Sensorineural Hearing Loss Group Research Articles

Impairment of auditory function in persons with type 2 diabetes mellitus depending on the level of peripheral myelin protein 22

Background. One of the priority tasks of modern medicine is early diagnosis and treatment of micro- and macrovascular complications of diabetes mellitus (DM) which cause a decrease in the quality of life of working age people and an increase in mortali­ty. Variability of carbohydrate metabolism indicators, metabolic dysfunction are leading factors in the development and progression of disabling complications of type 2 DM with hearing loss due to degenerative changes in nerve fibers. An important aspect of diagnostic and treatment algorithms of sensorineural hearing disorders in patients with type 2 DM is early detection of demyelinating processes to prevent damage to neuronal structures. The purpose of the study is to determine the relationship between the level of peripheral myelin protein 22 (PMP 22) and the condition of the auditory analyzer according to the data of instrumental examination in patients with type 2 DM combined with hearing impairment. Materials and methods. There were examined 30 patients with type 2 DM (15 men and 15 women aged 56.28 ± 4.54 years) associated with degree I–II sensorineural disorders of the auditory function; 15 people with signs of sensorineural hearing loss (SNHL) (8 men, 7 women aged 59.33 ± 2.65 years) without diabetes and 15 controls. During the examination, the patients with type 2 DM and SNHL, depending on the severity of the underlying disease, were divided into groups: the first group (n = 15) with or without isolated microvascular complications of type 2 DM, the second group (n = 15) with neuro-, nephro- and retinopathy. All patients underwent a set of laboratory tests to determine the content of PMP 22 in the blood serum, clinical and instrumental diagnosis of the auditory function. The obtained data were processed statistically, and correlations were identified. Results. The analysis of the results revealed that in patients with type 2 DM and SNHL (groups 1 and 2), the level of peripheral myelin protein 22 significantly increased compared to both controls and the comparison group, and more significantly in those with microangiopathies. The correlations were found bet­ween the most informative indicators reflecting the state of various structures of the hearing analyzer and the content of PMP 22 in the blood serum. Conclusions. A significant increase was revealed in the content of PMP 22 and manifestations of sensorineural hearing loss in patients with type 2 diabetes mellitus associated with microangiopathies that indicate demyelinating processes in the neural structures of the auditory analyzer.

How can the routine use of face masks by medical professionals affect hearing-impaired patients’ perception of speech? A case–control study

BackgroundFacemasks are routinely used among healthcare providers, especially after the COVID-19 pandemic. However, they negatively impact speech perception. Our study investigated how speech perception using the word discrimination score (WDS) was affected by wearing surgical and KN95 masks while dealing with hearing-impaired healthcare recipients.MethodThis case–control study included 60 participants [15 with normal hearing and 45 with varied degrees of sensorineural hearing loss (SNHL)], for whom word discrimination scores (WDS) were evaluated under various mask conditions.ResultsOn applying repeated measures of two-way analysis of variance (RM two-way ANOVA), there was statistically significant interaction (p = 0.0018), meaning that the level by which the mask affects the WDS depends on the underlying hearing level. Both main factors showed a statistically significant effect (p < 0.0001). Surgical masks had a lesser impact on speech discrimination compared to KN 95.ConclusionsIt was concluded that KN95 severely impacted the WDS among all groups relative to surgical mask and the no-mask condition. Although the high-frequency SNHL (HF-SNHL) group had mild hearing loss in the pure tone audiometry (PTA) average, they showed lower WDS relative to the mild to moderate flat SNHL (MM-SNHL). Moderately severe to severe SNHL expressed the worst values. As a result, the surgical mask is recommended over the KN95 mask since it provides better speech discrimination while giving adequate protection. These findings should be taken into consideration as they will have an impact on communication, especially in situations like hospitals where the patients must understand the instructors and healthcare providers very well.

Intracochlear electrocochleography findings in cochlear implant recipients with auditory neuropathy spectrum disorder.

This study aimed to compare intracochlear electrocochleography (ECochG) findings in a group of cochlear implant (CI) recipients with auditory neuropathy spectrum disorder (ANSD) with a group of CI recipients with sensorineural hearing loss (SNHL). Auditory outcome and spectral resolution findings were also compared among CI recipients with and without cochlear microphonic (CM) responses. This single-center, prospective cohort study was undertaken at a tertiary referral center. CM responses by the intracochlear ECochG test were recorded in CI recipients at 0.25-2kHz. Speech, spatial, and hearing quality (SSQ) outcomes and spectral resolution measured with the spectral-temporally modulated ripple test were obtained for each recipient. The study included 62 implanted ears in 46 recipients, of which 59% (n=27) were male and 41% (n=19) were female. Twenty-nine ears with ANSD and 33 ears with SNHL were included. The mean age of the participants was 11 years. The results compared the intracochlear ECochG findings of the ANSD group with those of the SNHL group. Participants were divided into two groups with and without obtainable CM responses. CM responses were obtained in 13 of 29 ears in the ANSD group and 14 of 33 ears in the SNHL group. CM thresholds obtained were better according to behavioral audiometric responses in some frequencies in the ANSD group. No significant difference was found in the auditory outcome and spectral resolution among CI recipients with and without CM responses. Intracochlear ECochG has a limited potential clinical value for monitoring ANSD. CM thresholds obtained using ECochG may not reflect behavioral hearing thresholds.

Effect of Lexical Neighbourhood on Word Recognition Test: A Study in Turkish

Background and Aim: Word Recognition Test (WRT) is a widely used component of routine audiology battery. Several studies were conducted on the effect of words in word recognition lists and whether word difficulty level had an effect in word recalling process of patients. This study aims to compare the scores of patients to the designed Başkent WRT and commonly used Hacettepe WRT by focusing on the lexical neighbourhood.&#x0D; Methods: Study carried out in an Ear Nose and Throat Department of a private university hospital between June and August 2021. 34 persons with sensorineural hearing loss and 34 persons without hearing loss was participated in the study. Designed WRT and widely used common WRT were presented to the participants.&#x0D; Results: Results showed that common WRT included words with more lexical neighbours and sensorineural hearing loss group scores were significantly lower compared to designed WRT.&#x0D; Conclusion: Persons with sensorineural hearing loss have a tendency to misunderstand presented words in WRT as they may trigger other words and misguide the patient.&#x0D; Keywords: Speech audiometry; speech discrimination tests; hearing tests; psychoacoustics

Significance of cytomegalovirus tests after three weeks of life in children with hearing loss

To determine the diagnostic role of viral markers for cytomegalovirus (CMV) when tested after the diagnostically critical period (postnatal 3 weeks) in children with sensorineural hearing loss (SNHL). A retrospective review of 104 subjects who underwent CMV diagnostic tests after the critical period of 3 postnatal three weeks but before 24 months of age. Infants included had not passed universal newborn hearing screening tests in at least one ear and thus underwent obligatory follow up audiology testing as well as either exome sequencing or magnetic resonance imaging in cases of SNHL. Our cohort was classified into four subgroups depending on the results from audiological and etiologic diagnostic tests (genetic and radiological tests): congenital CMV (cCMV)-related SNHL (Group 1, n=9), SNHL with another clear etiology (Group 2, n=34), and SNHL classified as neither Group 1 nor 2 (Group 3, n=18). We added age-matched, normal-hearing children (Group 4, n=43) as a control group. CMV related viral metrics were compared among these four groups. CMV PCR positivity, PCR titers, and culture positivity successfully differentiated Group 1 from Groups 2 and 4. Group 3 showed values of these parameters that were significantly different from Groups 2 and 4, while being more similar to those in Group 1, suggesting that a substantial portion of Group 3 truly had cCMV deafness. A hypothetical formula was developed to predict cCMV infections using logistic regression analysis. This is the first study to propose the clinical significance of CMV test results obtained after 3 weeks post-birth in children with SNHL and to suggest how we can utilize them.

Sudden Sensorineural Hearing Loss Is Related to Endothelial Progenitor Cells and Lipoprotein-Associated Phospholipase A2.

This study aimed to investigate the correlation between lipoprotein-associated phospholipase A2, endothelial progenitor cells, and sudden sensorineural hearing loss. The number of endothelial progenitor cells and lipoprotein-associated phospholipase A2 levels collected from peripheral blood samples were measured and compared between sudden sensorineural hearing loss group and control group. The number of endothelial progenitor cells was reduced in sudden sensorineural hearing loss group compared to control group (38.88 ± 10.73 in sudden sensorineural hearing loss group vs. 77.14 ± 8.56 in control group, P <.01). The lipoprotein-associated phospholipase A2 level was markedly increased in sudden sensorineural hearing loss group compared to control group (244.94 ± 59.547 in sudden sensorineural hearing loss group vs. 189.00 ± 50.987 in control group, P <.05). The number of endothelial progenitor cells was decreased and lipoprotein-associated phospholipase A2 levels were increased in sudden sensorineural hearing loss patients. Changes in the number of endothelial progenitor cells and lipoprotein-associated phospholipase A2 levels may be involved in the pathogenesis of sudden sensorineural hearing loss.

The Correlation between Binaural Interaction Component of the Auditory Brainstem Response and Total Score of the Persian Version of the Spatial Hearing Questionnaire

Background and Aim: People with spatial hearing impairment have difficulty perception of speech in the presence of noise, sound localization, and estimating the distance from the sound source. In this study, the comparison between amplitude and latency of the Binaural Interaction Component of the Auditory Brainstem Response (ABR-BIC) with the total score of the Persian version of the Spatial Hearing Questionnaire (SHQ) in adults with normal hearing and moderate sensorineural hearing loss (SNHL) was evaluated.&#x0D; Methods: In this cross-sectional comparative study 55, 18–45-year-old individuals including 35 of normal hearing and 20 moderate SNHL participated. All participants underwent the assessments of medical history, otoscopy, conventional audiometry, tympanometry, SHQ questionnaire, and auditory brainstem response (ABR).&#x0D; Results: There was no significant correlation between the amplitude and latency of the ABR- BIC and the Persian version of the SHQ in normal groups (r=–0.085, r=0.116) and in moderate SNHL groups (r=0.030, r=0.119). The mean value of ABR-BIC range of people with normal hearing and SNHL is statistically significant (p=0.001).&#x0D; Conclusion: The results showed that the amplitude and latency of ABR-BIC were not correlated with the Persian version of the SHQ in people with normal hearing and with moderate SNHL but statistically significant between the mean amplitude and latency of ABR- BIC in people with normal hearing and people with hearing loss.&#x0D; Keywords: Auditory brainstem response; spatial hearing questionnaire; binaural interaction component; spatial hearing; spatial hearing disorder

Vascular Factors in Patients with Midlife Sensorineural Hearing Loss and the Progression to Mild Cognitive Impairment.

Background and Objectives: Midlife hearing loss (HL) has been considered as a major modifiable risk factor for a later-life progression to dementia. Our aim was to detect a link between precocious sensorineural hearing loss (SNHL) and mild cognitive impairment (MCI) and their association to putative risk factors for a common pathology. Materials and methods: In this study, a retrospective case-control study was carried out. A total of 112 patients were enrolled as following: 81 patients with bilateral SNHL and 31 subjects with normal hearing, whose ages ranged from 50 to 65 years. Both groups performed pure tone audiometry, a tinnitus handicap inventory (THI), Mini-Mental State examination (MMSE), and the Montreal Cognitive Assessment (MoCA), Hospital Anxiety and Depression Scale (HADS-A and HADS-D). Results: The mean age was 58 ± 5.2 in SNHL patients and 53.2 ± 4.8 in the control group. The mean pure tone average in the SNHL group was 40.2 ± 18.7 dB HL on the right side and 41.2 ± 17.2 dB HL on the left side, while in the control group it was 12.5 ± 2.8 dB HL on right side and 12.4 ± 3.1 dB HL on left side. About 64% of patients with SNHL exhibited comorbidities, and the most common condition was hypertension. Altered MoCA test scores were significantly related to the pure tone averages in patients with SNHL compared to the control group (p = 0.0004), while the differences in the HADS-A and HADS-D were not significant. Furthermore, a significant correlation was observed in SNHL patients between an altered MoCA test and hypercholesterolemia (p = 0.043). Conclusions: Hearing impairment and screening tests to detect MCI should be considered in the midlife in order to carry out strategies to prevent the progression to dementia. Hypertension and hypercholesterolemia are two risk factors in the development of endothelial dysfunction, oxidative stress, and vascular inflammation, and may represent the common pathology linking the inner ear and brain damage.

Clinical Characteristics and Corticosteroid Responses of Acoustic Neuroma Treated as Idiopathic Sudden Sensorineural Hearing Loss.

Few investigations have been conducted on the clinical characteristics of the differential diagnosis of acoustic neuroma with acute sensorineural hearing loss and idiopathic sudden sensorineural hearing loss. The aim of the study was to investigate the clinical characteristics of the differential diagnoses between acoustic neuroma and idiopathic sudden sensorineural hearing loss. The medical records of patients with acute sensorineural hearing loss (142 ears), including acoustic neuroma (19 ears) and idiopathic sudden sensorineural hearing loss (123 ears), who underwent audiometric and hematologic examinations and received systemic corticosteroid treatment, were retrospectively reviewed. Hematological examination revealed that the erythrocyte sedimentation rate and fibrinogen values were significantly higher in the idiopathic sudden sensorineural hearing loss group compared to the acoustic neuroma group. Although all patients received corticosteroid treatment, hearing thresholds at the initial examination and 3 months after corticosteroid treatment were significantly higher in the idiopathic sudden sensorineural hearing loss group compared to the acoustic neuroma group at all frequencies. However, hearing recovery was worse in the acoustic neuroma group compared to the idiopathic sudden sensorineural hearing loss group. Furthermore, speech discrimination and short increment sensitivity index tests were not significantly different between the acoustic neuroma and idiopathic sudden sensorineural hearing loss groups. This is the first study to reveal that speech discrimination and short increment sensitivity index tests are not useful for the differential diagnoses between acoustic neuroma and idiopathic sudden sensorineural hearing loss, whereas erythrocyte sedimentation rate and fibrinogen, blood biomarkers of inflammation and blood viscosity, would be considered valuable. Furthermore, acoustic neuroma should be considered in cases where acute sensorineural hearing loss did not recover after corticosteroid treatment, although the initial hearing loss was mild.

Automated Adaptive Wideband Acoustic Stapedius Reflex Thresholds in Adults With Normal Hearing and Sensorineural Hearing Loss.

This study compared the measurement of the acoustic stapedius reflex threshold (ART) obtained using a traditional method with that obtained using an automated adaptive wideband (AAW) method. Participants included three groups of adults with normal hearing (NH), mild sensorineural hearing loss (SNHL), or moderate SNHL. The purpose of the study was to compare ARTs for the three groups and to determine which method had the best performance in detecting SNHL. Ipsilateral and contralateral ARTs were obtained using 0.5, 1, and 2 kHz tonal activators, and broadband noise (BBN) activators on a traditional admittance system (Clinical) at tympanometric peak pressures (TPP) and on an experimental wideband system using an AAW method at both ambient pressure and TPP. ART data previously reported for 39 NH adults with a mean age of 47.7 years were compared with data for 25 participants with mild SNHL with a mean age of 63.8 years, and 20 participants with moderate SNHL with a mean age of 65.7 years. Differences in ARTs between the normal-hearing and SNHL groups for the three methods were examined using a General Linear Model Repeated-Measures test. A receiver operating characteristic curve (ROC) analysis was also used to determine the ability of an ART test to detect SNHL. For the 0.5 kHz activator condition, there were no significant group mean differences in ART between NH and SNHL groups for either ipsilateral or contralateral activator presentation modes for the Clinical or AAW methods. There were significant group mean differences for the 1 and 2 kHz tonal activators and BBN activator for both ipsilateral and contralateral modes with greater differences in ART between groups for the AAW method than the Clinical method. In these conditions, the mean ART was lower for the AAW tests relative to the Clinical test. The greatest difference between groups was for the ipsilateral AAW tests for the comparison of NH with moderate SNHL for the BBN activator. This difference was approximately 20 dB for the AAW tests and 8 dB for the Clinical test. The ROC analysis showed that the area under the ROC curve (AUC) increased with the frequency of the activator stimulus and with the degree of hearing loss and was maximal for the BBN activator for both the AAW and Clinical methods for both ipsilateral and contralateral presentations. For ipsilateral and contralateral ART tests for activator frequencies above 0.5 kHz and BBN, listeners with SNHL generally had elevated ARTs compared with those with NH. The AAW method resulted in greater differences between SNHL groups and NH than the Clinical method. The AUC for detecting SNHL also increased with activator frequency and degree of hearing loss and was greatest for the BBN activator for the AAW method in both the ambient and TPP conditions. The results are encouraging for the use of an AAW ART method for the assessment of individuals with SNHL.

Neuropsychological criteria for diagnosing cognitive impairment in patients with occupational diseases caused by physical factors

The aim. To identify neuropsychological signs of a decrease in higher mental functions associated with professional exposure to physical factors.Materials and methods. The study involved 40 patients with vibration disease caused by local vibration (Group 1), 50 patients with vibration disease caused by combined exposure to local and general vibration (Group 2), 71 civil aviation pilots with an established diagnosis of occupational sensorineural hearing loss (Group 3), and 38 healthy men (Group 4, control group). Methods of neuropsychological testing were used.Results. In Groups 1–3 the state of functioning of the cognitive sphere is represented by a mildly pronounced nature of impairments. The results of MMSE and FAB tests in patients of Groups 1–2, when compared with Group 4, determine a decrease in the functional activity of the frontal lobes and subcortical structures (25 (24–27), 25 (22–26), 15 (14–16) and 15 (13–16) points respectively). The most informative feature associated with the fact of occupational exposure to local vibration is the indicator of long-term memory (F = 9.41; р = 0.003); with combined impact of local and general vibration – short-term memory (F = 11.0; р = 0.001); with aircraft noise – objective gnosis (F = 8.48; р = 0.001). The obtained features make it possible to track with a high degree of accuracy the development of a decrease in cognitive functions in this contingent (86.1 %, 84.8 % and 72.1 % respectively).Conclusion. Common signs of changes in the cognitive sphere and lesions of the brain structures in patients with vibration disease are a decrease in praxis, impressive speech, for occupational sensorineural hearing loss – the lack of analytical-synthetic and conceptual thinking, object and finger gnosis, characterizing the inferiority of the functioning of the frontal and parietal regions of the left hemisphere.

Can Video Head Impulse Test Determine the Early Effect of Cochlear Implantation on the Semicircular Canals Function?

Background and Aim: Although cochlear implantation (CI) is a safe surgical procedure for severe to profound sensorineural hearing loss (SNHL) but, due to the embryological and anatomical connection between the vestibular and cochlear structures, vestibular dysfunction may occur after CI. Video head impulse test (vHIT) is a reliable test for assessing the function of semicircular canals (SCCs). This study aimed to determine the early effect of CI on SCCs function, by comparing pre- and post-operative vHIT results.&#x0D; Methods: In this cross-sectional study, participants were 22 adults with SNHL scheduled for unilateral CI in the right ear and 22 age-matched healthy subjects as a control group. The vHIT was conducted before and two weeks after CI.&#x0D; Results: The mean vHIT gains in the SNHL group were significantly lower than in controls, with a large effect size. Furthermore, the mean vHIT gains in the right lateral SCCs (p&lt;0.001) and right anterior SCCs (p=0.003) were significantly reduced after CI, compared to the gain values before CI, with a large pooled effect size. However, these differences were not statistically significant for the right posterior SCCs. The comparison of vHIT gains in the non- implanted ear showed no statistically significant difference between pre- and post-operative phases.&#x0D; Conclusion: The vHIT is a useful clinical method to detect the early effects of CI on the function of SCCs. These effects are more obvious in the lateral and superior SCCs in the implanted ear.&#x0D; Keywords: Cochlear implantation; semicircular canals; video head impulse test

Evaluation of the relationship between prestin serum biomarker and sensorineural hearing loss: a case-control study.

There is not any routine serum biomarker for diagnosing hearing loss (HL). An inner ear-specific protein, prestin can be measured as a serum biochemical marker for HL diagnosis. The present study investigates, for the first time, the relationship between prestin serum levels and sensorineural HL (SNHL) in an Iranian population. In this case-control study, 176 samples were examined in four groups including two control and two SNHL groups of 20-50 and ≥ 50years with different severities of SNHL. Plasma prestin concentration was measured using Human Prestin (SLC26A5) ELISA Kit. Data analysis was conducted using SPSS v.23 with level of significance as 0.05. Groups with SNHL had higher prestin levels (Mean = 182.29, SD = 71.24) compared to the control groups (Mean = 122.50, SD = 57.1) (P < 0.001). Results of the multinomial logistic regression of relationship between prestin level and SNHL remained significant after controlling intervening variables (P < 0.001 and odds ratio = 1.017 and 95% CI OR: 1.01-1.024). Results of the ordinal logistic regression model revealed that prestin level was significantly associated with the degree of HL (P < 0.001 and Odds ratio = 1.009 and 95% CI and OR: 1.005-1.013), so that the likelihood of HL increased with the rise in prestin levels. The best cutoff point for the 20-50 group was the prestin content of 132.5pg/ml (sensitivity: 75%, specificity: 70.05%), while for the group of ≥ 50 was as 130pg/ml (sensitivity: 84.1%, specificity: 68.2%). Results of the present study revealed that prestin acts as a valuable biomarker for SNHL.

White matter structural network alterations in congenital bilateral profound sensorineural hearing loss children: A graph theory analysis

Functional magnetic resonance imaging (fMRI) studies have revealed a functional reorganization in patients with sensorineural hearing loss (SNHL). The structural basement of functional changes has also been investigated recently. Graph theory analysis brings a new understanding of the structural connectome and topological features in central neural system diseases. However, little is known about the structural network connectome changes in SNHL patients, especially in children. We explored the differences in topologic organization, rich-club organization, and structural connection between children with congenital bilateral profound SNHL and normal hearing under the age of three using graph theory analysis and probabilistic tractography. Compared with the normal-hearing (NH) group, the SNHL group showed no difference in global and nodal topological parameters. Increased structural connection strength were found in the right cortico-striatal-thalamus-cortical circuity. Decreased cross-hemisphere connections were found between the right precuneus and the left auditory cortex as well as the left subcortical regions. Rich-club organization analysis found increased local connection in the SNHL group. These results revealed structural organizations after hearing deprivation in congenital bilateral profound SNHL children.

Effect of N-acetyl-cysteine treatment on sensorineural hearing loss: a meta-analysis.

N‐acetyl‐cysteine (NAC) is an efficacious treatment for sensorineural hearing loss in animal models, such as noise‐induced hearing loss (NIHL), however previous research into the effect of NAC on patients with hearing loss produced contradictory results. In this study, we investigated the effect of NAC treatment on sensorineural hearing loss. PubMed, Web of Science and Embase databases were searched in their entirety using the key words: hearing loss, NAC, N‐acetylcysteine, and sensorineural hearing loss. Studies which included assessment of hearing loss with pure‐tone threshold (PTA) data were selected. Eligible studies regarding the effects of NAC treatment on patients with hearing loss were collected by two independent reviewers. A total of 1197 individuals were included from seven published studies. Two studies reported data for a sudden idiopathic sensorineural hearing loss (SISNHL) group. Three studies reported data for a NIHL group. Other studies reported data for drug‐induced hearing loss. The meta‐analysis demonstrated that the overall effect of NAC treatment on sensorineural hearing loss was invalid. However, NAC treatment was linked with improved patient outcomes of hearing tests in cases of sudden hearing loss, but did not prevent hearing loss induced by noise or ototoxicity. However, there is a need for better‐designed studies with larger samples to further prove the correlation between the effect of NAC and hearing loss.

Auditory and Speech Outcomes of Cochlear Implantation in Children With Auditory Neuropathy Spectrum Disorder: A Systematic Review and Meta-Analysis.

The aim of this meta-analysis was to critically assess the effect of cochlear implantation on auditory and speech performance outcomes of children with auditory neuropathy spectrum disorder (ANSD). A systematic literature search was conducted on PubMed, EMbase, and Web of Science. The outcomes included speech recognition score, Categories of Auditory Performance (CAP), Speech Intelligibility Rating (SIR) score, and open-set speech perception. Results were expressed as standardized mean difference (SMD) or risk ratio (RR) with a 95% confidence interval (95% CI). A total of 15 studies was included in this meta-analysis. Pooled data showed that, there were no significant differences between ANSD and sensorineural hearing loss (SNHL) groups in terms of speech recognition score (SMD = 0.01, 95% CI: -0.45, 0.47; P = .959),CAP (SMD = 0.71, 95% CI: -0.13, 1.54; P = .098), SIR score (SMD = -0.09, 95% CI: -0.49, 0.32; P = .667), and open-set speech perception (RR = 0.85, 95% CI: 0.69, 1.05; P = .142). Sensitivity analysis by removing individual studies one at a time showed that the overall estimate and level of heterogeneity did not change substantially. The current evidence suggested that children with ANSD who underwent cochlear implants achieved comparable effects in auditory and speech performance as children with non-ANSD SNHL.

The Onset-Offset N1-P2 Cortical Auditory Evoked Response in Individuals With High-Frequency Sensorineural Hearing Loss: Responses to High- and Low-Frequency Narrowband Noise.

This study aimed to determine whether onset-offset N1-P2 auditory evoked responses differ in amplitude, latency, and offset-to-onset trough-to-peak N1-P2 amplitude ratios (OOAR) between normal hearing (NH) sensitivity and moderate high-frequency sensorineural hearing loss (HFSNHL) groups when stimuli target regions of peripheral hearing sensitivity where the groups are in the normal range (i.e., 500 Hz) versus where they differ regarding presence of hearing loss (i.e., 4000 Hz). Onset-offset N1-P2 auditory evoked responses were measured from 10 participants with normal hearing sensitivity and seven participants with moderate HFSNHL using 500-Hz and 4000-Hz narrowband noise (NBN) stimuli. Stimuli were 2000 ms with 40-ms rise-fall times presented at 50 dB SL referenced to stimulus behavioral thresholds. Amplitudes and latencies were analyzed for N1 and P2 onset and offset components via repeated measures analysis of variance (ANOVA). OOARs were compared between groups using one-way ANOVA and across stimuli per group using paired samples t tests. Despite dB SPL stimulus presentation differences between groups, there were no significant differences in individual/absolute amplitude and latency waveform components between groups for either stimulus. Derived comparative calculations of OOAR for 4000-Hz NBN were significantly larger (p < .025; NH: .39; HFSNHL: .62) for the group with HFSNHL than the group with NH sensitivity; 500-Hz NBN OOAR did not reach significance. OOARs revealed no significant difference between stimuli for the group with normal hearing sensitivity, with .38 OOAR for both stimuli (p = .961). OOAR comparisons for the HFSNHL group across stimuli were significant (p = .012), with the 4000-Hz NBN OOAR being nearly double the size of the 500-Hz NBN OOAR. OOARs may provide insight to the balance of excitatory and inhibitory neural firing in the central auditory nervous system (CANS). Larger OOARs may be a biomarker of reduced CANS inhibition, perhaps indicative of a homeostatic central auditory gain mechanism.

Sensorineural Hearing Loss Affects Functional Connectivity of the Auditory Cortex, Parahippocampal Gyrus and Inferior Prefrontal Gyrus in Tinnitus Patients.

BackgroundTinnitus can interfere with a patient’s speech discrimination, but whether tinnitus itself or the accompanying sensorineural hearing loss (SNHL) causes this interference is still unclear. We analyzed event-related electroencephalograms (EEGs) to observe auditory-related brain function and explore the possible effects of SNHL on auditory processing in tinnitus patients.MethodsSpeech discrimination scores (SDSs) were recorded in 21 healthy control subjects, 24 tinnitus patients, 24 SNHL patients, and 27 patients with both SNHL and tinnitus. EEGs were collected under an oddball paradigm. Then, the mismatch negativity (MMN) amplitude and latency, the clustering coefficient and average path length of the whole network in the tinnitus and SNHL groups were compared with those in the control group. Additionally, we analyzed the intergroup differences in functional connectivity among the primary auditory cortex (AC), parahippocampal gyrus (PHG), and inferior frontal gyrus (IFG).ResultsSNHL patients with or without tinnitus had lower SDSs than the control subjects. Compared with control subjects, tinnitus patients with or without SNHL had decreased MMN amplitudes, and SNHL patients had longer MMN latencies. Tinnitus patients without SNHL had a smaller clustering coefficient and a longer whole-brain average path length than the control subjects. SNHL patients with or without tinnitus had a smaller clustering coefficient and a longer average path length than patients with tinnitus alone. The connectivity strength from the AC to the PHG and IFG was lower on the affected side in tinnitus patients than that in control subjects; the connectivity strength from the PHG to the IFG was also lower on the affected side in tinnitus patients than that in control subjects. However, the connectivity strength from the IFG to the AC was stronger in tinnitus patients than that in the control subjects. In SNHL patients with or without tinnitus, these changes were magnified.ConclusionChanges in auditory processing in tinnitus patients do not influence SDSs. Instead, SNHL might cause the activity of the AC, PHG and IFG to change, resulting in impaired speech recognition in tinnitus patients with SNHL.

Altered Functional Network in Infants With Profound Bilateral Congenital Sensorineural Hearing Loss: A Graph Theory Analysis.

Functional magnetic resonance imaging (fMRI) studies have suggested that there is a functional reorganization of brain areas in patients with sensorineural hearing loss (SNHL). Recently, graph theory analysis has brought a new understanding of the functional connectome and topological features in central neural system diseases. However, little is known about the functional network topology changes in SNHL patients, especially in infants. In this study, 34 infants with profound bilateral congenital SNHL and 28 infants with normal hearing aged 11–36 months were recruited. No difference was found in small-world parameters and network efficiency parameters. Differences in global and nodal topologic organization, hub distribution, and whole-brain functional connectivity were explored using graph theory analysis. Both normal-hearing infants and SNHL infants exhibited small-world topology. Furthermore, the SNHL group showed a decreased nodal degree in the bilateral thalamus. Six hubs in the SNHL group and seven hubs in the normal-hearing group were identified. The left middle temporal gyrus was a hub only in the SNHL group, while the right parahippocampal gyrus and bilateral temporal pole were hubs only in the normal-hearing group. Functional connectivity between auditory regions and motor regions, between auditory regions and default-mode-network (DMN) regions, and within DMN regions was found to be decreased in the SNHL group. These results indicate a functional reorganization of brain functional networks as a result of hearing loss. This study provides evidence that functional reorganization occurs in the early stage of life in infants with profound bilateral congenital SNHL from the perspective of complex networks.

Tinnitus and Underlying Theoretical Mechanism

Background and Aim: To evaluate the association between psychoacoustical characteristics of tinnitus and audiogram configurations and reveal which theoretical mechanism dominates tinnitus. Materials and Methods: The medical charts of 110 adult participants' 164 ears with tinnitus were retrospectively reviewed. Audiological results, edge frequency, and psychoacoustical characteristics of tinnitus were assessed. Participants were divided into two groups as follows: normal hearing (NH) and sensorineural hearing loss (SNHL). Results: No significant relationship was observed between age, gender, tinnitus pitch, and loudness between the two groups. In the SNHL group, there was a weak positive correlation between tinnitus pitch and frequency of maximum hearing loss (FMHL), and a strong positive correlation between the mean tinnitus loudness at the tinnitus pitch and FMHL. Besides, the edge frequency was positively and weakly correlated with the tinnitus pitch and FMHL. No statistically significant difference was observed between the groups regarding the tinnitus pitch. However, tinnitus loudness was statistically higher in the NH group. No relationship was observed between the audiogram shapes and tinnitus timbre, pitch, and FMHL. In addition, the most likened tinnitus timbre was found to be tonal/whistle in both groups. A moderate positive correlation was observed between the tinnitus pitch and edge frequency in the gradual slope audiograms. Conclusions: The findings obtained in this study supported homeostatic plasticity theories for the SNHL group, and hidden hearing loss for the NH group.