Effect of Aging on Speech Discrimination.

BACKGROUND AND OBJECTIVES: The aim of this study was to investigate the factors associated with decrease in speech discrimination ability seen in patients with presbycusis and whether aging has a significant effect on the observed decline. SUBJECTS AND METHODS: We retrospectively analyzed the medical records of patients aged >40 years who had undergone pure-tone audiometry, speech audiometry, and auditory brainstem response for hearing loss at our hospital from January 2019 to June 2021, and investigated the factors that correlated with speech discrimination score. RESULTS: We enrolled 103 patients with 120 ears, with a mean age of 65.8±11.9 years. The pure-tone average of the patients' thresholds at 0.5, 1, 2, and 4 kHz was 37.2±27.7 dB HL, and their mean speech discrimination score was 82.5%± 22.3%. A correlation analysis revealed a significant negative correlation between the patients' speech discrimination scores and age. In addition, all variables of pure-tone audiometry and the patients' auditory brainstem responses were significantly correlated with the speech discrimination scores. The pure-tone average had the strongest negative correlation. On analyzing the significant predictors of lower speech discrimination scores, using a multiple linear regression analysis, pure-tone average and age showed significant results. CONCLUSIONS: The speech discrimination ability of older patients with hearing loss significantly decreases with increasing pure-tone average and age.

Factors Affecting the Extrusion Rate and Complications After Ventilation Tube Insertion: A Multicenter Registry Study on the Effectiveness of Ventilation Tube Insertion in Pediatric Patients With Chronic Otitis Media With Effusion-Part II.

OBJECTIVES: The impacts of ventilation tube (VT) type and effusion composition on the VT extrusion rate and complications in children with otitis media remain unclear. This part II study evaluated the factors affecting the extrusion rate, recurrence rate, and complications of VT insertion. METHODS: A prospective study was conducted between June 2014 and December 2016 (the EVENT study [analysis of the effectiveness of ventilation tube insertion in pediatric patients with chronic otitis media]), with follow-up data collected until the end of 2017. Patients aged <15 years diagnosed with otitis media with effusion who received VT insertion were recruited at 15 tertiary hospitals. The primary outcomes were time to extrusion of VT, time to effusion recurrence, and complications. RESULTS: Data from 401 patients were analyzed. After excluding the. RESULTS: of long-lasting tubes (Paparella type II and T-tubes), silicone tubes (Paparella type I) exhibited a significantly longer extended time to extrusion (mean, 400 days) than titanium tubes (collar-button-type 1.0 mm: mean, 312 days; P<0.001). VT material (hazard ratio [HR], 2.117, 95% confidence interval [CI], 1.254-3.572; P=0.005), age (HR, 3.949; 95% CI, 1.239-12.590; P=0.02), and effusion composition (P=0.005) were significantly associated with the time to recurrence of middle ear effusion. Ears with purulent (mean, 567 days) and glue-like (mean, 588 days) effusions exhibited a shorter time to recurrence than ears with serous (mean, 846 days) or mucoid (mean, 925 days) effusions. The revision VT rates during follow-up were 3.5%, 15.5%, 10.4%, and 38.9% in ears with serous, mucoid, glue-like, and purulent effusions, respectively (P<0.001). The revision surgery rates were higher among patients aged <7 years than among those aged ≥7 years. CONCLUSION: Silicone tubes (Paparella type I) were less prone to early extrusion than titanium 1.0 mm tubes. VT type, patient age, and effusion composition affected the time to recurrence of effusion.

Effect of Hearing Rehabilitation Therapy Program in Hearing Aid Users: A Prospective Randomized Controlled Study.

OBJECTIVES: Despite sufficient hearing gains, many patients with hearing loss have difficulty using hearing aids due to poor word recognition ability. This study was performed to introduce our hearing rehabilitation therapy (HRT) program for hearing aid users and to evaluate its effect on hearing improvement. METHODS: In this prospective randomized case-control study, 37 participants with moderate or moderate-severe sensorineural hearing loss who had used bilateral hearing aids for more than 3 months with sufficient functional hearing gain were enrolled in this study. Nineteen participants were randomly assigned to the control group (CG) and 18 patients were assigned to participate in our HRT program once a week for 8 consecutive weeks (hearing rehabilitation therapy group [HRTG]). Their hearing results and questionnaire scores for hearing handicap and hearing aid outcomes were prospectively collected and compared between the two groups. RESULTS: After completing 8 weeks of the HRT program, the HRTG showed a significantly greater improvement in scores for consonant-only and consonant-vowel sound perception than the CG (P<0.05). In addition, the HRTG showed a significant improvement in hearing ability as measured by two questionnaires (p<0.05), while no differences were observed in the CG. However, word and sentence recognition test results did not show significant differences between the two groups. CONCLUSION: Even after short-term HRT, patients had subjectively better hearing outcomes and improved phoneme perception ability; this provides scientific evidence regarding a possible positive role for HRT programs in hearing aid users. Further validation in a larger population through a long-term follow-up study is needed.

Efficiency of a dexamethasone nanosuspension as an intratympanic injection for acute hearing loss.

Dexamethasone sodium phosphate (Dex-SP) is the most commonly used drug administered via intratympanic injection for the treatment of acute hearing loss, but its penetration efficiency into the inner ear is very low. To address this problem, we evaluated the possibility of administering dexamethasone nanosuspensions via intratympanic injection because hydrophobic drugs might be more effective in penetrating the inner ear. Three types of dexamethasone nanosuspensions were prepared; the dexamethasone nanoparticles in the three nanosuspensions were between approximately 250 and 350 nm in size. To compare the efficiency of Dex-SP and dexamethasone nanosuspension in delivering dexamethasone to the inner ear, the concentrations of dexamethasone in perilymph and cochlear tissues were compared by liquid chromatography-mass spectrometry. The dexamethasone nanosuspensions resulted in significantly higher drug concentrations in perilymph and cochlear tissues than Dex-SP at 6 h; interestingly, animals treated with nanosuspensions showed a 26-fold higher dexamethasone concentrations in their cochlear tissues than animals treated with Dex-SP. In addition, dexamethasone nanosuspension caused better glucocorticoid receptor phosphorylation than Dex-SP both in vitro and in vivo, and in the ototoxic animal model, the nanosuspension showed a significantly better hearing-protective effect against ototoxic drugs than Dex-SP. In the in vivo safety evaluation, the nanosuspension showed no toxicity at concentrations up to 20 mg/mL. In conclusion, a nanosuspension of dexamethasone was able to deliver dexamethasone to the cochlea very safely and efficiently and showed potential as a formula for intratympanic injection.

Effects of tympanic membrane perforation, middle ear cavity volume, and mastoid aeration on hearing impairment.

AIMS: To investigate the effects of the location and size of tympanic membrane (TM) perforation and middle ear cavity volume on conductive hearing loss in patients with TM perforation. METHODS: Data were collected via a retrospective medical chart review. RESULTS: We enrolled 128 patients with a mean age of 45.6 ± 10.1 years. The mean perforation size was 21.2 ± 8.6% of the TM area, and the mean air-bone gap (ABG) was 20.2 ± 8.6 dB HL on pure tone audiometry. Patients were divided into two groups based on mean ABG. Patients with a large ABG had a significantly larger TM perforation area and smaller mastoid volume. The TM perforation was most commonly located in the central section. However, regression analyses showed that the proportion of the perforated TM area was the only independent predictor of a large ABG (odds ratio, 1.053; 95% confidence interval, 1.022-1.085; p = 0.001). When we analyzed the frequencies in which hearing loss occurred due to TM perforation, we confirmed that hearing loss occurred mainly in the low-frequency range. CONCLUSION: In patients with TM perforation, conductive hearing loss occurs mainly at low frequencies and in proportion to the size of the TM perforation.

Sensorineural Hearing Loss After Surgery to Treat Chronic Otitis Media.

OBJECTIVE: We investigated the incidence of sensorineural hearing loss (SNHL) after chronic otitis media (COM) surgery and determined the associated factors. METHODS: Data were collected via retrospective medical chart review. RESULTS: Of the 192 patients, 82 underwent tympanoplasty, 26 underwent canal wall up mastoidectomy with tympanoplasty, and 84 underwent canal wall down mastoidectomy with tympanoplasty. After surgery, the average air conduction (AC) hearing threshold improved significantly, from 125 to 1000 Hz, but the average high-frequency AC and bone conduction (BC) hearing thresholds deteriorated significantly. In 21 (11%) cases, the BC hearing threshold worsened by more than 15 dB at 4000 Hz. When we compared these 21 cases to patients in whom hearing was preserved, the former group was found to be significantly younger and had a higher frequency of cholesteatomatous otitis media. However, when comparing the severity of inflammation in patients with temporal bone computed tomography, there was no significant difference between the 2 groups. CONCLUSIONS: High-frequency SNHL may develop after surgery to treat COM, especially in young patients with cholesteatoma.

Intratympanic administration of alpha-lipoic acid-loaded pluronic F-127 nanoparticles ameliorates acute hearing loss.

We used antioxidant-containing nanoparticles (NPs) to treat acute hearing loss. Alpha-lipoic acid (ALA) served as the antioxidant; we employed Pluronic F127 to fabricate NPs. In vitro, ALA-NPs protected cells of the organ of Corti in HEI-OC1 mice, triggering nuclear translocation of NRF2 and increases in the levels of antioxidant proteins, including Nrf2, HO-1, SOD-1, and SOD-2. In vivo, the hearing of mice that received ALA-NP injections into the middle ear cavity was better preserved after induction of ototoxicity than in control animals. The cochlear Nrf2 level increased in test mice, indicating that the ALA-NPs protected hearing via the antioxidant mechanism observed in vitro. ALA-NPs effectively protected against acute hearing loss by activating the Nrf2/HO-1 pathway.

Typewriter tinnitus: An investigative comparison with middle ear myoclonic tinnitus and its long-term therapeutic response to carbamazepine.

OBJECTIVES: Due to its rarity and similar sound, typewriter tinnitus (TT) can be misdiagnosed as middle ear myoclonic tinnitus (MEMT). We aim to clarify the characteristics of TT compared to MEMT, and the long-term therapeutic response to carbamazepine. METHODS: Fourteen patients with TT and 28 patients with MEMT were enrolled. RESULTS: TT patients were older than MEMT patients, and their tinnitus symptoms were mostly unilateral. Tinnitus symptoms, which is associated with dizziness, facial spasm, and head motion, were more common in TT, whereas MEMT were more related to noise. Acoustic reflex decay perturbation and low loudness discomfort level were diagnostic signs in MEMT patients, while decreased level of wave II in ABR was the most reliable sign in TT patients. All TT patients exhibited partial or complete response to carbamazepine, but there was a relapse rate after withdrawal of the drug was 60%. Increase in age and longer duration of symptoms were the risk factors of relapse of TT. CONCLUSION: The different characteristics observed in this study will be helpful to diagnose TT and MENT. Duration of tinnitus was the most important long-term prognostic factor of the carbamazepine trial, which indicates the importance of its earlier diagnosis.

α-Lipoic acid prevents against cisplatin cytotoxicity via activation of the NRF2/HO-1 antioxidant pathway.

The production of reactive oxygen species (ROS) by cisplatin is one of the major mechanisms of cisplatin-induced cytotoxicity. We examined the preventive effect of α-lipoic acid (LA) on cisplatin-induced toxicity via its antioxidant effects on in vitro and ex vivo culture systems. To elucidate the mechanism of the antioxidant activity of LA, NRF2 was inhibited using NRF2 siRNA, and the change in antioxidant activity of LA was characterized. MTT assays showed that LA was safe at concentrations up to 0.5 mM in HEI-OC1 cells and had a protective effect against cisplatin-induced cytotoxicity. Intracellular ROS production in HEI-OC1 cells was rapidly increased by cisplatin for up to 48 h. However, treatment with LA significantly reduced the production of ROS and increased the expression of the antioxidant proteins HO-1 and SOD1. Ex vivo, the organs of Corti of the group pretreated with LA exhibited better preservation than the group that received cisplatin alone. We also confirmed the nuclear translocation of NRF2 after LA administration, and that NRF2 inhibition decreased the antioxidant activity of LA. Together, these results indicate that the antioxidant activity of LA was through the activation of the NRF2/HO-1 antioxidant pathway.

Cartilage Fascia Composite Canalplasty for External Auditory Canal Cholesteatoma: Case Analysis and Long-term Surgical Results.

OBJECTIVE: To analyze surgical outcomes of cartilage-fascia composite canalplasty (CFCC) for external auditory canal cholesteatoma (EACC). STUDY DESIGN: Retrospective case review study. SETTING: Tertiary referral center. PATIENTS: A total of 13 patients with EACC (n = 14 ears due to one patient with bilateral EACC). INTERVENTION: Surgical method of CFCC using well designed-conchal cartilage and temporalis muscle fascia after complete removal of EACC. MAIN OUTCOME MEASURES: Clinical characteristics and EACC stages were determined by oto-endoscopic examination and computed tomography (CT) findings. The surgical results of CFCC were analyzed. RESULTS: The median age of patients was 43 years (range, 12-75 yr), with a male to female ratio of 6 to 7. EACC stages were from II to IV. Cortical bone erosion in the inferior part of the bony EAC was the most common finding. All patients had satisfactory results: no more ear symptoms related with cholesteatoma and no need of dressing. Postoperative hearing gain was observed in four patients. No complications or recurrence occurred during the mean follow-up period of 34.4 months. CONCLUSION: Surgical technique of CFCC was effective for EACC not responding to conservative management.

A pilot study to investigate the therapeutic effect of Valsalva maneuver on otitis media with effusion in adults.

OBJECTIVE: This pilot study was performed to investigate the therapeutic effect of Valsalva maneuver on otitis media in adults and to evaluate the prognostic factors for the good response. METHODS: Thirty nine ears of 32 adult patients who were diagnosed as otitis media with effusion and managed by one-week Valsalva maneuver (>20/day) without any other medication were included in this study. Its therapeutic efficacy was evaluated and the prognostic factors which predict the response of Valsalva maneuver were analyzed by comparing various clinical and audiological factors between success and failure groups. RESULTS: Mean duration of otitis media in the study subjects was 30.9 days (SD 31.6 days). A success rate of 1-week Valsalva maneuver as a single therapeutic modality was up to 64.1% (25/39 ears) and hearing was significantly recovered in success group. No recurrence or side effects were observed. Successful Valsalva maneuver checked and confirmed as bulging of the tympanic membrane by otoendoscopic examination was an excellent indicator of therapeutic response in a week (p<0.05). Age, sex, duration of otitis media, history of previous upper respiratory tract infection, initial hearing levels and type of audiogram were not significant prognostic factors for the therapeutic efficacy of Valsalva maneuver. CONCLUSION: One-week Valsalva maneuver seems to be considered as a first line therapeutic modality in otitis media with effusion in adult patients who demonstrate the successful maneuver result on oto-endoscopic examination.

Safety and Effectiveness of Peramivir in Korean Adult Influenza Patients: Prospective Observational Study Based on Post-Marketing Surveillance Data.

BACKGROUND: The safety and clinical effectiveness data of peramivir in the real clinical field are limited. A prospective observational study was conducted based on the post-marketing surveillance data to evaluate the post-marketing safety and effectiveness of peramivir in Korean adults with seasonal influenza. METHODS: Among adults aged 20 years or older who were diagnosed with influenza A or B, patients who started peramivir within 48 hours from the initial symptoms of influenza were enrolled. All adverse events (AEs) that occurred within 7 days after administration of peramivir were checked. For the evaluation of effectiveness, changes in the severity of influenza symptoms and daily living performance were examined before and 7 days after the administration of peramivir. The date on which influenza related symptoms disappeared was checked. RESULTS: A total of 3,024 patients were enrolled for safety evaluation and 2,939 patients were for effectiveness evaluation. In the safety evaluation, 42 AEs were observed in 35 (1.16%) patients. The most common AE was fever. AEs were mostly rated as mild in severity. Serious AEs were observed in 10 patients and two of them died. However, both deaths were considered to be less relevant to peramivir. In the effectiveness evaluation, the severity of influenza symptoms decreased by 10.68 ± 4.01 points and daily living performance was improved 5.59 ± 2.16 points. Influenza related symptoms disappeared on average 3.02 ± 2.39 days after peramivir administration. CONCLUSION: Peramivir showed a tolerable safety profile and acceptable effectiveness in Korean adult patients with seasonal influenza.

The effect of urban particulate matter on cultured human nasal fibroblasts.

BACKGROUND: Exposure to urban particulate matter (UPM) has been linked to aggravation of various health problems. Although the effects of UPM on the lower respiratory tract have been extensively studied, more research is required on the impact of UPM on the upper respiratory tract and the underlying mechanisms. Thus, we investigated the cytotoxic effects of UPM on cultured human nasal fibroblasts, the underlying signaling pathways involved, and changes in cytokine levels. METHODS: Human turbinate tissue specimens were collected during partial turbinectomies performed on 6 patients, and then cultured. The effect of UPM on nasal fibroblast viability was explored. Real-time reverse transcription-polymerase chain reaction was used to measure the mRNA levels of genes encoding cytokines and chemokines (interleukin [IL]-4, IL-6, IL-8, and tumor necrosis factor-α) before and after 24 hours of UPM treatment. Enzyme-linked immunosorbent assays were employed to measure IL-6 and IL-8 levels. The status of the p38 and nuclear factor (NF)-κB signaling pathways was analyzed by Western blotting. RESULTS: UPM reduced cell viability in a dose-dependent manner and increased IL-6 and IL-8 expression at both the mRNA and protein levels. UPM induced the phosphorylation of p38 and NF-κB p65; inhibitors of the actions of these proteins repressed phosphorylation and the expression of IL-6 and IL-8. CONCLUSION: UPM induced IL-6 and IL-8 expression by fibroblasts via p38 and NF-κB classical signaling, suggesting that UPM can induce or aggravate allergic and/or chronic rhinitis.

Swing-Door Overlay Tympanoplasty: Surgical Technique and Outcomes.

OBJECTIVES: The classical overlay tympanoplasty is technically difficult with some disadvantages and thus less popular. However, it is particularly useful for large, anterior perforations. In this study, we describe the technique of a modified overlay graft in the tympanoplasty coined as the swing-door overlay tympanoplasty and report its outcomes. METHODS: Retrospective review of patients undergoing the swing-door overlay tympanoplasty at a tertiary referral center between 2003 and 2016 was performed. Patient who had ossicular abnormality, previous tympanoplasty, and profound hearing loss were excluded. The surgical technique is described in detail. The outcomes were evaluated by the graft success rate, complication rate, and hearing results. The hearing level was determined by four pure-tone average at 0.5, 1, 2, and 4 kHz. Air-bone gap closure was mainly assessed. RESULTS: A total of 306 patients (110 males and 196 females) were included. The mean age was 49.1±16.6 years. Follow-up periods ranged from 6 to 108 months with an average of 18.4 months. The overall graft success rate reached 98.4%. Five graft failures occurred with reperforation in three cases and lateralization in two cases. Postoperative complications occurred in 12 cases (3.9%). Air-bone gap changes (closures) were 7.8±12.8, 5.2±12.2, 5.7±10.2, and 6.0± 12.8 dB at 0.5, 1, 2, and 4 kHz, respectively (all P<0.001) with an average improvement of 6.2 dB. Postoperative airbone gap was closed to ≤20 dB in 86.9%. CONCLUSION: The swing-door overlay tympanoplasty is a highly successful surgical technique suitable for all types of tympanic membrane perforations. This approach is technically easier than classical overlay tympanoplasty and affords an excellent graft success rate with satisfying hearing results.

Optimized phospholipid-based nanoparticles for inner ear drug delivery and therapy.

To develop efficient carriers for inner ear drug delivery, we prepared four kinds of phospholipid-based nanoparticles: neutral, anionic, cationic, and cationic-PEG (polyethyleneglycol) particles. PEG was used to maintain long-term particle circulation in the perilymph, avoiding non-specific binding of particles to proteins. All four nanoparticles were about 200 nm in diameter, and their zeta potentials were -4.32, -26.0, +25.8, and -0.28, respectively, for neutral, anionic, cationic, and cationic-PEG nanoparticles. To test particle efficacy in vitro, we used an artificial mucosa 100 µm in thickness to model the round window membrane (RWM) and HEI-OC1 cells, which were treated with particles containing Nile Red dye. Based on the levels of particle penetration and cellular uptake in this model system, we selected an optimal particle for further study. We also observed the movement of particles in ex vivo organotypic cultures of the organ of Corti. In mice, we analyzed the biodistribution of dexamethasone (Dex) in the inner ear after intratympanic injection of Dex-loaded nanoparticles. Then, we tested the therapeutic utility of the Dex-loaded nanoparticles in a mouse model of ototoxicity. In the auditory brainstem response (ABR) test, particle provided improved hearing loss recovery at all tested frequencies, more so than did the Dex sodium phosphate (Dex-SP) solution in current clinical use. Furthermore, quantitative PCR showed that nanoparticles reduced the levels of pro-inflammatory cytokines, exhibiting anti-inflammatory effects superior to those of Dex-SP. Thus, the surface properties of nanoparticles play pivotal roles in particle penetration and distribution after intratympanic injection. Our in vitro screening system using an artificial mucosa will also be valuable in the development of carriers for inner ear drug delivery.

Microbiological Results From Middle Ear Effusion in Pediatric Patients Receiving Ventilation Tube Insertion: Multicenter Registry Study on the Effectiveness of Ventilation Tube Insertion in Pediatric Patients With Chronic Otitis Media With Effusion: Part I.

OBJECTIVES: The aim of this multicenter registry study was to investigate the effectiveness of ventilation tube insertion and the microbiology of otitis media with effusion (OME) in children. This part I study was conducted to evaluate the microbiological profile of children with OME who needed ventilation tube insertion. METHODS: Patients <15 years old who were diagnosed as having OME and received ventilation tube insertion were prospectively enrolled in 16 tertiary hospitals from June 2014 to December 2016. After excluding patients with missing data, the data of 397 patients were analyzed among a total of 433 enrolled patients. The clinical symptoms, findings of the tympanic membrane, hearing level, and microbiological findings were collected. RESULTS: In 103 patients (25.9%), antibiotics were used within 3 weeks before surgery. Ventilation tube insertion was performed in a total of 710 ears (626 in both ears in 313 patients, 55 in the left ear only, and 29 in the right ear only). Culture of middle ear effusion was done in at least one ear in 221 patients (55.7%), and in a total of 346 ears. Only 46 ears (13.3%) showed positive results in middle ear effusion culture. Haemophilus influenzae (17.3%, followed by coagulase-negative Staphylococcus and Staphylococcus auricularis) was the most common bacteria detected. CONCLUSION: H. influenzae was the most commonly found bacteria in middle ear effusion. Relatively low rates of culture positivity were noted in middle ear effusion of patients with OME in Korea.

Bony cochlear nerve canal stenosis in pediatric unilateral sensorineural hearing loss.

OBJECTIVES: This study was performed to evaluate the frequency of bony cochlear nerve canal (BCNC) stenosis and its clinical significance in pediatric patients with unilateral sensorineural hearing loss (SNHL) of unknown etiology. MATERIALS AND METHODS: We analyzed the medical records and temporal bone computed tomography (CT) results of patients less than 13 years of age with a diagnosis of unilateral SNHL of unknown etiology between July 2007 and July 2017. We compared the BCNC diameter between both sides and analyzed the age at diagnosis, degree of hearing loss, and accompanying inner ear anomalies. RESULTS: In 42 patients, the mean age at diagnosis was 7.4 ±â€¯3.6 years, and the average hearing level in the affected ear was 87.9 ±â€¯20.0 dB HL (decibels hearing level). The average diameter of the BCNC was 1.22 ±â€¯0.75 mm on the affected side and 1.96 ±â€¯0.52 mm on the normal side. The most suitable criterion for BCNC stenosis appeared to be a diameter of 1.2 mm by the recursive partitioning procedure. With application of this criterion, the rate of BCNC stenosis was significantly greater on the affected side than on the normal side (52.4% vs. 4.8%, respectively; P < 0.05). A narrow internal acoustic canal was found in two patients, and vestibular and cochlear anomalies were found in three patients each. CONCLUSIONS: Our results suggest that it is reasonable to set a diameter of 1.2 mm as a cutoff for BCNC stenosis, and also that BCNC stenosis is a common cause of unilateral SNHL of unknown etiology in childhood.

Cognitive decline and increased hippocampal p-tau expression in mice with hearing loss.

Hearing and cognition are commonly involved in both normal and pathological aging. Current clinical interest lies in whether peripheral hearing loss promotes cognitive decline. In our previous publication, the authors have shown a causal relationship between hearing and cognitive impairments in C57BL/6 mice. Here we extended the follow-up to 12 months to determine the long-term effects of hearing loss on cognition and to observe hippocampal p-tau and lipofuscin. One month old male mice were randomly allocated into two groups, the control (n = 12) and noise-induced hearing loss (NIHL) (n = 12). After baseline hearing and cognitive measurements, the mice in the NIHL group were exposed to 110 dB SPL white noise for 1 h every day for 20 consecutive days. Cognitive function was assessed by radial arm maze and novel object recognition tests. p-Tau was observed by the western blot, immunofluorescence, and immunogold staining. The mice in the NIHL group showed elevated auditory brainstem response thresholds and poorer performances in spatial working and recognition memories than the controls. They exhibited more p-tau and lipofuscin in the hippocampus. The cognitive impact of hearing loss varied with the types of memory. Working memory impairment was reversible, whereas recognition memory impairment was permanent. Our results provide behavioral and histopathological evidence for hearing-related cognitive decline. Early hearing loss is suggested to be one of the important determinants between normal and pathological cognitive aging.

Nanomedicine for Inner Ear Diseases: A Review of Recent In Vivo Studies.

Nanoparticles are promising therapeutic options for inner ear disease. In this report, we review in vivo animal studies in the otologic field using nanoparticles over the past 5 years. Many studies have used nanoparticles to deliver drugs, genes, and growth factors, and functional and morphological changes have been observed. The constituents of nanoparticles are also diversifying into various biocompatible materials, including poly(lactic-co-glycolic acid) (PLGA). The safe and effective delivery of drugs or genes in the inner ear will be a breakthrough for the treatment of inner ear diseases, including age-related hearing loss.

Prognostic factors for profound sudden idiopathic sensorineural hearing loss: a multicenter retrospective study.

The aim of this study was to assess the outcomes of various treatment modalities for profound idiopathic sudden sensorineural hearing loss (ISSNHL) and confirm the prognostic factors. In total, 191 patients were enrolled after a thorough medical chart review of patients diagnosed with unilateral, profound ISSNHL (≥90 dB). Epidemiological profiles, therapeutic regimens, and the results of pure tone audiometry tests were recorded for all patients. Final recovery was assessed according to Siegel's criteria and by comparing the final hearing level of the affected ear with that of the unaffected ear. The mean follow-up duration and the final hearing level were 75 ± 54 days and 77 ± 24 dB, respectively. None of the evaluated prognostic factors were significantly associated with complete recovery (<25 dB). However, improved hearing in both ears, the absence of dizziness, the use of lipo-prostaglandin E1 (lipo-PGE1), and the use of plasma volume expanders were independently associated with a final hearing level of up to 45 dB (p < 0.05). Steroid dose reduction, worse initial hearing, and non-use of lipo-PGE1 increased the possibility of no recovery. Although the efficacy of oral steroid treatment for profound ISSNHL has been questioned, steroid dose reduction was significantly associated with no recovery. Therefore, adequate oral corticosteroid doses should be considered in the absence of contraindications. In addition, the use of lipo-PGE1 and/or a plasma volume expander seems preferable for better recovery, and their use for the management of profound ISSNHL should be considered.