Middle ear and cochlear disorders result in different DPOAE growth behaviour: implications for the differentiation of sound conductive and cochlear hearing loss

Gehr, Daniel D.; Janssen, Thomas; Michaelis, Cornelia; Deingruber, Kerstin; Lamm, Kerstin

doi:10.1016/j.heares.2004.03.018

Cited by 40 publications

(33 citation statements)

References 30 publications

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“…These changes were attributed to alteration of the middle ear (suggested anatomical causes include open bulla, middle ear fluid accumulation, laxity in the ossicular chain). The shape and steepness of the I/O function was consistent with observed changes in I/O functions due to middle ear alteration (injection of saline in the bulla) in guinea pigs (Gehr et al, 2004). One of the four animals anesthetized with Na-P in week three (see Table 1) survived MEM sectioning; however, the DPOAE I/O functions after MEM sectioning were considerably steeper than those recorded before MEM sectioning, consistent with cochlear damage (Gehr et al, 2004), so that animal's data following MEM sectioning were discarded.…”

Section: Resultssupporting

confidence: 87%

Effects of anesthesia on DPOAE level and phase in rats

et al. 2008

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Section: Resultssupporting

confidence: 87%

Effects of anesthesia on DPOAE level and phase in rats

et al. 2008

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“…Middle ear defects are associated with elevated ABR thresholds and abnormal DPOAE, and can contribute to protection from environmental injury (Gehr et al, 2004; Qin et al, 2010). We therefore analyzed middle ears isolated from a subset of wild type (N=5) and Chd7 Gt/+ (N=7) mice exposed to noise (described above).…”

Section: Resultsmentioning

confidence: 99%

Mature middle and inner ears express Chd7 and exhibit distinctive pathologies in a mouse model of CHARGE syndrome

et al. 2011

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Heterozygous mutations in the gene encoding chromodomain-DNA-binding-protein 7 (CHD7) cause CHARGE syndrome, a multiple anomaly condition which includes vestibular dysfunction and hearing loss. Mice with heterozygous Chd7 mutations exhibit semicircular canal dysgenesis and abnormal inner ear neurogenesis, and are an excellent model of CHARGE syndrome. Here we characterized Chd7 expression in mature middle and inner ears, analyzed morphological features of mutant ears and tested whether Chd7 mutant mice have altered responses to noise exposure and correlated those responses to inner and middle ear structure. We found that Chd7 is highly expressed in mature inner and outer hair cells, spiral ganglion neurons, vestibular sensory epithelia and middle ear ossicles. There were no obvious defects in individual hair cell morphology by Prestin immunostaining or scanning electron microscopy, and cochlear innervation appeared normal in Chd7Gt/+ mice. Hearing thresholds by auditory brainstem response (ABR) testing were elevated at 4 and 16 kHz in Chd7Gt/+ mice, and there were reduced distortion product otoacoustic emissions (DPOAE). Exposure of Chd7Gt/+ mice to broadband noise resulted in variable degrees of hair cell loss which inversely correlated with severity of stapedial defects. The degrees of hair cell loss and threshold shifts after noise exposure were more severe in wild type mice than in mutants. Together, these data indicate that Chd7Gt/+ mice have combined conductive and sensorineural hearing loss, correlating with changes in both middle and inner ears.

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“…This result was expected, as the literature shows higher incidence of hearing alteration first in the higher frequencies as they are more susceptible, especially in the region between 3 and 6 KHz, in individuals exposed to noise 1,29,32,33 . 12,37,38 .…”

Section: Discussionmentioning

confidence: 99%

Otoacoustic emissions in young adults exposed to drums noise of a college band

2017

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Purpose: to identify cochlear dysfunction and occurrence of tinnitus in young adults exposed to drums noise of a college band.Methods: the sample included 50 subjects: 25 musicians (study group) and 25 non--musicians (control group). The procedures included anamnesis, pure tone audiometry, acoustic impedance and Transient Evoked Otoacoustic Emissions, Distortion Product Otoacoustic Emissions and Distortion Product Otoacoustic Emissions InputOutput function.Results: positive correlation between the occurrence of tinnitus and the variables exposure time and use of personal stereos was found. Overall, the study group showed significantly lower Transient Evoked Otoacoustic Emissions, when compared to the control group. In the study group, there was a tendency toward worse response in 6 kHz(f2) in Distortion Product Otoacoustic Emissions in both ears. The Distortion Product Otoacoustic Emissions Input-Output function did not differ between groups nor did its slope.Conclusion: in general, otoacoustic emissions were worse in noise-exposed young people (study group) when compared to the unexposed (control group), indicating that the test may be important in early identification of cochlear changes.

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Middle ear and cochlear disorders result in different DPOAE growth behaviour: implications for the differentiation of sound conductive and cochlear hearing loss

Cited by 40 publications

References 30 publications

Effects of anesthesia on DPOAE level and phase in rats

Effects of anesthesia on DPOAE level and phase in rats

Mature middle and inner ears express Chd7 and exhibit distinctive pathologies in a mouse model of CHARGE syndrome

Otoacoustic emissions in young adults exposed to drums noise of a college band

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