Three-Dimensional High-Resolution Temporal Bone Histopathology Identifies Areas of Vascular Vulnerability in the Inner Ear

<b><i>Objectives:</i></b> Hypothesized causes of vestibular neuritis/labyrinthitis include neuroinflammatory or vascular disorders, yet vascular disorders of the inner ear are poorly understood. Guided by known microvascular diseases of the retina, we developed 2 hypotheses: (1) there exist vascular vulnerabilities of artery channels in cases of hypothetical nerve swelling for the superior, inferior, and vestibulocochlear artery and (2) there are arteriovenous crossings that could compromise vascular flow in disease states. <b><i>Methods:</i></b> Two fully mounted and stained temporal bones were used to render three-dimensional reconstructions of the labyrinth blood supply. Using these maps, areas of potential vascular compression were quantified in 50 human temporal bones. <b><i>Results:</i></b> Although inner ear arteries and veins mostly travel within their own bony channels, they may be exposed (1) at the entrance into the otic capsule, and (2) where the superior vestibular vein crosses the inferior vestibular artery. At the entry into the otic capsule, the ratio of the soft tissue to total space for the superior vestibular artery was significantly greater than the inferior vestibular artery/cochleovestibular artery (median 44, interquartile range 34–55 vs. 14 [9–17], <i>p</i> &#x3c; 0.0001). <b><i>Conclusions:</i></b> Three-dimensional reconstruction of human temporal bone histopathology can guide vascular studies of the human inner ear. Studies of retinal microvascular disease helped identify areas of vascular vulnerability in cases of hypothetical nerve swelling at the entrance into the otic capsule and at an arteriovenous crossing near the saccular macula. These data may help explain patterns of clinical findings in peripheral vestibular lesions.

Speech-in-Noise Audiometry in Adults: A Review of the Available Tests for French Speakers

<b><i>Background:</i></b> Difficulty understanding speech in background noise is the reason of consultation for most people who seek help for their hearing. With the increased use of speech-in-noise (SpIN) testing, audiologists and otologists are expected to evidence disabilities in a greater number of patients with sensorineural hearing loss. The purpose of this study is to list validated available SpIN tests for the French-speaking population. <b><i>Summary:</i></b> A review was conducted according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. PubMed and Scopus databases were searched. Search strategies used a combination of 4 keywords: speech, audiometry, noise, and French. There were 10 validated SpIN tests dedicated to the Francophone adult population at the time of the review. Some tests use digits triplets as speech stimuli and were originally designed for hearing screening. The others were given a broader range of indications covering diagnostic or research purposes, determination of functional capacities and fitness for duty, as well as assessment of hearing amplification benefit. <b><i>Key Messages:</i></b> As there is a SpIN test for almost any type of clinical or rehabilitation needs, both the accuracy and duration should be considered for choosing one or the other. In an effort to meet the needs of a rapidly aging population, fast adaptive procedures can be favored to screen large groups in order to limit the risk of ignoring the early signs of forthcoming presbycusis and to provide appropriate audiological counseling.

Increased Monocyte Chemotactic Protein-1 Accompanying Pro-Inflammatory Processes are Associated with Progressive Hearing Impairment and Bilateral Disability of Meniere’s Disease

<b><i>Background:</i></b> The progression of hearing impairment and the bilateral involvement of Meniere’s disease (MD) may depend on the disease duration and aging. Recent studies reported that MD might involve dysfunction of the microvascular circulation damaged due to inflammatory changes. <b><i>Objectives:</i></b> The aim of this study was to determine that the progress of the MD’s hearing impairment and bilateral disability may be associated with the pathogenesis of several pro-inflammatory processes. <b><i>Patients and Methods:</i></b> We recruited 30 unilateral MD patients (56.8 ± 14.7 years old), 7 bilateral MD patients (65.3 ± 13.9 years old), and 17 age-matched control subjects (53.5 ± 14.4 years old, <i>p</i> &#x3e; 0.05). We measured the plasma vascular endothelial growth factor (VEGF), plasma interleukin-6 (IL-6), plasma tumor-necrosis factor α (TNFα), and plasma monocyte chemotactic protein-1 (MCP-1). <b><i>Results:</i></b> The bilateral MD group and the unilateral MD group had higher plasma MCP-1 (204.7 ± 41.0 pg/mL and 169.5 ± 32.0 pg/mL) than the control group (149.2 ± 30.7 pg/mL) (<i>p</i> &#x3c; 0.05). There was no significant difference in plasma TNFα, IL-6, and VEGF among 3 groups (<i>p</i> &#x3e; 0.05). There was a strong correlation between the plasma MCP-1 and age in MD patients (<i>r</i> = 0.58, <i>p</i> &#x3c; 0.01); however, no significant correlation between the plasma MCP-1 and age was found in control subjects (<i>p</i> &#x3e; 0.05). The plasma MCP-1 significantly correlated with the average hearing level of 500, 1,000, 2,000, and 4,000 Hz, and the maximum slow phase eye velocity in caloric test in the better side (<i>p</i> &#x3c; 0.05). Also, the plasma MCP-1 showed significant positive correlations with the plasma IL-6 (<i>r</i> = 0.49, <i>p</i> &#x3c; 0.01) and plasma TNFα (<i>r</i> = 0.32, <i>p</i> &#x3c; 0.05) in MD group. <b><i>Conclusions:</i></b> Our results suggest that the increased plasma MCP-1 accompanying pro-inflammatory processes are associated with the progression of the hearing impairment and the bilateral disability of MD.

Influence of Postponed Follow-Up after Cochlear Implant Activation during the COVID-19 Pandemic on Aided Sound Field Detection and Speech Recognition

<b><i>Introduction:</i></b> The objective of this study was to assess the influence of postponing the first post-activation follow-up due to the COVID-19 pandemic on the aided sound field detection thresholds and speech recognition of cochlear implant (CI) users. <b><i>Methods:</i></b> A retrospective review was performed at a tertiary referral center. Two groups of adult CI recipients were evaluated: (1) patients whose first post-activation follow-up was postponed due to COVID-19 closures (postponed group; <i>n</i> = 10) and (2) a control group that attended recommended post-activation follow-ups prior to the COVID-19 pandemic (control group; <i>n</i> = 18). For both groups, electric thresholds were estimated at initial activation based on comfort levels and were measured behaviorally at subsequent post-activation follow-ups. For the control group, behavioral thresholds were measured at the 1-month follow-up. For the postponed group, behavioral thresholds were not measured until 3 months post-activation since the 1-month follow-up was postponed. The aided pure-tone average (PTA) and word recognition results were compared between groups at the 3-month follow-up and at an interim visit 2–9 weeks later. <b><i>Results:</i></b> At the 3-month follow-up, the postponed group had significantly poorer word recognition (23 vs. 42%, <i>p</i> = 0.027) and aided PTA (42 vs. 37 dB HL, <i>p</i> = 0.041) than the control group. No significant differences were observed between 3-month data from the control group and interim data from the postponed group. <b><i>Conclusions:</i></b> The postponed follow-up after CI activation was associated with poorer outcomes, both in terms of speech recognition and aided audibility. However, these detrimental effects were reversed following provision of an individualized map, with behaviorally measured electric threshold and comfort levels. While adult CI recipients demonstrate an improvement in speech recognition with estimated electric thresholds, the present results suggest that behavioral mapping within the initial weeks of device use may support optimal outcomes.

Identifying Subclinical Hearing Loss: Extended Audiometry and Word Recognition in Noise

<b><i>Introduction:</i></b> Normal-hearing people often have complaints about the ability to recognize speech in noise. Such disabilities are not typically assessed with conventional audiometry. Suprathreshold temporal deficits might contribute to reduced word recognition in noise as well as reduced temporally based binaural release of masking for speech. Extended high-frequency audibility (&#x3e;8 kHz) has also been shown to contribute to speech perception in noise. The primary aim of this study was to compare conventional audiometric measures with measures that could reveal subclinical deficits. <b><i>Methods:</i></b> Conventional and extended high-frequency audiometry was done with 119 normal-hearing people ranging in age from 18 to 72. The ability to recognize words in noise was evaluated with and without differences in temporally based spatial cues. A low-uncertainty, closed-set word recognition task was used to limit cognitive influences. <b><i>Results:</i></b> In normal-hearing listeners, word recognition in noise ability decreases significantly with increasing pure-tone average (PTA). On average, signal-to-noise ratios worsened by 5.7 and 6.0 dB over the normal range, for the diotic and dichotic conditions, respectively. When controlling for age, a significant relationship remained in the diotic condition. Measurement error was estimated at 1.4 and 1.6 dB for the diotic and dichotic conditions, respectively. Controlling for both PTA and age, EHF-PTAs showed significant partial correlations with SNR50 in both conditions (<i>ρ</i> = 0.30 and 0.23). Temporally based binaural release of masking worsened with age by 1.94 dB from 18 to 72 years old but showed no significant relationship with either PTA. <b><i>Conclusions:</i></b> All three assessments in this study demonstrated hearing problems independently of those observed in conventional audiometry. Considerable degradations in word recognition in noise abilities were observed as PTAs increased within the normal range. The use of an efficient words-in-noise measure might help identify functional hearing problems for individuals that are traditionally normal hearing. Extended audiometry provided additional predictive power for word recognition in noise independent of both the PTA and age. Temporally based binaural release of masking for word recognition decreased with age independent of PTAs within the normal range, indicating multiple mechanisms of age-related decline with potential clinical impact.

Efficacy of Hyperbaric Oxygen on Idiopathic Sudden Sensorineural Hearing Loss and Its Correlation with Treatment Course: Prospective Clinical Research

<b><i>Objectives:</i></b> This study was conducted to explore the effectiveness of hyperbaric oxygen (HBO) in the treatment of idiopathic sudden sensorineural hearing loss (ISSNHL) and recommend the appropriate course of treatment. <b><i>Methods:</i></b> 102 patients (105 diseased ears) with ISSNHL were recruited from the Department of Neurology and Otorhinolaryngology, West China Fourth Hospital, Sichuan University, between January 2018 and September 2020. Of them, 45 patients (group A) received intravenous steroid (IVS), and the remaining patients (group B) received IVS and HBO therapy (HBOT). Pure-tone audiometry (PTA) was performed twice at baseline and 10 days after treatment. Patients in group B were subdivided into group 1 (≤10 sessions) and group 2 (&#x3e;11 sessions) to verify the correlation between the efficacy and course of HBOT, at the follow-up endpoint, the PTA was performed again. The multivariate logistical regression model was used to analyze the related factors of prognosis. <b><i>Results:</i></b> Compared with the control group, significantly larger hearing gains and better hearing recovery rate were observed in the IVS + HBOT group (<i>p</i> &#x3c; 0.05). The time of treatment and course of HBOT were significantly correlated with the hearing threshold after treatment (<i>p</i> &#x3c; 0.05) and had no significant relationship with tinnitus and age (<i>p</i> &#x3e; 0.05). <b><i>Conclusion:</i></b> HBOT + IVS is an effective method for ISSNHL, especially for the recovery of low-frequency hearing and initial hearing levels of severe and profound. Tinnitus is the most common concomitant symptom of ISSNHL, and prolonging the course of HBOT did not significantly improve it. Initiating HBOT within 7 days for 10–25 sessions of treatment was more beneficial.

Does Oral Monosodium Glutamate Have a Cochleotoxic Effect? An Experimental Study

<b><i>Introduction:</i></b> The effect of orally consumed monosodium glutamate (MSG), which is a common additive in the food industry, on the cochlea has not been investigated. The present study aimed to investigate the possible cochleotoxic effects of oral MSG in guinea pigs using electrophysiological, biochemical, and histopathological methods. <b><i>Methods:</i></b> Thirty guinea pigs were equally divided into control and intervention groups (MSG 100 mg/kg/day; MSG 300 mg/kg/day). At 1 month, 5 guinea pigs from each group were sacrificed; the rest were observed for another month. Electrophysiological measurements (distortion product otoacoustic emission [DPOAE] and auditory brainstem response [ABR]), glutamate levels in the perilymph and blood samples, and histopathological examinations were evaluated at 1 and 2 months. <b><i>Results:</i></b> Change in signal-to-noise ratio at 2 months was significantly different in the MSG 300 group at 0.75 kHz and 2 kHz (<i>p</i> = 0.013 and <i>p</i> = 0.044, respectively). There was no statistically significant difference in ABR wave latencies of the guinea pigs given MSG compared to the control group after 1 and 2 months; an increase was noted in ABR thresholds, although the difference was not statistically significant. In the MSG groups, moderate-to-severe degeneration and cell loss in outer hair cells, support cells, and spiral ganglia, lateral surface junction irregularities, adhesions in stereocilia, and partial loss of outer hair cell stereocilia were noted. <b><i>Conclusion:</i></b> MSG, administered in guinea pigs at a commonly utilized quantity and route of administration in humans, may be cochleotoxic.

Talker Adaptation and Lexical Difficulty Impact Word Recognition in Adults with Cochlear Implants

<b><i>Introduction:</i></b> Talker-specific adaptation facilitates speech recognition in normal-hearing listeners. This study examined talker adaptation in adult cochlear implant (CI) users. Three hypotheses were tested: (1) high-performing adult CI users show improved word recognition following exposure to a talker (“talker adaptation”), particularly for lexically hard words, (2) individual performance is determined by auditory sensitivity and neurocognitive skills, and (3) individual performance relates to real-world functioning. <b><i>Methods:</i></b> Fifteen high-performing, post-lingually deaf adult CI users completed a word recognition task consisting of 6 single-talker blocks (3 female/3 male native English speakers); words were lexically “easy” and “hard.” Recognition accuracy was assessed “early” and “late” (first vs. last 10 trials); adaptation was assessed as the difference between late and early accuracy. Participants also completed measures of spectral-temporal processing and neurocognitive skills, as well as real-world measures of multiple-talker sentence recognition and quality of life (QoL). <b><i>Results:</i></b> CI users showed limited talker adaptation overall, but performance improved for lexically hard words. Stronger spectral-temporal processing and neurocognitive skills were weakly to moderately associated with more accurate word recognition and greater talker adaptation for hard words. Finally, word recognition accuracy for hard words was moderately related to multiple-talker sentence recognition and QoL. <b><i>Conclusion:</i></b> Findings demonstrate a limited talker adaptation benefit for recognition of hard words in adult CI users. Both auditory sensitivity and neurocognitive skills contribute to performance, suggesting additional benefit from adaptation for individuals with stronger skills. Finally, processing differences related to talker adaptation and lexical difficulty may be relevant to real-world functioning.

Audiological Patterns in Patients with Autoimmune Hearing Loss

<b><i>Introduction:</i></b> The aim of this study was to illustrate clinical and audiological patterns of hearing impairment in patients with autoimmune hearing loss (AIHL). <b><i>Methods:</i></b> Fifty-three patients with AIHL were retrospectively recruited, and a tapering schema of steroid treatment was administered in all these patients. The diagnosis of AIHL was essentially based on clinical symptoms, such as recurrent, sudden (sensorineural hearing loss [SSHL]), fluctuating, or quickly progressing (&#x3c;12 months) SSHL (uni-/bilateral), in association with the coexistence of autoimmune diseases, high antinuclear antibodies (ANA) and the presence of human leukocyte antigen (HLA) B27, B35, B51, C04, and C07. Logistic regression analysis was applied to correlate the clinical data and laboratory features of AIHL with final outcomes. <b><i>Results:</i></b> The onset of AIHL was mainly progressive (49%), followed by SSHL (39.6%) or fluctuating (11.3%). The pure-tone audiogram showed more commonly a downsloping pattern (42.6% of ears), but also an upsloping, flat, cookie-bite, or inverse cookie-bite shape. Bilateral progressive AIHL was more frequently simultaneous (23 patients) than heterochronous (4 patients). Nineteen patients (35.8%) showed a favorable response to steroid therapy. The presence of recurrent, bilateral SSHL versus recurrent, unilateral SSHL had statistically negative effect on hearing recovery (OR = 0.042, <i>p</i> &#x3c; 0.05). The heterochronous bilateral SSHL may have better prognosis than simultaneous bilateral SSHL (OR = 10.000, <i>p</i> = 0.099). The gender, age, concomitant autoimmune disease, high ANA, HLA alleles, tinnitus, and vestibular symptoms had no statistical effect on a favorable outcome of AIHL. <b><i>Conclusions:</i></b> A bilateral, simultaneous, and progressive hearing loss combined with downsloping audiogram occurred more often in patients with AIHL. Bilateral simultaneous SSHL with recurrences represents the worse prognostic form of AIHL.

Subjective Cognitive Dysfunction in Patients with Dizziness and Vertigo

<b><i>Introduction:</i></b> Patients with vestibular disorders sometimes report cognitive difficulties, but there is no consensus about the type or degree of cognitive complaint. We therefore investigated subjective cognitive dysfunction in a well-defined sample of neuro-otology patients and used demographic factors and scores from a measure of depression, anxiety, and stress to control for potential confounding factors. <b><i>Methods:</i></b> We asked 126 neuro-otology clinic outpatients whether they experienced difficulties with thinking, memory, or concentration as a result of dizziness or vertigo. They and 42 nonvertiginous control subjects also completed the Neuropsychological Vertigo Inventory (NVI, which measures cognitive, emotional, vision, and motor complaints), the Everyday Memory Questionnaire (EMQ), and Depression, Anxiety, and Stress Scales (DASS). <b><i>Results:</i></b> In the initial interview questions, 60% of patients reported experiencing cognitive difficulties. Cognitive questionnaire scores were positively correlated with the overall DASS score and to a lesser extent with age and gender. Therefore, we compared patients and controls on the NVI and EMQ, using these mood and demographic variables as covariates. Linear regression analyses revealed that patients scored significantly worse on the total NVI, NVI cognitive composite, and 3 individual NVI cognition subscales (Attention, Space Perception, and Time Perception), but not the EMQ. Patients also scored significantly worse on the NVI Emotion and Motor subscales. <b><i>Conclusions:</i></b> Patients with dizziness and vertigo reported high levels of cognitive dysfunction, affecting attention, perceptions of space and time. Although perceptions of cognitive dysfunction were correlated with emotional distress, they were significantly elevated in patients over and above the impact of depression, anxiety, or stress.