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Devolder P, Keppler H, Keshishzadeh S, Taghon B, Dhooge I, Verhulst S. The role of hidden hearing loss in tinnitus: Insights from early markers of peripheral hearing damage. Hear Res 2024; 450:109050. [PMID: 38852534 DOI: 10.1016/j.heares.2024.109050] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/01/2024] [Revised: 05/24/2024] [Accepted: 05/28/2024] [Indexed: 06/11/2024]
Abstract
Since the presence of tinnitus is not always associated with audiometric hearing loss, it has been hypothesized that hidden hearing loss may act as a potential trigger for increased central gain along the neural pathway leading to tinnitus perception. In recent years, the study of hidden hearing loss has improved with the discovery of cochlear synaptopathy and several objective diagnostic markers. This study investigated three potential markers of peripheral hidden hearing loss in subjects with tinnitus: extended high-frequency audiometric thresholds, the auditory brainstem response, and the envelope following response. In addition, speech intelligibility was measured as a functional outcome measurement of hidden hearing loss. To account for age-related hidden hearing loss, participants were grouped according to age, presence of tinnitus, and audiometric thresholds. Group comparisons were conducted to differentiate between age- and tinnitus-related effects of hidden hearing loss. All three markers revealed age-related differences, whereas no differences were observed between the tinnitus and non-tinnitus groups. However, the older tinnitus group showed improved performance on low-pass filtered speech in noise tests compared to the older non-tinnitus group. These low-pass speech in noise scores were significantly correlated with tinnitus distress, as indicated using questionnaires, and could be related to the presence of hyperacusis. Based on our observations, cochlear synaptopathy does not appear to be the underlying cause of tinnitus. The improvement in low-pass speech-in-noise could be explained by enhanced temporal fine structure encoding or hyperacusis. Therefore, we recommend that future tinnitus research takes into account age-related factors, explores low-frequency encoding, and thoroughly assesses hyperacusis.
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Affiliation(s)
- Pauline Devolder
- Hearing Technology @ WAVES, Department of Information Technology, Ghent University, Zwijnaarde, Belgium; Department of Rehabilitation Sciences, Ghent University, Ghent, Belgium.
| | - Hannah Keppler
- Department of Rehabilitation Sciences, Ghent University, Ghent, Belgium; Department of Ear, Nose and Throat, Ghent University Hospital, Ghent, Belgium
| | - Sarineh Keshishzadeh
- Hearing Technology @ WAVES, Department of Information Technology, Ghent University, Zwijnaarde, Belgium
| | - Baziel Taghon
- Hearing Technology @ WAVES, Department of Information Technology, Ghent University, Zwijnaarde, Belgium
| | - Ingeborg Dhooge
- Department of Ear, Nose and Throat, Ghent University Hospital, Ghent, Belgium; Department of Head and Skin, Ghent University, Ghent, Belgium
| | - Sarah Verhulst
- Hearing Technology @ WAVES, Department of Information Technology, Ghent University, Zwijnaarde, Belgium
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Wertz J, Rüttiger L, Bender B, Klose U, Stark RS, Dapper K, Saemisch J, Braun C, Singer W, Dalhoff E, Bader K, Wolpert SM, Knipper M, Munk MHJ. Differential cortical activation patterns: pioneering sub-classification of tinnitus with and without hyperacusis by combining audiometry, gamma oscillations, and hemodynamics. Front Neurosci 2024; 17:1232446. [PMID: 38239827 PMCID: PMC10794389 DOI: 10.3389/fnins.2023.1232446] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2023] [Accepted: 10/16/2023] [Indexed: 01/22/2024] Open
Abstract
The ongoing controversies about the neural basis of tinnitus, whether linked with central neural gain or not, may hamper efforts to develop therapies. We asked to what extent measurable audiometric characteristics of tinnitus without (T) or with co-occurrence of hyperacusis (TH) are distinguishable on the level of cortical responses. To accomplish this, electroencephalography (EEG) and concurrent functional near-infrared spectroscopy (fNIRS) were measured while patients performed an attentionally demanding auditory discrimination task using stimuli within the individual tinnitus frequency (fTin) and a reference frequency (fRef). Resting-state-fMRI-based functional connectivity (rs-fMRI-bfc) in ascending auditory nuclei (AAN), the primary auditory cortex (AC-I), and four other regions relevant for directing attention or regulating distress in temporal, parietal, and prefrontal cortex was compiled and compared to EEG and concurrent fNIRS activity in the same brain areas. We observed no group differences in pure-tone audiometry (PTA) between 10 and 16 kHz. However, the PTA threshold around the tinnitus pitch was positively correlated with the self-rated tinnitus loudness and also correlated with distress in T-groups, while TH experienced their tinnitus loudness at minimal loudness levels already with maximal suffering scores. The T-group exhibited prolonged auditory brain stem (ABR) wave I latency and reduced ABR wave V amplitudes (indicating reduced neural synchrony in the brainstem), which were associated with lower rs-fMRI-bfc between AAN and the AC-I, as observed in previous studies. In T-subjects, these features were linked with elevated spontaneous and reduced evoked gamma oscillations and with reduced deoxygenated hemoglobin (deoxy-Hb) concentrations in response to stimulation with lower frequencies in temporal cortex (Brodmann area (BA) 41, 42, 22), implying less synchronous auditory responses during active auditory discrimination of reference frequencies. In contrast, in the TH-group gamma oscillations and hemodynamic responses in temporoparietal regions were reversed during active discrimination of tinnitus frequencies. Our findings suggest that T and TH differ in auditory discrimination and memory-dependent directed attention during active discrimination at either tinnitus or reference frequencies, offering a test paradigm that may allow for more precise sub-classification of tinnitus and future improved treatment approaches.
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Affiliation(s)
- Jakob Wertz
- Department of Otolaryngology, Head and Neck Surgery, Tübingen Hearing Research Centre, University of Tübingen, Tübingen, Germany
| | - Lukas Rüttiger
- Department of Otolaryngology, Head and Neck Surgery, Tübingen Hearing Research Centre, University of Tübingen, Tübingen, Germany
| | - Benjamin Bender
- Department of Diagnostic and Interventional Neuroradiology, University of Tübingen, Tübingen, Germany
| | - Uwe Klose
- Department of Diagnostic and Interventional Neuroradiology, University of Tübingen, Tübingen, Germany
| | - Robert S. Stark
- Department of Psychiatry and Psychotherapy, University of Tübingen, Tübingen, Germany
| | - Konrad Dapper
- Department of Otolaryngology, Head and Neck Surgery, Tübingen Hearing Research Centre, University of Tübingen, Tübingen, Germany
- Department of Biology, Technical University Darmstadt, Darmstadt, Germany
| | - Jörg Saemisch
- Department of Otolaryngology, Head and Neck Surgery, Tübingen Hearing Research Centre, University of Tübingen, Tübingen, Germany
| | | | - Wibke Singer
- Department of Otolaryngology, Head and Neck Surgery, Tübingen Hearing Research Centre, University of Tübingen, Tübingen, Germany
| | - Ernst Dalhoff
- Section of Physiological Acoustics and Communication, Department of Otolaryngology, Head and Neck Surgery, University of Tübingen, Tübingen, Germany
| | - Katharina Bader
- Section of Physiological Acoustics and Communication, Department of Otolaryngology, Head and Neck Surgery, University of Tübingen, Tübingen, Germany
| | - Stephan M. Wolpert
- Department of Otolaryngology, Head and Neck Surgery, Tübingen Hearing Research Centre, University of Tübingen, Tübingen, Germany
| | - Marlies Knipper
- Department of Otolaryngology, Head and Neck Surgery, Tübingen Hearing Research Centre, University of Tübingen, Tübingen, Germany
| | - Matthias H. J. Munk
- Department of Psychiatry and Psychotherapy, University of Tübingen, Tübingen, Germany
- Department of Biology, Technical University Darmstadt, Darmstadt, Germany
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Aazh H, Kartsonaki C, Moore BCJ. Psychometric evaluation of the 4C tinnitus management questionnaire for patients with tinnitus alone or tinnitus combined with hyperacusis. Int J Audiol 2024; 63:21-29. [PMID: 36426916 DOI: 10.1080/14992027.2022.2143430] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2022] [Accepted: 10/28/2022] [Indexed: 11/27/2022]
Abstract
OBJECTIVE To assess the psychometric properties of a new questionnaire evaluating patients' confidence in managing their tinnitus, the 4C tinnitus management questionnaire (4C), which was designed to be used in the process of cognitive behavioural therapy. DESIGN Retrospective cross-sectional based on patient records. STUDY SAMPLES 99 consecutive patients who sought help for tinnitus (with or without hyperacusis) from an audiology clinic in the UK. Pure tone average (PTA) hearing thresholds, Uncomfortable Loudness Levels (ULLs), and responses to the 4C questionnaire, Tinnitus Handicap Inventory (THI), Hyperacusis Questionnaire (HQ), and Screening for Anxiety and Depression in Tinnitus (SAD-T) questionnaire were gathered from the records of patients held at the audiology department. RESULTS Cronbach's alpha for the 4C was 0.91, indicating high internal consistency. Exploratory factor analysis suggested a one-factor solution. Discriminant validity was supported by weak correlations between 4C scores and PTA across ears and ULLmin (the across-frequency average ULL for the ear with lower average ULL). Convergent validity was supported by moderate correlations between 4C scores and scores for the THI, HQ, and SAD-T. CONCLUSIONS The 4C is an internally consistent questionnaire with high convergent and discriminant validity, which can be used to assess patients' confidence in managing their tinnitus.
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Affiliation(s)
- Hashir Aazh
- Audiology Department, Royal Surrey NHS Foundation Trust, Guildford, UK
- Department of Communication Sciences & Disorders, Florida Atlantic University, Boca Raton, USA
- Faculty of Engineering and Physical Sciences, University of Surrey, Guildford, UK
| | - Christiana Kartsonaki
- MRC Population Health Research Unit, Clinical Trials Service Unit and Epidemiological Studies Unit, Nuffield Department of Population Health, University of Oxford, Oxford, UK
| | - Brian C J Moore
- Cambridge Hearing Group, Department of Psychology, University of Cambridge, Cambridge, UK
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Shin SH, Byun SW, Lee ZY, Park Y, Lee HY. Clinical Features of Non-Lateralized Tinnitus. J Int Adv Otol 2023; 19:497-502X. [PMID: 38088323 PMCID: PMC10765226 DOI: 10.5152/iao.2023.22901] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2022] [Accepted: 06/26/2023] [Indexed: 12/18/2023] Open
Abstract
BACKGROUND We aimed to analyze and confirm the clinical features of patients with non-lateralized tinnitus and to identify clues that can be used in their management. METHODS Data from 469 patients who visited a university hospital complaining of tinnitus between March 2020 and December 2021 were reviewed. The patients' medical histories, Tinnitus Handicap Inventory, Beck Depression Inventory, and numerical rating scale scores on tinnitus awareness, annoyance, loudness, and effect on life, audiological profiles, and quantitative electroencephalography findings were documented. RESULTS Forty-nine (10.4%) patients had non-lateralized tinnitus. They were older and had a shorter duration of symptoms (13.91 ± 34.16 months) than patients with bilateral tinnitus (duration: 39.15 ± 80.82 months) (P -lt; .05). The accompanying symptoms, Tinnitus Handicap Inventory scores, and numerical rating scale scores were not significantly different between the 2 groups (P -gt; .05). Patients with non-lateralized tinnitus had worse hearing at 12 kHz on the left side than those with unilateral tinnitus. Hearing asymmetry was least common in non-lateralized tinnitus (n=11/49, 10.4%), followed by bilateral tinnitus (n=54/198, 42.2%) and unilateral tinnitus (n=97/222, 47.3%) (P-lt; .001). Regarding quantitative electroencephalography, there were significant differences in the absolute power of the theta, alpha, beta, gamma, and total frequency bands based on tinnitus lateralization (P -lt; .001). CONCLUSION Non-lateralized tinnitus can be perceived in elderly patients with symmetric and extended high-frequency hearing loss before habituation is achieved at an early stage of tinnitus. However, there was no difference in the questionnaire scores and accompanying symptoms; therefore, it may not be worth managing non-lateralized tinnitus separately from tinnitus in the ear.
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Affiliation(s)
| | - Sung Wan Byun
- Department of Otorhinolaryngology, College of Medicine, Ewha Womans University, Seoul, South Korea
| | - Zoo Young Lee
- Department of Otorhinolaryngology, College of Medicine, Ewha Womans University, Seoul, South Korea
| | - Yelin Park
- Department of Otorhinolaryngology, College of Medicine, Ewha Womans University, Seoul, South Korea
| | - Ho Yun Lee
- Department of Otorhinolaryngology, College of Medicine, Ewha Womans University, Seoul, South Korea
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Morse K, Vander Werff K. The Effect of Tinnitus and Related Characteristics on Subcortical Auditory Processing. Ear Hear 2023; 44:1344-1353. [PMID: 37127904 DOI: 10.1097/aud.0000000000001376] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
OBJECTIVES The primary aim of this study was to evaluate whether individuals with tinnitus exhibited evidence of reduced inhibition and increased excitation at the subcortical auditory processing level. Based on the proposed mechanism of tinnitus generation, including peripheral auditory insult that triggers reduced inhibition and subcortical hyperactivity, it was hypothesized that a tinnitus group would yield reduced amplitudes for the most peripheral auditory brainstem response (ABR) component (wave I) and larger amplitudes for the most central ABR component (wave V) relative to controls matched on factors of age, sex, and hearing loss. Further, this study assessed the relative influence of tinnitus presence versus other related individual characteristics, including hearing loss, age, noise exposure history, and speech perception in noise on these ABR outcomes. DESIGN Subcortical processing was examined using click-evoked ABR in an independent groups experimental design. A group of adults who perceived daily unilateral or bilateral tinnitus were matched with a control group counterpart without tinnitus by age, hearing, and sex (in each group n = 18; 10 females, 8 males). Amplitudes for ABR waves I, III, V, and the V/I ratio were compared between groups by independent t-tests. The relative influence of tinnitus (presence/absence), age (in years), noise exposure history (subjective self-report), hearing loss (audiometric thresholds), and speech perception in noise (SNR-50) was determined based on the proportional reduction in error associated with accounting for each variable of interest using multiple regression. RESULTS Between-group trends were consistent with smaller amplitudes for all ABR components in individuals with tinnitus. Contrary to our hypotheses, however, none of the tinnitus compared with control group differences in ABR outcomes were statistically significant. In the multiple regression models, none of the factors including tinnitus presence, age, noise exposure history, hearing loss, and speech perception in noise significantly predicted ABR V/I ratio outcomes. CONCLUSIONS The presence of reduced inhibition and subcortical hyperactivity in the tinnitus group was not supported in the current study. There were trends in ABR outcomes consistent with reduced peripheral to central brainstem auditory activity in the tinnitus group, but none of the group differences reached significance. It should also be noted that the tinnitus group had poorer extended high-frequency thresholds compared with controls. Regardless, neither tinnitus presence nor any of the proposed related characteristics were found to significantly influence the ABR V/I ratio. These findings suggest that either reduced subcortical inhibition was not a primary underlying mechanism for the tinnitus perceived by these subjects, or that ABR was not a reliable indicator of reduced subcortical inhibition possibly due to characteristics of the sample including a skewed distributions toward young and normal hearing individuals with little tinnitus distress.
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Affiliation(s)
- Kenneth Morse
- Division of Communication Sciences and Disorders, West Virginia University, Morgantown, West Virginia, USA
| | - Kathy Vander Werff
- Department of Communication Sciences and Disorders, Syracuse University, Syracuse, New York, USA
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Rosemann S, Rauschecker JP. Disruptions of default mode network and precuneus connectivity associated with cognitive dysfunctions in tinnitus. Sci Rep 2023; 13:5746. [PMID: 37029175 PMCID: PMC10082191 DOI: 10.1038/s41598-023-32599-0] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2022] [Accepted: 03/29/2023] [Indexed: 04/09/2023] Open
Abstract
Tinnitus is the perception of a ringing, buzzing or hissing sound "in the ear" without external stimulation. Previous research has demonstrated changes in resting-state functional connectivity in tinnitus, but findings do not overlap and are even contradictory. Furthermore, how altered functional connectivity in tinnitus is related to cognitive abilities is currently unknown. Here we investigated resting-state functional connectivity differences between 20 patients with chronic tinnitus and 20 control participants matched in age, sex and hearing loss. All participants underwent functional magnetic resonance imaging, audiometric and cognitive assessments, and filled in questionnaires targeting anxiety and depression. Significant differences in functional connectivity between tinnitus patients and control participants were not obtained. However, we did find significant associations between cognitive scores and functional coupling of the default mode network and the precuneus with the superior parietal lobule, supramarginal gyrus, and orbitofrontal cortex. Further, tinnitus distress correlated with connectivity between the precuneus and the lateral occipital complex. This is the first study providing evidence for disruptions of default mode network and precuneus coupling that are related to cognitive dysfunctions in tinnitus. The constant attempt to decrease the tinnitus sensation might occupy certain brain resources otherwise available for concurrent cognitive operations.
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Affiliation(s)
- Stephanie Rosemann
- Laboratory of Integrative Neuroscience and Cognition, Department of Neuroscience, Georgetown University Medical Center, 3970 Reservoir Rd NW, Washington, DC, 20057, USA.
| | - Josef P Rauschecker
- Laboratory of Integrative Neuroscience and Cognition, Department of Neuroscience, Georgetown University Medical Center, 3970 Reservoir Rd NW, Washington, DC, 20057, USA
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Shin SH, Byun SW, Lee ZY, Kim MJ, Kim EH, Lee HY. Clinical Findings That Differentiate Co-Occurrence of Hyperacusis and Tinnitus from Tinnitus Alone. Yonsei Med J 2022; 63:1035-1042. [PMID: 36303312 PMCID: PMC9629898 DOI: 10.3349/ymj.2022.0274] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/12/2022] [Revised: 08/03/2022] [Accepted: 08/27/2022] [Indexed: 12/03/2022] Open
Abstract
PURPOSE We aimed to assess the characteristics of patients with concurrent tinnitus and hyperacusis, determine the best audiological criteria for predicting hyperacusis, and confirm whether objective evidence of changes in the brain exists. MATERIALS AND METHODS The medical records of patients with tinnitus who visited the hospital between March 2020 and December 2021 were reviewed. Data on accompanying hyperacusis, audiological profiles, and questionnaires including the Tinnitus Handicap Inventory (THI), Beck Depression Inventory, and numerical rating scale were analyzed. Resting-state quantitative electroencephalography (qEEG) using power spectral density (PSD) and event-related spectral perturbation (ERSP) were performed to objectively quantify changes in the brain. RESULTS A total of 194 patients were analyzed. Among them, 51 (26.3%) reported combined subjective hyperacusis with tinnitus. However, the proportions widely varied from 7.4% to 68.4% based on three audiological criteria for assessment. A higher score on the THI questionnaire was independently associated with the co-occurrence of tinnitus and hyperacusis. Fair agreement was observed between subjective hyperacusis and the audiological criterion based on a loudness discomfort level (LDL) of ≤90 dB at two or more frequencies for the diagnosis of hyperacusis. An increased beta-PSD and decreased levels of gamma-PSD, all-ERSP, and delta-ERSP were observed in patients with hyperacusis (p<0.05). CONCLUSION Patients with co-occurring tinnitus and hyperacusis had more severe tinnitus distress. An LDL of ≤90 dB at two or more frequencies may be applicable to predict accompanying hyperacusis in subjects with tinnitus, and qEEG also provides more objective information.
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Affiliation(s)
- Seung-Ho Shin
- Department of Otorhinolaryngology, Ewha Womans University School of Medicine, Seoul, Korea
| | - Sung Wan Byun
- Department of Otorhinolaryngology, Ewha Womans University School of Medicine, Seoul, Korea
| | - Zoo Young Lee
- Department of Otorhinolaryngology, Ewha Womans University School of Medicine, Seoul, Korea
| | - Min-Jee Kim
- Department of Pediatrics, Asan Medical Center Children's Hospital, Ulsan University College of Medicine, Seoul, Korea
| | - Eun Hye Kim
- Department of Otorhinolaryngology, Ewha Womans University School of Medicine, Seoul, Korea
| | - Ho Yun Lee
- Department of Otorhinolaryngology, Ewha Womans University School of Medicine, Seoul, Korea.
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Fuksa J, Profant O, Tintěra J, Svobodová V, Tóthová D, Škoch A, Syka J. Functional changes in the auditory cortex and associated regions caused by different acoustic stimuli in patients with presbycusis and tinnitus. Front Neurosci 2022; 16:921873. [PMID: 36340777 PMCID: PMC9626994 DOI: 10.3389/fnins.2022.921873] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2022] [Accepted: 08/31/2022] [Indexed: 09/30/2023] Open
Abstract
Presbycusis and tinnitus are the two most common hearing related pathologies. Although both of these conditions presumably originate in the inner ear, there are several reports concerning their central components. Interestingly, the onset of presbycusis coincides with the highest occurrence of tinnitus. The aim of this study was to identify age, hearing loss, and tinnitus related functional changes, within the auditory system and its associated structures. Seventy-eight participants were selected for the study based on their age, hearing, and tinnitus, and they were divided into six groups: young controls (Y-NH-NT), subjects with mild presbycusis (O-NH-NT) or expressed presbycusis (O-HL-NT), young subjects with tinnitus (Y-NH-T), subjects with mild presbycusis and tinnitus (O-NH-T), and subjects with expressed presbycusis and tinnitus (O-HL-T). An MRI functional study was performed with a 3T MRI system, using an event related design (different types of acoustic and visual stimulations and their combinations). The amount of activation of the auditory cortices (ACs) was dependent on the complexity of the stimuli; higher complexity resulted in a larger area of the activated cortex. Auditory stimulation produced a slightly greater activation in the elderly, with a negative effect of hearing loss (lower activation). The congruent audiovisual stimulation led to an increased activity within the default mode network, whereas incongruent stimulation led to increased activation of the visual cortex. The presence of tinnitus increased activation of the AC, specifically in the aged population, with a slight prevalence in the left AC. The occurrence of tinnitus was accompanied by increased activity within the insula and hippocampus bilaterally. Overall, we can conclude that expressed presbycusis leads to a lower activation of the AC, compared to the elderly with normal hearing; aging itself leads to increased activity in the right AC. The complexity of acoustic stimuli plays a major role in the activation of the AC, its support by visual stimulation leads to minimal changes within the AC. Tinnitus causes changes in the activity of the limbic system, as well as in the auditory AC, where it is bound to the left hemisphere.
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Affiliation(s)
- Jakub Fuksa
- Department of Otorhinolaryngology, 3rd Faculty of Medicine, Faculty Hospital Královské Vinohrady, Charles University, Prague, Czechia
- Department of Auditory Neuroscience, Institute of Experimental Medicine, The Czech Academy of Sciences, Prague, Czechia
| | - Oliver Profant
- Department of Otorhinolaryngology, 3rd Faculty of Medicine, Faculty Hospital Královské Vinohrady, Charles University, Prague, Czechia
- Department of Auditory Neuroscience, Institute of Experimental Medicine, The Czech Academy of Sciences, Prague, Czechia
| | - Jaroslav Tintěra
- MR Unit, Institute for Clinical and Experimental Medicine, Prague, Czechia
| | - Veronika Svobodová
- Department of Auditory Neuroscience, Institute of Experimental Medicine, The Czech Academy of Sciences, Prague, Czechia
- Department of Otorhinolaryngology, Head and Neck Surgery, 1st Faculty of Medicine, Charles University in Prague and University Hospital Motol, Prague, Czechia
| | - Diana Tóthová
- Department of Auditory Neuroscience, Institute of Experimental Medicine, The Czech Academy of Sciences, Prague, Czechia
- Department of Otorhinolaryngology, Head and Neck Surgery, 1st Faculty of Medicine, Charles University in Prague and University Hospital Motol, Prague, Czechia
| | - Antonin Škoch
- MR Unit, Institute for Clinical and Experimental Medicine, Prague, Czechia
| | - Josef Syka
- Department of Auditory Neuroscience, Institute of Experimental Medicine, The Czech Academy of Sciences, Prague, Czechia
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Guthrie OW, Wong BA, McInturf SM, Mattie DR. Degenerate brainstem circuitry after combined physiochemical exposure to jet fuel and noise. JOURNAL OF TOXICOLOGY AND ENVIRONMENTAL HEALTH. PART A 2022; 85:175-183. [PMID: 34913848 DOI: 10.1080/15287394.2021.1980166] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Degenerate neural circuits exhibit "different" circuit properties yet produce similar circuit outcomes (many-to-one) which ensures circuit robustness and complexity. However, neuropathies may hijack degeneracy to yield robust and complex pathological circuits. The aim of the current study was to test the hypothesis that physiochemical exposure to combined jet fuel and noise might induce degeneracy in the brainstem. The auditory brainstem of pigmented rats was used as a model system. The animals were randomized into the following experimental groups: Fuel+Noise, fuel-only, noise-only, and control. Ascending volume conductance from various auditory brainstem regions were evaluated simultaneously with peripheral nervous system (PNS) input to brainstem circuitry. Data demonstrated normal PNS inputs for all groups. However, the Fuel+Noise exposure group produced different caudal brainstem circuit properties while rostral brainstem circuitry initiated outputs that were similar to that of control. This degenerative effect was specific to Fuel+Noise exposure, since neither noise-alone or fuel-alone produced the same result. Degeneracy in the auditory brainstem is consistent with perceptual abnormalities, such as poor speech discrimination (hear but not understand), tinnitus (ringing in the ear), hyperacusis (hypersensitivity to even low-level sound), and loudness intolerance. Therefore, a potential consequence of Fuel+Noise exposure among military and civilian populations may be evidenced as increased rates of super-threshold auditory perceptual abnormalities. This is particularly important because to date, the ototoxic profile of Fuel+Noise exposure has remained unresolved.
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Affiliation(s)
- O'neil W Guthrie
- Cell & Molecular Pathology Laboratory, Communication Sciences and Disorders, Northern Arizona University, Flagstaff, AZ, USA
| | - Brian A Wong
- Naval Medical Research Unit Dayton, Wright-Patterson Air Force Base, OH, USA
- Oak Ridge Institute for Science and Education (Orise), Oak Ridge, TN, USA
| | - Shawn M McInturf
- Naval Medical Research Unit Dayton, Wright-Patterson Air Force Base, OH, USA
| | - David R Mattie
- 711 Human Performance Wing, Wright-Patterson Air Force Base, OH, USA
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10
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Knipper M, Singer W, Schwabe K, Hagberg GE, Li Hegner Y, Rüttiger L, Braun C, Land R. Disturbed Balance of Inhibitory Signaling Links Hearing Loss and Cognition. Front Neural Circuits 2022; 15:785603. [PMID: 35069123 PMCID: PMC8770933 DOI: 10.3389/fncir.2021.785603] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2021] [Accepted: 12/08/2021] [Indexed: 12/19/2022] Open
Abstract
Neuronal hyperexcitability in the central auditory pathway linked to reduced inhibitory activity is associated with numerous forms of hearing loss, including noise damage, age-dependent hearing loss, and deafness, as well as tinnitus or auditory processing deficits in autism spectrum disorder (ASD). In most cases, the reduced central inhibitory activity and the accompanying hyperexcitability are interpreted as an active compensatory response to the absence of synaptic activity, linked to increased central neural gain control (increased output activity relative to reduced input). We here suggest that hyperexcitability also could be related to an immaturity or impairment of tonic inhibitory strength that typically develops in an activity-dependent process in the ascending auditory pathway with auditory experience. In these cases, high-SR auditory nerve fibers, which are critical for the shortest latencies and lowest sound thresholds, may have either not matured (possibly in congenital deafness or autism) or are dysfunctional (possibly after sudden, stressful auditory trauma or age-dependent hearing loss linked with cognitive decline). Fast auditory processing deficits can occur despite maintained basal hearing. In that case, tonic inhibitory strength is reduced in ascending auditory nuclei, and fast inhibitory parvalbumin positive interneuron (PV-IN) dendrites are diminished in auditory and frontal brain regions. This leads to deficits in central neural gain control linked to hippocampal LTP/LTD deficiencies, cognitive deficits, and unbalanced extra-hypothalamic stress control. Under these conditions, a diminished inhibitory strength may weaken local neuronal coupling to homeostatic vascular responses required for the metabolic support of auditory adjustment processes. We emphasize the need to distinguish these two states of excitatory/inhibitory imbalance in hearing disorders: (i) Under conditions of preserved fast auditory processing and sustained tonic inhibitory strength, an excitatory/inhibitory imbalance following auditory deprivation can maintain precise hearing through a memory linked, transient disinhibition that leads to enhanced spiking fidelity (central neural gain⇑) (ii) Under conditions of critically diminished fast auditory processing and reduced tonic inhibitory strength, hyperexcitability can be part of an increased synchronization over a broader frequency range, linked to reduced spiking reliability (central neural gain⇓). This latter stage mutually reinforces diminished metabolic support for auditory adjustment processes, increasing the risks for canonical dementia syndromes.
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Affiliation(s)
- Marlies Knipper
- Department of Otolaryngology, Head and Neck Surgery, Tübingen Hearing Research Center (THRC), Molecular Physiology of Hearing, University of Tübingen, Tübingen, Germany
- *Correspondence: Marlies Knipper,
| | - Wibke Singer
- Department of Otolaryngology, Head and Neck Surgery, Tübingen Hearing Research Center (THRC), Molecular Physiology of Hearing, University of Tübingen, Tübingen, Germany
| | - Kerstin Schwabe
- Experimental Neurosurgery, Department of Neurosurgery, Hannover Medical School, Hanover, Germany
| | - Gisela E. Hagberg
- Department of Biomedical Magnetic Resonance, University Hospital Tübingen (UKT), Tübingen, Germany
- High-Field Magnetic Resonance, Max Planck Institute for Biological Cybernetics, Tübingen, Germany
| | - Yiwen Li Hegner
- MEG Center, University of Tübingen, Tübingen, Germany
- Center of Neurology, Hertie-Institute for Clinical Brain Research, University of Tübingen, Tübingen, Germany
| | - Lukas Rüttiger
- Department of Otolaryngology, Head and Neck Surgery, Tübingen Hearing Research Center (THRC), Molecular Physiology of Hearing, University of Tübingen, Tübingen, Germany
| | - Christoph Braun
- MEG Center, University of Tübingen, Tübingen, Germany
- Center of Neurology, Hertie-Institute for Clinical Brain Research, University of Tübingen, Tübingen, Germany
| | - Rüdiger Land
- Department of Experimental Otology, Institute for Audioneurotechnology, Hannover Medical School, Hanover, Germany
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11
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Koch L, Gaese BH, Nowotny M. Strain Comparison in Rats Differentiates Strain-Specific from More General Correlates of Noise-Induced Hearing Loss and Tinnitus. J Assoc Res Otolaryngol 2021; 23:59-73. [PMID: 34796410 PMCID: PMC8782999 DOI: 10.1007/s10162-021-00822-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2021] [Accepted: 10/19/2021] [Indexed: 11/20/2022] Open
Abstract
Experiments in rodent animal models help to reveal the characteristics and underlying mechanisms of pathologies related to hearing loss such as tinnitus or hyperacusis. However, a reliable understanding is still lacking. Here, four different rat strains (Sprague Dawley, Wistar, Long Evans, and Lister Hooded) underwent comparative analysis of electrophysiological (auditory brainstem responses, ABRs) and behavioral measures after noise trauma induction to differentiate between strain-dependent trauma effects and more consistent changes across strains, such as frequency dependence or systematic temporal changes. Several hearing- and trauma-related characteristics were clearly strain-dependent. Lister Hooded rats had especially high hearing thresholds and were unable to detect a silent gap in continuous background noise but displayed the highest startle amplitudes. After noise exposure, ABR thresholds revealed a strain-dependent pattern of recovery. ABR waveforms varied in detail among rat strains, and the difference was most prominent at later peaks arising approximately 3.7 ms after stimulus onset. However, changes in ABR waveforms after trauma were small compared to consistent strain-dependent differences between individual waveform components. At the behavioral level, startle-based gap-prepulse inhibition (gap-PPI) was used to evaluate the occurrence and characteristics of tinnitus after noise exposure. A loss of gap-PPI was found in 33% of Wistar, 50% of Sprague Dawley, and 75% of Long Evans rats. Across strains, the most consistent characteristic was a frequency-specific pattern of the loss of gap-PPI, with the highest rates at approximately one octave above trauma. An additional range exhibiting loss of gap-PPI directly below trauma frequency was revealed in Sprague Dawley and Long Evans rats. Further research should focus on these frequency ranges when investigating the underlying mechanisms of tinnitus induction.
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Affiliation(s)
- L Koch
- Institute of Cell Biology and Neuroscience, Goethe University, Frankfurt am Main, Germany
| | - B H Gaese
- Institute of Cell Biology and Neuroscience, Goethe University, Frankfurt am Main, Germany
| | - Manuela Nowotny
- Institute of Cell Biology and Neuroscience, Goethe University, Frankfurt am Main, Germany. .,Animal Physiology Group, Institute of Zoology and Evolutionary Research, Friedrich-Schiller-University, Jena, Germany.
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12
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Knipper M, Mazurek B, van Dijk P, Schulze H. Too Blind to See the Elephant? Why Neuroscientists Ought to Be Interested in Tinnitus. J Assoc Res Otolaryngol 2021; 22:609-621. [PMID: 34686939 PMCID: PMC8599745 DOI: 10.1007/s10162-021-00815-1] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2021] [Accepted: 08/30/2021] [Indexed: 01/13/2023] Open
Abstract
A curative therapy for tinnitus currently does not exist. One may actually exist but cannot currently be causally linked to tinnitus due to the lack of consistency of concepts about the neural correlate of tinnitus. Depending on predictions, these concepts would require either a suppression or enhancement of brain activity or an increase in inhibition or disinhibition. Although procedures with a potential to silence tinnitus may exist, the lack of rationale for their curative success hampers an optimization of therapeutic protocols. We discuss here six candidate contributors to tinnitus that have been suggested by a variety of scientific experts in the field and that were addressed in a virtual panel discussion at the ARO round table in February 2021. In this discussion, several potential tinnitus contributors were considered: (i) inhibitory circuits, (ii) attention, (iii) stress, (iv) unidentified sub-entities, (v) maladaptive information transmission, and (vi) minor cochlear deafferentation. Finally, (vii) some potential therapeutic approaches were discussed. The results of this discussion is reflected here in view of potential blind spots that may still remain and that have been ignored in most tinnitus literature. We strongly suggest to consider the high impact of connecting the controversial findings to unravel the whole complexity of the tinnitus phenomenon; an essential prerequisite for establishing suitable therapeutic approaches.
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Affiliation(s)
- Marlies Knipper
- Molecular Physiology of Hearing, Tübingen Hearing Research Centre (THRC), Department of Otolaryngology, Head & Neck Surgery, University of Tübingen, Elfriede-Aulhorn-Straße 5, 72076, Tübingen, Germany.
| | - Birgit Mazurek
- Tinnitus Center Charité, Universitätsmedizin Berlin, Berlin, Germany
| | - Pim van Dijk
- Department of Otorhinolaryngology/Head and Neck Surgery, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
- Graduate School of Medical Sciences (Research School of Behavioural and Cognitive Neurosciences), University of Groningen, Groningen, The Netherlands
| | - Holger Schulze
- Experimental Otolaryngology, Friedrich-Alexander Universität Erlangen-Nürnberg, Waldstrasse 1, 91054, Erlangen, Germany
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13
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Longenecker RJ, Gu R, Homan J, Kil J. Development of Tinnitus and Hyperacusis in a Mouse Model of Tobramycin Cochleotoxicity. Front Mol Neurosci 2021; 14:715952. [PMID: 34539342 PMCID: PMC8440845 DOI: 10.3389/fnmol.2021.715952] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2021] [Accepted: 08/10/2021] [Indexed: 11/13/2022] Open
Abstract
Aminoglycosides (AG) antibiotics are a common treatment for recurrent infections in cystic fibrosis (CF) patients. AGs are highly ototoxic, resulting in a range of auditory dysfunctions. It was recently shown that the acoustic startle reflex (ASR) can assess behavioral evidence of hyperacusis and tinnitus in an amikacin cochleotoxicity mouse model. The goal of this study was to establish if tobramycin treatment led to similar changes in ASR behavior and to establish whether ebselen can prevent the development of these maladaptive neuroplastic symptoms. CBA/Ca mice were divided into three groups: Group 1 served as a control and did not receive tobramycin or ebselen, Group 2 received tobramycin (200 mg/kg/s.c.) and the vehicle (DMSO/saline/i.p.) daily for 14 continuous days, and Group 3 received the same dose/schedule of tobramycin as Group 2 and ebselen at (20 mg/kg/i.p.). Auditory brainstem response (ABR) and ASR hearing assessments were collected at baseline and 2, 6, 10, 14, and 18 weeks from the start of treatment. ASR tests included input/output (I/O) functions which assess general hearing and hyperacusis, and Gap-induced prepulse inhibition of the acoustic startle (GPIAS) to assess tinnitus. At 18 weeks, histologic analysis showed predominantly normal appearing hair cells and spiral ganglion neuron (SGN) synapses. Following 14 days of tobramycin injections, 16 kHz thresholds increased from baseline and fluctuated over the 18-week recovery period. I/O functions revealed exaggerated startle response magnitudes in 50% of mice over the same period. Gap detection deficits, representing behavioral evidence of tinnitus, were observed in a smaller subset (36%) of animals. Interestingly, increases in ABR wave III/wave I amplitude ratios were observed. These tobramycin data corroborate previous findings that AGs can result in hearing dysfunctions. We show that a 14-day course of tobramycin treatment can cause similar levels of hearing loss and tinnitus, when compared to a 14-day course of amikacin, but less hyperacusis. Evidence suggests that tinnitus and hyperacusis might be common side effects of AG antibiotics.
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Affiliation(s)
| | - Rende Gu
- Sound Pharmaceuticals Inc., Seattle, WA, United States
| | | | - Jonathan Kil
- Sound Pharmaceuticals Inc., Seattle, WA, United States
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