Jaro-Journal of the Association for Research in Otolaryngology最新文献

Purpose: The efficacy of the Cochlear Implant (CI) in listeners with single-sided deafness (SSD) was evaluated by comparing single-ear speech perception in SSD listeners and bilateral cochlear implant listeners (BCI).

Methods: Consonant-nucleus-consonant (CNC) speech perception scores for the CI-only ear in SSD listeners (N = 55; 36 female, 19 male) were compared to single-ear performance in age and device experience-matched BCI listeners (N = 55; 29 female, 26 male). Separate analyses examined: (1) a matched ear from the BCI listeners (for sequentially implanted BCI listeners, the first-implanted ear in sequential BCI listeners, or, for simultaneously implanted BCI listeners, the ear on the same side as the CI in the matching SSD listener), and (2) the lower-performing ear across BCI listeners. Additional models included moderators such as age, time since activation, CI usage, and etiology. A final analysis compared first and second implants for sequential BCI listeners.

Results: SSD listeners showed significantly lower CNC performance after controlling for age, time since activation, CI usage, and etiology. Sequential BCI listeners exhibited significantly lower CNC performance on their second ear, compared to their first ear.

Conclusion: Speech perception with CIs is reduced in SSD listeners compared to BCI users, likely due to blocking, where the normal-hearing ear diminishes reliance on the CI. Lower performance in the second implanted ear of sequential BCI listeners also suggests greater reliance on the more experienced ear. These findings highlight the need for additional training, resources, and support to optimize CI performance in SSD listeners, despite prior evidence of positive CNC outcomes.

Purpose: Birth cohort differences capture secular trends in population health. We aimed to determine birth cohort differences, defined by generation, in hearing-related outcomes.

Methods: Participants were from a community-based cohort study. Generation was classified according to birth year: Greatest (1901-1924), Silent (1925-1945), Baby Boom (1946-1964), Generation X (1965-1980), or Millennial (1981-1996) and Gen Z (1997-2012). Primary outcomes were audiometric hearing loss, defined as a worse ear pure-tone average (PTA) of thresholds at frequencies 0.5, 1.0, 2.0, and 4.0 kHz > 25 dB HL, and self-reported hearing difficulty, defined as a score ≥ 6 on the Revised Hearing Handicap Inventory (RHHI). Analyses focused on hearing aid use included only participants with audiometric hearing loss. We used multivariable adjusted logistic regression models to evaluate associations between generation and each outcome. Models were stratified to sex when there was evidence of effect modification.

Results: This cross-sectional study included 1554 participants (mean age 63.7 [SD 14.4] years; 56.8% female, 20.0% racial Minority). The prevalence of audiometric hearing loss, self-reported hearing difficulty, and hearing aid use (among participants with audiometric hearing loss) was 48.9%, 48.8%, and 22.0%, respectively. Generation was associated with audiometric hearing loss in the entire sample and males only. Generation was not consistently associated with self-reported hearing difficulty or hearing aid use.

Conclusion: More recent generations had lower prevalence of audiometric hearing loss. There were no generational differences in self-reported hearing difficulty or hearing aid use. Secular hearing-related trends can inform accurate projections of the burden of hearing loss and health care utilization.

Purpose: Age-related hearing loss (ARHL) is one of the most prevalent conditions affecting the elderly. ARHL is influenced by a combination of environmental and genetic factors; the identification of the genes that confer risk will aid in the prevention and treatment of ARHL. The mouse and human inner ears are functionally and genetically homologous. We used Carworth Farms White (CFW) mice to study the genetic basis of ARHL because they are genetically diverse and exhibit variability in the age of onset and severity of ARHL.

Methods: Hearing at a range of frequencies was measured using auditory brainstem response (ABR) thresholds in 946 male and female CFW mice at the age of 1, 6, and 10 months. We genotyped the mice using low-coverage (mean coverage 0.27 ×) whole-genome sequencing (lcWGS) followed by imputation using STITCH. To determine the accuracy of the genotypes, we sequenced 8 samples at > 30 × coverage and used those data to estimate the accuracy of lcWGS genotyping, which was > 99.5%. We performed a genome-wide association study (GWAS) for the ABR thresholds for each frequency at each age, and we also performed a GWAS for age at deafness.

Results: We obtained genotypes at 4.18 million single nucleotide polymorphisms (SNP). The SNP heritability for traits ranged from 0 to 42%. GWAS identified 10 significant associations with ARHL that contained potential candidate genes, including Dnah11, Rapgef5, Cpne4, Prkag2, and Nek11. Genetic ablation of Prkag2 caused ARHL at high frequencies, strongly suggesting that Prkag2 is the causal gene for one of the associations.

Conclusions: GWAS for ARHL in CFW outbred mice identified genetic risk factors for ARHL, including Prkag2. Our results will help to define novel therapeutic targets for the treatment and prevention of this common disorder.

This article reviews basic and clinical research on the human middle ear. The topics include the use of temporal bones as models of the human middle ear; the integration of mechanical measurements, clinical results and middle-ear models to direct lines of inquiry; hearing with no tympanic membrane or ossicular chain; hearing after tympanic membrane replacement; the function of the tympanic membrane; and sound conduction through the ossicular chain.

Chronic suppurative otitis media (CSOM) affects up to 330 million people globally and is one of the leading causes of pediatric hearing loss. Defined by a state of chronic infection in the middle ear in the setting of a tympanic membrane perforation, CSOM is traditionally most frequently associated with infection with Pseudomonas and Staphylococcus aureus species. The current therapeutic options for CSOM include medical therapy in the form of topical antibiotics or antiseptics (i.e., boric acid, acetic acid, povo-iodine), as well as surgical intervention with tympanoplasty or tympanomastoidectomy in refractory cases. While topical fluoroquinolones have the strongest level of evidence supporting their use for CSOM treatment, they are frequently associated with long-term treatment failure. Treatment failure is secondary to the presence of persister cells in CSOM, which are antibiotic tolerant and have the potential to proliferate and gain additional antibiotic resistance. As biofilms and persister cells are not routinely tested for in clinical medicine, there is limited data on therapeutic options that may eradicate biofilms and persister cells while limiting ototoxic effects. While future research should aim to identify such ototopical treatment options, clinicians may also consider surgical intervention earlier in patients with disease refractory to topical treatment to both minimize the risk of encouraging antibiotic resistance and to maximize the ability to debride the biofilm.

Purpose: Present-day cochlear-implant (CI) users can achieve high levels of speech reception in quiet surroundings. Nevertheless, sensitivity to the temporal pitch of sounds is limited, which contributes to deficits in speech reception amid multiple talkers and in appreciation of musical melodies. Short-term, invasive neurophysiological studies in animals have demonstrated limitations in neural phase locking in the tonotopic range of the auditory pathway that is activated by CIs. It remains an open question, however, whether those neural limitations can account for perceptual deficits in those animal species, let alone in human CI users. For that reason, we have evaluated non-invasive recordings of phase locking from cats chronically implanted with a CI.

Methods: Ten deafened cats (eight female) were implanted with an animal version of a clinical CI array. The electrically evoked frequency following response (eFFRs) was recorded from the scalps of sedated animals at ≥ 10 weeks post-implantation. Stimuli consisted of constant-amplitude electrical pulse trains at rates from ~ 40 to 640 pulses per second.

Results: Recordings of the eFFR demonstrated robust responses synchronized to electrical pulse trains across all stimulus rates. Analyses of eFFR amplitude and phase transfer functions confirmed that the eFFR, as with its normal-hearing counterpart, originates from multiple subcortical and cortical generators. The slopes of segments of eFFR phase transfer functions revealed stimulus-to-response latencies of generators that dominated the eFFR across restricted ranges of pulse rates. Those rate ranges must coincide with the limits of phase locking by putative generators at successive levels of the auditory neuroaxis and could inform our understanding of the limits to perceptual temporal acuity.

Conclusion: The eFFR demonstrated here in an animal model provides a valuable non-invasive measure of temporal processing in electric cochlear stimulation that can be related to ongoing perceptual measures in the same animals and is well-suited to evaluate novel modes of auditory prosthesis for enhancing temporal acuity.

Studies of hearing often conclude that the ear is "remarkable" or that its performance is "exceptional." Some common examples include the following: $▹$  the ears of mammals are encased in the hardest bone in the body; $▹$  the ear contains the most vascularized tissue in body; $▹$  the ear has the highest resting potential in the body; $▹$  ears have a unique "fingerprint"; $▹$  the ear can detect signals below the thermal noise floor; and $▹$  the ear is highly nonlinear (or highly linear, depending upon who you ask). Some claims hold up to further scrutiny, while others do not. Additionally, several claims hold for animals in one taxon, while others are shared across taxa. Most frequently, our sense of wonder results from the differences between ears as products of natural selection (over eons) and artificial systems as products of engineering design. Our goal in analyzing claims of remarkable or exceptional performance is to deepen our appreciation of these differences.

Objective: Differentiating between Meniere's disease (MD) and vestibular migraine (VM) is challenging due to overlapping symptoms and limited diagnostic tools. Traditional statistical methods often rely on physician judgment and struggle with complex, high-dimensional data. This study applies the random forest (RF) machine learning algorithm to enhance the clinical differentiation between MD and VM.

Methods: We retrospectively analyzed data from 36 VM (26 female) and 100 unilateral MD patients (51 female). The data were anonymized and labeled. Symptomatic and examination parameters were selected as features, and exploratory data analysis identified key parameters for diagnosis. An RF model was used to rank these features.

Results: MD patients more commonly experienced ear-related symptoms, while VM patients reported more headaches and dizziness. Examination findings showed greater asymmetry in vHIT saccade latency in MD patients, particularly on the affected side. A total of 40 key parameters were identified. Heatmap and clustering analysis revealed that time constant (Tc) in velocity step test (VST) correlated more strongly with headache and other symptoms, while saccade latencies and velocities correlated with pure tone averages. The RF model selected 27 parameters for prediction, achieving 91.86% accuracy (95% confidence interval [85.37%, 95.18%]). Tc and saccade velocity were among the top 10 contributing features. Additionally, MD patients had earlier saccades and shorter Tc values on the affected side compared to both healthy controls and VM patients.

Conclusions: Machine learning successfully classified MD and VM patients, with Tc and saccade velocity identified as key diagnostic indicators alongside symptoms.

Purpose: Several therapeutic approaches for hearing disorders involve attaching medical devices to the tympanic membrane. The attachment of these devices can change the mechanical and acoustical properties of the middle ear, affecting the middle-ear vibrations. The alteration of passive mechanical properties results from the mass, stiffness, and geometry of the attached device. Additionally, procedures like tympanostomy tube attachment create perforations on the tympanic membrane, altering both the mechanical and acoustical properties of the middle ear. This study examined the acoustical effects of these as well as the combination of acoustical and mechanical effects of the attached devices on middle-ear vibrations.

Methods: A finite-element model of the middle ear, including the middle-ear cavity, was used to systematically study the effects of perforation size and location on vibration outputs. Experimental data from the literature were used to tune the model. This model was then employed to investigate the combined mechanical and acoustical effects of tympanostomy tubes on vibration outputs.

Results: In presence of both the mechanical effects of the device (due to its mass and stiffness) and the acoustical effects of it (due to perforations), the reduction in the motion of the stapes footplate resulting from the acoustical effects is more remarkable at low frequencies (below about 1 kHz). However, at higher frequencies, the mechanical effects of the device are dominant.

Conclusion: The findings of this study provide insights into the optimal design of the shape, location, and other characteristics of medical devices implanted on the tympanic membrane.

Purpose: To explore the feasibility of cochlear-implant (CI) processing strategies that aim to improve pitch perception by presenting information on the stimulus temporal fine structure (TFS) in low-frequency channels to the corresponding apical electrodes.

Methods: Eight users of the MED-EL CI pitch-ranked stimuli consisting of isochronous pulse trains presented concurrently to the four most apical CI electrodes.

Results: When the same rate was applied to all electrodes, pitch ranks increased with increasing rates up to 200-300 pulses-per-second (pps), consistent with previous research. Presenting rates of 100, 200, 300, and 400 pps to one electrode per rate produced a pitch rank between that of the 100- and 200-pps same-rate stimuli. The assignation of pulse rate to electrode did not have a consistent effect on pitch ranks. However, maximising the delay between pulses on the different electrodes generally produced higher pitch ranks compared to when the between-electrode pulse delay was very short.

Conclusion: Our results show no evidence that listeners combine the rates of TFS applied to different channels so as to estimate the fundamental frequency but do show that pitch can be affected by between-electrode delays. We conclude that presenting different temporal patterns to adjacent electrodes is unlikely to produce a clear and robust pitch and propose an alternative method for conveying the F0 of complex sounds on multiple electrodes of a CI.