Relevance of the Implementation of Teeth in Three-Dimensional Vocal Tract Models

Purpose

Recently, efforts have been made to investigate the vocal tract using magnetic resonance imaging (MRI). Due to technical limitations, teeth were omitted in many previous studies on vocal tract acoustics. However, the knowledge of how teeth influence vocal tract acoustics might be important in order to estimate the necessity of implementing teeth in vocal tract models. The aim of this study was therefore to estimate the effect of teeth on vocal tract acoustics.

Method

The acoustic properties of 18 solid (3-dimensional printed) vocal tract models without teeth were compared to the same 18 models including teeth in terms of resonance frequencies (f _Rn). The f _Rn were obtained from the transfer functions of these models excited by white noise at the glottis level. The models were derived from MRI data of 2 trained singers performing 3 different vowel conditions (/i/, /a/, and /u/) in speech and low-pitched and high-pitched singing.

Results

Depending on the oral configuration, models exhibiting side cavities or side branches were characterized by major changes in the transfer function when teeth were implemented via the introduction of pole-zero pairs.

Conclusions

To avoid errors in modeling, teeth should be included in 3-dimensional vocal tract models for acoustic evaluation.

Supplemental Material

http://ift.tt/2wnkzL9

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Relevance of the Implementation of Teeth in Three-Dimensional Vocal Tract Models

Purpose

Recently, efforts have been made to investigate the vocal tract using magnetic resonance imaging (MRI). Due to technical limitations, teeth were omitted in many previous studies on vocal tract acoustics. However, the knowledge of how teeth influence vocal tract acoustics might be important in order to estimate the necessity of implementing teeth in vocal tract models. The aim of this study was therefore to estimate the effect of teeth on vocal tract acoustics.

Method

The acoustic properties of 18 solid (3-dimensional printed) vocal tract models without teeth were compared to the same 18 models including teeth in terms of resonance frequencies (f _Rn). The f _Rn were obtained from the transfer functions of these models excited by white noise at the glottis level. The models were derived from MRI data of 2 trained singers performing 3 different vowel conditions (/i/, /a/, and /u/) in speech and low-pitched and high-pitched singing.

Results

Depending on the oral configuration, models exhibiting side cavities or side branches were characterized by major changes in the transfer function when teeth were implemented via the introduction of pole-zero pairs.

Conclusions

To avoid errors in modeling, teeth should be included in 3-dimensional vocal tract models for acoustic evaluation.

Supplemental Material

http://ift.tt/2wnkzL9

from #Audiology via ola Kala on Inoreader http://article/doi/10.1044/2017_JSLHR-S-16-0395/2654188/Relevance-of-the-Implementation-of-Teeth-in
via IFTTT

Relevance of the Implementation of Teeth in Three-Dimensional Vocal Tract Models

Purpose

Recently, efforts have been made to investigate the vocal tract using magnetic resonance imaging (MRI). Due to technical limitations, teeth were omitted in many previous studies on vocal tract acoustics. However, the knowledge of how teeth influence vocal tract acoustics might be important in order to estimate the necessity of implementing teeth in vocal tract models. The aim of this study was therefore to estimate the effect of teeth on vocal tract acoustics.

Method

The acoustic properties of 18 solid (3-dimensional printed) vocal tract models without teeth were compared to the same 18 models including teeth in terms of resonance frequencies (f _Rn). The f _Rn were obtained from the transfer functions of these models excited by white noise at the glottis level. The models were derived from MRI data of 2 trained singers performing 3 different vowel conditions (/i/, /a/, and /u/) in speech and low-pitched and high-pitched singing.

Results

Depending on the oral configuration, models exhibiting side cavities or side branches were characterized by major changes in the transfer function when teeth were implemented via the introduction of pole-zero pairs.

Conclusions

To avoid errors in modeling, teeth should be included in 3-dimensional vocal tract models for acoustic evaluation.

Supplemental Material

http://ift.tt/2wnkzL9

from #Audiology via xlomafota13 on Inoreader http://article/doi/10.1044/2017_JSLHR-S-16-0395/2654188/Relevance-of-the-Implementation-of-Teeth-in
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Amplitude modulation rate dependent topographic organization of the auditory steady-state response in human auditory cortex

Publication date: Available online 11 September 2017
Source:Hearing Research
Author(s): Nathan Weisz, Chrysoula Lithari
Periodic modulations of an acoustic feature, such as amplitude over a certain frequency range, leads to phase locking of neural responses to the envelope of the modulation. Using electrophysiological methods this neural activity pattern, also called the auditory steady-state response (aSSR), is visible following frequency transformation of the evoked response as a clear spectral peak at the modulation frequency. Despite several studies employing the aSSR that show, for example, strongest responses for ∼40 Hz and an overall right-hemispheric dominance, it has not been investigated so far to what extent within auditory cortex different modulation frequencies elicit aSSRs at a homogenous source or whether the localization of the aSSR is topographically organized in a systematic manner. The latter would be suggested by previous neuroimaging works in monkeys and humans showing a periodotopic organization within and across distinct auditory fields. However, the sluggishness of the signal from these neuroimaging works prohibit inferences with regards to the fine-temporal features of the neural response. In the present study, we employed amplitude-modulated (AM) sounds over a range between 4 and 85 Hz to elicit aSSRs while recording brain activity via magnetoencephalography (MEG). Using beamforming and a fine spatially resolved grid restricted to auditory cortical processing regions, our study revealed a topographic representation of the aSSR that depends on AM rate, in particular in the medial-lateral (bilateral) and posterior-anterior (right auditory cortex) direction. In summary, our findings confirm previous studies that showing different AM rates to elicit maximal response in distinct neural populations. They extend these findings however by also showing that these respective neural ensembles in auditory cortex actually phase lock their activity over a wide modulation frequency range.



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A methodological assessment of studies that use voxel based morphometry to study neural changes in tinnitus patients

Publication date: Available online 11 September 2017
Source:Hearing Research
Author(s): Nicholas Scott-Wittenborn, Omar A. Karadaghy, Jay F. Piccirillo, Jonathan E. Peelle
BackgroundThe scientific understanding of tinnitus and its etiology have transitioned from thinking of tinnitus as solely a peripheral auditory problem to an increasing awareness that cortical networks may play a critical role in tinnitus percept or bother. With this change, studies that seek to use structural brain imaging techniques to better characterize tinnitus patients have become more common. These studies include using voxel-based morphometry (VBM) to determine if there are differences in regional gray matter volume in individuals who suffer from tinnitus and those who do not. However, studies using VBM in patients with tinnitus have produced inconsistent and sometimes contradictory results.ObjectiveThis paper is a systematic review of all of the studies to date that have used VBM to study regional gray matter volume in people with tinnitus, and explores ways in which methodological differences in these studies may account for their heterogeneous results. We also aim to provide guidance on how to conduct future studies using VBM to produce more reproducible results to further our understanding of disease processes such as tinnitus.MethodsStudies about tinnitus and VBM were searched for using PubMed and Embase. These returned 15 and 25 results respectively. Of these, nine met the study criteria and were included for review. An additional 5 studies were identified in the literature as pertinent to the topic at hand and were added to the review, for a total of 13 studies.ResultsThere was significant heterogeneity among the studies in several areas, including inclusion and exclusion criteria, software programs, and statistical analysis. We were not able to find publicly shared data or code for any study.DiscussionThe differences in study design, software analysis, and statistical methodology make direct comparisons between the different studies difficult. Especially problematic are the differences in the inclusion and exclusion criteria of the study, and the statistical design of the studies, both of which could radically alter findings. Thus, heterogeneity has complicated efforts to explore the etiology of tinnitus using structural MRI.ConclusionThere is a pressing need to standardize the use of VBM when evaluating tinnitus patients. While some heterogeneity is expected given the rapid advances in the field, more can be done to ensure that there is internal validity between studies.



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Severe streptomycin ototoxicity in the mouse utricle leads to a flat epithelium but the peripheral neural degeneration is delayed

Publication date: Available online 11 September 2017
Source:Hearing Research
Author(s): Guo-Peng Wang, Ishani Basu, Lisa A. Beyer, Hiu Tung Wong, Donald L. Swiderski, Shu-Sheng Gong, Yehoash Raphael
The damaged vestibular sensory epithelium of mammals has a limited capacity for spontaneous hair cell regeneration, which largely depends on the transdifferentiation of surviving supporting cells. Little is known about the response of vestibular supporting cells to a severe insult. In the present study, we evaluated the impact of a severe ototoxic insult on the histology of utricular supporting cells and the changes in innervation that ensued. We infused a high dose of streptomycin into the mouse posterior semicircular canal to induce a severe lesion in the utricle. Both scanning electron microscopy and light microscopy of plastic sections showed replacement of the normal cytoarchitecture of the epithelial layer with a flat layer of cells in most of the samples. Immunofluorescence staining showed numerous cells in the severely damaged epithelial layer that were negative for hair cell and supporting cell markers. Nerve fibers under the flat epithelium had high density at the 1 month time point but very low density by 3 months. Similarly, the number of vestibular ganglion neurons was unchanged at 1 month after the lesion, but was significantly lower at 3 months. We therefore determined that the mouse utricular epithelium turns into a flat epithelium after a severe lesion, but the degeneration of neural components is slow, suggesting that treatments to restore balance by hair cell regeneration, stem cell therapy or vestibular prosthesis implantation will likely benefit from the short term preservation of the neural substrate.



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Facilitation and refractoriness of the electrically evoked compound action potential

Publication date: Available online 11 September 2017
Source:Hearing Research
Author(s): Matthias Hey, Joachim Müller-Deile, Horst Hessel, Matthijs Killian
In this study we aim to resolve the contributions of facilitation and refractoriness at very short pulse intervals. Measurements of the refractory properties of the electrically evoked compound action potential (ECAP) of the auditory nerve in cochlear implant (CI) users at inter pulse intervals below 300 μs are influenced by facilitation and recovery effects. ECAPs were recorded using masker pulses with a wide range of current levels relative to the probe pulse levels, for three suprathreshold probe levels and pulse intervals of 13 … 200 μs. Evoked potentials were measured for 21 CI patients by using the masked response extraction artifact cancellation procedure.During analysis of the measurements the stimulation current was not used as absolute value, but in relation to the patient's individual ECAP threshold. This enabled a more general approach to describe facilitation as a probe level independent effect. Maximum facilitation was found for all tested inter pulse intervals at masker levels near patient's individual ECAP threshold, independent from probe level. For short inter pulse intervals an increased N1P1 amplitude was measured for subthreshold masker levels down to 120 CL below patient's individual ECAP threshold in contrast to the recreated state.ECAPs recorded with inter pulse intervals up to 200 μs are influenced by facilitation and recovery. Facilitation effects are most pronounced for masker levels at or below ECAP threshold, while recovery effects increase with higher masker levels above ECAP threshold. The local maximum of the ECAP amplitude for masker levels around ECAP threshold can be explained by the mutual influence of maximum facilitation and minimal refractoriness.



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via IFTTT

Amplitude modulation rate dependent topographic organization of the auditory steady-state response in human auditory cortex

Publication date: Available online 11 September 2017
Source:Hearing Research
Author(s): Nathan Weisz, Chrysoula Lithari
Periodic modulations of an acoustic feature, such as amplitude over a certain frequency range, leads to phase locking of neural responses to the envelope of the modulation. Using electrophysiological methods this neural activity pattern, also called the auditory steady-state response (aSSR), is visible following frequency transformation of the evoked response as a clear spectral peak at the modulation frequency. Despite several studies employing the aSSR that show, for example, strongest responses for ∼40 Hz and an overall right-hemispheric dominance, it has not been investigated so far to what extent within auditory cortex different modulation frequencies elicit aSSRs at a homogenous source or whether the localization of the aSSR is topographically organized in a systematic manner. The latter would be suggested by previous neuroimaging works in monkeys and humans showing a periodotopic organization within and across distinct auditory fields. However, the sluggishness of the signal from these neuroimaging works prohibit inferences with regards to the fine-temporal features of the neural response. In the present study, we employed amplitude-modulated (AM) sounds over a range between 4 and 85 Hz to elicit aSSRs while recording brain activity via magnetoencephalography (MEG). Using beamforming and a fine spatially resolved grid restricted to auditory cortical processing regions, our study revealed a topographic representation of the aSSR that depends on AM rate, in particular in the medial-lateral (bilateral) and posterior-anterior (right auditory cortex) direction. In summary, our findings confirm previous studies that showing different AM rates to elicit maximal response in distinct neural populations. They extend these findings however by also showing that these respective neural ensembles in auditory cortex actually phase lock their activity over a wide modulation frequency range.



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A methodological assessment of studies that use voxel based morphometry to study neural changes in tinnitus patients

Publication date: Available online 11 September 2017
Source:Hearing Research
Author(s): Nicholas Scott-Wittenborn, Omar A. Karadaghy, Jay F. Piccirillo, Jonathan E. Peelle
BackgroundThe scientific understanding of tinnitus and its etiology have transitioned from thinking of tinnitus as solely a peripheral auditory problem to an increasing awareness that cortical networks may play a critical role in tinnitus percept or bother. With this change, studies that seek to use structural brain imaging techniques to better characterize tinnitus patients have become more common. These studies include using voxel-based morphometry (VBM) to determine if there are differences in regional gray matter volume in individuals who suffer from tinnitus and those who do not. However, studies using VBM in patients with tinnitus have produced inconsistent and sometimes contradictory results.ObjectiveThis paper is a systematic review of all of the studies to date that have used VBM to study regional gray matter volume in people with tinnitus, and explores ways in which methodological differences in these studies may account for their heterogeneous results. We also aim to provide guidance on how to conduct future studies using VBM to produce more reproducible results to further our understanding of disease processes such as tinnitus.MethodsStudies about tinnitus and VBM were searched for using PubMed and Embase. These returned 15 and 25 results respectively. Of these, nine met the study criteria and were included for review. An additional 5 studies were identified in the literature as pertinent to the topic at hand and were added to the review, for a total of 13 studies.ResultsThere was significant heterogeneity among the studies in several areas, including inclusion and exclusion criteria, software programs, and statistical analysis. We were not able to find publicly shared data or code for any study.DiscussionThe differences in study design, software analysis, and statistical methodology make direct comparisons between the different studies difficult. Especially problematic are the differences in the inclusion and exclusion criteria of the study, and the statistical design of the studies, both of which could radically alter findings. Thus, heterogeneity has complicated efforts to explore the etiology of tinnitus using structural MRI.ConclusionThere is a pressing need to standardize the use of VBM when evaluating tinnitus patients. While some heterogeneity is expected given the rapid advances in the field, more can be done to ensure that there is internal validity between studies.



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via IFTTT

Severe streptomycin ototoxicity in the mouse utricle leads to a flat epithelium but the peripheral neural degeneration is delayed

Publication date: Available online 11 September 2017
Source:Hearing Research
Author(s): Guo-Peng Wang, Ishani Basu, Lisa A. Beyer, Hiu Tung Wong, Donald L. Swiderski, Shu-Sheng Gong, Yehoash Raphael
The damaged vestibular sensory epithelium of mammals has a limited capacity for spontaneous hair cell regeneration, which largely depends on the transdifferentiation of surviving supporting cells. Little is known about the response of vestibular supporting cells to a severe insult. In the present study, we evaluated the impact of a severe ototoxic insult on the histology of utricular supporting cells and the changes in innervation that ensued. We infused a high dose of streptomycin into the mouse posterior semicircular canal to induce a severe lesion in the utricle. Both scanning electron microscopy and light microscopy of plastic sections showed replacement of the normal cytoarchitecture of the epithelial layer with a flat layer of cells in most of the samples. Immunofluorescence staining showed numerous cells in the severely damaged epithelial layer that were negative for hair cell and supporting cell markers. Nerve fibers under the flat epithelium had high density at the 1 month time point but very low density by 3 months. Similarly, the number of vestibular ganglion neurons was unchanged at 1 month after the lesion, but was significantly lower at 3 months. We therefore determined that the mouse utricular epithelium turns into a flat epithelium after a severe lesion, but the degeneration of neural components is slow, suggesting that treatments to restore balance by hair cell regeneration, stem cell therapy or vestibular prosthesis implantation will likely benefit from the short term preservation of the neural substrate.



from #Audiology via ola Kala on Inoreader http://ift.tt/2xXQ4N1
via IFTTT

Facilitation and refractoriness of the electrically evoked compound action potential

Publication date: Available online 11 September 2017
Source:Hearing Research
Author(s): Matthias Hey, Joachim Müller-Deile, Horst Hessel, Matthijs Killian
In this study we aim to resolve the contributions of facilitation and refractoriness at very short pulse intervals. Measurements of the refractory properties of the electrically evoked compound action potential (ECAP) of the auditory nerve in cochlear implant (CI) users at inter pulse intervals below 300 μs are influenced by facilitation and recovery effects. ECAPs were recorded using masker pulses with a wide range of current levels relative to the probe pulse levels, for three suprathreshold probe levels and pulse intervals of 13 … 200 μs. Evoked potentials were measured for 21 CI patients by using the masked response extraction artifact cancellation procedure.During analysis of the measurements the stimulation current was not used as absolute value, but in relation to the patient's individual ECAP threshold. This enabled a more general approach to describe facilitation as a probe level independent effect. Maximum facilitation was found for all tested inter pulse intervals at masker levels near patient's individual ECAP threshold, independent from probe level. For short inter pulse intervals an increased N1P1 amplitude was measured for subthreshold masker levels down to 120 CL below patient's individual ECAP threshold in contrast to the recreated state.ECAPs recorded with inter pulse intervals up to 200 μs are influenced by facilitation and recovery. Facilitation effects are most pronounced for masker levels at or below ECAP threshold, while recovery effects increase with higher masker levels above ECAP threshold. The local maximum of the ECAP amplitude for masker levels around ECAP threshold can be explained by the mutual influence of maximum facilitation and minimal refractoriness.



from #Audiology via ola Kala on Inoreader http://ift.tt/2wnxLPX
via IFTTT

Amplitude modulation rate dependent topographic organization of the auditory steady-state response in human auditory cortex

Publication date: Available online 11 September 2017
Source:Hearing Research
Author(s): Nathan Weisz, Chrysoula Lithari
Periodic modulations of an acoustic feature, such as amplitude over a certain frequency range, leads to phase locking of neural responses to the envelope of the modulation. Using electrophysiological methods this neural activity pattern, also called the auditory steady-state response (aSSR), is visible following frequency transformation of the evoked response as a clear spectral peak at the modulation frequency. Despite several studies employing the aSSR that show, for example, strongest responses for ∼40 Hz and an overall right-hemispheric dominance, it has not been investigated so far to what extent within auditory cortex different modulation frequencies elicit aSSRs at a homogenous source or whether the localization of the aSSR is topographically organized in a systematic manner. The latter would be suggested by previous neuroimaging works in monkeys and humans showing a periodotopic organization within and across distinct auditory fields. However, the sluggishness of the signal from these neuroimaging works prohibit inferences with regards to the fine-temporal features of the neural response. In the present study, we employed amplitude-modulated (AM) sounds over a range between 4 and 85 Hz to elicit aSSRs while recording brain activity via magnetoencephalography (MEG). Using beamforming and a fine spatially resolved grid restricted to auditory cortical processing regions, our study revealed a topographic representation of the aSSR that depends on AM rate, in particular in the medial-lateral (bilateral) and posterior-anterior (right auditory cortex) direction. In summary, our findings confirm previous studies that showing different AM rates to elicit maximal response in distinct neural populations. They extend these findings however by also showing that these respective neural ensembles in auditory cortex actually phase lock their activity over a wide modulation frequency range.



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via IFTTT

A methodological assessment of studies that use voxel based morphometry to study neural changes in tinnitus patients

Publication date: Available online 11 September 2017
Source:Hearing Research
Author(s): Nicholas Scott-Wittenborn, Omar A. Karadaghy, Jay F. Piccirillo, Jonathan E. Peelle
BackgroundThe scientific understanding of tinnitus and its etiology have transitioned from thinking of tinnitus as solely a peripheral auditory problem to an increasing awareness that cortical networks may play a critical role in tinnitus percept or bother. With this change, studies that seek to use structural brain imaging techniques to better characterize tinnitus patients have become more common. These studies include using voxel-based morphometry (VBM) to determine if there are differences in regional gray matter volume in individuals who suffer from tinnitus and those who do not. However, studies using VBM in patients with tinnitus have produced inconsistent and sometimes contradictory results.ObjectiveThis paper is a systematic review of all of the studies to date that have used VBM to study regional gray matter volume in people with tinnitus, and explores ways in which methodological differences in these studies may account for their heterogeneous results. We also aim to provide guidance on how to conduct future studies using VBM to produce more reproducible results to further our understanding of disease processes such as tinnitus.MethodsStudies about tinnitus and VBM were searched for using PubMed and Embase. These returned 15 and 25 results respectively. Of these, nine met the study criteria and were included for review. An additional 5 studies were identified in the literature as pertinent to the topic at hand and were added to the review, for a total of 13 studies.ResultsThere was significant heterogeneity among the studies in several areas, including inclusion and exclusion criteria, software programs, and statistical analysis. We were not able to find publicly shared data or code for any study.DiscussionThe differences in study design, software analysis, and statistical methodology make direct comparisons between the different studies difficult. Especially problematic are the differences in the inclusion and exclusion criteria of the study, and the statistical design of the studies, both of which could radically alter findings. Thus, heterogeneity has complicated efforts to explore the etiology of tinnitus using structural MRI.ConclusionThere is a pressing need to standardize the use of VBM when evaluating tinnitus patients. While some heterogeneity is expected given the rapid advances in the field, more can be done to ensure that there is internal validity between studies.



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via IFTTT

Severe streptomycin ototoxicity in the mouse utricle leads to a flat epithelium but the peripheral neural degeneration is delayed

Publication date: Available online 11 September 2017
Source:Hearing Research
Author(s): Guo-Peng Wang, Ishani Basu, Lisa A. Beyer, Hiu Tung Wong, Donald L. Swiderski, Shu-Sheng Gong, Yehoash Raphael
The damaged vestibular sensory epithelium of mammals has a limited capacity for spontaneous hair cell regeneration, which largely depends on the transdifferentiation of surviving supporting cells. Little is known about the response of vestibular supporting cells to a severe insult. In the present study, we evaluated the impact of a severe ototoxic insult on the histology of utricular supporting cells and the changes in innervation that ensued. We infused a high dose of streptomycin into the mouse posterior semicircular canal to induce a severe lesion in the utricle. Both scanning electron microscopy and light microscopy of plastic sections showed replacement of the normal cytoarchitecture of the epithelial layer with a flat layer of cells in most of the samples. Immunofluorescence staining showed numerous cells in the severely damaged epithelial layer that were negative for hair cell and supporting cell markers. Nerve fibers under the flat epithelium had high density at the 1 month time point but very low density by 3 months. Similarly, the number of vestibular ganglion neurons was unchanged at 1 month after the lesion, but was significantly lower at 3 months. We therefore determined that the mouse utricular epithelium turns into a flat epithelium after a severe lesion, but the degeneration of neural components is slow, suggesting that treatments to restore balance by hair cell regeneration, stem cell therapy or vestibular prosthesis implantation will likely benefit from the short term preservation of the neural substrate.



from #Audiology via xlomafota13 on Inoreader http://ift.tt/2xXQ4N1
via IFTTT

Facilitation and refractoriness of the electrically evoked compound action potential

Publication date: Available online 11 September 2017
Source:Hearing Research
Author(s): Matthias Hey, Joachim Müller-Deile, Horst Hessel, Matthijs Killian
In this study we aim to resolve the contributions of facilitation and refractoriness at very short pulse intervals. Measurements of the refractory properties of the electrically evoked compound action potential (ECAP) of the auditory nerve in cochlear implant (CI) users at inter pulse intervals below 300 μs are influenced by facilitation and recovery effects. ECAPs were recorded using masker pulses with a wide range of current levels relative to the probe pulse levels, for three suprathreshold probe levels and pulse intervals of 13 … 200 μs. Evoked potentials were measured for 21 CI patients by using the masked response extraction artifact cancellation procedure.During analysis of the measurements the stimulation current was not used as absolute value, but in relation to the patient's individual ECAP threshold. This enabled a more general approach to describe facilitation as a probe level independent effect. Maximum facilitation was found for all tested inter pulse intervals at masker levels near patient's individual ECAP threshold, independent from probe level. For short inter pulse intervals an increased N1P1 amplitude was measured for subthreshold masker levels down to 120 CL below patient's individual ECAP threshold in contrast to the recreated state.ECAPs recorded with inter pulse intervals up to 200 μs are influenced by facilitation and recovery. Facilitation effects are most pronounced for masker levels at or below ECAP threshold, while recovery effects increase with higher masker levels above ECAP threshold. The local maximum of the ECAP amplitude for masker levels around ECAP threshold can be explained by the mutual influence of maximum facilitation and minimal refractoriness.



from #Audiology via xlomafota13 on Inoreader http://ift.tt/2wnxLPX
via IFTTT

Amplitude modulation rate dependent topographic organization of the auditory steady-state response in human auditory cortex

Publication date: Available online 11 September 2017
Source:Hearing Research
Author(s): Nathan Weisz, Chrysoula Lithari
Periodic modulations of an acoustic feature, such as amplitude over a certain frequency range, leads to phase locking of neural responses to the envelope of the modulation. Using electrophysiological methods this neural activity pattern, also called the auditory steady-state response (aSSR), is visible following frequency transformation of the evoked response as a clear spectral peak at the modulation frequency. Despite several studies employing the aSSR that show, for example, strongest responses for ∼40 Hz and an overall right-hemispheric dominance, it has not been investigated so far to what extent within auditory cortex different modulation frequencies elicit aSSRs at a homogenous source or whether the localization of the aSSR is topographically organized in a systematic manner. The latter would be suggested by previous neuroimaging works in monkeys and humans showing a periodotopic organization within and across distinct auditory fields. However, the sluggishness of the signal from these neuroimaging works prohibit inferences with regards to the fine-temporal features of the neural response. In the present study, we employed amplitude-modulated (AM) sounds over a range between 4 and 85 Hz to elicit aSSRs while recording brain activity via magnetoencephalography (MEG). Using beamforming and a fine spatially resolved grid restricted to auditory cortical processing regions, our study revealed a topographic representation of the aSSR that depends on AM rate, in particular in the medial-lateral (bilateral) and posterior-anterior (right auditory cortex) direction. In summary, our findings confirm previous studies that showing different AM rates to elicit maximal response in distinct neural populations. They extend these findings however by also showing that these respective neural ensembles in auditory cortex actually phase lock their activity over a wide modulation frequency range.



from #Audiology via ola Kala on Inoreader http://ift.tt/2xXKvhj
via IFTTT

A methodological assessment of studies that use voxel based morphometry to study neural changes in tinnitus patients

Publication date: Available online 11 September 2017
Source:Hearing Research
Author(s): Nicholas Scott-Wittenborn, Omar A. Karadaghy, Jay F. Piccirillo, Jonathan E. Peelle
BackgroundThe scientific understanding of tinnitus and its etiology have transitioned from thinking of tinnitus as solely a peripheral auditory problem to an increasing awareness that cortical networks may play a critical role in tinnitus percept or bother. With this change, studies that seek to use structural brain imaging techniques to better characterize tinnitus patients have become more common. These studies include using voxel-based morphometry (VBM) to determine if there are differences in regional gray matter volume in individuals who suffer from tinnitus and those who do not. However, studies using VBM in patients with tinnitus have produced inconsistent and sometimes contradictory results.ObjectiveThis paper is a systematic review of all of the studies to date that have used VBM to study regional gray matter volume in people with tinnitus, and explores ways in which methodological differences in these studies may account for their heterogeneous results. We also aim to provide guidance on how to conduct future studies using VBM to produce more reproducible results to further our understanding of disease processes such as tinnitus.MethodsStudies about tinnitus and VBM were searched for using PubMed and Embase. These returned 15 and 25 results respectively. Of these, nine met the study criteria and were included for review. An additional 5 studies were identified in the literature as pertinent to the topic at hand and were added to the review, for a total of 13 studies.ResultsThere was significant heterogeneity among the studies in several areas, including inclusion and exclusion criteria, software programs, and statistical analysis. We were not able to find publicly shared data or code for any study.DiscussionThe differences in study design, software analysis, and statistical methodology make direct comparisons between the different studies difficult. Especially problematic are the differences in the inclusion and exclusion criteria of the study, and the statistical design of the studies, both of which could radically alter findings. Thus, heterogeneity has complicated efforts to explore the etiology of tinnitus using structural MRI.ConclusionThere is a pressing need to standardize the use of VBM when evaluating tinnitus patients. While some heterogeneity is expected given the rapid advances in the field, more can be done to ensure that there is internal validity between studies.



from #Audiology via ola Kala on Inoreader http://ift.tt/2wn0hBg
via IFTTT

Severe streptomycin ototoxicity in the mouse utricle leads to a flat epithelium but the peripheral neural degeneration is delayed

Publication date: Available online 11 September 2017
Source:Hearing Research
Author(s): Guo-Peng Wang, Ishani Basu, Lisa A. Beyer, Hiu Tung Wong, Donald L. Swiderski, Shu-Sheng Gong, Yehoash Raphael
The damaged vestibular sensory epithelium of mammals has a limited capacity for spontaneous hair cell regeneration, which largely depends on the transdifferentiation of surviving supporting cells. Little is known about the response of vestibular supporting cells to a severe insult. In the present study, we evaluated the impact of a severe ototoxic insult on the histology of utricular supporting cells and the changes in innervation that ensued. We infused a high dose of streptomycin into the mouse posterior semicircular canal to induce a severe lesion in the utricle. Both scanning electron microscopy and light microscopy of plastic sections showed replacement of the normal cytoarchitecture of the epithelial layer with a flat layer of cells in most of the samples. Immunofluorescence staining showed numerous cells in the severely damaged epithelial layer that were negative for hair cell and supporting cell markers. Nerve fibers under the flat epithelium had high density at the 1 month time point but very low density by 3 months. Similarly, the number of vestibular ganglion neurons was unchanged at 1 month after the lesion, but was significantly lower at 3 months. We therefore determined that the mouse utricular epithelium turns into a flat epithelium after a severe lesion, but the degeneration of neural components is slow, suggesting that treatments to restore balance by hair cell regeneration, stem cell therapy or vestibular prosthesis implantation will likely benefit from the short term preservation of the neural substrate.



from #Audiology via ola Kala on Inoreader http://ift.tt/2xXQ4N1
via IFTTT

Facilitation and refractoriness of the electrically evoked compound action potential

Publication date: Available online 11 September 2017
Source:Hearing Research
Author(s): Matthias Hey, Joachim Müller-Deile, Horst Hessel, Matthijs Killian
In this study we aim to resolve the contributions of facilitation and refractoriness at very short pulse intervals. Measurements of the refractory properties of the electrically evoked compound action potential (ECAP) of the auditory nerve in cochlear implant (CI) users at inter pulse intervals below 300 μs are influenced by facilitation and recovery effects. ECAPs were recorded using masker pulses with a wide range of current levels relative to the probe pulse levels, for three suprathreshold probe levels and pulse intervals of 13 … 200 μs. Evoked potentials were measured for 21 CI patients by using the masked response extraction artifact cancellation procedure.During analysis of the measurements the stimulation current was not used as absolute value, but in relation to the patient's individual ECAP threshold. This enabled a more general approach to describe facilitation as a probe level independent effect. Maximum facilitation was found for all tested inter pulse intervals at masker levels near patient's individual ECAP threshold, independent from probe level. For short inter pulse intervals an increased N1P1 amplitude was measured for subthreshold masker levels down to 120 CL below patient's individual ECAP threshold in contrast to the recreated state.ECAPs recorded with inter pulse intervals up to 200 μs are influenced by facilitation and recovery. Facilitation effects are most pronounced for masker levels at or below ECAP threshold, while recovery effects increase with higher masker levels above ECAP threshold. The local maximum of the ECAP amplitude for masker levels around ECAP threshold can be explained by the mutual influence of maximum facilitation and minimal refractoriness.



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Amplitude modulation rate dependent topographic organization of the auditory steady-state response in human auditory cortex

Publication date: Available online 11 September 2017
Source:Hearing Research
Author(s): Nathan Weisz, Chrysoula Lithari
Periodic modulations of an acoustic feature, such as amplitude over a certain frequency range, leads to phase locking of neural responses to the envelope of the modulation. Using electrophysiological methods this neural activity pattern, also called the auditory steady-state response (aSSR), is visible following frequency transformation of the evoked response as a clear spectral peak at the modulation frequency. Despite several studies employing the aSSR that show, for example, strongest responses for ∼40 Hz and an overall right-hemispheric dominance, it has not been investigated so far to what extent within auditory cortex different modulation frequencies elicit aSSRs at a homogenous source or whether the localization of the aSSR is topographically organized in a systematic manner. The latter would be suggested by previous neuroimaging works in monkeys and humans showing a periodotopic organization within and across distinct auditory fields. However, the sluggishness of the signal from these neuroimaging works prohibit inferences with regards to the fine-temporal features of the neural response. In the present study, we employed amplitude-modulated (AM) sounds over a range between 4 and 85 Hz to elicit aSSRs while recording brain activity via magnetoencephalography (MEG). Using beamforming and a fine spatially resolved grid restricted to auditory cortical processing regions, our study revealed a topographic representation of the aSSR that depends on AM rate, in particular in the medial-lateral (bilateral) and posterior-anterior (right auditory cortex) direction. In summary, our findings confirm previous studies that showing different AM rates to elicit maximal response in distinct neural populations. They extend these findings however by also showing that these respective neural ensembles in auditory cortex actually phase lock their activity over a wide modulation frequency range.



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A methodological assessment of studies that use voxel based morphometry to study neural changes in tinnitus patients

Publication date: Available online 11 September 2017
Source:Hearing Research
Author(s): Nicholas Scott-Wittenborn, Omar A. Karadaghy, Jay F. Piccirillo, Jonathan E. Peelle
BackgroundThe scientific understanding of tinnitus and its etiology have transitioned from thinking of tinnitus as solely a peripheral auditory problem to an increasing awareness that cortical networks may play a critical role in tinnitus percept or bother. With this change, studies that seek to use structural brain imaging techniques to better characterize tinnitus patients have become more common. These studies include using voxel-based morphometry (VBM) to determine if there are differences in regional gray matter volume in individuals who suffer from tinnitus and those who do not. However, studies using VBM in patients with tinnitus have produced inconsistent and sometimes contradictory results.ObjectiveThis paper is a systematic review of all of the studies to date that have used VBM to study regional gray matter volume in people with tinnitus, and explores ways in which methodological differences in these studies may account for their heterogeneous results. We also aim to provide guidance on how to conduct future studies using VBM to produce more reproducible results to further our understanding of disease processes such as tinnitus.MethodsStudies about tinnitus and VBM were searched for using PubMed and Embase. These returned 15 and 25 results respectively. Of these, nine met the study criteria and were included for review. An additional 5 studies were identified in the literature as pertinent to the topic at hand and were added to the review, for a total of 13 studies.ResultsThere was significant heterogeneity among the studies in several areas, including inclusion and exclusion criteria, software programs, and statistical analysis. We were not able to find publicly shared data or code for any study.DiscussionThe differences in study design, software analysis, and statistical methodology make direct comparisons between the different studies difficult. Especially problematic are the differences in the inclusion and exclusion criteria of the study, and the statistical design of the studies, both of which could radically alter findings. Thus, heterogeneity has complicated efforts to explore the etiology of tinnitus using structural MRI.ConclusionThere is a pressing need to standardize the use of VBM when evaluating tinnitus patients. While some heterogeneity is expected given the rapid advances in the field, more can be done to ensure that there is internal validity between studies.



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Severe streptomycin ototoxicity in the mouse utricle leads to a flat epithelium but the peripheral neural degeneration is delayed

Publication date: Available online 11 September 2017
Source:Hearing Research
Author(s): Guo-Peng Wang, Ishani Basu, Lisa A. Beyer, Hiu Tung Wong, Donald L. Swiderski, Shu-Sheng Gong, Yehoash Raphael
The damaged vestibular sensory epithelium of mammals has a limited capacity for spontaneous hair cell regeneration, which largely depends on the transdifferentiation of surviving supporting cells. Little is known about the response of vestibular supporting cells to a severe insult. In the present study, we evaluated the impact of a severe ototoxic insult on the histology of utricular supporting cells and the changes in innervation that ensued. We infused a high dose of streptomycin into the mouse posterior semicircular canal to induce a severe lesion in the utricle. Both scanning electron microscopy and light microscopy of plastic sections showed replacement of the normal cytoarchitecture of the epithelial layer with a flat layer of cells in most of the samples. Immunofluorescence staining showed numerous cells in the severely damaged epithelial layer that were negative for hair cell and supporting cell markers. Nerve fibers under the flat epithelium had high density at the 1 month time point but very low density by 3 months. Similarly, the number of vestibular ganglion neurons was unchanged at 1 month after the lesion, but was significantly lower at 3 months. We therefore determined that the mouse utricular epithelium turns into a flat epithelium after a severe lesion, but the degeneration of neural components is slow, suggesting that treatments to restore balance by hair cell regeneration, stem cell therapy or vestibular prosthesis implantation will likely benefit from the short term preservation of the neural substrate.



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Facilitation and refractoriness of the electrically evoked compound action potential

Publication date: Available online 11 September 2017
Source:Hearing Research
Author(s): Matthias Hey, Joachim Müller-Deile, Horst Hessel, Matthijs Killian
In this study we aim to resolve the contributions of facilitation and refractoriness at very short pulse intervals. Measurements of the refractory properties of the electrically evoked compound action potential (ECAP) of the auditory nerve in cochlear implant (CI) users at inter pulse intervals below 300 μs are influenced by facilitation and recovery effects. ECAPs were recorded using masker pulses with a wide range of current levels relative to the probe pulse levels, for three suprathreshold probe levels and pulse intervals of 13 … 200 μs. Evoked potentials were measured for 21 CI patients by using the masked response extraction artifact cancellation procedure.During analysis of the measurements the stimulation current was not used as absolute value, but in relation to the patient's individual ECAP threshold. This enabled a more general approach to describe facilitation as a probe level independent effect. Maximum facilitation was found for all tested inter pulse intervals at masker levels near patient's individual ECAP threshold, independent from probe level. For short inter pulse intervals an increased N1P1 amplitude was measured for subthreshold masker levels down to 120 CL below patient's individual ECAP threshold in contrast to the recreated state.ECAPs recorded with inter pulse intervals up to 200 μs are influenced by facilitation and recovery. Facilitation effects are most pronounced for masker levels at or below ECAP threshold, while recovery effects increase with higher masker levels above ECAP threshold. The local maximum of the ECAP amplitude for masker levels around ECAP threshold can be explained by the mutual influence of maximum facilitation and minimal refractoriness.



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Estimating Vocal Effort from the Aerodynamics of Labial Fricatives: A Feasibility Study

Publication date: Available online 12 September 2017
Source:Journal of Voice
Author(s): Yohann Meynadier, Anita El Hajj, Michel Pitermann, Thierry Legou, Antoine Giovanni
Objective and HypothesisVocal effort in loud voice is produced with increased subglottal pressure during vowels and increased supraglottal pressure during consonants. In the paper, our main objective is to check whether it was supported by a parallel increase in the airflow resistance of the laryngeal articulator and of the supralaryngeal articulator, here the lips.Study Design and MethodFor this comparison, our choice fell on the fricative consonants, as their production allows perfectly synchronous air pressure and airflow measurements. Also, the calculation of the real instantaneous aerodynamic resistance is possible with fricatives—as it is with vowels—whereas it is not possible with plosives. The present feasibility study on a healthy subject is based on direct subglottal and intraoral pressures and airflow measured for /f/ or /v/ and from the contiguous vowel produced in VCVCV nonsense words at different levels of intensity.Results and ConclusionThe results support that the airflow resistances at the lips and that at the larynx are quite parallel. The airflow resistance at the lips during labial fricative production could provide a good picture of the laryngeal resistance during the production of continuous speech. This suggests clinical applications using both noninvasive inferred measurements of subglottal pressure variation and direct noninferred airflow measurements from more natural speech production tasks.



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Vertigo in Vestibular Schwannoma Patients Due to Other Pathologies.

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Vertigo in Vestibular Schwannoma Patients Due to Other Pathologies.

Otol Neurotol. 2017 Sep 07;:

Authors: Sahyouni R, Moshtaghi O, Haidar YM, Mahboubi H, Moshtaghi A, Lin HW, Djalilian HR

Abstract
OBJECTIVE: To report findings from a cohort of vestibular schwannoma (VS) patients presenting with vertigo from a secondary comorbid vestibular disorder; and to discuss management strategies for this subset of patients presenting with both episodic vertigo and VS.
PATIENTS: All VS patients who presented with vertigo as the primary symptom from 2012 to 2015 and endorsing no other major complaints were examined.
INTERVENTION: Treatment with migraine lifestyle and prophylactic therapy, or Epley maneuver.
MAIN OUTCOME MEASURE: Resolution of vertigo following medical treatment alone.
RESULTS: Of the nine patients studied, seven (78%) suffered from vestibular migraine, and two (22%) experienced benign positional vertigo. All patients experienced complete resolution of symptoms after treatment. As a result of symptomatic improvement, seven patients (78%) avoided surgery in favor of observation, while two patients (22%) underwent radiosurgery due to continued tumor growth and other nonvertigo symptoms.
CONCLUSION: VS patients can sometimes present with a history of recurrent episodic vertigo. The etiology of the vertigo could be due to the tumor itself or may be due to an underlying comorbidity such as vestibular migraine or benign positional vertigo. VS patients presenting with vertigo should undergo a standard vertigo history and examination to identify other potential causes of vertigo. Most VS patients in our cohort avoided intervention and had resolution of their vertigo.

PMID: 28891872 [PubMed - as supplied by publisher]

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Using tablet-based technology to deliver time-efficient ototoxicity monitoring

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Using tablet-based technology to deliver time-efficient ototoxicity monitoring

.


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Using tablet-based technology to deliver time-efficient ototoxicity monitoring

.


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Prevalence of hearing loss and associated factors in subjects with normal otoscopy: a national cross-sectional study.

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Prevalence of hearing loss and associated factors in subjects with normal otoscopy: a national cross-sectional study.

Int J Audiol. 2017 Sep 11;:1-7

Authors: Park HJ, Yoo MH, Woo SY, Kim SW, Cho YS

Abstract
OBJECTIVE: To report the prevalence of hearing loss (HL) and associated factors in a nationwide study.
DESIGN: Cross-sectional study.
STUDY SAMPLE: We investigated the prevalence of HL in 10,845 participants ≥12 years of age and analysed the associated factors with HL from 7434 participants ≥40 years of age.
RESULTS: The prevalence of worse ear HL was 21.9% (1.2% in youngest and 81.9% in oldest) and that of better ear was 12.5% (none in youngest and 65.3% in oldest). Based on the worse ear HL, the prevalence of HL was more common in men, and related with low education and income. In univariable analysis, hypertension, smoking, diabetes, depressive mood, stroke or cardiac disease, anaemia, hypercholesterolaemia and underweight showed positive associations with HL, and alcohol consumption and regular walking showed negative associations with HL. There were five associated factors in multivariable analysis, including smoking (OR =1.36 for smokers with <20 pack years; OR =1.55 for smokers with ≥20 pack years), noise exposure at workplace (OR = 1.28), stroke (OR = 1.72), anaemia (OR = 1.36) and depressive mood (OR = 1.29).
CONCLUSION: Prevention of smoking and reduction of noise, as well as awareness of the association with stroke, anaemia and depression would help to reduce the burden of HL.

PMID: 28889780 [PubMed - as supplied by publisher]

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Prevalence of hearing loss and associated factors in subjects with normal otoscopy: a national cross-sectional study.

Related Articles

Prevalence of hearing loss and associated factors in subjects with normal otoscopy: a national cross-sectional study.

Int J Audiol. 2017 Sep 11;:1-7

Authors: Park HJ, Yoo MH, Woo SY, Kim SW, Cho YS

Abstract
OBJECTIVE: To report the prevalence of hearing loss (HL) and associated factors in a nationwide study.
DESIGN: Cross-sectional study.
STUDY SAMPLE: We investigated the prevalence of HL in 10,845 participants ≥12 years of age and analysed the associated factors with HL from 7434 participants ≥40 years of age.
RESULTS: The prevalence of worse ear HL was 21.9% (1.2% in youngest and 81.9% in oldest) and that of better ear was 12.5% (none in youngest and 65.3% in oldest). Based on the worse ear HL, the prevalence of HL was more common in men, and related with low education and income. In univariable analysis, hypertension, smoking, diabetes, depressive mood, stroke or cardiac disease, anaemia, hypercholesterolaemia and underweight showed positive associations with HL, and alcohol consumption and regular walking showed negative associations with HL. There were five associated factors in multivariable analysis, including smoking (OR =1.36 for smokers with <20 pack years; OR =1.55 for smokers with ≥20 pack years), noise exposure at workplace (OR = 1.28), stroke (OR = 1.72), anaemia (OR = 1.36) and depressive mood (OR = 1.29).
CONCLUSION: Prevention of smoking and reduction of noise, as well as awareness of the association with stroke, anaemia and depression would help to reduce the burden of HL.

PMID: 28889780 [PubMed - as supplied by publisher]

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Vestibular rehabilitation following surgical repair for Superior Canal Dehiscence Syndrome: A complicated case report.

Vestibular rehabilitation following surgical repair for Superior Canal Dehiscence Syndrome: A complicated case report.

Physiother Theory Pract. 2017 Sep 11;:1-11

Authors: Carender WJ, Grzesiak M

Abstract
Superior Canal Dehiscence Syndrome (SCDS) causes auditory and vestibular symptoms. Following surgical repair of the dehiscence, patients often experience dizziness and imbalance. This case report describes a postoperative vestibular exercise program, focusing on the principles of central compensation and habituation, and how it was modified for a patient with delayed progress secondary to strabismus and visual vertigo. A 63-year-old male with history of strabismus eye surgery, right hearing loss, aural fullness, and sensitivity to loud sounds was referred for vestibular rehabilitation (VR). He was seen for one preoperative and six postoperative PT visits over eight months. Outcome measures two weeks postoperative were as follows: Dizziness Handicap Inventory (DHI) 38/100; Timed Up & Go (TUG) 9.92 seconds; Dynamic Gait Index (DGI) 16/24; and a 3-line difference in Dynamic Visual Acuity (DVA). Improved outcomes at discharge included: DHI 18/100; TUG 6.87 seconds; DGI 23/24; and 1-line difference in DVA. He was able to return to work and previously enjoyed recreational activities. Postoperative vestibular rehabilitation programs are functionally and symptomatically beneficial following surgical repair for SCDS. Deviations from expected recovery should be addressed to achieve optimal outcomes as demonstrated in this complicated case report.

PMID: 28891720 [PubMed - as supplied by publisher]

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Motor function deficits in the 12 month-old female 5xFAD mouse model of Alzheimer's disease.

Related Articles

Motor function deficits in the 12 month-old female 5xFAD mouse model of Alzheimer's disease.

Behav Brain Res. 2017 Sep 07;:

Authors: O'Leary TP, Robertson A, Chipman PH, Rafuse VF, Brown RE

Abstract
Motor problems occur early in some patients with Alzheimer's disease (AD) and as the disease progresses many patients develop motor dysfunction. Motor dysfunction has been reported in some mouse models of AD, including the 5xFAD mouse, thus this model may be particularly useful for studying motor dysfunction in AD. In order to determine the extent of motor dysfunction in these mice, we tested 11-13 month old female 5xFAD and wildtype (WT) control mice in a battery of motor behaviour tasks. The 5xFAD mice showed hind limb clasping, weighed less and had slower righting reflexes than WT mice. In the open field, the 5xFAD mice travelled a shorter distance than the WT mice, spent less time moving and had a slower movement speed. The 5xFAD mice fell faster than the WT mice from the balance beam, wire suspension, grid suspension and rotarod tasks, indicating dysfunctions in balance, grip strength, motor co-ordination and motor learning. The 5xFAD mice had a short, shuffling gait with a shorter stride length than WT mice and had a slower swim speed. The 5xFAD mice also failed to show an acoustic startle response, likely due to motor dysfunction and previously reported hearing impairment. The 5xFAD mice did not show deficits in the ability of peripheral motor nerves to drive muscle output, suggesting that motor impairments are not due to dysfunction in peripheral motor nerves. These results indicate that the aged 5xFAD mice are deficient in numerous motor behaviours, and suggest that these mice may prove to be a good model for studying the mechanisms of motor dysfunction in AD, and motor behaviour might prove useful for assessing the efficacy of AD therapeutics. Motor dysfunction in 5xFAD mice must also be considered in behavioural tests of sensory and cognitive function so that performance is not confounded by impaired locomotor or swimming behaviour.

PMID: 28890389 [PubMed - as supplied by publisher]

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Vestibular rehabilitation following surgical repair for Superior Canal Dehiscence Syndrome: A complicated case report.

Vestibular rehabilitation following surgical repair for Superior Canal Dehiscence Syndrome: A complicated case report.

Physiother Theory Pract. 2017 Sep 11;:1-11

Authors: Carender WJ, Grzesiak M

Abstract
Superior Canal Dehiscence Syndrome (SCDS) causes auditory and vestibular symptoms. Following surgical repair of the dehiscence, patients often experience dizziness and imbalance. This case report describes a postoperative vestibular exercise program, focusing on the principles of central compensation and habituation, and how it was modified for a patient with delayed progress secondary to strabismus and visual vertigo. A 63-year-old male with history of strabismus eye surgery, right hearing loss, aural fullness, and sensitivity to loud sounds was referred for vestibular rehabilitation (VR). He was seen for one preoperative and six postoperative PT visits over eight months. Outcome measures two weeks postoperative were as follows: Dizziness Handicap Inventory (DHI) 38/100; Timed Up & Go (TUG) 9.92 seconds; Dynamic Gait Index (DGI) 16/24; and a 3-line difference in Dynamic Visual Acuity (DVA). Improved outcomes at discharge included: DHI 18/100; TUG 6.87 seconds; DGI 23/24; and 1-line difference in DVA. He was able to return to work and previously enjoyed recreational activities. Postoperative vestibular rehabilitation programs are functionally and symptomatically beneficial following surgical repair for SCDS. Deviations from expected recovery should be addressed to achieve optimal outcomes as demonstrated in this complicated case report.

PMID: 28891720 [PubMed - as supplied by publisher]

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Motor function deficits in the 12 month-old female 5xFAD mouse model of Alzheimer's disease.

Related Articles

Motor function deficits in the 12 month-old female 5xFAD mouse model of Alzheimer's disease.

Behav Brain Res. 2017 Sep 07;:

Authors: O'Leary TP, Robertson A, Chipman PH, Rafuse VF, Brown RE

Abstract
Motor problems occur early in some patients with Alzheimer's disease (AD) and as the disease progresses many patients develop motor dysfunction. Motor dysfunction has been reported in some mouse models of AD, including the 5xFAD mouse, thus this model may be particularly useful for studying motor dysfunction in AD. In order to determine the extent of motor dysfunction in these mice, we tested 11-13 month old female 5xFAD and wildtype (WT) control mice in a battery of motor behaviour tasks. The 5xFAD mice showed hind limb clasping, weighed less and had slower righting reflexes than WT mice. In the open field, the 5xFAD mice travelled a shorter distance than the WT mice, spent less time moving and had a slower movement speed. The 5xFAD mice fell faster than the WT mice from the balance beam, wire suspension, grid suspension and rotarod tasks, indicating dysfunctions in balance, grip strength, motor co-ordination and motor learning. The 5xFAD mice had a short, shuffling gait with a shorter stride length than WT mice and had a slower swim speed. The 5xFAD mice also failed to show an acoustic startle response, likely due to motor dysfunction and previously reported hearing impairment. The 5xFAD mice did not show deficits in the ability of peripheral motor nerves to drive muscle output, suggesting that motor impairments are not due to dysfunction in peripheral motor nerves. These results indicate that the aged 5xFAD mice are deficient in numerous motor behaviours, and suggest that these mice may prove to be a good model for studying the mechanisms of motor dysfunction in AD, and motor behaviour might prove useful for assessing the efficacy of AD therapeutics. Motor dysfunction in 5xFAD mice must also be considered in behavioural tests of sensory and cognitive function so that performance is not confounded by impaired locomotor or swimming behaviour.

PMID: 28890389 [PubMed - as supplied by publisher]

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Prevalence of hearing loss and associated factors in subjects with normal otoscopy: a national cross-sectional study.

Related Articles

Prevalence of hearing loss and associated factors in subjects with normal otoscopy: a national cross-sectional study.

Int J Audiol. 2017 Sep 11;:1-7

Authors: Park HJ, Yoo MH, Woo SY, Kim SW, Cho YS

Abstract
OBJECTIVE: To report the prevalence of hearing loss (HL) and associated factors in a nationwide study.
DESIGN: Cross-sectional study.
STUDY SAMPLE: We investigated the prevalence of HL in 10,845 participants ≥12 years of age and analysed the associated factors with HL from 7434 participants ≥40 years of age.
RESULTS: The prevalence of worse ear HL was 21.9% (1.2% in youngest and 81.9% in oldest) and that of better ear was 12.5% (none in youngest and 65.3% in oldest). Based on the worse ear HL, the prevalence of HL was more common in men, and related with low education and income. In univariable analysis, hypertension, smoking, diabetes, depressive mood, stroke or cardiac disease, anaemia, hypercholesterolaemia and underweight showed positive associations with HL, and alcohol consumption and regular walking showed negative associations with HL. There were five associated factors in multivariable analysis, including smoking (OR =1.36 for smokers with <20 pack years; OR =1.55 for smokers with ≥20 pack years), noise exposure at workplace (OR = 1.28), stroke (OR = 1.72), anaemia (OR = 1.36) and depressive mood (OR = 1.29).
CONCLUSION: Prevention of smoking and reduction of noise, as well as awareness of the association with stroke, anaemia and depression would help to reduce the burden of HL.

PMID: 28889780 [PubMed - as supplied by publisher]

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Prevalence of hearing loss and associated factors in subjects with normal otoscopy: a national cross-sectional study.

Related Articles

Prevalence of hearing loss and associated factors in subjects with normal otoscopy: a national cross-sectional study.

Int J Audiol. 2017 Sep 11;:1-7

Authors: Park HJ, Yoo MH, Woo SY, Kim SW, Cho YS

Abstract
OBJECTIVE: To report the prevalence of hearing loss (HL) and associated factors in a nationwide study.
DESIGN: Cross-sectional study.
STUDY SAMPLE: We investigated the prevalence of HL in 10,845 participants ≥12 years of age and analysed the associated factors with HL from 7434 participants ≥40 years of age.
RESULTS: The prevalence of worse ear HL was 21.9% (1.2% in youngest and 81.9% in oldest) and that of better ear was 12.5% (none in youngest and 65.3% in oldest). Based on the worse ear HL, the prevalence of HL was more common in men, and related with low education and income. In univariable analysis, hypertension, smoking, diabetes, depressive mood, stroke or cardiac disease, anaemia, hypercholesterolaemia and underweight showed positive associations with HL, and alcohol consumption and regular walking showed negative associations with HL. There were five associated factors in multivariable analysis, including smoking (OR =1.36 for smokers with <20 pack years; OR =1.55 for smokers with ≥20 pack years), noise exposure at workplace (OR = 1.28), stroke (OR = 1.72), anaemia (OR = 1.36) and depressive mood (OR = 1.29).
CONCLUSION: Prevention of smoking and reduction of noise, as well as awareness of the association with stroke, anaemia and depression would help to reduce the burden of HL.

PMID: 28889780 [PubMed - as supplied by publisher]

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