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John J. Rosowski - One of the best experts on this subject based on the ideXlab platform.

  • identification of induced and naturally occurring Conductive Hearing Loss in mice using bone conduction
    Hearing Research, 2017
    Co-Authors: David Chhan, John J. Rosowski, Melissa L Mckinnon
    Abstract:

    Abstract While many mouse models of Hearing Loss have been described, a significant fraction of the genetic defects in these models affect both the inner ear and middle ears. A common method used to separate inner-ear (sensory-neural) from middle-ear (Conductive) pathologies in the Hearing clinic is the combination of air-conduction and bone-conduction audiometry. In this report, we investigate the use of air- and bone-conducted evoked auditory brainstem responses to perform a similar separation in mice. We describe a technique by which we stimulate the mouse ear both acoustically and via whole-head vibration. We investigate the sensitivity of this technique to Conductive Hearing Loss by introducing middle-ear lesions in normal Hearing mice. We also use the technique to investigate the presence of an age-related Conductive Hearing Loss in a common mouse model of presbycusis, the BALB/c mouse.

  • Controlled exploration of the effects of Conductive Hearing Loss on wideband acoustic immittance in human cadaveric preparations.
    Hearing Research, 2016
    Co-Authors: Gabrielle R. Merchant, Saumil N. Merchant, John J. Rosowski, Hideko Heidi Nakajima
    Abstract:

    Current clinical practice cannot distinguish, with any degree of certainty, the multiple pathologies that produce Conductive Hearing Loss in patients with an intact tympanic membrane and a well-aerated middle ear without exploratory surgery. The lack of an effective non-surgical diagnostic procedure leads to unnecessary surgery and limits the accuracy of information available during pre-surgical consultations with the patient. A non-invasive measurement to determine the pathology responsible for a Conductive Hearing Loss prior to surgery would be of great value. This work investigates the utility of wideband acoustic immittance (WAI), a non-invasive measure of middle-ear mobility, in the differential diagnosis of pathologies responsible for Conductive Hearing Loss. We focus on determining whether power reflectance (PR), a derivative of WAI, is a possible solution to this problem. PR is a measure of the fraction of sound power reflected from the middle ear when a sound stimulus is presented to the ear canal. PR and other metrics of middle-ear performance (such as ossicular motion via laser Doppler vibrometry) were measured in well-controlled human temporal bone preparations with simulated pathologies. We report measurements before and after simulation of stapes fixation (n = 8), malleus fixation (n = 10), ossicular disarticulation (n = 10), and superior canal dehiscence (n = 8). Our results are consistent with the small set of previously published reflectance measurements made in temporal bones and patients. In this present study, these temporal bone experiments with different middle- and inner-ear pathologies were compared to the initial normal state by analyzing both WAI and ossicular motion, demonstrating that WAI can be a valuable tool in the diagnosis of Conductive Hearing Loss.

  • Measurement of Conductive Hearing Loss in Mice
    Hearing Research, 2009
    Co-Authors: Zhaobing Qin, Melissa Wood, John J. Rosowski
    Abstract:

    Abstract In order to discriminate Conductive Hearing Loss from sensorineural impairment, quantitative measurements were used to evaluate the effect of artificial Conductive pathology on distortion-product otoacoustic emissions (DPOAEs), auditory brainstem responses (ABRs) and laser-Doppler vibrometry (LDV) in mice. The Conductive manipulations were created by perforating the pars flaccida of the tympanic membrane, filling or partially filling the middle-ear cavity with saline, fixing the ossicular chain, and interrupting the incudo-stapedial joint. In the saline-filled and ossicular-fixation groups, averaged DPOAE thresholds increased relative to the control state by 20–36 and 25–39 dB, respectively with the largest threshold shifts occurring at frequencies less than 20 kHz, while averaged ABR thresholds increased 12–19 and 12–25 dB, respectively without the predominant low-frequency effect. Both DPOAE and ABR thresholds were elevated by less than 10 dB in the half-filled saline condition; no significant change was observed after pars flaccida perforation. Conductive pathology generally produced a change in DPOAE threshold in dB that was 1.5–2.5 times larger than the ABR threshold change at frequencies less than 30 kHz; the changes in the two thresholds were nearly equal at the highest frequencies. While mild Conductive pathology (ABR threshold shifts of 10 dB) were associated with significant deceases in DPOAE growth rate. Our LDV measurements are consistent with others and suggest that measurements of umbo velocity are not an accurate indicator of Conductive Hearing Loss produced by ossicular lesions in mice.

  • Conductive Hearing Loss caused by third-window lesions of the inner ear.
    Otology & Neurotology, 2008
    Co-Authors: Saumil N. Merchant, John J. Rosowski
    Abstract:

    Background Various authors have described Conductive Hearing Loss (CHL), defined as an air-bone gap on audiometry, in patients without obvious middle ear pathologic findings. Recent investigations have suggested that many of these cases are due to disorders of the inner ear, resulting in pathologic third windows.

  • Superior semicircular canal dehiscence presenting as Conductive Hearing Loss without vertigo
    Otology and Neurotology, 2004
    Co-Authors: Anthony A Mikulec, Mitchell J. Ramsey, Barbara S. Herrmann, Steven D. Rauch, Hugh D. Curtin, M J Mckenna, John J. Rosowski, Saumil N. Merchant
    Abstract:

    OBJECTIVE: The objective of this study was to describe superior semicircular canal dehiscence (SSCD) presenting as otherwise unexplained Conductive Hearing Loss without vestibular symptoms. STUDY DESIGN: Retrospective. SETTING: Tertiary referral center. PATIENTS: The study comprised 8 patients (10 ears), 5 males and 5 females aged 27 to 59 years. All 10 ears had SSCD on high-resolution computed tomography scan of the temporal bone. DIAGNOSTIC TESTS AND RESULTS: All 10 ears had significant Conductive Hearing Loss. The air-bone gaps were largest in the lower frequencies at 250, 500, and 1000 Hz; the mean gaps for these 3 frequencies for the 10 ears were 49, 37, and 35 dB, respectively. Bone-conduction thresholds below 2000 Hz were negative (-5 dB to -15 dB) at one or more frequencies in 8 of the 10 ears. There were no middle ear abnormalities to explain the air-bone gaps in these 10 ears. Computed tomography scan and laboratory testing indicated lack of middle ear pathology; acoustic reflexes were present, vestibular evoked myogenic potentials (VEMPs) were present with abnormally low thresholds, and umbo velocity measured by laser Doppler vibrometry was above mean normal. Middle ear exploration was negative in six ears; of these six, stapedectomy had been performed in three ears and ossiculoplasty in two ears, but the air-bone gap was unchanged postoperatively. The data are consistent with the hypothesis that the SSCD introduced a third mobile window into the inner ear, which in turn produced the Conductive Hearing Loss by 1) shunting air-conducted sound away from the cochlea, thus elevating air-conduction thresholds; and 2) increasing the difference in impedance between the oval and round windows, thus improving thresholds for bone-conducted sound. CONCLUSION: SSCD can present with a Conductive Hearing Loss that mimics otosclerosis and could explain some cases of persistent Conductive Hearing Loss after uneventful stapedectomy. Audiometric testing with attention to absolute bone-conduction thresholds, acoustic reflex testing, VEMP testing, laser vibrometry of the umbo, and computed tomograph scanning can help to identify patients with SSCD presenting with Conductive Hearing Loss without vertigo.

Saumil N. Merchant - One of the best experts on this subject based on the ideXlab platform.

  • Controlled exploration of the effects of Conductive Hearing Loss on wideband acoustic immittance in human cadaveric preparations.
    Hearing Research, 2016
    Co-Authors: Gabrielle R. Merchant, Saumil N. Merchant, John J. Rosowski, Hideko Heidi Nakajima
    Abstract:

    Current clinical practice cannot distinguish, with any degree of certainty, the multiple pathologies that produce Conductive Hearing Loss in patients with an intact tympanic membrane and a well-aerated middle ear without exploratory surgery. The lack of an effective non-surgical diagnostic procedure leads to unnecessary surgery and limits the accuracy of information available during pre-surgical consultations with the patient. A non-invasive measurement to determine the pathology responsible for a Conductive Hearing Loss prior to surgery would be of great value. This work investigates the utility of wideband acoustic immittance (WAI), a non-invasive measure of middle-ear mobility, in the differential diagnosis of pathologies responsible for Conductive Hearing Loss. We focus on determining whether power reflectance (PR), a derivative of WAI, is a possible solution to this problem. PR is a measure of the fraction of sound power reflected from the middle ear when a sound stimulus is presented to the ear canal. PR and other metrics of middle-ear performance (such as ossicular motion via laser Doppler vibrometry) were measured in well-controlled human temporal bone preparations with simulated pathologies. We report measurements before and after simulation of stapes fixation (n = 8), malleus fixation (n = 10), ossicular disarticulation (n = 10), and superior canal dehiscence (n = 8). Our results are consistent with the small set of previously published reflectance measurements made in temporal bones and patients. In this present study, these temporal bone experiments with different middle- and inner-ear pathologies were compared to the initial normal state by analyzing both WAI and ossicular motion, demonstrating that WAI can be a valuable tool in the diagnosis of Conductive Hearing Loss.

  • Conductive Hearing Loss caused by third-window lesions of the inner ear.
    Otology & Neurotology, 2008
    Co-Authors: Saumil N. Merchant, John J. Rosowski
    Abstract:

    Background Various authors have described Conductive Hearing Loss (CHL), defined as an air-bone gap on audiometry, in patients without obvious middle ear pathologic findings. Recent investigations have suggested that many of these cases are due to disorders of the inner ear, resulting in pathologic third windows.

  • Superior semicircular canal dehiscence presenting as Conductive Hearing Loss without vertigo
    Otology and Neurotology, 2004
    Co-Authors: Anthony A Mikulec, Mitchell J. Ramsey, Barbara S. Herrmann, Steven D. Rauch, Hugh D. Curtin, M J Mckenna, John J. Rosowski, Saumil N. Merchant
    Abstract:

    OBJECTIVE: The objective of this study was to describe superior semicircular canal dehiscence (SSCD) presenting as otherwise unexplained Conductive Hearing Loss without vestibular symptoms. STUDY DESIGN: Retrospective. SETTING: Tertiary referral center. PATIENTS: The study comprised 8 patients (10 ears), 5 males and 5 females aged 27 to 59 years. All 10 ears had SSCD on high-resolution computed tomography scan of the temporal bone. DIAGNOSTIC TESTS AND RESULTS: All 10 ears had significant Conductive Hearing Loss. The air-bone gaps were largest in the lower frequencies at 250, 500, and 1000 Hz; the mean gaps for these 3 frequencies for the 10 ears were 49, 37, and 35 dB, respectively. Bone-conduction thresholds below 2000 Hz were negative (-5 dB to -15 dB) at one or more frequencies in 8 of the 10 ears. There were no middle ear abnormalities to explain the air-bone gaps in these 10 ears. Computed tomography scan and laboratory testing indicated lack of middle ear pathology; acoustic reflexes were present, vestibular evoked myogenic potentials (VEMPs) were present with abnormally low thresholds, and umbo velocity measured by laser Doppler vibrometry was above mean normal. Middle ear exploration was negative in six ears; of these six, stapedectomy had been performed in three ears and ossiculoplasty in two ears, but the air-bone gap was unchanged postoperatively. The data are consistent with the hypothesis that the SSCD introduced a third mobile window into the inner ear, which in turn produced the Conductive Hearing Loss by 1) shunting air-conducted sound away from the cochlea, thus elevating air-conduction thresholds; and 2) increasing the difference in impedance between the oval and round windows, thus improving thresholds for bone-conducted sound. CONCLUSION: SSCD can present with a Conductive Hearing Loss that mimics otosclerosis and could explain some cases of persistent Conductive Hearing Loss after uneventful stapedectomy. Audiometric testing with attention to absolute bone-conduction thresholds, acoustic reflex testing, VEMP testing, laser vibrometry of the umbo, and computed tomograph scanning can help to identify patients with SSCD presenting with Conductive Hearing Loss without vertigo.

  • diagnostic utility of laser doppler vibrometry in Conductive Hearing Loss with normal tympanic membrane
    Otology & Neurotology, 2003
    Co-Authors: John J. Rosowski, Ritvik P Mehta, Saumil N. Merchant
    Abstract:

    Laser-Doppler vibrometry (LDV) has been used to investigate middle ear function in animals (1–3), human temporal bones (4–10), and living humans (11–18). Most investigations using LDV in living humans have been concerned with the sound-induced motion of the tympanic membrane in normal ears (11–16), but some studies have investigated tympanic membrane motion in patients with Hearing Loss (11,16,18) as well as intraoperative measurements of ossicular motion (17). Although the direct measurement of tympanic membrane mobility seems to be a natural tool for investigating Conductive Hearing Loss, little work has been published to explore its possibilities. The potential utility of LDV in the differential diagnosis of Conductive Hearing Loss with an intact tympanic membrane is of interest, because neither otology, audiometry, nor tympanometry can reliably differentiate different ossicular pathologic conditions before surgery (19,20), Reliable presurgical diagnosis of ossicular interruption, stapes fixation, and mallear fixation would permit better preoperative counseling and better surgical planning, and may help decrease the incidence of surgical failures. In the current study, we report preoperative LDV measurements from 17 patients with Conductive Hearing Loss and a normal, intact tympanic membrane. The LDV measurements of the velocity of the tympanic membrane made near the umbo demonstrated a correlation between preoperative tympanic membrane mobility and the intraoperative diagnosis of ossicular interruption or fixation. We also report postsurgical measurements of the mobility of the tympanic membrane after small-fenestra stapedectomy in 10 ears.

Bram Van Dun - One of the best experts on this subject based on the ideXlab platform.

  • consequences of early Conductive Hearing Loss on long term binaural processing
    Ear and Hearing, 2017
    Co-Authors: Kelley Graydon, Gary Rance, Richard C Dowell, Bram Van Dun
    Abstract:

    OBJECTIVES The aim of the study was to investigate the long-term effects of early Conductive Hearing Loss on binaural processing in school-age children. DESIGN One hundred and eighteen children participated in the study, 82 children with a documented history of Conductive Hearing Loss associated with otitis media and 36 controls who had documented histories showing no evidence of otitis media or Conductive Hearing Loss. All children were demonstrated to have normal-Hearing acuity and middle ear function at the time of assessment. The Listening in Spatialized Noise Sentence (LiSN-S) task and the masking level difference (MLD) task were used as the two different measures of binaural interaction ability. RESULTS Children with a history of Conductive Hearing Loss performed significantly poorer than controls on all LiSN-S conditions relying on binaural cues (DV90, p = <0.001 and SV90, p = 0.003). No significant difference was found between the groups in listening conditions without binaural cues. Fifteen children with a Conductive Hearing Loss history (18%) showed results consistent with a spatial processing disorder. No significant difference was observed between the Conductive Hearing Loss group and the controls on the MLD task. Furthermore, no correlations were found between LiSN-S and MLD. CONCLUSIONS Results show a relationship between early Conductive Hearing Loss and listening deficits that persist once Hearing has returned to normal. Results also suggest that the two binaural interaction tasks (LiSN-S and MLD) may be measuring binaural processing at different levels. Findings highlight the need for a screening measure of functional listening ability in children with a history of early otitis media.

  • Consequences of Early Conductive Hearing Loss on Long-Term Binaural Processing.
    Ear and Hearing, 2017
    Co-Authors: Kelley Graydon, Gary Rance, Richard C Dowell, Bram Van Dun
    Abstract:

    OBJECTIVES The aim of the study was to investigate the long-term effects of early Conductive Hearing Loss on binaural processing in school-age children. DESIGN One hundred and eighteen children participated in the study, 82 children with a documented history of Conductive Hearing Loss associated with otitis media and 36 controls who had documented histories showing no evidence of otitis media or Conductive Hearing Loss. All children were demonstrated to have normal-Hearing acuity and middle ear function at the time of assessment. The Listening in Spatialized Noise Sentence (LiSN-S) task and the masking level difference (MLD) task were used as the two different measures of binaural interaction ability. RESULTS Children with a history of Conductive Hearing Loss performed significantly poorer than controls on all LiSN-S conditions relying on binaural cues (DV90, p =

Hugh D. Curtin - One of the best experts on this subject based on the ideXlab platform.

  • Imaging of Conductive Hearing Loss With a Normal Tympanic Membrane
    American Journal of Roentgenology, 2016
    Co-Authors: Hugh D. Curtin
    Abstract:

    OBJECTIVE. This article presents an approach to imaging Conductive Hearing Loss in patients with normal tympanic membranes and discusses entities that should be checked as the radiologist evaluates this potentially complicated issue. CONCLUSION. Conductive Hearing Loss in a patient with a normal tympanic membrane is a complicated condition that requires a careful imaging approach. Imaging should focus on otosclerosis, and possible mimics and potential surgical considerations should be evaluated. The radiologist should examine the ossicular chain and the round window and keep in mind that a defect in the superior semicircular canal can disturb the hydraulic integrity of the labyrinth.

  • Superior semicircular canal dehiscence presenting as Conductive Hearing Loss without vertigo
    Otology and Neurotology, 2004
    Co-Authors: Anthony A Mikulec, Mitchell J. Ramsey, Barbara S. Herrmann, Steven D. Rauch, Hugh D. Curtin, M J Mckenna, John J. Rosowski, Saumil N. Merchant
    Abstract:

    OBJECTIVE: The objective of this study was to describe superior semicircular canal dehiscence (SSCD) presenting as otherwise unexplained Conductive Hearing Loss without vestibular symptoms. STUDY DESIGN: Retrospective. SETTING: Tertiary referral center. PATIENTS: The study comprised 8 patients (10 ears), 5 males and 5 females aged 27 to 59 years. All 10 ears had SSCD on high-resolution computed tomography scan of the temporal bone. DIAGNOSTIC TESTS AND RESULTS: All 10 ears had significant Conductive Hearing Loss. The air-bone gaps were largest in the lower frequencies at 250, 500, and 1000 Hz; the mean gaps for these 3 frequencies for the 10 ears were 49, 37, and 35 dB, respectively. Bone-conduction thresholds below 2000 Hz were negative (-5 dB to -15 dB) at one or more frequencies in 8 of the 10 ears. There were no middle ear abnormalities to explain the air-bone gaps in these 10 ears. Computed tomography scan and laboratory testing indicated lack of middle ear pathology; acoustic reflexes were present, vestibular evoked myogenic potentials (VEMPs) were present with abnormally low thresholds, and umbo velocity measured by laser Doppler vibrometry was above mean normal. Middle ear exploration was negative in six ears; of these six, stapedectomy had been performed in three ears and ossiculoplasty in two ears, but the air-bone gap was unchanged postoperatively. The data are consistent with the hypothesis that the SSCD introduced a third mobile window into the inner ear, which in turn produced the Conductive Hearing Loss by 1) shunting air-conducted sound away from the cochlea, thus elevating air-conduction thresholds; and 2) increasing the difference in impedance between the oval and round windows, thus improving thresholds for bone-conducted sound. CONCLUSION: SSCD can present with a Conductive Hearing Loss that mimics otosclerosis and could explain some cases of persistent Conductive Hearing Loss after uneventful stapedectomy. Audiometric testing with attention to absolute bone-conduction thresholds, acoustic reflex testing, VEMP testing, laser vibrometry of the umbo, and computed tomograph scanning can help to identify patients with SSCD presenting with Conductive Hearing Loss without vertigo.

Kelley Graydon - One of the best experts on this subject based on the ideXlab platform.

  • consequences of early Conductive Hearing Loss on long term binaural processing
    Ear and Hearing, 2017
    Co-Authors: Kelley Graydon, Gary Rance, Richard C Dowell, Bram Van Dun
    Abstract:

    OBJECTIVES The aim of the study was to investigate the long-term effects of early Conductive Hearing Loss on binaural processing in school-age children. DESIGN One hundred and eighteen children participated in the study, 82 children with a documented history of Conductive Hearing Loss associated with otitis media and 36 controls who had documented histories showing no evidence of otitis media or Conductive Hearing Loss. All children were demonstrated to have normal-Hearing acuity and middle ear function at the time of assessment. The Listening in Spatialized Noise Sentence (LiSN-S) task and the masking level difference (MLD) task were used as the two different measures of binaural interaction ability. RESULTS Children with a history of Conductive Hearing Loss performed significantly poorer than controls on all LiSN-S conditions relying on binaural cues (DV90, p = <0.001 and SV90, p = 0.003). No significant difference was found between the groups in listening conditions without binaural cues. Fifteen children with a Conductive Hearing Loss history (18%) showed results consistent with a spatial processing disorder. No significant difference was observed between the Conductive Hearing Loss group and the controls on the MLD task. Furthermore, no correlations were found between LiSN-S and MLD. CONCLUSIONS Results show a relationship between early Conductive Hearing Loss and listening deficits that persist once Hearing has returned to normal. Results also suggest that the two binaural interaction tasks (LiSN-S and MLD) may be measuring binaural processing at different levels. Findings highlight the need for a screening measure of functional listening ability in children with a history of early otitis media.

  • Consequences of Early Conductive Hearing Loss on Long-Term Binaural Processing.
    Ear and Hearing, 2017
    Co-Authors: Kelley Graydon, Gary Rance, Richard C Dowell, Bram Van Dun
    Abstract:

    OBJECTIVES The aim of the study was to investigate the long-term effects of early Conductive Hearing Loss on binaural processing in school-age children. DESIGN One hundred and eighteen children participated in the study, 82 children with a documented history of Conductive Hearing Loss associated with otitis media and 36 controls who had documented histories showing no evidence of otitis media or Conductive Hearing Loss. All children were demonstrated to have normal-Hearing acuity and middle ear function at the time of assessment. The Listening in Spatialized Noise Sentence (LiSN-S) task and the masking level difference (MLD) task were used as the two different measures of binaural interaction ability. RESULTS Children with a history of Conductive Hearing Loss performed significantly poorer than controls on all LiSN-S conditions relying on binaural cues (DV90, p =