Brimonidine Protects Auditory Hair Cells from in vitro-Induced Toxicity of Gentamicin

Brimonidine, an alpha-2 adrenergic receptor (α₂-AR) agonist, has neuroprotective effects in the visual system and in spiral ganglion neurons. Auditory hair cells (HCs) express all 3 α₂-AR subtypes, but their roles in HCs remain unknown. This study investigated the effects of brimonidine on auditory HCs that were also exposed to gentamicin, which is toxic to HCs. Organ of Corti explants were exposed to gentamicin in the presence or absence of brimonidine, and the α₂-AR protein expression levels and Erk1/2 and Akt phosphorylation levels were determined. Brimonidine had a protective effect on auditory HCs against gentamicin-induced toxicity that was blocked by yohimbine. This suggested that the protective effect of brimonidine on HCs was mediated by the α₂-AR. None of the treatments altered α₂-AR protein expression levels, and brimonidine did not significantly change the activation levels of the Erk1/2 and Akt proteins. These observations indicated that brimonidine, acting directly via α₂-AR, protects HCs from gentamicin-induced toxicity. Therefore, brimonidine shows potential for preventing or treating sensorineural hearing loss.
Audiol Neurotol 2017;22:125-134

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Assessing the Relationship Between the Electrically Evoked Compound Action Potential and Speech Recognition Abilities in Bilateral Cochlear Implant Recipients.

Objectives: The primary objective of the present study was to examine the relationship between suprathreshold electrically evoked compound action potential (ECAP) measures and speech recognition abilities in bilateral cochlear implant listeners. We tested the hypothesis that the magnitude of ear differences in ECAP measures within a subject (right-left) could predict the difference in speech recognition performance abilities between that subject's ears (right-left). Design: To better control for across-subject variables that contribute to speech understanding, the present study used a within-subject design. Subjects were 10 bilaterally implanted adult cochlear implant recipients. We measured ECAP amplitudes and slopes of the amplitude growth function in both ears for each subject. We examined how each of these measures changed when increasing the interphase gap of the biphasic pulses. Previous animal studies have shown correlations between these ECAP measures and auditory nerve survival. Speech recognition measures included speech reception thresholds for sentences in background noise, as well as phoneme discrimination in quiet and in noise. Results: Results showed that the between-ear difference (right-left) of one specific ECAP measure (increase in amplitude growth function slope as the interphase gap increased from 7 to 30 [micro]s) was significantly related to the between-ear difference (right-left) in speech recognition. Frequency-specific response patterns for ECAP data and consonant transmission cues support the hypothesis that this particular ECAP measure may represent localized functional acuity. Conclusions: The results add to a growing body of literature suggesting that when using a well-controlled research design, there is evidence that underlying neural function is related to postoperative performance with a cochlear implant. Copyright (C) 2017 Wolters Kluwer Health, Inc. All rights reserved.

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Assessing the Relationship Between the Electrically Evoked Compound Action Potential and Speech Recognition Abilities in Bilateral Cochlear Implant Recipients.

Objectives: The primary objective of the present study was to examine the relationship between suprathreshold electrically evoked compound action potential (ECAP) measures and speech recognition abilities in bilateral cochlear implant listeners. We tested the hypothesis that the magnitude of ear differences in ECAP measures within a subject (right-left) could predict the difference in speech recognition performance abilities between that subject's ears (right-left). Design: To better control for across-subject variables that contribute to speech understanding, the present study used a within-subject design. Subjects were 10 bilaterally implanted adult cochlear implant recipients. We measured ECAP amplitudes and slopes of the amplitude growth function in both ears for each subject. We examined how each of these measures changed when increasing the interphase gap of the biphasic pulses. Previous animal studies have shown correlations between these ECAP measures and auditory nerve survival. Speech recognition measures included speech reception thresholds for sentences in background noise, as well as phoneme discrimination in quiet and in noise. Results: Results showed that the between-ear difference (right-left) of one specific ECAP measure (increase in amplitude growth function slope as the interphase gap increased from 7 to 30 [micro]s) was significantly related to the between-ear difference (right-left) in speech recognition. Frequency-specific response patterns for ECAP data and consonant transmission cues support the hypothesis that this particular ECAP measure may represent localized functional acuity. Conclusions: The results add to a growing body of literature suggesting that when using a well-controlled research design, there is evidence that underlying neural function is related to postoperative performance with a cochlear implant. Copyright (C) 2017 Wolters Kluwer Health, Inc. All rights reserved.

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Assessing the Relationship Between the Electrically Evoked Compound Action Potential and Speech Recognition Abilities in Bilateral Cochlear Implant Recipients.

Objectives: The primary objective of the present study was to examine the relationship between suprathreshold electrically evoked compound action potential (ECAP) measures and speech recognition abilities in bilateral cochlear implant listeners. We tested the hypothesis that the magnitude of ear differences in ECAP measures within a subject (right-left) could predict the difference in speech recognition performance abilities between that subject's ears (right-left). Design: To better control for across-subject variables that contribute to speech understanding, the present study used a within-subject design. Subjects were 10 bilaterally implanted adult cochlear implant recipients. We measured ECAP amplitudes and slopes of the amplitude growth function in both ears for each subject. We examined how each of these measures changed when increasing the interphase gap of the biphasic pulses. Previous animal studies have shown correlations between these ECAP measures and auditory nerve survival. Speech recognition measures included speech reception thresholds for sentences in background noise, as well as phoneme discrimination in quiet and in noise. Results: Results showed that the between-ear difference (right-left) of one specific ECAP measure (increase in amplitude growth function slope as the interphase gap increased from 7 to 30 [micro]s) was significantly related to the between-ear difference (right-left) in speech recognition. Frequency-specific response patterns for ECAP data and consonant transmission cues support the hypothesis that this particular ECAP measure may represent localized functional acuity. Conclusions: The results add to a growing body of literature suggesting that when using a well-controlled research design, there is evidence that underlying neural function is related to postoperative performance with a cochlear implant. Copyright (C) 2017 Wolters Kluwer Health, Inc. All rights reserved.

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Comparison of Localized and Systemic Otitis Media With ANCA-associated Vasculitis.

Objective: To investigate differences in immune activity based on the presence of multiple organ involvement in patients with antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) and whether hearing outcomes are different between patients with AAV localized to the ear and patients with systemic AAV. Study Design: Retrospective case review. Setting: University hospital. Patients: Twenty patients with otitis media with AAV (OMAAV) who met the criteria proposed by the OMAAV study group in Japan. Main Outcome Measure(s): Serum levels of C-reactive protein, ANCA titer, soluble interleukin-2 receptor levels, and hearing outcome. Results: Thirteen patients had disease involvement of organs other than the ear (systemic OMAAV group); involvement was localized to the ear in seven patients (localized OMAAV group). Serum levels of C-reactive protein, ANCA titer, and soluble interleukin-2 receptor were not significantly different between the groups. Hearing levels at diagnosis and in remission were significantly worse in the localized OMAAV group compared with the systemic OMAAV group. Hearing gain was not significantly different between groups. Conclusion: It is suggested that immune activity in patients with AAV localized to the ear is equivalent to activity in patients with systemic AAV. Therefore, we may need treatment for OMAAV equal in intensity to that for systemic AAV. As the hearing level at diagnosis was worse in patients with AAV localized to the ear than in patients with systemic AAV, earlier diagnosis may be needed to improve hearing outcome. Copyright (C) 2017 by Otology & Neurotology, Inc. Image copyright (C) 2010 Wolters Kluwer Health/Anatomical Chart Company

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Assessing Readability and Reliability of Online Patient Information Regarding Vestibular Schwannoma.

Hypothesis: The aim of this study is to objectively assess the quality and readability of websites related to vestibular schwannomas. Background: Patients are increasingly seeking information on confirmed or suspected diagnoses through the Internet. Clinicians are often concerned regarding the accuracy, quality, and readability of web-based sites. Methods: Online information relating to vestibular schwannoma was searched using the three most popular search engines. The terms "acoustic neuroma" and "vestibular schwannoma" were used. The top 50 results from each site were assessed for readability using the Flesch-Kincaid Grade Level, Flesch Reading Ease Score, and the Gunning-Fog Index. Quality of website information was scored using the DISCERN tool. Results: Of 300 search results analyzed, 58 separate appropriate websites were identified. The mean readability score using Flesch-Kincaid Grade Level was 10.27 (95% confidence interval [CI] 9.84-10.70). The mean Flesch Reading Ease Score was 48.75 (95% CI 46.57-50.92). The Gunning-Fog Index was 13.40 (95% CI 12.92-13.89). These scores equate to someone finishing secondary school/first year university student. DISCERN scores were highly variable but consistently demonstrated great variability in quality of information. Conclusion: Online patient information on vestibular schwannoma is highly variable in quality. Although there are a wide range of different websites easily available to patients on their condition and its treatment options, the information is written at a difficult level which may exceed the understanding level of many patients as it is written at a higher than average level of expected reading ability. Copyright (C) 2017 by Otology & Neurotology, Inc. Image copyright (C) 2010 Wolters Kluwer Health/Anatomical Chart Company

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Comparison of an Electromagnetic Middle Ear Implant and Hearing Aid Word Recognition Performance to Word Recognition Performance Obtained Under Earphones.

Objective: To report the results of patients with the Maxum middle ear implant (MEI) and compare word recognition scores (WRS) and speech perception gap (SP Gap) of Maxum versus optimally fit hearing aids (HA). Study Design: Case series with chart review. Setting: Single, private otology clinic. Patients: Eleven ears, in nine adult patients (two women; average age 62.7 yr). Interventions: Twelve consecutive ears with moderate to severe (SNHL) underwent implantation of the Maxum system. One patient was not included due to inadequate preoperative testing. Main Outcome Measures: Primary outcome measures included word recognition score (WRS) and SP Gap (maximum word understanding [PB max] - WRSaided) improvement compared with HAs. Results: The average Maxum WRS was 64.7% (range, 28-94%), a 41.6% improvement (range, 10-66%) over HAs (p

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