.8% in the BCI group; P = .21). The BCI group performed significantly better than the UCI group when noise came from different directions (median speech reception threshold in noise, 14.4 dB, BCI group; 5.6 dB, BCI group; P

International audience; Mutations in the type II transmembrane serine protease 3 (TMPRSS3) gene cause non-syndromic autosomal recessive deafness (DFNB8/10), characterized by congenital or childhood onset bilateral profound hearing loss. In order to explore the physiopathology of TMPRSS3 related deafness, we have generated an ethyl-nitrosourea-induced mutant mouse carrying a protein-truncating nonsense mutation in Tmprss3 (Y260X) and characterized the functional and histological consequences of Tmprss3 deficiency. Auditory brainstem response revealed that wild type and heterozygous mice have normal hearing thresholds up to 5 months of age, whereas Tmprss3 Y260X homozygous mutant mice exhibit severe deafness. Histological examination showed degeneration of the organ of Corti in adult mutant mice. Cochlear hair cell degeneration starts at the onset of hearing, postnatal day 12, in the basal turn and progresses very rapidly toward the apex, reaching completion within 2 days. Given that auditory and vestibular deficits often co-exist, we evaluated the balancing abilities of Tmprss3 Y260X mice by using rotating rod and vestibular behavioral tests. Tmprss3 Y260X mice effectively displayed mild vestibular syndrome that correlated histologi-cally with a slow degeneration of saccular hair cells. In situ hybridization in the developing inner ear showed that Tmprss3 mRNA is localized in sensory hair cells in the cochlea and the vestibule. Our results show that Tmprss3 acts as a permissive factor for cochlear hair cells survival and activation at the onset of hearing and is required for saccular hair cell survival. This mouse model will certainly help to decipher the molecular mechanisms underlying DFNB8/10 deafness and cochlear function.

Summary American mink (Neovison vison) kits are born altricial and fully dependent 40 on maternal care, for which the kits' vocalisations appear essential. We used Auditory Brainstem Recording (ABR) to determine (1) hearing sensitivity of adult females from two breeding lines known to differ in maternal behaviour and (2) development of hearing in kits 8-52 days of age. We also studied sound production in 20 kits throughout postnatal days 1 to 44. Adult female mink had a broad hearing range from 1 kHz to above 70 kHz, with peak sensitivity (threshold of 20 dB SPL) at 8-10 kHz, and no difference in sensitivity between the two breeding lines (P>0.22) to explain the difference in maternal care. Mink kits showed no signs of hearing up to postnatal day 24. From day 30 all kits had ABRs indicative of hearing. Hearing sensitivity increased with age, but was still below the adult level at postnatal day 52. When separated from their mothers kits vocalized loudly. Until age 22 days, 90% of all kits vocalized with no significant decline with age (P=0.27). From day 25, concurrent with the start of hearing, the number of vocalizing kits decreased with age (P

OBJECTIVE Cochlear nerve preservation during surgery for vestibular schwannoma (VS) may be challenging. Brainstem auditory evoked potentials and cochlear compound nerve action potentials have clearly shown their limitations in surgeries for large VSs. In this paper, the authors report their preliminary results after direct electrical intraoperative cochlear nerve stimulation and recording of the postauricular muscle response (PAMR) during resection of large VSs. METHODS The details for the electrode setup, stimulation, and recording parameters are provided. Data of patients for whom PAMR was recorded during surgery were prospectively collected and analyzed. RESULTS PAMRs were recorded in all patients at the ipsilateral vertex-earlobe scalp electrode, and in 90% of the patients they were also observed in the contralateral electrode. The optimal stimulation intensity was found to be 1 mA at 1 Hz, with a good cochlear response and an absent response from other nerves. At that intensity, the ipsilateral cochlear response had an initial peak at a mean (± SEM) latency of 11.6 ± 1.5 msec with an average amplitude of 14.4 ± 5.4 µV. One patient experienced a significant improvement in his audition, while that of the other patients remained stable. CONCLUSIONS PAMR monitoring may be useful in mapping the position and trajectory of the cochlear nerve to enable hearing preservation during surgery.