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Background: Infants admitted to the neonatal intensive care unit (NICU) have a higher incidence of congenital hearing loss compared with the healthy newborn population.Objectives: To clarify the relationship between risk factors for hearing impairment in NICU-treated infants and deterioration of the auditory brainstem response (ABR) threshold during childhood.Method: We screened 1,071 high-risk infants admitted to the NICU for hearing impairment. One-hundred forty-eight infants exhibited an abnormal ABR threshold of ≥40 dB nHL. We analyzed the correlation of change in ABR threshold with risk factors for future hearing impairment.Results: Among infants treated in the NICU, 148 (13.8%) exhibited an ABR threshold of ≥40 dB nHL; 107 of these 148 (72.3%) showed hearing change in the process (102 showed improvement to normal hearing level, whereas 5 showed further deterioration). Our analysis showed that the factors contributing to the elevation of ABR threshold were oxygen administration and chromosomal aberrations.Conclusions: Factors related to the elevation of ABR threshold were oxygen administration and the presence of chromosomal aberrations. Awareness of risk factors that are more likely to cause hearing loss in infants may aid in follow-up treatment of these children. [ABSTRACT FROM AUTHOR]

We analyzed 356 patients with idiopathic sudden sensorineural hearing loss treated with hyperbaric oxygen therapy and systemic steroids (n = 161), systemic steroids alone (n = 160), or intratympanic and systemic steroids (n = 35). The main outcome measure was the hearing recovery rate. The effect of other variables, including the initial averaged 5-frequency hearing level, patient age, interval between the onset of symptoms and treatment, presence of vertigo as a complication, presence of diabetes mellitus, smoking history, and presence of hypertension, on the hearing recovery rate was also evaluated. The overall hearing recovery rate was significantly higher for the patients treated with hyperbaric oxygen therapy and systemic steroids than for those treated with systemic steroids alone (p < 0.001) or systemic and intratympanic steroids (p < 0.001). The presence of vertigo negatively affected hearing recovery. Our findings suggest that hyperbaric oxygen therapy confers a significant additional therapeutic benefit when used in combination with steroid therapy for idiopathic sudden sensorineural hearing loss. [ABSTRACT FROM AUTHOR]

Acoustic neuroma sometimes presents with sudden-onset sensorineural hearing loss as a primary symptom. We investigated 848 untreated cases that included 20 cases with acoustic neuroma with sudden-onset sensorineural hearing loss and 828 cases without acoustic neuroma. Fourteen of the 20 acoustic neuroma and 90 of the 828 cases of sudden-onset sensorineural hearing loss showed a trough-shaped audiogram with the greatest amount of hearing loss in the mid-frequency range. The incidence of a trough-shaped audiogram was significantly higher in patients with acoustic neuroma than in those without (p < 0.01). This study suggests that a trough audiogram is a significant finding in patients with sudden-onset sensorineural hearing loss and indicates the presence of acoustic neuroma. [ABSTRACT FROM AUTHOR]

We evaluated the outcomes of and prognostic factors for idiopathic sudden sensorineural hearing loss (ISSNHL) treated with adjuvant hyperbaric oxygen therapy (HBOT). A retrospective review of clinical data was performed for 167 patients with ISSNHL who failed to respond to systemic steroids and were treated by adjuvant HBOT at Shizuoka Saiseikai General Hospital. We analysed the clinical outcomes, the averaged 5-frequency hearing level after systemic steroids, patient age, the interval between post-steroids and pre-HBOT, vertigo as a complication, the presence of diabetes mellitus, smoking history, and hypertension. Overall, after HBOT, complete recovery occurred in 16 (9.6%) of the patients, with definite improvement in 16 (9.6%) and slight improvement in 45 (26.9%). The overall rate of hearing improvement was higher in the study group (77/167 cases, 46.1%) than in the control group (52/160 cases, 32.5%; p = 0.021). If performed appropriately, HBOT should be able to improve hearing in many cases unresponsive to initial therapy. [ABSTRACT FROM AUTHOR]

Cochlin, a product of the COCH gene, is a major constituent of the inner ear extracellular matrix. Type II collagen, a protein that contributes to structural stability, is also a component of this extracellular matrix. In this study, using the postembedding immunogold method, we demonstrate the localization of cochlin and type II collagen in the cochlear duct at the ultrastructural level. The immunolabeling of cochlin was observed in the fibrillar substance in the spiral limbus, beneath the inner sulcus cells, and in the basilar membrane, the spiral prominence and the spiral ligament. Immunolabeling of type II collagen was observed in the same fibrillar substance in the extracellular matrix of the cochlear duct. This localization of cochlin is consistent with the expected localization of type II collagen. The localization of cochlin and type II collagen indicates the important roles played by these proteins in the hearing process. Copyright © 2009 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]