Sound coding in the auditory nerve of gerbils

Publication date: Available online 21 May 2016
Source:Hearing Research
Author(s): Antoine Huet, Charlène Batrel, Yong Tang, Gilles Desmadryl, Jing Wang, Jean-Luc Puel, Jérôme Bourien
Gerbils possess a very specialized cochlea in which the low-frequency inner hair cells (IHCs) are contacted by auditory nerve fibers (ANFs) having a high spontaneous rate (SR), whereas high frequency IHCs are innervated by ANFs with a greater SR-based diversity. This specificity makes this animal a unique model to investigate, in the same cochlea, the functional role of different pools of ANFs. The distribution of the characteristic frequencies of fibers shows a clear bimodal shape (with a first mode around 1.5 kHz and a second around 12 kHz) and a notch in the histogram near 3.5 kHz. Whereas the mean thresholds did not significantly differ in the two frequency regions, the shape of the rate-intensity functions does vary significantly with the fiber characteristic frequency. Above 3.5 kHz, the sound-driven rate is greater and the slope of the rate-intensity function is steeper. Interestingly, high-SR fibers show a very good synchronized onset response in quiet (small first-spike latency jitter) but a weak response under noisy conditions. The low-SR fibers exhibit the opposite behavior, with poor onset synchronization in quiet but a robust response in noise. Finally, the greater vulnerability of low-SR fibers to various injuries including noise- and age-related hearing loss is discussed with regard to patients with poor speech intelligibility in noisy environments. Together, these results emphasize the need to perform relevant clinical tests to probe the distribution of ANFs in humans, and develop appropriate techniques of rehabilitation.



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Cochlear perfusion with a viscous fluid

Publication date: Available online 21 May 2016
Source:Hearing Research
Author(s): Yi Wang, Elizabeth S. Olson
The flow of viscous fluid in the cochlea induces shear forces, which could provide benefit in clinical practice, for example to guide cochlear implant insertion or produce static pressure to the cochlear partition or wall. From a research standpoint, studying the effects of a viscous fluid in the cochlea provides data for better understanding cochlear fluid mechanics. However, cochlear perfusion with a viscous fluid may damage the cochlea. In this work we studied the physiological and anatomical effects of perfusing the cochlea with a viscous fluid. Gerbil cochleae were perfused at a rate of 2.4 μL/min with artificial perilymph (AP) and sodium hyaluronate (Healon, HA) in four different concentrations (0.0625%, 0.125%, 0.25%, 0.5%). The different HA concentrations were applied either sequentially in the same cochlea or individually in different cochleae. The perfusion fluid entered from the round window and was withdrawnfrom basal scala vestibuli, in order to perfuse the entire perilymphatic space. Compound action potentials (CAP) were measured after each perfusion. After perfusion with increasing concentrations of HA in the order of increasing viscosity, the CAP thresholds generally increased. The threshold elevation after AP and 0.0625% HA perfusion was small or almost zero, and the 0.125% HA was a borderline case, while the higher concentrations significantly elevated CAP thresholds. Histology of the cochleae perfused with the 0.0625% HA showed an intact Reissner’s membrane, while in cochleae perfused with 0.125% and 0.25% HA Reissner's membrane (RM) was torn. Thus, the CAP threshold elevation was likely due to the broken of RM, which likely caused by the shear stress produced by the flow of the viscous fluid. Our results and analysis indicate that the cochlea can sustain, without a significant CAP threshold shift, up to a 1.5 Pa shear stress. Beside these finding, in the 0.125% and 0.25% HA perfusion cases, a temporary CAP threshold shift was observed, perhaps due to the presence and then clearance of viscous fluid within the cochlea, or to a temporary position shift of the Organ of Corti. After 0.5% HA perfusion, a short latency positive peak (P0) appeared in the CAP wavefrom. This P0 might be due to a change in the cochlea’s traveling-wave pattern, or distortion in the cochlear microphonic.



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Sound coding in the auditory nerve of gerbils

Publication date: Available online 21 May 2016
Source:Hearing Research
Author(s): Antoine Huet, Charlène Batrel, Yong Tang, Gilles Desmadryl, Jing Wang, Jean-Luc Puel, Jérôme Bourien
Gerbils possess a very specialized cochlea in which the low-frequency inner hair cells (IHCs) are contacted by auditory nerve fibers (ANFs) having a high spontaneous rate (SR), whereas high frequency IHCs are innervated by ANFs with a greater SR-based diversity. This specificity makes this animal a unique model to investigate, in the same cochlea, the functional role of different pools of ANFs. The distribution of the characteristic frequencies of fibers shows a clear bimodal shape (with a first mode around 1.5 kHz and a second around 12 kHz) and a notch in the histogram near 3.5 kHz. Whereas the mean thresholds did not significantly differ in the two frequency regions, the shape of the rate-intensity functions does vary significantly with the fiber characteristic frequency. Above 3.5 kHz, the sound-driven rate is greater and the slope of the rate-intensity function is steeper. Interestingly, high-SR fibers show a very good synchronized onset response in quiet (small first-spike latency jitter) but a weak response under noisy conditions. The low-SR fibers exhibit the opposite behavior, with poor onset synchronization in quiet but a robust response in noise. Finally, the greater vulnerability of low-SR fibers to various injuries including noise- and age-related hearing loss is discussed with regard to patients with poor speech intelligibility in noisy environments. Together, these results emphasize the need to perform relevant clinical tests to probe the distribution of ANFs in humans, and develop appropriate techniques of rehabilitation.



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Cochlear perfusion with a viscous fluid

Publication date: Available online 21 May 2016
Source:Hearing Research
Author(s): Yi Wang, Elizabeth S. Olson
The flow of viscous fluid in the cochlea induces shear forces, which could provide benefit in clinical practice, for example to guide cochlear implant insertion or produce static pressure to the cochlear partition or wall. From a research standpoint, studying the effects of a viscous fluid in the cochlea provides data for better understanding cochlear fluid mechanics. However, cochlear perfusion with a viscous fluid may damage the cochlea. In this work we studied the physiological and anatomical effects of perfusing the cochlea with a viscous fluid. Gerbil cochleae were perfused at a rate of 2.4 μL/min with artificial perilymph (AP) and sodium hyaluronate (Healon, HA) in four different concentrations (0.0625%, 0.125%, 0.25%, 0.5%). The different HA concentrations were applied either sequentially in the same cochlea or individually in different cochleae. The perfusion fluid entered from the round window and was withdrawnfrom basal scala vestibuli, in order to perfuse the entire perilymphatic space. Compound action potentials (CAP) were measured after each perfusion. After perfusion with increasing concentrations of HA in the order of increasing viscosity, the CAP thresholds generally increased. The threshold elevation after AP and 0.0625% HA perfusion was small or almost zero, and the 0.125% HA was a borderline case, while the higher concentrations significantly elevated CAP thresholds. Histology of the cochleae perfused with the 0.0625% HA showed an intact Reissner’s membrane, while in cochleae perfused with 0.125% and 0.25% HA Reissner's membrane (RM) was torn. Thus, the CAP threshold elevation was likely due to the broken of RM, which likely caused by the shear stress produced by the flow of the viscous fluid. Our results and analysis indicate that the cochlea can sustain, without a significant CAP threshold shift, up to a 1.5 Pa shear stress. Beside these finding, in the 0.125% and 0.25% HA perfusion cases, a temporary CAP threshold shift was observed, perhaps due to the presence and then clearance of viscous fluid within the cochlea, or to a temporary position shift of the Organ of Corti. After 0.5% HA perfusion, a short latency positive peak (P0) appeared in the CAP wavefrom. This P0 might be due to a change in the cochlea’s traveling-wave pattern, or distortion in the cochlear microphonic.



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Sound coding in the auditory nerve of gerbils

Publication date: Available online 21 May 2016
Source:Hearing Research
Author(s): Antoine Huet, Charlène Batrel, Yong Tang, Gilles Desmadryl, Jing Wang, Jean-Luc Puel, Jérôme Bourien
Gerbils possess a very specialized cochlea in which the low-frequency inner hair cells (IHCs) are contacted by auditory nerve fibers (ANFs) having a high spontaneous rate (SR), whereas high frequency IHCs are innervated by ANFs with a greater SR-based diversity. This specificity makes this animal a unique model to investigate, in the same cochlea, the functional role of different pools of ANFs. The distribution of the characteristic frequencies of fibers shows a clear bimodal shape (with a first mode around 1.5 kHz and a second around 12 kHz) and a notch in the histogram near 3.5 kHz. Whereas the mean thresholds did not significantly differ in the two frequency regions, the shape of the rate-intensity functions does vary significantly with the fiber characteristic frequency. Above 3.5 kHz, the sound-driven rate is greater and the slope of the rate-intensity function is steeper. Interestingly, high-SR fibers show a very good synchronized onset response in quiet (small first-spike latency jitter) but a weak response under noisy conditions. The low-SR fibers exhibit the opposite behavior, with poor onset synchronization in quiet but a robust response in noise. Finally, the greater vulnerability of low-SR fibers to various injuries including noise- and age-related hearing loss is discussed with regard to patients with poor speech intelligibility in noisy environments. Together, these results emphasize the need to perform relevant clinical tests to probe the distribution of ANFs in humans, and develop appropriate techniques of rehabilitation.



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via IFTTT

Cochlear perfusion with a viscous fluid

Publication date: Available online 21 May 2016
Source:Hearing Research
Author(s): Yi Wang, Elizabeth S. Olson
The flow of viscous fluid in the cochlea induces shear forces, which could provide benefit in clinical practice, for example to guide cochlear implant insertion or produce static pressure to the cochlear partition or wall. From a research standpoint, studying the effects of a viscous fluid in the cochlea provides data for better understanding cochlear fluid mechanics. However, cochlear perfusion with a viscous fluid may damage the cochlea. In this work we studied the physiological and anatomical effects of perfusing the cochlea with a viscous fluid. Gerbil cochleae were perfused at a rate of 2.4 μL/min with artificial perilymph (AP) and sodium hyaluronate (Healon, HA) in four different concentrations (0.0625%, 0.125%, 0.25%, 0.5%). The different HA concentrations were applied either sequentially in the same cochlea or individually in different cochleae. The perfusion fluid entered from the round window and was withdrawnfrom basal scala vestibuli, in order to perfuse the entire perilymphatic space. Compound action potentials (CAP) were measured after each perfusion. After perfusion with increasing concentrations of HA in the order of increasing viscosity, the CAP thresholds generally increased. The threshold elevation after AP and 0.0625% HA perfusion was small or almost zero, and the 0.125% HA was a borderline case, while the higher concentrations significantly elevated CAP thresholds. Histology of the cochleae perfused with the 0.0625% HA showed an intact Reissner’s membrane, while in cochleae perfused with 0.125% and 0.25% HA Reissner's membrane (RM) was torn. Thus, the CAP threshold elevation was likely due to the broken of RM, which likely caused by the shear stress produced by the flow of the viscous fluid. Our results and analysis indicate that the cochlea can sustain, without a significant CAP threshold shift, up to a 1.5 Pa shear stress. Beside these finding, in the 0.125% and 0.25% HA perfusion cases, a temporary CAP threshold shift was observed, perhaps due to the presence and then clearance of viscous fluid within the cochlea, or to a temporary position shift of the Organ of Corti. After 0.5% HA perfusion, a short latency positive peak (P0) appeared in the CAP wavefrom. This P0 might be due to a change in the cochlea’s traveling-wave pattern, or distortion in the cochlear microphonic.



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Sound coding in the auditory nerve of gerbils

Publication date: Available online 21 May 2016
Source:Hearing Research
Author(s): Antoine Huet, Charlène Batrel, Yong Tang, Gilles Desmadryl, Jing Wang, Jean-Luc Puel, Jérôme Bourien
Gerbils possess a very specialized cochlea in which the low-frequency inner hair cells (IHCs) are contacted by auditory nerve fibers (ANFs) having a high spontaneous rate (SR), whereas high frequency IHCs are innervated by ANFs with a greater SR-based diversity. This specificity makes this animal a unique model to investigate, in the same cochlea, the functional role of different pools of ANFs. The distribution of the characteristic frequencies of fibers shows a clear bimodal shape (with a first mode around 1.5 kHz and a second around 12 kHz) and a notch in the histogram near 3.5 kHz. Whereas the mean thresholds did not significantly differ in the two frequency regions, the shape of the rate-intensity functions does vary significantly with the fiber characteristic frequency. Above 3.5 kHz, the sound-driven rate is greater and the slope of the rate-intensity function is steeper. Interestingly, high-SR fibers show a very good synchronized onset response in quiet (small first-spike latency jitter) but a weak response under noisy conditions. The low-SR fibers exhibit the opposite behavior, with poor onset synchronization in quiet but a robust response in noise. Finally, the greater vulnerability of low-SR fibers to various injuries including noise- and age-related hearing loss is discussed with regard to patients with poor speech intelligibility in noisy environments. Together, these results emphasize the need to perform relevant clinical tests to probe the distribution of ANFs in humans, and develop appropriate techniques of rehabilitation.



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Sound coding in the auditory nerve of gerbils

Publication date: Available online 21 May 2016
Source:Hearing Research
Author(s): Antoine Huet, Charlène Batrel, Yong Tang, Gilles Desmadryl, Jing Wang, Jean-Luc Puel, Jérôme Bourien
Gerbils possess a very specialized cochlea in which the low-frequency inner hair cells (IHCs) are contacted by auditory nerve fibers (ANFs) having a high spontaneous rate (SR), whereas high frequency IHCs are innervated by ANFs with a greater SR-based diversity. This specificity makes this animal a unique model to investigate, in the same cochlea, the functional role of different pools of ANFs. The distribution of the characteristic frequencies of fibers shows a clear bimodal shape (with a first mode around 1.5 kHz and a second around 12 kHz) and a notch in the histogram near 3.5 kHz. Whereas the mean thresholds did not significantly differ in the two frequency regions, the shape of the rate-intensity functions does vary significantly with the fiber characteristic frequency. Above 3.5 kHz, the sound-driven rate is greater and the slope of the rate-intensity function is steeper. Interestingly, high-SR fibers show a very good synchronized onset response in quiet (small first-spike latency jitter) but a weak response under noisy conditions. The low-SR fibers exhibit the opposite behavior, with poor onset synchronization in quiet but a robust response in noise. Finally, the greater vulnerability of low-SR fibers to various injuries including noise- and age-related hearing loss is discussed with regard to patients with poor speech intelligibility in noisy environments. Together, these results emphasize the need to perform relevant clinical tests to probe the distribution of ANFs in humans, and develop appropriate techniques of rehabilitation.



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Cochlear perfusion with a viscous fluid

Publication date: Available online 21 May 2016
Source:Hearing Research
Author(s): Yi Wang, Elizabeth S. Olson
The flow of viscous fluid in the cochlea induces shear forces, which could provide benefit in clinical practice, for example to guide cochlear implant insertion or produce static pressure to the cochlear partition or wall. From a research standpoint, studying the effects of a viscous fluid in the cochlea provides data for better understanding cochlear fluid mechanics. However, cochlear perfusion with a viscous fluid may damage the cochlea. In this work we studied the physiological and anatomical effects of perfusing the cochlea with a viscous fluid. Gerbil cochleae were perfused at a rate of 2.4 μL/min with artificial perilymph (AP) and sodium hyaluronate (Healon, HA) in four different concentrations (0.0625%, 0.125%, 0.25%, 0.5%). The different HA concentrations were applied either sequentially in the same cochlea or individually in different cochleae. The perfusion fluid entered from the round window and was withdrawnfrom basal scala vestibuli, in order to perfuse the entire perilymphatic space. Compound action potentials (CAP) were measured after each perfusion. After perfusion with increasing concentrations of HA in the order of increasing viscosity, the CAP thresholds generally increased. The threshold elevation after AP and 0.0625% HA perfusion was small or almost zero, and the 0.125% HA was a borderline case, while the higher concentrations significantly elevated CAP thresholds. Histology of the cochleae perfused with the 0.0625% HA showed an intact Reissner’s membrane, while in cochleae perfused with 0.125% and 0.25% HA Reissner's membrane (RM) was torn. Thus, the CAP threshold elevation was likely due to the broken of RM, which likely caused by the shear stress produced by the flow of the viscous fluid. Our results and analysis indicate that the cochlea can sustain, without a significant CAP threshold shift, up to a 1.5 Pa shear stress. Beside these finding, in the 0.125% and 0.25% HA perfusion cases, a temporary CAP threshold shift was observed, perhaps due to the presence and then clearance of viscous fluid within the cochlea, or to a temporary position shift of the Organ of Corti. After 0.5% HA perfusion, a short latency positive peak (P0) appeared in the CAP wavefrom. This P0 might be due to a change in the cochlea’s traveling-wave pattern, or distortion in the cochlear microphonic.



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via IFTTT

Cochlear perfusion with a viscous fluid

Publication date: Available online 21 May 2016
Source:Hearing Research
Author(s): Yi Wang, Elizabeth S. Olson
The flow of viscous fluid in the cochlea induces shear forces, which could provide benefit in clinical practice, for example to guide cochlear implant insertion or produce static pressure to the cochlear partition or wall. From a research standpoint, studying the effects of a viscous fluid in the cochlea provides data for better understanding cochlear fluid mechanics. However, cochlear perfusion with a viscous fluid may damage the cochlea. In this work we studied the physiological and anatomical effects of perfusing the cochlea with a viscous fluid. Gerbil cochleae were perfused at a rate of 2.4 μL/min with artificial perilymph (AP) and sodium hyaluronate (Healon, HA) in four different concentrations (0.0625%, 0.125%, 0.25%, 0.5%). The different HA concentrations were applied either sequentially in the same cochlea or individually in different cochleae. The perfusion fluid entered from the round window and was withdrawnfrom basal scala vestibuli, in order to perfuse the entire perilymphatic space. Compound action potentials (CAP) were measured after each perfusion. After perfusion with increasing concentrations of HA in the order of increasing viscosity, the CAP thresholds generally increased. The threshold elevation after AP and 0.0625% HA perfusion was small or almost zero, and the 0.125% HA was a borderline case, while the higher concentrations significantly elevated CAP thresholds. Histology of the cochleae perfused with the 0.0625% HA showed an intact Reissner’s membrane, while in cochleae perfused with 0.125% and 0.25% HA Reissner's membrane (RM) was torn. Thus, the CAP threshold elevation was likely due to the broken of RM, which likely caused by the shear stress produced by the flow of the viscous fluid. Our results and analysis indicate that the cochlea can sustain, without a significant CAP threshold shift, up to a 1.5 Pa shear stress. Beside these finding, in the 0.125% and 0.25% HA perfusion cases, a temporary CAP threshold shift was observed, perhaps due to the presence and then clearance of viscous fluid within the cochlea, or to a temporary position shift of the Organ of Corti. After 0.5% HA perfusion, a short latency positive peak (P0) appeared in the CAP wavefrom. This P0 might be due to a change in the cochlea’s traveling-wave pattern, or distortion in the cochlear microphonic.



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Measuring motivation using the transtheoretical (stages of change) model: A follow-up study of people who failed an online hearing screening

10.1080/14992027.2016.1182650<br/>Elisabeth Ingo

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Clinical validation of automated audiometry with continuous noise-monitoring in a clinically heterogeneous population outside a sound-treated environment

10.1080/14992027.2016.1178858<br/>Christopher G. Brennan-Jones

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Measuring motivation using the transtheoretical (stages of change) model: A follow-up study of people who failed an online hearing screening

10.1080/14992027.2016.1182650<br/>Elisabeth Ingo

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Clinical validation of automated audiometry with continuous noise-monitoring in a clinically heterogeneous population outside a sound-treated environment

10.1080/14992027.2016.1178858<br/>Christopher G. Brennan-Jones

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Measuring motivation using the transtheoretical (stages of change) model: A follow-up study of people who failed an online hearing screening

10.1080/14992027.2016.1182650<br/>Elisabeth Ingo

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Clinical validation of automated audiometry with continuous noise-monitoring in a clinically heterogeneous population outside a sound-treated environment

10.1080/14992027.2016.1178858<br/>Christopher G. Brennan-Jones

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Measuring motivation using the transtheoretical (stages of change) model: A follow-up study of people who failed an online hearing screening

10.1080/14992027.2016.1182650<br/>Elisabeth Ingo

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Clinical validation of automated audiometry with continuous noise-monitoring in a clinically heterogeneous population outside a sound-treated environment

10.1080/14992027.2016.1178858<br/>Christopher G. Brennan-Jones

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Measuring motivation using the transtheoretical (stages of change) model: A follow-up study of people who failed an online hearing screening

10.1080/14992027.2016.1182650<br/>Elisabeth Ingo

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Clinical validation of automated audiometry with continuous noise-monitoring in a clinically heterogeneous population outside a sound-treated environment

10.1080/14992027.2016.1178858<br/>Christopher G. Brennan-Jones

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Cochlear Implant Impedance Fluctuation in Ménière's Disease: A Case Study.

Cochlear Implant Impedance Fluctuation in Ménière's Disease: A Case Study.

Otol Neurotol. 2016 May 19;

Authors: McNeill C, Eykamp K

Abstract
OBJECTIVE: To contribute to the understanding of hearing fluctuation in Ménière's disease (MD) by disseminating a case study of a cochlear implanted ear with ongoing fluctuation of electrode impedances with episodic tinnitus and no associated vestibular symptoms.
STUDY DESIGN: Retrospective case review.
SETTING: Tertiary referral audiology clinic.
PATIENT: Man, born in 1936, with a total hearing loss in the right ear because of Mumps at age 8 years and a fluctuating progressive hearing loss in the left ear because of Ménière's disease since age 63 years.
INTERVENTION: Sequential bilateral cochlear implantation right ear in August 2002 and left ear in March 2006.
MAIN OUTCOME MEASURE: Impedance measurements of implanted intracochlear electrodes via common ground stimulation using proprietor programming software.
RESULTS: Electrode impedances in the MD showed significant ongoing variation since implantation, whereas the contralateral non-MD ear remained stable over a period of 9 years.
CONCLUSION: Electrode impedances in the ear with MD showed a variation pattern similar to that found in the hearing fluctuation characteristic of the disease. These findings raise the possibility that the same physiological mechanisms of hearing fluctuation may be responsible for intracochlear electrode impedance changes. We hypothesize that impedance fluctuation is because of changes in the permeability of the blood-labyrinth barrier because of cyclic immune activity in the inner ear which alters the electrical resistance between scala tympani and blood.

PMID: 27203844 [PubMed - as supplied by publisher]

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Cochlear Implant Impedance Fluctuation in Ménière's Disease: A Case Study.

Cochlear Implant Impedance Fluctuation in Ménière's Disease: A Case Study.

Otol Neurotol. 2016 May 19;

Authors: McNeill C, Eykamp K

Abstract
OBJECTIVE: To contribute to the understanding of hearing fluctuation in Ménière's disease (MD) by disseminating a case study of a cochlear implanted ear with ongoing fluctuation of electrode impedances with episodic tinnitus and no associated vestibular symptoms.
STUDY DESIGN: Retrospective case review.
SETTING: Tertiary referral audiology clinic.
PATIENT: Man, born in 1936, with a total hearing loss in the right ear because of Mumps at age 8 years and a fluctuating progressive hearing loss in the left ear because of Ménière's disease since age 63 years.
INTERVENTION: Sequential bilateral cochlear implantation right ear in August 2002 and left ear in March 2006.
MAIN OUTCOME MEASURE: Impedance measurements of implanted intracochlear electrodes via common ground stimulation using proprietor programming software.
RESULTS: Electrode impedances in the MD showed significant ongoing variation since implantation, whereas the contralateral non-MD ear remained stable over a period of 9 years.
CONCLUSION: Electrode impedances in the ear with MD showed a variation pattern similar to that found in the hearing fluctuation characteristic of the disease. These findings raise the possibility that the same physiological mechanisms of hearing fluctuation may be responsible for intracochlear electrode impedance changes. We hypothesize that impedance fluctuation is because of changes in the permeability of the blood-labyrinth barrier because of cyclic immune activity in the inner ear which alters the electrical resistance between scala tympani and blood.

PMID: 27203844 [PubMed - as supplied by publisher]

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Prevalence of Cochlear-Facial Dehiscence in a Study of 1,020 Temporal Bone Specimens.

Objective: To determine the prevalence of cochlear-facial dehiscence (CFD) and to examine the influence of otic capsule area, age, sex, and race on CFD. Study Design: Descriptive study of archived temporal bone specimens. Materials and Methods: Targeted sections from 1,020 temporal bone specimens were scanned and examined for CFD. Cochlear-facial partition width (CFPW) and otic capsule area (OCA), a marker of bone thickness, were measured using image analysis software. Demographic data were analyzed using multiple linear regression analysis. Results: The mean CFPW was 0.23 mm (range, 0-0.92 mm; SD, 0.15 mm). Six patients were completely dehiscent (0.59%). Fallopian canal width, age, sex, race, and OCA were found to be significant predictors of CFPW. Age was found to be negatively correlated with CFPW ([beta] = -0.001) (p

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Cochlear Implant Impedance Fluctuation in Meniere's Disease: A Case Study.

Objective: To contribute to the understanding of hearing fluctuation in Meniere's disease (MD) by disseminating a case study of a cochlear implanted ear with ongoing fluctuation of electrode impedances with episodic tinnitus and no associated vestibular symptoms. Study Design: Retrospective case review. Setting: Tertiary referral audiology clinic. Patient: Man, born in 1936, with a total hearing loss in the right ear because of Mumps at age 8 years and a fluctuating progressive hearing loss in the left ear because of Meniere's disease since age 63 years. Intervention: Sequential bilateral cochlear implantation right ear in August 2002 and left ear in March 2006. Main Outcome Measure: Impedance measurements of implanted intracochlear electrodes via common ground stimulation using proprietor programming software. Results: Electrode impedances in the MD showed significant ongoing variation since implantation, whereas the contralateral non-MD ear remained stable over a period of 9 years. Conclusion: Electrode impedances in the ear with MD showed a variation pattern similar to that found in the hearing fluctuation characteristic of the disease. These findings raise the possibility that the same physiological mechanisms of hearing fluctuation may be responsible for intracochlear electrode impedance changes. We hypothesize that impedance fluctuation is because of changes in the permeability of the blood-labyrinth barrier because of cyclic immune activity in the inner ear which alters the electrical resistance between scala tympani and blood. Copyright (C) 2016 by Otology & Neurotology, Inc. Image copyright (C) 2010 Wolters Kluwer Health/Anatomical Chart Company

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Influence of Marital Status on Vestibular Schwannoma in the United States.

Objective: To evaluate the influence of marital status on sporadic vestibular schwannoma (VS) in the United States. Study Design: Analysis of the Surveillance, Epidemiology, and End Results (SEER) database. Setting: National, population-based tumor registry. Subjects and Methods: The SEER database was queried to identify all patients with sporadic VS between 2004 and 2012. Univariable and multivariable analyses were used to identify differences in tumor size at presentation, management strategy, and mortality on the basis of patient marital status. Results: Eight thousand and eight hundred thirty eight patients met inclusion criteria. When comparing patient groups on the basis of marital status, significant differences emerged. Univariable and multivariable analyses revealed that married subjects were older, had smaller tumors at presentation, and had better overall survival compared with non-married patients. After adjusting for baseline differences between groups, non-married subjects were more likely to undergo observation (odds ratio [OR] 1.2, 95% confidence interval [CI] 1.08-1.35, p = 0.009), and were less likely to undergo surgery (OR 0.85, 95% CI 0.76-0.94, p = 0.002) than married subjects, while there was no difference between groups with regard to radiation treatment (OR 0.99, 95% CI 0.88-1.11, p = 0.828). Individual differences between non-married subgroups (i.e., single, separated/divorced, and widowed) are also reported. Conclusion: Marital status influences disease presentation, treatment, and outcome in patients with sporadic VS in the United States. The authors speculate that greater social support of married subjects may drive many of these differences between groups. Future research is needed to further elucidate the underlying causes for these findings as well as the influence of other important demographic variables such as socioeconomic status and general health status. Copyright (C) 2016 by Otology & Neurotology, Inc. Image copyright (C) 2010 Wolters Kluwer Health/Anatomical Chart Company

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Transient Hearing Loss and Objective Tinnitus Induced by Mouth Opening: A Rare Connection Between the Temporomandibular Joint and Middle Ear Space.

Objectives: To describe objective tinnitus complicated with transient low-tone hearing loss coinciding with mouth opening, which was related to the connection between the mandibular fossa and middle ear space. Patients: A 41-year-old man presented with tinnitus, ear fullness, and hearing loss in the left ear on mouth opening. Main Outcome Measures: Clinical case records, audiological data, and radiological analyses including computed tomography (CT) and magnetic resonance imaging. Results: Hearing thresholds on the affected side, which were evaluated with mouth opening, showed elevations of approximately 20 dB in the frequencies below 1000 Hz. Again, peak pressure on the tympanogram deviated negatively to -220 mmH2O under mouth opening without changing peak amplitude. CT showed a connection between the mandibular fossa and middle ear space, as revealed by a gas collection around the joint capsule evaluated in two phases (with and without mouth closing). Ear symptoms resolved after myringotomy. Conclusions: Although an influence of temporomandibular disorder (TMD) on tinnitus perception has been debated, whether this association is causal or fortuitous has remained contentious. The present case showed a unique feature of tinnitus attributed to a connection between the mandibular fossa and middle ear space. Copyright (C) 2016 by Otology & Neurotology, Inc. Image copyright (C) 2010 Wolters Kluwer Health/Anatomical Chart Company

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Maturation of Subjective Visual Vertical in Children.

Objective: The attraction of the subjective visual vertical (SVV) to the side of initial rod presentation has already been described in adults. The aim of this study was to evaluate this phenomenon in children and to analyze the effect of sex and maturation in this population. Study Design: Retrospective cross-sectional study. Setting: Tertiary referral center. Patients: Six hundred and one individuals aged between 4 and 19 years. Intervention: All subjects underwent a complete balance workup. SVV was measured by presenting a laser line 12 times in total darkness with a 45 degrees deviation from the vertical alternatively on the left and the right. The patient was seated and asked to replace the bar vertically with a remote control. Results: On average, SVV was tilted to the side of the rod presentation at each iteration. The cumulative tilt to the side of presentation after 12 measures was higher in the 4 to 7 years age group and decreased progressively with age (25 +/- 2.2 degrees in 4-7 years, n = 109 versus 5 +/- 1.4 in 15-19 years, n = 204, p

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Reactive but not predictive locomotor adaptability is impaired in young parkinson's disease patients

Publication date: Available online 20 May 2016
Source:Gait & Posture
Author(s): María Moreno Catalá, Dirk Woitalla, Adamantios Arampatzis
BackgroundGait and balance disorders are common in Parkinson‘s disease (PD) and major contributors to increased falling risk. Predictive and reactive adjustments can improve recovery performance after gait perturbations. However, these mechanisms have not been investigated in young-onset PD.ObjectiveWe aimed to investigate the effect of gait perturbations on dynamic stability control as well as predictive and reactive adaptability to repeated gait perturbations in young PD patients.MethodsFifteen healthy controls and twenty-five young patients (48±5yrs.) walked on a walkway. By means of a covered exchangeable element, the floor surface condition was altered to induce gait perturbations. The experimental protocol included a baseline on a hard surface, an unexpected trial on a soft surface and an adaptation phase with 5 soft trials to quantify the reactive adaptation. After the first and sixth soft trials, the surface was changed to hard, to examine after-effects and, thus, predictive motor control. Dynamic stability was assessed using the ‘extrapolated center of mass’ concept.ResultsPatients’ unperturbed walking was less stable than controls’ and this persisted in the perturbed trials. Both groups demonstrated after-effects directly after the first perturbation, showing similar predictive responses. However, PD patients did not improve their reactive behavior after repeated perturbations while controls showed clear locomotor adaptation.ConclusionsOur data suggest that more unstable gait patterns and a less effective reactive adaptation to perturbed walking may be a disease-related characteristic in young PD patients. These deficits were related to reduced ability to increase the base of support.



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Reactive but not predictive locomotor adaptability is impaired in young parkinson's disease patients

Publication date: Available online 20 May 2016
Source:Gait & Posture
Author(s): María Moreno Catalá, Dirk Woitalla, Adamantios Arampatzis
BackgroundGait and balance disorders are common in Parkinson‘s disease (PD) and major contributors to increased falling risk. Predictive and reactive adjustments can improve recovery performance after gait perturbations. However, these mechanisms have not been investigated in young-onset PD.ObjectiveWe aimed to investigate the effect of gait perturbations on dynamic stability control as well as predictive and reactive adaptability to repeated gait perturbations in young PD patients.MethodsFifteen healthy controls and twenty-five young patients (48±5yrs.) walked on a walkway. By means of a covered exchangeable element, the floor surface condition was altered to induce gait perturbations. The experimental protocol included a baseline on a hard surface, an unexpected trial on a soft surface and an adaptation phase with 5 soft trials to quantify the reactive adaptation. After the first and sixth soft trials, the surface was changed to hard, to examine after-effects and, thus, predictive motor control. Dynamic stability was assessed using the ‘extrapolated center of mass’ concept.ResultsPatients’ unperturbed walking was less stable than controls’ and this persisted in the perturbed trials. Both groups demonstrated after-effects directly after the first perturbation, showing similar predictive responses. However, PD patients did not improve their reactive behavior after repeated perturbations while controls showed clear locomotor adaptation.ConclusionsOur data suggest that more unstable gait patterns and a less effective reactive adaptation to perturbed walking may be a disease-related characteristic in young PD patients. These deficits were related to reduced ability to increase the base of support.



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Reactive but not predictive locomotor adaptability is impaired in young parkinson's disease patients

Publication date: Available online 20 May 2016
Source:Gait & Posture
Author(s): María Moreno Catalá, Dirk Woitalla, Adamantios Arampatzis
BackgroundGait and balance disorders are common in Parkinson‘s disease (PD) and major contributors to increased falling risk. Predictive and reactive adjustments can improve recovery performance after gait perturbations. However, these mechanisms have not been investigated in young-onset PD.ObjectiveWe aimed to investigate the effect of gait perturbations on dynamic stability control as well as predictive and reactive adaptability to repeated gait perturbations in young PD patients.MethodsFifteen healthy controls and twenty-five young patients (48±5yrs.) walked on a walkway. By means of a covered exchangeable element, the floor surface condition was altered to induce gait perturbations. The experimental protocol included a baseline on a hard surface, an unexpected trial on a soft surface and an adaptation phase with 5 soft trials to quantify the reactive adaptation. After the first and sixth soft trials, the surface was changed to hard, to examine after-effects and, thus, predictive motor control. Dynamic stability was assessed using the ‘extrapolated center of mass’ concept.ResultsPatients’ unperturbed walking was less stable than controls’ and this persisted in the perturbed trials. Both groups demonstrated after-effects directly after the first perturbation, showing similar predictive responses. However, PD patients did not improve their reactive behavior after repeated perturbations while controls showed clear locomotor adaptation.ConclusionsOur data suggest that more unstable gait patterns and a less effective reactive adaptation to perturbed walking may be a disease-related characteristic in young PD patients. These deficits were related to reduced ability to increase the base of support.



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