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Objective: Transient-evoked otoacoustic emissions (TEOAEs) monitor cochlear function. High pass rates have been reported for industrialized countries. Pass rates in low and middle income countries such as Sub-Saharan Africa are rare, essentially lower and available for children up to 4 years of age and frequently based on hospital recruitments. This study aims at providing additional TEOAE pass rates of a healthy Sub-Saharan cohort aged 1-10 years with data from Gabon, Ghana and Kenya. Potentially confounding factors (recruitment site, age) are taken into consideration., Methods: Healthy children were recruited in hospitals, schools and kindergartens. Inclusion criteria were age 1-10 years and normal otoscopic findings. Exclusion criteria were any sickness or physical ailment potentially impairing the hearing capacity. Five measurements per ear were performed with Capella Cochlear Emission Analyzer (MADSEN, Germany). An overall wave reproducibility of above 60% served as pass-criterion. Pass rates were compared between recruitment sites and age groups (1-5 and 6-10 years)., Results: Overall pass rate was 87.5% (n = 264; 231 passes vs. 33 fails). Of these 84.0% of hospital recruited children passed (n = 156; 131 passes vs. 25 fails), compared to 92.6% of community recruitments (n = 108; 100 passes vs. 8 fails), which was significantly different p = 0.039). If analyzed by age groups, this difference was only observed in children younger than 6 years (p = 0.007)., Conclusion: Hospitals as recruitment sites for healthy controls seem to affect TEOAE pass rates. We advise for a cautious approach when recruiting healthy TEOAE control collectives under the age of 6 in a hospital setting. In children older than 6 years conventional pure-tone audiometry remains the standard method for hearing screening., (Copyright © 2017 Elsevier B.V. All rights reserved.)

In this study different malformations of the cochlea could be demonstrated. Nevertheless, we could not delineate a distinct malformation of the inner ear, that can be linked to a neural tube defect. Neural tube defects are a frequent and heterogeneous group of malformations, ranging from the survivable spina bifida to fatal anencephaly. In multiple animal models an involvement of the vestibulocochlear system has been demonstrated. In this article human fetal temporal bones of neural tube defects were analysed in a multimodular work-up. The morphologic study was performed with light microscopy, transmission electron microscopy and synchrotron radiation-based microcomputed tomography. Immunohistochemistry for different neuronal markers such as peripherin, beta-III-tubulin and vimentin helped to evaluate ontogenetic tissue development. Eight fetal temporal bones with neural tube defects and five control temporal bones were included into the morphologic study. The morphologic results of the neural tube defect temporal bones showed six regularly developed cochleas and two with only a single cochlear turn. Three of the neural tube defect temporal bones were further examined with immunohistochemical analysis. No differences in the staining pattern for peripherin, beta-III-tubulin and vimentin were detected.

Hypothesis: Growth hormones have beneficial effects on increasing height in adults with Turner syndrome (TS) and may also affect auditory function., Background: Turner syndrome is the most common sex-linked chromosomal abnormality in female conceptions. Epidermal growth factor and its receptor (EGFR) affect differentiation, proliferation, and migration of epithelial cells and function as survival factors. The expression of EGFR is found in the developing and juvenile inner ear of experimental animals but is absent in adults., Methods: To determine whether EGFR plays a role in TS, its expression was analyzed in the cochlea of healthy fetus and fetus with TS and in healthy adults., Results: In healthy fetuses, EGFR protein expression was localized to the inner and outer hair cells and the Reissner membrane. The fetuses with TS on the 13th gestational week (GW) showed a similar pattern of immunoreactivity as the normal 16th and 20th GW cochlea. By the 23rd GW, EGFR immunoreactivity was not detectable in the TS hair cells or the Reissner membrane, and less intensive staining was found in the surrounding fibrocytes of the spiral ganglion., Conclusion: This is the first demonstration of EGFR immunoreactivity in the human cochlea and illustrates how EGFR expression is altered during development in TS. These findings indicate the importance of growth hormone receptors for inner ear development in humans.

Objectives: Turner syndrome (TS) is the most frequent sex chromosome abnormality, and sensorineural hearing loss is common. We aimed to determine whether there are consistent morphologic cochlear abnormalities during gestational development that could be associated with TS., Design: The histology of nine fetal temporal bones of TS autopsied after spontaneous abortion was studied., Results: Gross morphologic examination of the TS cochleae failed to reveal a pattern of structural abnormalities that would explain the development of sensorineural hearing loss. Mondini-like cochlear dysplasia was observed in one 13-wk-old TS fetus., Conclusion: We could not demonstrate a consistent pattern of cochlear malformations.

Globally, over the next few decades, more than 2.5 billion people will suffer from hearing impairment, including profound hearing loss, and millions could potentially benefit from a cochlea implant. To date, several studies have focused on tissue trauma caused by cochlea implantation. The direct immune reaction in the inner ear after an implantation has not been well studied. Recently, therapeutic hypothermia has been found to positively influence the inflammatory reaction caused by electrode insertion trauma. The present study aimed to evaluate the hypothermic effect on the structure, numbers, function and reactivity of macrophages and microglial cells. Therefore, the distribution and activated forms of macrophages in the cochlea were evaluated in an electrode insertion trauma cochlea culture model in normothermic and mild hypothermic conditions. In 10-day-old mouse cochleae, artificial electrode insertion trauma was inflicted, and then they were cultured for 24 h at 37 °C and 32 °C. The influence of mild hypothermia on macrophages was evaluated using immunostaining of cryosections using antibodies against IBA1, F4/80, CD45 and CD163. A clear influence of mild hypothermia on the distribution of activated and non-activated forms of macrophages and monocytes in the inner ear was observed. Furthermore, these cells were located in the mesenchymal tissue in and around the cochlea, and the activated forms were found in and around the spiral ganglion tissue at 37 °C. Our findings suggest that mild hypothermic treatment has a beneficial effect on immune system activation after electrode insertion trauma. [ABSTRACT FROM AUTHOR]

Introduction: Cochlea implants can cause severe trauma leading to intracochlear apoptosis, fibrosis, and eventually to loss of residual hearing. Mild hypothermia has been shown to reduce toxic or mechanical noxious effects, which can result in inflammation and subsequent hearing loss. This paper evaluates the usability of standard surgical otologic rinsing as cooling medium during cochlea implantation as a potential hearing preservation technique. Material and Methods: Three human temporal bones were prepared following standard mastoidectomy and posterior tympanotomy. Applying a retrocochlear approach leaving the mastoidectomy side intact, temperature probes were placed into the basal turn (n = 4), the middle turn (n = 2), the helicotrema, and the modiolus. Temperature probe positions were visualized by microcomputed tomography (μCT) imaging and manually segmented using Amira® 7.6. Through the posterior tympanotomy, the tympanic cavity was rinsed at 37°C in the control group, at room temperature (in the range between 22 and 24°C), and at iced water conditions. Temperature changes were measured in the preheated temporal bone. In each temperature model, rinsing was done for 20 min at the pre-specified temperatures measured in 0.5-s intervals. At least five repetitions were performed. Data were statistically analyzed using pairwise t -tests with Bonferroni correction. Results: Steady-state conditions achieved in all three different temperature ranges were compared in periods between 150 and 300 s. Temperature in the inner ear started dropping within the initial 150 s. Temperature probes placed at basal turn, the helicotrema, and middle turn detected statistically significant fall in temperature levels following body temperature rinses. Irrigation at iced conditions lead to the most significant temperature drops. The curves during all measurements remained stable with 37°C rinses. Conclusion: Therapeutic hypothermia is achieved with standard surgical irrigation fluid, and temperature gradients are seen along the cochlea. Rinsing of 120 s duration results in a therapeutic local hypothermia throughout the cochlea. This otoprotective procedure can be easily realized in clinical practice. [ABSTRACT FROM AUTHOR]

Conclusion: In agreement with previously published findings, our results demonstrate that Pelizaeus Merzbacher disease (PMD) does not affect the development and morphology of the peripheral vestibulo-cochlear system. Objective: PMD is a consequence of X-linked mutation of the main central nervous system (CNS) myelin protein resulting in a complex neurological syndrome. Otorhinolaryngological symptoms include nystagmus and alterations of auditory-evoked brainstem responses. To date no histopathological analysis of the inner ear has been performed. Materials and methods: The temporal bone morphology of an affected fetus was examined with light microscopy and synchrotron radiation-based micro computed tomography . Results: The regular structure of the vestibulo-cochlear system was shown in this multi-modular analysis. [ABSTRACT FROM AUTHOR]