Deep Learning Model to Evaluate Sensorimotor System Ability in Patients With Dizziness for Postural Control

Balanced posture without dizziness is achieved via harmonious coordination of visual, vestibular, and somatosensory systems. Specific frequency bands of center of pressure (COP) signals during quiet standing are closely related to the sensory inputs of the sensorimotor system. In this study, we proposed a deep learning-based novel protocol using the COP signal frequencies to estimate the equilibrium score (ES), a sensory system contribution. Sensory organization test was performed with normal controls (n=125), patients with Meniere's disease (n=72) and vestibular neuritis (n=105). The COP signals preprocessed via filtering, detrending and augmenting during quiet standing were converted to frequency domains utilizing Short-time Fourier Transform. Four different types of CNN backbone including GoogleNet, ResNet-18, SqueezeNet, and VGG16 were trained and tested using the frequency transformed data of COP and the ES under conditions #2 to #6. Additionally, the 100 original output classes (1 to 100 ESs) were encoded into 50, 20, 10 and 5 sub-classes to improve the performance of the prediction model. Absolute difference between the measured and predicted ES was about 1.7 (ResNet-18 with encoding of 20 sub-classes). The average error of each sensory analysis calculated using the measured ES and predicted ES was approximately 1.0%. The results suggest that the sensory system contribution of patients with dizziness can be quantitatively assessed using only the COP signal from a single test of standing posture. This study has potential to reduce balance testing time (spent on six conditions with three trials each in sensory organization test) and the size of computerized dynamic posturography (movable visual surround and force plate), and helps achieve the widespread application of the balance assessment.

Safety and efficacy of preauricular fistulectomy with fascia-anchoring suture technique: A large case series

OBJECTIVE

This study aimed to analyze the safety and efficacy of preauricular fistulectomy with fascia-anchoring suture technique through large case series. In addition, differences in surgical outcomes according to preoperative status and age were investigated.

METHODS

In this retrospective study, 380 patients (450 ears) with preauricular fistula (PAF) who underwent preauricular fistulectomy with fascia-anchoring suture technique by a single surgeon (E.P) were enrolled. Patients were divided into fresh, previous incision and drainage (I&D), and the revision surgery groups according to the preoperative status. Additionally, they were divided into adult and pediatric groups according to age. Patient's demographics, postoperative infections, and recurrence rates were analyzed.

RESULTS

The mean age of the patients was 28.3 years, and there were 119 males and 261 females. Out of 450 PAFs (n = 281 in the fresh groups, n = 119 in the previous I&D groups, and n = 50 in the revision groups), 21 (4.7 %) cases had postoperative infections and 12 (2.7 %) cases had recurrence. There was no difference in postoperative infections, regardless of the preoperative condition (I&D group, p = 0.701; revision group, p = 0.658). The recurrence rate was higher in the revision group than in the fresh and I&D groups (p = 0.004). There was no significant difference in postoperative infection (p = 0.221) or recurrence (p = 0.161) between adults and children.

CONCLUSIONS

The study found that performing preauricular fistulectomy with a fascia-anchoring suture technique led to low rates of postoperative infections and recurrences. These positive outcomes were consistent across different patient groups categorized by preoperative status and age, indicating the technique's safety and effectiveness for all patients with preauricular fistulas.

Dynamic Range and Neural Response Threshold in Cochlear Implant Mapping Can Be Useful in Predicting Prognosis Related to Postoperative Speech Perception

BACKGROUND AND OBJECTIVES

To analyze mapping changes in dynamic range (DR) and neural response threshold (NRT) as prognostic factors for cochlear implant (CI). To analyze whether postoperative speech perception performance could be predicted using DR change and initial NRT.

SUBJECTS AND METHODS

The speech comprehension data of 33 patients with CI were retrospectively analyzed after 1, 3, 6, and 12 months of device use. All subjects were adult, postlingually hearing-impaired, and Cochlear Nucleus CI users. Speech perception performance was evaluated using aided pure tone audiometry, consonant, vowel, one-word, two-word, and sentence tests.

RESULTS

The averages of initial NRT and DR changes were 197.8±25.9 CU (104-236) and 22.2±18.4 CU (-15-79), respectively. The initial DR was 40.8±16.6 CU. The postoperative DR was 50.3±16.4 CU at 3 months, 58±12.3 CU at 6 months, and 62.9±10.4 CU at 12 months. A gradual increase of DR was observed during the first year of CI. Compared with the initial DR, significant increases in DR were observed at 3 (p<0.05), 6 (p<0.001), and 12 (p<0.001) months. Compared with initial speech performance outcomes, a significant gain in all performance outcomes was achieved at 12 months (p<0.001).

CONCLUSIONS

Patients with low NRT after CI surgery could initially set DR to a wider range and had better final speech perception outcomes. Conversely, patients with high NRT after CI surgery had to set up a gradual increase in DR while adjusting the T-C level, and the final speech perception outcomes were worse. DR and NRT, the main CI mapping variables, can help predict prognosis related to speech perception outcomes after CI surgery. In conclusion, the post-CI speech perception is better with a lower initial NRT, wider final DR, or younger age.

Hydrophilic and lipophilic statin use and risk of hearing loss in hyperlipidemia using a Common Data Model: multicenter cohort study

Hearing impairment, the third largest health burden worldwide, currently lacks definitive treatments or preventive drugs. This study compared the effects of hydrophilic and lipophilic statin on hearing loss using a common database model. This retrospective multicenter study was conducted in three hospitals in South Korea (Anam, Guro, Ansan). We enrolled patients with hyperlipidemia with an initial hearing loss diagnosis. Data were collected during January 1, 2022-December 31, 2021 using the Observational Health Data Science and Informatics open-source software and Common Data Model database. The primary outcome was the occurrence of first-time hearing loss following a hyperlipidemia diagnosis, as documented in the Common Data Model cohort database. The measures of interest were hearing loss risk between hydrophilic and lipophilic statin use. Variables were compared using propensity score matching, Cox proportional regression, and meta-analysis. Among 37,322 patients with hyperlipidemia, 13,751 (7669 men and 6082 women) and 23,631 (11,390 men and 12,241 women) were treated with hydrophilic and lipophilic statins, respectively. After propensity score matching, according to the Kaplan-Meier curve, hearing loss risk did not significantly differ among the hospitals. The hazard ratio (HR) of the male patients from Anam (0.29, [95% confidence interval (CI), 0.05-1.51]), Guro (HR, 0.56, [95% CI 0.18-1.71]), and Ansan (hazard ratio, 0.29, [95% CI 0.05-1.51]) hospitals were analyzed using Cox proportional regression. Overall effect size (HR, 0.40, [95% CI 0.18-0.91]) was estimated using meta-analysis, which indicated that hearing loss risk among hydrophilic statin users was less than that among lipophilic statin users and was statistically significant. Men in the hydrophilic statin group had a lower risk of hearing impairment than those in the lipophilic statin group.

Status of the Newborn Hearing Screening in the 4-Months Age National Infant Health Checkup in Korea: A Nationwide Population-Based Study

BACKGROUND

The aims of this study are to review data on 4-months age National Health Screening Program for Infants and Children (NHSPIC) using a National Health Insurance Service (NHIS) database, and to analyze the newborn hearing screening (NHS) results and related characteristics of the 4-months NHSPIC for 7 years in South Korea.

METHODS

We analyzed a NHIS database of infants who had participated in the 4-month age NHSPIC from 2010 to 2016. According to the results of hearing questionnaires and physical examination, we analyzed the outcomes of NHS and related infantile and socioeconomic factors.

RESULTS

Among 3,128,924 of total eligible infants in Korea between the year 2010 and 2016, 69.2% (2,164,621 infants) conducted 4-months age NHSPIC, and 94.4% (2,042,577 infants) of which performed hearing questionnaires regarding NHS. Among the total hearing examinees, premature infants accounted for 3.6%, infants who were hospitalized in the neonatal intensive care unit (NICU) for more than 5 days accounted for 5.6%, and infants with head and neck abnormalities were 0.6%. The NHS performing rate was 79.1% for total hearing examinees in 2010, but gradually increased to 88.9% in 2016. The NHS performing rate in 2016 was 93.4% for premature infants, 91.7% for NICU hospitalized babies. The mean referral rate was 0.6% for total hearing examinees, 1.4% for premature infants, and 2.3% for NICU hospitalized babies. When we analyzed the NHS performing rate and the referral rate according to the household income level, the NHS performing rate of infants in Medical Aid programs was the lowest as 65.6%, and the NHS performing rates in other five levels of NHIS was higher ranging between 85.1% to 86.0%. The referral rate of infants in the Medical Aid program (3.8%) was significantly higher than those of infants in other classes (1.10-1.25%).

CONCLUSION

The estimated overall NHS performing rate in Korea gradually increased and was 88.9% in 2016. The overall referral rate was low as 0.6%, and it was significantly different depending on the infant's health condition and household income levels. We assume that our finding would help to establish policies managing hearing impaired children, and to develop the customized hearing care service programs considering the household economic levels.

Transcriptomic Analysis of the Effect of Metformin against Cisplatin-Induced Ototoxicity: A Potential Mechanism of Metformin-Mediated Inhibition of Thioredoxin-Interacting Protein (Txnip) Gene Expression

Ototoxicity is the drug-induced damage of the inner ear, causing bilateral irreversible sensorineural hearing loss. Cisplatin is a widely used chemotherapeutic agent which causes ototoxicity as its side effect. Pretreatment with metformin prior to the application of cisplatin significantly decreased the late apoptosis and attenuated the cisplatin-induced increase in ROS. To understand the molecular mechanisms that are involved in the preventive effect of metformin, we evaluated the change of gene expression induced by cisplatin at several different time points (0 h, 6 h, 15 h, 24 h and 48 h) and the alteration of gene expression according to pretreatment with metformin in HEI-OC1 cells through microarray analysis. Cisplatin exposure induced a total of 89 DEGs (differentially expressed genes) after 6 h, with a total of 433 DEGs after 15 h, a total of 941 DEGs after 24 h, and a total of 2764 DEGs after 48 h. When cells were pretreated with metformin for 24 h, we identified a total of 105 DEGs after 6 h of cisplatin exposure, a total of 257 DEGs after 15 h, a total of 1450 DEGs after 24 h, and a total of 1463 DEGs after 48 h. The analysis was performed based on the gene expression, network analyses, and qRT-PCR, and we identified several genes (CSF2, FOS, JUN, TNFα, NFκB, Txnip, ASK1, TXN2, ATF3, TP53, IL6, and IGF1) as metformin-related preventive biomarkers in cisplatin ototoxicity.

Evaluation of users' level of satisfaction for an artificial intelligence-based diagnostic program in pediatric rare genetic diseases

The artificial intelligence (AI)-based genetic diagnostic program has been applied to genome sequencing to facilitate the diagnostic process. The objective of the current study was to evaluate the experience and level of satisfaction of participants using an AI-based diagnostic program for rare pediatric genetic diseases. The patients with neurodevelopmental disorders or hearing impairments, their guardians, and their physicians from 16 tertiary general hospitals were enrolled. The study period was from April 2020 to March 2021. A survey was designed to assess their experience and level of satisfaction. A total of 30 physicians and 243 patients and guardians (199 neurodevelopmental disorders and 44 hearing impairments) completed the survey. DNA samples of the subjects were collected through buccal swabs or blood collection: 211 subjects (86.8%) through buccal swab and 29 subjects (11.9%) through blood collection. Average turnaround time for result receipt was 57.54 ± 32.42 days. For the sampling method, 193 patients and guardians (81.1%) and 28 physicians (93.3%) preferred buccal swab. The level of satisfaction of the 2 groups participating in the AI-based diagnostic program was 8.31 ± 1.71 out of 10 in the patient and guardian group and 8.42 ± 1.23 in the physician group. Clinicians, patients, and guardians are satisfied with the AI-based diagnostic program in general. With an increase in AI-based precision medicine solutions, the evaluation of the user's satisfaction with appropriate provision will help improve personal health care.

A novel optimization-based convolution neural network to estimate the contribution of sensory inputs to postural stability during quiet standing

Adequate postural control is maintained by integrating signals from the visual, somatosensory, and vestibular systems. The purpose of this study is to propose a novel convolutional neural network (CNN)-based protocol that can evaluate the contributions of each sensory input for postural stability (calculated a sensory analysis index) using center of pressure (COP) signals in a quiet standing posture. Raw COP signals in the anterior/posterior and medial/lateral directions were extracted from 330 patients in a quiet standing with their eyes open for 20 seconds. The COP signals augmented using jittering and pooling techniques were transformed into the frequency domain. The sensory analysis indices were used as the output information from the deep learning models. A ResNet-50 CNN was combined with the k-nearest neighbor, random forest, and support vector machine classifiers for the training model. Additionally, a novel optimization process was proposed to include an encoding design variable that can group outputs into sub-classes along with hyperparameters. The results of optimization considering only hyperparameters showed low performance, with an accuracy of 55% or less and F-1 scores of 54% or less in all models. However, when optimization was performed using the encoding design variable, the performance was markedly increased in the CNN-classifier combined models (r = 0.975). These results suggest it is possible to evaluate the contribution of sensory inputs for postural stability using COP signals during a quiet standing. This study will facilitate the expanded dissemination of a system that can quantitatively evaluate the balance ability and rehabilitation progress of patients with dizziness.

Protective Effect of Agmatine Against Cisplatin- Induced Cellular Apoptosis in an Auditory Cell Line

BACKGROUND

The aims of this study were to evaluate the protective effects of agmatine against cisplatin-induced cellular apoptosis in an audi- tory cell line and to prove the protective mechanism of agmatine.

METHODS

The House Ear Institute-Organ of Corti 1 cells were co-treated with agmatine at different concentrations and 15 μM of cisplatin for 48 hours. Cell viability and proliferation were measured. Annexin V-fluorescein isothiocyanate /propidium iodide staining was performed to analyze apoptosis. The levels of intracellular reactive oxygen species were measured using flow cytometry. The expression of BCL2-associated X protein and the enzymatic activity of caspase-3 was measured to examine the pathway of apoptosis induction.

RESULTS

In normal conditions, the maximal protective effect occurred with 10 mM of agmatine. However, in the presence of cisplatin, the maximal protective effect was observed from 8 mM of agmatine. Thus, 8 mM was chosen as the ideal agmatine concentration for the analysis of protective effects against cisplatin-induced cytotoxicity. Agmatine exerted a significant protective effect against 15 μM of cisplatin when applied for 48 hours and reduced the proportion of necrotic and late apoptotic cells. Agmatine did not significantly reduce the cisplatin-induced increase in reactive oxygen species but decreased the expression of BCL2-associated X protein and the activity of caspase-3.

CONCLUSION

Agmatine protected against cisplatin-induced cellular apoptosis in an auditory cell line. These effects were mediated by the pro- tection of mitochondrial function and inhibition of apoptosis.

Results of a 10-year hearing screening using automated auditory brainstem response in newborns: The two-step AABR method

OBJECTIVES

Approximately 1-6 in every 1000 children are born with hearing loss. An automated auditory brainstem response (AABR) test is essential for screening newborns for abnormal hearing. At the tertiary hospital, we have been using a two-step AABR protocol for newborn hearing assessment since 2005. This study aimed to report the 10-year hearing screening results of newborns at the institution, and prove the efficacy of the two-step AABR protocol.

METHODS

From August 2005 to January 2015, 3059 newborns were screened through AABR testing using the MASTER ABaer system. The first screening test was performed after the first 24 h of life. If a newborn was referred, the test was performed within 1 month after discharge from the hospital. The results were regarded as pass when the point optimized variance ratio was >3.5, using a stimulus level of 35 dB HL. When newborns were referred for the second AABR, they received follow-up tests including tympanometry, ABR, auditory steady-state response, and otoacoustic emission within 3 months.

RESULTS

A total of 3059 newborns underwent newborn hearing screening tests over a period of 10 years. One hundred and twenty (3.9%) newborns were referred with the initial AABR, and 104 (3.4%) were referred with a subsequent AABR. Of the newborns, 42 (1.37%) were confirmed to have a bilateral hearing impairment.

CONCLUSIONS

It is known that the referral rate for the AABR test is 3-4%, as recommended by the Joint Committee on Infant Hearing. Our data showed a referral rate of 3.4%. The two-step AABR test has been useful for screening hearing loss in newborns at tertiary hospital.

Exploratory fall risk and preventive intervention in acute vestibular neuritis

Objective

To analyze recovery from dizziness in patients with acute vestibular neuritis (AVN) after applying the “Dizziness & Fall Risk Assessment and Intervention (DFRAI)”.

Methods

This prospective study involved patients with AVN who underwent a survey of dizziness and fall risk. The patients received medical treatment and customized vestibular rehabilitation, and vestibular function was evaluated at the initial attack and 3 months later.

Results

Forty-one patients underwent subjective questionnaire assessments, which showed significant improvement in visual analog scale-dizziness handicap inventory-fear of falling (VAS-DHI-FOF) results from the initial vertigo attack to 3 months later. In the sensory organization test (SOT), the initial composite score was 63 ± 13.1, which improved to 77.5 ± 4.9 3 months later. In caloric testing, the canal paresis (CP) score was 42.9 ± 35.2, which improved to 29.9 ± 23.5 3 months later.

Conclusions

Subjective improvement in dizziness and objective recovery of vestibular function were confirmed. DFRAI is a comprehensive solution for dizziness, and appropriate application of the DFRAI is expected to have a positive effect on recovery from dizziness and fall prevention in patients with AVN.

Effects of Glycemic Control on Hearing Outcomes in Diabetes Patients With Idiopathic Sudden Sensorineural Hearing Loss

Objective:

This study aimed to analyze the effects of glycemic control on the hearing outcomes of type 2 diabetes patients with idiopathic sudden sensorineural hearing loss (ISSHL).

Methods:

Type 2 diabetes patients with ISSHL were enrolled. All patients were admitted for 5 days and received systemic corticosteroid treatment. Patients were divided into groups according to their degree of glycemic control pre- (glycosylated hemoglobin) and post- (mean blood glucose) onset of ISSHL. Demographic, audiometric, and hearing outcome data were analyzed. Furthermore, a multivariate analysis was performed to determine the prognostic factors affecting the hearing outcomes in these patients.

Results:

One hundred forty-four patients were enrolled. The hearing recovery rates were as follows: complete recovery, 19%; partial recovery, 15%; slight improvement, 22%; and no improvement, 44%. Initial hearing levels and diabetes duration were significantly higher in the pre-onset poor-controlled group (glycosylated hemoglobin ≥ 7.0%) than those in the well-controlled group. The hearing recovery rates did not differ significantly pre- or post-onset. In a multivariate analysis, duration from hearing loss onset to treatment, presence of vertigo, and initial hearing level were negative prognostic factors that affected hearing recovery.

Conclusion:

The degree of pre- or post-onset glycemic control did not affect hearing outcomes in patients with ISSHL and type 2 diabetes. Therefore, the administration of systemic corticosteroid is required for diabetes patients with ISSHL within allowable blood glucose levels.

Evidence of Cochlear Synaptopathy and the Effect of Systemic Steroid in Acute Idiopathic Tinnitus With Normal Hearing

OBJECTIVE

To evaluate the electrophysiologic evidence of cochlear synaptopathy and the effects of systemic steroids in acute idiopathic tinnitus with normal hearing.

STUDY DESIGN

Retrospective review of medical data.

SETTING

Tertiary referral center.

PATIENTS

Fifty-nine patients who experienced acute-onset idiopathic tinnitus (within 12 weeks) with normal hearing and the same number of age- and pure-tone threshold-matched control groups.

INTERVENTION

Electrophysiologic studies of the auditory pathway, oral steroids, and ginkgo biloba.

MAIN OUTCOME MEASURES

Pure-tone thresholds, wave I and wave V amplitudes of the auditory brainstem response (ABR), tinnitus handicap inventory (THI), and visual analog scale (VAS).

RESULTS

Significantly reduced ABR wave I amplitude and wave I/wave V ratio were found in the tinnitus group compared with the no tinnitus group. Age and pure-tone threshold were significantly correlated with reduced wave I amplitude and small wave I/wave V ratio. The THI and VAS scores were decreased at 3 and 12 weeks after steroid administration; however, overall changes in THI and VAS scores were not significantly different between the steroid and ginkgo biloba groups.

CONCLUSION

Potential cochlear synaptopathy was suspected in the early stage of acute idiopathic tinnitus, even in patients with normal hearing. Age and hearing threshold were potentially associated with the development of cochlear synaptopathy. Low-dose oral steroids and ginkgo biloba induced early subjective relief of tinnitus, which maintained up to 12 weeks, however, those changes did not differ between groups.

Auditory brainstem response test results in normal hearing adolescents with subjective tinnitus

OBJECTIVES

The objective of the study was to analyze the auditory brainstem response (ABR) test results of adolescents with normal hearing threshold who have subjective tinnitus in an effort to determine the probable site of origin of tinnitus.

METHODS

Among the patients who visited the outpatient clinic of the Department of Otolaryngology at our tertiary hospital from January 2016 to December 2019, adolescents aged 13-18 years with the chief complaint of unilateral subjective tinnitus and pure tone audiometry (PTA) within 25 dB HL were enrolled and retrospectively reviewed. The ABR test parameters (amplitudes and latencies of waves I, III, and V and interpeak latencies [IPLs] of waves I-III, III-V, and I-V) were analyzed and compared between tinnitus ears and contralateral ears without tinnitus. Study participants were divided into the chronic tinnitus (tinnitus duration ≥6 months) and non-chronic tinnitus (tinnitus duration <6 months) groups, and the difference between the two groups was analyzed.

RESULTS

Ten adolescents were included in the study, and their ABR test results were reviewed. IPL III-V was significantly prolonged in tinnitus ears compared to non-tinnitus ears (p = 0.035). Although other parameters were found to be statistically non-significant, there was preponderance in ABR wave I amplitude; it was smaller in tinnitus ears of chronic tinnitus adolescents than in those of non-chronic tinnitus adolescents (p = 0.114).

CONCLUSION

The probable site of origin of tinnitus in adolescents with normal hearing might be in the upper brainstem of the auditory pathway. Further analysis of ABR test results in adolescents with tinnitus and normal hearing can help clarify the pathophysiology of tinnitus in adolescents.

Nationwide Analysis of Mortality Rates and Related Surgical Procedures in Hearing Disability Patients in South Korea

Background and Objectives

Hearing loss (HL) and its repercussions are major problems in today’s society. There are limited data on the relationship between degree of HL and otologic disorders. The aim of this study is to estimate mortality rates, rates of sudden idiopathic HL and related otologic surgical procedures in hearing disability patients in South Korea.

Subjects and Methods

Retrospective medical data for 160,205 patients with hearing disability was extracted. Mortality rates, rates of sudden idiopathic HL and related otologic surgical procedures were compared with a normal control group consisting of 865,475 people; approximately 5 times the number of hearing disability patients.

Results

According to the Korean National Disability Registry (NDR), 0.458% of the population in South Korea suffered from hearing disability in 2015. Higher rates of mortality and sudden idiopathic HL were reported in hearing disability patients, increasing up to a maximum of 1.594 times and 1,039.695 times, respectively, compared to the normal control group. Mastoidectomy surgery was 2.5 times more frequently performed and pressure equalizing (PE) tube insertion was about 15 times more frequently performed in hearing disability patients.

Conclusions

Hearing disability is related to higher risks of mortality, sudden idiopathic HL and otologic surgical procedures, including mastoidectomy and PE tubing.

Status of early hearing detection and intervention in South Korea: a nationwide population-based study of national infant health checkup

The aim of this study was to evaluate the status of early hearing detection and intervention after newborn hearing screening (NHS) in South Korea. A retrospective review of Korean national health insurance service data of all infants receiving the 4-month old national infant health checkup between 2010 and 2016 from a nationwide population-based database was conducted. Based on the results of the NHS-administered hearing questionnaires as part of the national infant health checkup, individuals were classified into "pass" (1,730,615 infants) or "refer" (10,941 infants) groups. Next, an analysis was conducted of age and the frequencies of tracking audiologic tests and surgeries of the middle ear (ME) and cochlear implants (CI). Diagnostic auditory brainstem response and audiometry, and surgeries of ME and CI were significantly performed more and earlier in the refer group compared with the pass group. For infants in the pass group who were presumed to have delayed or acquired hearing loss, the time of the first audiology tests and CI surgery was significantly delayed compared to those in the refer group; the average ages for first CI were 37 and 52 months in the refer group and pass group, respectively. Therefore, for early detection of delayed-onset hearing loss, regular hearing screening programs should be considered throughout the preschool ages.

Rate of chronic otitis media operations and cholesteatoma surgeries in South Korea: a nationwide population-based study (2006-2018)

The aim of this study was to estimate the total number and rate of chronic otitis media (COM) operations and cholesteatoma surgeries in South Korea, using a nationwide survey which analysed a 13-year trend (2006–2018). This study also analysed the trend of COM operations and cholesteatoma surgeries according to year, sex, and age using a nationwide population-based database, and the 13-year trend was analysed according to age groups. This study used nationwide data from the National Health Information Database (NHID), which is a government-affiliated agency under the Korean Ministry of Health and Welfare that supervises all medical activities in Korea. Retrospective medical data of patients of all ages were extracted from the NHID from January 2006 to December 2018 (NHIS-2018). This study was conducted by the Research Committee of the Korean Society of Otorhinolaryngology-Head and Neck Surgery, and the Korean Audiological Society reviewed and confirmed the study. There was a 1.5 fold increase in COM operation rates in 2018, compared to 2007 figures. The annual total number of COM operations was 5,935 in 2007, 8,999 in 2012 (peak), and 8,870 in 2018 (17 in 100,000). Meanwhile, the total annual number of cholesteatoma surgeries decreased from 3,502 in 2006 to 3,199 in 2018 (6 in 100,000). The rate of COM operations was higher (1.27 fold) in the female population than in the males in 2018. However, cholesteatoma surgery rates were higher (1.2 fold) in the male population than in the females in 2018. According to the 2018 data, COM operations were most commonly performed in patients in their 50s. COM operation rates increased rapidly in patients aged 51–80. In other age groups however, rates were constant or showed a decrease in figures, especially in the 40s age group (1st rank in 2006 to 3rd rank in 2018). According to the 2018 data, cholesteatoma surgery was most commonly performed in patients in their 50s. Cholesteatoma surgery rates increased dramatically from 2006 to 2018 in patients aged 0–10 years due to congenital cholesteatoma. Cholesteatoma surgery rates also increased in patients aged 61–80 years due to ageing population. Cholesteatoma surgery rates decreased in patients aged 41–50 years, ranking 1st in 2006 and 4th in 2018. In conclusion, the annual rate of COM operations was 0.017%, and no longer increases, but stabilizes/decreased after a peak point in the advanced country. The mean rate of cholesteatoma surgery was 0.006%, and decreased annually. There was female dominance in COM operations, but male dominance in cholesteatoma surgery. Major age groups of patients who underwent COM/cholesteatoma surgery were the 50s and 60s, and congenital cholesteatoma (0–10 years) accounted for about 20% of all cholesteatoma surgery.

The change of prevalence and recurrence of acute otitis media in Korea

OBJECTIVES

Acute otitis media (AOM) is the most common infectious disease in infants and children. However, there have been few studies on the recent prevalence and trends of pediatric AOM in Korea. This study aimed to evaluate the prevalence and trends of pediatric AOM in Korea.

METHODS

The data for patients with AOM in 2012, 2015, and 2017 were extracted from the Health Insurance Review and Assessment Service's Big Database. The prevalence rate, recurrence rate, and data on gender, region, month, and medical facilities of AOM were evaluated.

RESULTS

The prevalence rate (per 1000 persons) decreased from 152.7 in 2012 to 137.4 in 2017. The recurrence rate declined from 34.0% in 2012 to 28.2% in 2015. In 2015, the recurrence rate of 0-2 years group decreased significantly. In 2017, the prevalence of AOM of 3-6 years group decreased the most. The prevalence is higher in urban areas and recurrence rate is higher in rural areas. But those are no significant difference. AOM is more common in male, mainly in winter and spring.

CONCLUSIONS AND SIGNIFICANCE

The prevalence and recurrence rate of pediatric AOM in Korea are gradually decreasing. The decrease of prevalence resulted from declination in AOM recurrence of 0-2 years group in 2015 and AOM occurrence of 3-6 years group in 2017.

Psychiatric Distress as a Common Risk Factor for Tinnitus and Joint Pain: A National Population-Based Survey

OBJECTIVES

This study aimed to investigate the relationship between tinnitus and joint pain from representative samples of Koreans.

METHODS

The demographics and the responses to a questionnaire about tinnitus and joint pain severity and mental health status of adults aged ≥50 years in the 2010-2012 Korean National Health and Nutrition Examination Survey were analyzed.

RESULTS

Among 9,032 individuals, 26.7% reported experiencing tinnitus within the past year. Participants with tinnitus were more frequently older, hearing loss, and had lower education levels, income, and body weight. Participants with regular exercise and sleep had a lower tinnitus prevalence. The incidences of stress, depressed mood, and suicidal ideation were significantly higher in the tinnitus group and participants with joint pain. The rates of participants with tinnitus according to the number of joint pain sites (zero, one, two, and three) was 22.1%, 31.4%, 33.3%, and 44.2%, and those of participants with severely annoying tinnitus according to the number of joint pain sites (zero, one, two, and three) were 3.3%, 6.8%, 7.9%, and 10.7%, respectively.

CONCLUSION

Tinnitus prevalence and severity were significantly related to joint pain, and both conditions were related to psychiatric distress. Thus, the authors suggest that psychiatric distress as a common risk factor for tinnitus and joint pain should be considered when deciding treatment strategies and in guiding public health policy.

The optimal and safe intensity for facial nerve stimulation during intraoperative neuromonitoring in middle ear surgery

Objective

This study aimed to investigate the optimal and safe intensity for facial nerve stimulation during middle ear surgery.

Methods

Thirty-seven patients who had their facial nerve exposed prior to surgery were prospectively enrolled in this study, and electromyography (EMG) recordings were obtained from the orbicularis oculi and orbicularis oris muscles. Four pigs were also enrolled in an animal study, and continuous stimulation was performed on the facial nerves of the pigs for 10 minutes. The EMG responses were measured and the pathologic outcomes of the facial nerve after stimulation were determined.

Results

In the human study, the mean intensity of the minimal electrical stimulation threshold was 0.21 mA (range: 0.1–0.3 mA). A linear correlation was observed between stimulus intensity and response amplitude for intensities below 0.4 mA. Response amplitudes reached a plateau between 0.4 mA and 1.0 mA. The minimal stimulus intensity that could generate a maximal response was 0.4 mA in the orbicularis oculi (244 μV) and orbicularis oris (545 μV). In the animal study, there were no observed changes in EMG or nerve damage incidence after the continuous stimulation of 3.0 mA.

Conclusions

0.4 mA is considered to be the optimal intensity of facial nerve stimulation during middle ear surgery, and it was estimated through the animal study that a stimulation of 3.0 mA is safe from facial nerve damage.

Analysis of Inner Ear Anomalies in Unilateral Congenital Aural Atresia Combined With Microtia

Objectives

The aim of this study was to analyze the incidence of inner ear anomalies in patients with unilateral congenital aural atresia (CAA) combined with microtia.

Methods

We retrospectively reviewed 61 patients with unilateral CAA combined with microtia who underwent high-resolution temporal bone computed tomography (TBCT) and hearing examination. Inner ear anomalies were analyzed using TBCT and evaluated according to the Jahrsdoerfer grading system, Marx classification, and extent of inferior displacement of the mastoid tegmen.

Results

Inner ear anomalies were observed in 14 patients (23.0%). Lateral semicircular canal (LSCC) dysplasia was the most common inner ear anomaly, with an incidence of 16.4%. The incidence was significantly higher on the pathologic side than on the unaffected side (P=0.002). All vascular anomalies were observed in the high-riding jugular bulb, with an incidence of 24.6%. The incidence was significantly higher on the pathologic side than on the unaffected side (P<0.001). LSCC dysplasia was significantly more common in patients with a lower Jahrsdoerfer score (odds ratio, 0.66; P=0.004).

Conclusion

The incidence of inner ear anomalies was relatively high in patients with unilateral CAA combined with microtia; LSCC dysplasia was the most common anomaly and the probability of coexistence was higher in patients with a lower Jahrsdoerfer score.

Prevalence of severe-profound hearing loss in South Korea: a nationwide population-based study to analyse a 10-year trend (2006-2015)

To estimate prevalence of severe-profound hearing loss (HL) in South Korea, and analyse a 10-year trend of HL according to age, sex, and region by using a nationwide population-based database. Retrospective review from Korean National Health Insurance Service from 2006 to 2015. The degree of severe-profound HL was classified into six grades, based mostly on HL worse than 60 dB HL for both ears. Absolute number of HL was the highest in 2011 (0.25 million; males, 0.14 million; females, 0.11 million); it decreased gradually until 2015. Total HL prevalence was the highest in 2010 (0.5%; 251,954), and decreased annually to 2015 (0.46%; 237,272). The trend of HL prevalence showed a gradual decrease from 2010 to 2015. Prevalence of severe-profound HL was always higher in the male population (1.19 times higher than female in 2015). Prevalence of HL was higher in rural areas than in urban areas (1.4 times higher in 2015). Number of severe-profound HL in South Korea decreased gradually in all age groups annually, even though some older age groups had the highest peak in 2010–2011. Prevalence of severe-profound HL decreases gradually in all age groups annually in South Korea, although the absolute number of HL cases increases rapidly among those aged over 80 years.

Effect of electronic cigarettes on human middle ear

OBJECTIVE

Electronic cigarettes (e-cigarettes) are the most commonly used electronic nicotine delivery systems and are a relatively new product designed for smoking cessation. The market scale of electronic cigarettes is growing rapidly, but the potential impact of e-cigarettes on public health has not yet been verified. In this study, we examined the effect of e-liquids on a human middle ear epithelial cell (HMEEC) line.

MATERIAL AND METHODS

The main components of e-liquids are propylene glycol, vegetable glycerin and flavoring agents with or without nicotine. We analyzed 73 bottles of e-liquids from 12 different manufacturers, evaluated the trace elements in e-liquids, and identified the cytotoxicity of e-liquids on HMEECs in the presence or absence of nicotine.

RESULTS

In the trace elements analysis, nickel, arsenic, cadmium, and lead were detected in the e-liquids. E-liquids without nicotine decreased cell viability, and the average IC 50 value of total e-liquids (n = 73) was 2.48 ± 0.93%. Among the different flavors, menthol-flavored e-liquids significantly reduced cell viability, and their average IC 50 value (n = 28) was 1.85 ± 0.80%. The average IC 50 values were distinct among manufacturers and the proportion of the solvents.

CONCLUSION

The present study provides evidence that e-cigarettes influence and reduce human middle ear cell viability even without the application of nicotine. Additionally, the cytotoxicity of e-liquids was affected by the flavoring agents.

Impact of Nicotine Exposure on Hair Cell Toxicity and Embryotoxicity During Zebrafish Development

Objectives

Nicotine has various adverse effects including negative impacts associated with maternal exposure. In the current study, we examined nicotine-induced damage of hair cells and embryotoxicity during zebrafish development.

Methods

Zebrafish embryos were exposed to nicotine at several concentrations (5, 10, 20, and 40 μM) and embryotoxicity were evaluated at 72 hours, including hatching rate, mortality, teratogenicity rate, and heart rate. Hair cells within the supraorbital (SO1 and SO2), otic (O1), and occipital (OC1) neuromasts were identified at 120 hours. Apoptosis and mitochondrial damage of hair cells were analyzed using TUNEL (terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling) and DASPEI (2-[4-(dimethylamino)styryl]-N-ethylpyridinium iodide) assays, respectively, and changes of ultrastructure were observed by scanning electron microscopy.

Results

The control group without nicotine appeared normal with overall mortality and teratogenicity rate <5%. The hatching rate and mortality rate was not significantly different according to nicotine concentration (n=400 each). The abnormal morphology rate (n=400) increased and heart rate (n=150) decreased with increasing nicotine concentration (P<0.05). Nicotine-induced hair cell damage significantly increased as nicotine concentration increased. A significantly greater number of TUNEL-positive cells (P<0.01) and markedly smaller DASPEI area (P<0.01) were shown as nicotine concentration increased.

Conclusion

The current results suggest that nicotine induces dose-dependent hair cell toxicity in embryos by promoting apoptosis and mitochondrial and structural damage.

Analysis of Eustachian Tube Dysfunction by Dynamic Slow Motion Video Endoscopy and Eustachian Tube Dysfunction Questionnaire in Chronic Otitis Media

OBJECTIVES

Eustachian tube dysfunction has been associated with most cases of middle-ear disease. We aimed to assess the effectiveness of dynamic slow motion video endoscopy (DSVE) as a test of eustachian tube dysfunction. Furthermore, we assessed the correlation of the test with the Valsalva maneuver, the seven-item Eustachian Tube Dysfunction Questionnaire (ETDQ-7), and intraoperative findings of the eustachian tube.

METHODS

We retrospectively reviewed medical records from April to September 2014 to identify patients who were diagnosed with chronic otitis media (COM) at Korea University Ansan Hospital. They all underwent surgery because of COM without cholesteatoma and were assessed via the DSVE and ETDQ-7 to determine eustachian tube function.

RESULTS

We reviewed 46 COM patients and examined 46 ears with COM and 46 ears on the contralateral side to COM that were thought to be normal. The mean DSVE grade in COM ears was 1.57±0.96, while the mean DSVE grade in contralateral ears was 1.15±0.94. The difference in DSVE between COM ears and normal ears was statistically significant (P=0.006). In the ETDQ-7, a higher score was related to intraoperative obstruction of the eustachian tube (P=0.012).

CONCLUSION

DSVE and ETDQ-7 can provide information regarding preoperative status of eustachian tube dysfunction by measuring dynamic structural changes of the eustachian tube in combination with other diagnostic tests.

In vitro Multi-Species Biofilms of Methicillin-Resistant Staphylococcus aureus and Pseudomonas aeruginosa and Their Host Interaction during In vivo Colonization of an Otitis Media Rat Model

Staphylococcus aureus (SA) and Pseudomonas aeruginosa (PA) are known to cause biofilm-related infections. MRSA and PA have been frequently isolated from chronically infected wounds, cystic fibrosis, chronic suppurative otitis media (CSOM), and from indwelling medical devices, and these bacteria co-exist; however, their interaction with each-other or with the host is not well known. In this study, we investigated MRSA and PA multi-species biofilm communities in vitro and their interaction with the host during in vivo colonization using an OM rat-model. In-vitro biofilm formation and in-vivo colonization were studied using CV-microtiter plate assay and OM rat-model respectively. The biofilms were viewed under scanning electron microscope and bacteria were enumerated using cfu counts. The differential gene expressions of rat mucosa colonized with single or multi-species of MRSA or PA were studied using RNA-sequencing of total transcriptome. In multi-species in-vitro biofilms PA partially inhibited SA growth. However, no significant inhibition of MRSA was detected during in-vivo colonization of multi-species in rat bullae. A total of 1,797 genes were significantly (p < 0.05) differentially expressed in MRSA or PA or MRSA + PA colonized rat middle ear mucosa with respect to the control. The poly-microbial colonization of MRSA and PA induced the differential expression of a significant number of genes that are involved in immune response, inflammation, signaling, development, and defense; these were not expressed with single species colonization by either MRSA or PA. Genes involved in defense, immune response, inflammatory response, and developmental process were exclusively up-regulated, and genes that are involved in nervous system signaling, development and transmission, regulation of cell growth and development, anatomical and system development, and cell differentiation were down-regulated after multi-species inoculation. These results indicate that poly-microbial colonization induces a host response that is different from that induced by single species infection.

Analysis of Effect of Eggshell Membrane Patching for Moderate-to-Large Traumatic Tympanic Membrane Perforation

Background and Objectives

To evaluate the effect of eggshell membrane (ESM) patching for tympanic membrane (TM) perforation, and to investigate correlations between healing time and age, gender, patching time, perforation size, and perforation location.

Subjects and Methods

One hundred and seventy-five patients diagnosed with traumatic TM perforation at the Department of Otorhinolaryngology-Head and Neck Surgery, Korea University Ansan Hospital, between January 2008 and October 2013. Patients were divided into two groups, according to perforation edge approximation or ESM patching treatment. Healing time was compared between the group that received perforation edge approximation and the group that received ESM patching. Perforation grade, age, onset, and location were also compared between the two groups.

Results

ESM patching significantly improved healing time compared to spontaneous healing, especially in patients with moderate or large traumatic TM perforations (≥grade II). However, patient age, gender, perforation location, and especially timing of procedure, did not significantly affect healing time.

Conclusions

ESM patching can be a good treatment choice to promote tympanic membrane healing in large traumatic TM perforations.

Comparison of the effects of lipoic acid and glutathione against cisplatin-induced ototoxicity in auditory cells

OBJECTIVES

The aims of this study were to examine lipoic acid (LA)- or glutathione (GSH)-mediated protection against cytotoxicity following cisplatin exposure in HEI-OC1 auditory cells and measure the potential of LA and GSH to scavenge reactive oxygen species (ROS). This study also compares their protective effects and discusses the determination of a preventive or therapeutic dose.

METHODS

HEI-OC1 cells were pretreated with LA or GSH for 24 h and then exposed to 15 μM cisplatin for 48 h. The resulting cytotoxicity was measured using a cell counting kit-8, and intracellular ROS level was measured using flow cytometry. The protective or anti-ROS effects of LA and GSH were compared. Measurement of caspase 3, 8, 9 activity and Western blot analysis of PARP were performed.

RESULTS

Pretreatment with LA at 300 μM and GSH at 3 mM protected HEI-OC1 cells against cisplatin-induced cytotoxicity and significantly reduced the cisplatin-induced increase in ROS. LA showed a significantly more effective protection against cisplatin-induced ototoxicity compared to that shown by GSH (85.4% vs. 73.1% cell viability). Both LA and GSH showed the maximal protective effect at different concentrations in normal or cisplatin-induced cytotoxic conditions. The preventive or therapeutic dose for harmful conditions is quite different for the two drugs and needs careful adjustments.

CONCLUSION

This comparative study on the protective effects of LA and GSH against cisplatin-induced ototoxicity in an auditory cell line posed many challenges. Although LA and GSH showed a significant protective effect against cisplatin, the LA's effect was superior. The concentration at which the maximal protective effect of LA or GSH was noted was 3 times higher in cytotoxic conditions than in normal conditions, which suggests the need for drug dose adjustments based on the purpose (preventive or therapeutic).

The suppressive effects of metformin on inflammatory response of otitis media model in human middle ear epithelial cells

OBJECTIVE

Metformin is a well-known anti-diabetic agent, but its mechanism is unclear. Recently, many reports have described the anti-inflammatory effects of metformin on various cell types, including human vascular smooth muscle cells and endothelial cells. This study was designed to investigate the anti-inflammatory effect of metformin on lipopolysaccharide (LPS) induced inflammation in human middle ear epithelial cell lines (HMEECs).

METHODS

The effect of pretreatment by metformin (0, 1, 2, 4 mM) was evaluated by the inflammatory response in the HMEECs exposed to LPS (10 ng/ml). For verifying the suppression effect of metformin on the inflammatory cytokines, tumor necrosis factor-alpha (TNF-α) was evaluated by real-time polymerase chain reaction, and COX-2 protein was assessed by western blotting. Intracellular reactive oxygen species (ROS) was measured using 2', 7'-dichlorofluorescein diacetate (DCFHDA) fluorocytometer.

RESULTS

Stimulation by LPS 10 ng/ml concentration showed 12.4 folds increase the expression of TNF-α mRNA compared to control on HMEECs. Pretreatment of metformin dose dependently suppressed the expression of TNF-α mRNA induced by LPS (2 mM, p = 0.03). The amount of COX-2 protein production was significantly decreased by metformin pretreatment (4 mM, p = 0.01). The production of ROS was decreased significantly by pretreatment of metformin (p = 0.03).

CONCLUSIONS

These findings suggest that the inflammatory response and oxidative stress induced by LPS could be suppressed by metformin in HMEECs. Therefore, metformin may have a therapeutic potential for the treatment of the otitis media.

Effect of Tianeptine on Depressed Tinnitus Patients

Background and Objectives

Tianeptine is a tricyclic antidepressant that has a novel pharmacological property: it increases the reuptake of 5-hydroxytryptamine. Recent studies have reported that the prevalence of depression is greater in patients with tinnitus than in control subjects who do not have tinnitus. The purpose of this study was to assess the efficacy of tianeptine for the relief of tinnitus, especially in patients with depressive mood.

Subjects and Methods

Among a total of 52 tinnitus patients, 15 had depressive mood. The depressed tinnitus patients were prescribed Stablon® 12.5 mg once daily for 1 month without any other drug. We assessed the severity of tinnitus, level of depression, and the quality of sleep in these patients by using the Tinnitus Handicap Inventory (THI), Beck Depression Inventory (BDI), and Pittsburgh Sleep Quality Index (PSQI). Hearing impairment and severity of tinnitus were measured with pure tone audiometry, speech audiometry, and tinnitograms. These evaluations were conducted before and after medication treatment.

Results

For the 15 depressed tinnitus patients, THI scores significantly correlated with BDI and PSQI scores prior to medication treatment. These results showed that the discomfort of tinnitus was closely related to depression and sleep disorder. After medication treatment, THI and BDI scores significantly decreased, indicating that tinnitus and depression improved. However, no significant alteration in PSQI score was observed, indicating that there was no improvement in sleep quality.

Conclusions

In the treatment of depressed tinnitus patients, tianeptine might be an efficient drug to treat both tinnitus and depression. However, tianeptine is unlikely to improve the quality of sleep in these patients.

The effects of the antioxidant α-tocopherol succinate on cisplatin-induced ototoxicity in HEI-OC1 auditory cells

CONCLUSION

D-α-tocopherol succinate significantly reduced a cisplatin-induced hair cell loss in HEI-OC1 cell lines. These effects were mediated by its scavenging activity against reactive oxygen species (ROS) and inhibition of apoptosis.

OBJECTIVES

Alpha-tocopherol is a class of methylated phenols, known as fat-soluble antioxidants, and is a different form of vitamin E, which reduces free radicals and acts as an antioxidant. We hypothesized that the antioxidative effect of α-tocopherol could protect against cisplastin-induced cytotoxicity, and thus evaluated its effects on cisplatin-induced ototoxicity in HEI-OC1 auditory cells.

METHODS

HEI-OC1 cells were pretreated with D-α-tocopherol succinate at a concentration of 10 µM for 24 h, and then exposed to 15 µM cisplatin for 48 h. The cellular viability was measured by using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) method. The intracellular ROS level was measured by using a fluorescent dye, 2',7'-dichlorofluorescein diacetate (DCFH-DA). Both Annexin V-FITC and propidium iodide (PI) staining were performed to analyze the pattern of apoptosis. The enzymatic activity of caspase-3 was assayed with caspase3/CPP32 fluorometric assay kit. Also, it was assessed by immunoblotting technique of poly-ADP-ribose polymerase (PARP).

RESULTS

Pretreatment with 10 µM D-α-tocopherol succinate protected HEI-OC1 auditory cells against cisplatin-induced cytotoxicity. D-α-tocopherol succinate significantly reduced the cisplatin-induced increase in ROS. D-α-tocopherol succinate treatment induced a 15% reduction of ROS and 50% decrease in necrosis and late apoptosis as compared to cisplatin treatment. D-α-tocopherol succinate also decreased the activation of caspase-3 and reduced levels of cleaved poly-ADP-ribose polymerase (PARP).

Analysis of audio-vestibular assessment in acute low-tone hearing loss

Conclusion This study demonstrated excellent hearing recovery following the combined treatment of diuretic and oral steroid, and electrocochleography (ECoG) was significantly higher than normal side. This study reports characteristics of acute low-tone hearing loss (ALHL) that show the greater low-tone hearing loss, the higher ECoG, and excellent recovery, even-though low-tone hearing loss is worse, which can be different compared with sudden deafness. Objective To analyze ALHL without vertigo, this study compared the ALHL group with all patients exhibiting low-tone hearing loss and ear fullness. Hearing changes and vestibular functions were analyzed. Materials and methods ALHL was defined as a mean hearing loss of ≥ 30 dB at 125, 250, and 500 Hz, and ≤ 20 dB at 2, 4, and 8 kHz. From 156 cases of low-tone hearing loss of more than 10 dB without vertigo, 31 met the ALHL criteria and were subjected to audio-vestibular assessments including PTA, ECoG, vestibular evoked myogenic potential (VEMP) testing, and caloric testing. Results In ALHL, low-tone hearing loss was 42.7 ± 9.5 dB, and 83.9% of ALHL significantly recovered by more than 10 dB. The ECoG in ALHL was 0.334 ± 0.11 (higher than 0.25 ± 0.08 on the normal side) and ECoG abnormality was 35.5% (the greater low-tone hearing loss, the higher ECoG value).

Sarcopenia and Hearing Loss in Older Koreans: Findings from the Korea National Health and Nutrition Examination Survey (KNHANES) 2010

Age-related hearing impairment (ARHI) is becoming a more significant issue as geriatric population increases. Sarcopenia in older people is known to have a diverse health problem in various circumstances in recent studies. We assessed whether the decrease in muscle mass is related to ARHI. We used the 2010 data of the Korea National Health and Nutrition Examination Survey (KNHANES) to examine the associations between sarcopenia and ARHI. A total number of participants was 1,622 including 746 males and 876 females aged 60 years or older. Muscle mass was assessed as an appendicular skeletal muscle mass, and hearing loss was defined as the pure-tone averages (PTA) of test frequencies 0.5, 1, 2, 4 kHz at a threshold of 40 dB or higher in worse hearing side of the ear. Among 1,622 participants, 298 men and 256 women had hearing loss. Appendicular muscle mass (ASM), expressed as kg, was categorized in tertiles. In female population, after adjusting for age, smoking, drinking, amount of exercise, total body fat, education level, income level, and tinnitus, the odds ratio (OR) for hearing loss was 1.57 (95% confidence interval (CI) = 0.92–2.68) in the middle tertile and 1.79 (1.03–3.08) in the lowest tertile, compared with the highest tertile. P for trend in this model was 0.036. Controlling further for hypertension, diabetes mellitus, chronic kidney disease, and three types of noise exposure did not change the association. Larger muscle mass is associated with lower prevalence of hearing loss in elderly Korean females.

Sodium Selenite Acts as an Otoprotectant against Neomycin-Induced Hair Cell Damage in a Zebrafish Model

Sodium selenite is a trace element essential for many physiological functions in the body. It is involved in various biological processes; it acts as a cofactor for antioxidant enzymes that protect against free radicals and is reported to limit metal-mediated oxidative DNA damage. In the present study, we investigated the effect of sodium selenite on neomycin ototoxicity in wild-type and transgenic zebrafish (Brn3C: EGFP). Five or six days post-fertilization, zebrafish larvae were co-exposed to 125 μM neomycin and various concentrations (10 μM, 100 μM, 250 μM, and 500 μM) of sodium selenite for 1 h. Hair cells within neuromasts of the supraorbital (SO1 and SO2), otic (O1), and occipital (OC1) lateral lines were analyzed by fluorescence microscopy (n = 10 fish per treatment). Hair cell survival was estimated as the ratio of the hair cell numbers in each group compared to those of the control group that were not exposed to neomycin. Apoptosis and hair cell damage of neuromasts were evaluated using the terminal deoxynucleotidyl transferase (TdT)-mediated dUTP-biotin nick end labeling (TUNEL) assay and 2-[4-(dimethylamino) styryl]-N-ethylpyridinium iodide (DASPEI) assay, respectively. Ultrastructural changes were evaluated using scanning electron microscopy and transmission electron microscopy. Neuromast hair cells were preserved in zebrafish exposed to 125 μM neomycin and 500 μM sodium selenite for 1 h. Sodium selenite protected against neomycin-induced hair cell loss of neuromasts, reduced apoptosis, and prevented zebrafish ultrastructural changes. We propose that sodium selenite protects against neomycin-induced hair cell damage by inhibiting apoptosis, decreasing the disarray of stereocilia, and preventing ultrastructural changes in the neuromast hair cells of the zebrafish.

Analysis of Bacterial Biofilms on a Cochlear Implant Following Methicillin-Resistant Staphylococcus Aureus Infection

To demonstrate biofilm formations on a cochlear implant magnet of a pediatric patient suffering from a methicillin-resistant Staphylococcus aureus (MRSA) infection. The appearance of biofilm colonies was analyzed on different magnet sections. The appearance of MRSA biofilms on the surface of an explanted cochlear implant was analyzed by scanning electron microscopy (SEM), focusing on the pattern of extracellular polymeric substances (EPS) within the biofilms. SEM revealed unique biofilms with a three-dimensional EPS complex and tower-like formations. Biofilm configurations changed from the margin to the center of the magnet. Biofilms were solitary and scattered at the margin; large and plate-like in the center; and stacked in layers, forming towers and water channels, in the middle region. After a MRSA infection, biofilm formations were observed on the surface of a magnet. Bacterial biofilms provide optimal conditions for bacterial growth and antibiotic resistance and can cause intractable infections that lead to device failure.

Eugenol: a phyto-compound effective against methicillin-resistant and methicillin-sensitive Staphylococcus aureus clinical strain biofilms

Background

Inhibition and eradication of Staphylococcus aureus biofilms with conventional antibiotic is difficult, and the treatment is further complicated by the rise of antibiotic resistance among staphylococci. Consequently, there is a need for novel antimicrobials that can treat biofilm-related infections and decrease antibiotics burden. Natural compounds such as eugenol with anti-microbial properties are attractive agents that could reduce the use of conventional antibiotics. In this study we evaluated the effect of eugenol on MRSA and MSSA biofilms in vitro and bacterial colonization in vivo.

Methods and Results

Effect of eugenol on in vitro biofilm and in vivo colonization were studied using microtiter plate assay and otitis media-rat model respectively. The architecture of in vitro biofilms and in vivo colonization of bacteria was viewed with SEM. Real-time RT-PCR was used to study gene expression. Check board method was used to study the synergistic effects of eugenol and carvacrol on established biofilms. Eugenol significantly inhibited biofilms growth of MRSA and MSSA in vitro in a concentration-dependent manner. Eugenol at MIC or 2×MIC effectively eradicated the pre-established biofilms of MRSA and MSSA clinical strains. In vivo, sub-MIC of eugenol significantly decreased 88% S. aureus colonization in rat middle ear. Eugenol was observed to damage the cell-membrane and cause a leakage of the cell contents. At sub-inhibitory concentration, it decreases the expression of biofilm-and enterotoxin-related genes. Eugenol showed a synergistic effect with carvacrol on the eradication of pre-established biofilms.

Conclusion/Major Finding

This study demonstrated that eugenol exhibits notable activity against MRSA and MSSA clinical strains biofilms. Eugenol inhibited biofilm formation, disrupted the cell-to-cell connections, detached the existing biofilms, and killed the bacteria in biofilms of both MRSA and MSSA with equal effectiveness. Therefore, eugenol may be used to control or eradicate S. aureus biofilm-related infections.

Synaptic calcium regulation in hair cells of the chicken basilar papilla

Cholinergic inhibition of hair cells occurs by activation of calcium-dependent potassium channels. A near-membrane postsynaptic cistern has been proposed to serve as a store from which calcium is released to supplement influx through the ionotropic ACh receptor. However, the time and voltage dependence of acetylcholine (ACh)-evoked potassium currents reveal a more complex relationship between calcium entry and release from stores. The present work uses voltage steps to regulate calcium influx during the application of ACh to hair cells in the chicken basilar papilla. When calcium influx was terminated at positive membrane potential, the ACh-evoked potassium current decayed exponentially over ∼100 ms. However, at negative membrane potentials, this current exhibited a secondary rise in amplitude that could be eliminated by dihydropyridine block of the voltage-gated calcium channels of the hair cell. Calcium entering through voltage-gated channels may transit through the postsynaptic cistern, since ryanodine and sarcoendoplasmic reticulum calcium-ATPase blockers altered the time course and magnitude of this secondary, voltage-dependent contribution to ACh-evoked potassium current. Serial section electron microscopy showed that efferent and afferent synaptic structures are juxtaposed, supporting the possibility that voltage-gated influx at afferent ribbon synapses influences calcium homeostasis during long-lasting cholinergic inhibition. In contrast, spontaneous postsynaptic currents ("minis") resulting from stochastic efferent release of ACh were made briefer by ryanodine, supporting the hypothesis that the synaptic cistern serves primarily as a calcium barrier and sink during low-level synaptic activity. Hypolemmal cisterns such as that at the efferent synapse of the hair cell can play a dynamic role in segregating near-membrane calcium for short-term and long-term signaling.

Protective role of edaravone against neomycin-induced ototoxicity in zebrafish

Aminoglycosides such as neomycin are one of the most commonly prescribed types of antibiotics worldwide. However, these drugs appear to generate free radicals within the inner ear, which can result in permanent hearing loss. We evaluated the effects of edaravone, a neuroprotective agent, on neomycin-induced ototoxicity in transgenic zebrafish. The 5-day post fertilization (dpf) zebrafish larvae were exposed to 125 μM neomycin and various concentrations of edaravone for 1 h. Hair cell survival was calculated as average numbers of the hair cells in the control group, which was not exposed to neomycin. Ultrastructural changes were evaluated using a scanning electron microscope (SEM) and transmission electron microscope (TEM). Edaravone protected against neomycin-induced hair cell loss in the neuromasts (1000 μM: 11.6 ± 1.1 cells, neomycin only: 5.5 ± 0.5 cells; n = 10, P<0.05) and decreased the TUNEL reaction for detecting apoptosis. In ultrastructural analysis, structures of mitochondria and hair cells within neuromasts were preserved in zebrafish exposed to 125 μM neomycin and 1000 μM edaravone for 1 h. Edaravone protected against neomycin-induced hair cell loss by preventing apoptosis.

Bilateral muscular tinnitus due to myoclonus of extrinsic auricular muscles

The muscular tinnitus due to an extrinsic auricular myoclonus is an extremely rare disorder which demonstrates a semirhythmic involuntary movement of the ear. We report a 33-year-old man with clicking tinnitus caused by focal myoclonic jerks of bilateral posterior auricularis muscle and bilateral temporalis muscle. This muscular tinnitus persisted except for when he was sleeping or breath holding. His symptom responded poorly to medical therapy but was controlled by botulinum toxin type A injection under electromyography monitoring with favorable outcome. Previous reports of this condition and possible therapeutic approaches are discussed.

Protective effects of caffeic acid phenethyl ester (CAPE) against neomycin-induced hair cell damage in zebrafish

OBJECTIVE

Caffeic acid phenethyl ester (CAPE) is known to reduce the generation of oxygen-derived free radicals, which is a major mechanism of aminoglycoside-induced ototoxicity. The objective of the present study was to evaluate the effects of CAPE on neomycin-induced ototoxicity in zebrafish (Brn3c: EGFP).

METHODS

Five-day post-fertilization zebrafish larvae (n=10) were exposed to 125 μM neomycin and one of the following CAPE concentrations for 1h: 50, 100, 250, 500, or 1000 μM. Ultrastructural changes were evaluated using scanning electron microscopy (SEM). The terminal deoxynucleotidyl transferase (TdT)-mediated dUTP-biotin nick-end labeling (TUNEL) assay and 2-[4-(dimethylamino)styryl]-N-ethylpyridiniumiodide (DASPEI) assay were performed for evaluation of apoptosis and mitochondrial damage.

RESULTS

CAPE decreased neomycin-induced hair cell loss in the neuromasts (500 μM CAPE: 12.7 ± 1.1 cells, 125 μM neomycin only: 6.3 ± 1.1 cells; n = 10, P < 0.05). In the ultrastructural analysis, structures of mitochondria and hair cells were preserved when exposed to 125 μM neomycin and 500 μM CAPE. CAPE decreased apoptosis and mitochondrial damage.

CONCLUSION

In the present study, CAPE attenuated neomycin-induced hair cell damage in zebrafish. The results of the current study suggest that neomycin induces apoptosis, and the apoptotic cell death can be prevented by treatment with CAPE in zebrafish.

Can we use electrocochleography as a clinical tool in the diagnosis of Meniere's disease during the early symptomatic period?

CONCLUSION

Our results indicate that electrocochleography (ECoG) has limited value in diagnosing Meniere's disease during the early symptomatic period.

OBJECTIVE

We hypothesized that if endolymphatic hydrops is a cause of Meniere's disease, ECoG results obtained in normal subjects would differ from those obtained during the early symptomatic period of Meniere's disease. We aimed to investigate the usefulness of ECoG in the diagnosis of Meniere's disease during the early symptomatic period.

METHODS

Extratympanic ECoG was used to evaluate 60 patients in a Meniere's group (17 men, 43 women; mean age 43.6 years, range 19-62 years) and 30 controls (11 men, 19 women; mean age 43.5 years, range 21-63 years). The summating potential/action potential (SP/AP) amplitude ratio and SP/AP area ratio were compared between the groups.

RESULTS

Statistically significant differences were not demonstrated in the SP/AP amplitude ratio between the definite Meniere's, probable Meniere's, overall Meniere's, or control groups (0.35 ± 0.02, 0.30 ± 0.03, 0.33 ± 0.02, and 0.30 ± 0.01, respectively). Additionally, statistically significant differences were not indicated in the mean SP/AP area ratio between the definite Meniere's, probable Meniere's, overall Meniere's, or control groups (5.18 ± 0.98, 4.78 ± 0.21, 4.01 ± 0.78, and 3.72 ± 0.66, respectively).

Effect of urban particles on human middle ear epithelial cells

OBJECTIVES

The aim of this study was to examine the cytotoxic effect and inflammatory response of human middle ear epithelial cells (HMEECs) induced by urban particles (UP).

MATERIALS AND METHODS

Cell viability following UP exposure was assessed in HMEECs using the CCK 8 assay. The expression levels of the inflammation-related genes (COX-2 and MUC5AC) were analyzed using semi-quantitative real-time reverse transcriptase-polymerase chain reaction (RT-PCR) and COX-2 production was analyzed using western blotting.

RESULTS

Treatment with UP decreased cell viability in HMEECs in a dose- and time-dependent manner. UP exposure induced the significantly increased expression of COX-2 and MUC5AC. Western blotting showed dose dependently increased expression of COX-2 production.

CONCLUSIONS

UP decreased cell viability, increased the inflammatory response, and increased mucin gene production in HMEECs. These findings indicate that exposure to UP can contribute to the development of otitis media.

The extent of inferior displacement of the mastoid tegmen is related to the severity of congenital aural atresia

CONCLUSION

The extent of inferior displacement of the mastoid tegmen is related to the severity of congenital aural atresia (CAA).

OBJECTIVE

To analyze anatomic variations observed on high-resolution temporal bone computed tomography (TBCT) in patients with CAA, the extent of inferior displacement of the mastoid tegmen and the size of the incudo-stapedial (IS) joint angle were compared with surgical parameters for atresiaplasty, such as Jahrsdoerfer score and hearing acuity.

METHODS

Sixty-one patients with unilateral CAA underwent high-resolution TBCT and hearing tests. We evaluated TBCTs in terms of Jahrsdoerfer criteria and analyzed the relationships among the inferior displacement of the mastoid tegmen, size of the IS joint angle, hearing acuity, and the Jahrsdoerfer score on the atretic side.

RESULTS

IS joint angle on the atretic side was found to be 120.6 ± 11°, which was significantly greater than the corresponding value of 103.4 ± 5.4° on the normal side. Cholesteatoma occurred significantly more often in CAA patients with narrow external auditory canals (EACs) (9/27; 33.3%), compared with CAA patients with no EAC opening (2/34; 5.9%). There was a significant relation between the extent of inferior displacement of the mastoid tegmen (28.9% in the atretic side and 17.3% in the normal side) and the Jahrsdoerfer score (p < 0.0001).

Protective effects of edaravone against cisplatin-induced hair cell damage in zebrafish

OBJECTIVE

Edaravone is known to have a potent free radical scavenging effect. The objective of the present study was to evaluate the effects of edaravone on cisplatin-induced ototoxicity in transgenic zebrafish (Brn3C: EGFP).

METHODS

Five day post-fertilization zebrafish larvae were exposed to 1000 μM cisplatin and 50 μM, 100 μM, 250 μM, 500 μM, 750 μM, and 1000 μM concentrations of edaravone for 4h. Hair cells within neuromasts of the supraorbital (SO1 and SO2), otic (O1), and occipital (OC1) lateral lines were analyzed by fluorescence microscopy and confocal microscopy (n=10). Hair cell survival was calculated as a percentage of the hair cells in the control group that were not exposed to cisplatin. Ultrastructural changes were evaluated using scanning electron microscopy and transmission electron microscopy.

RESULTS

Edaravone protected cisplatin-induced hair cell loss of neuromasts (edaravone 750 μM: 8.7 ± 1.5 cells, cisplatin 1000 μM only: 3.7 ± 0.9 cells; n=10, p<0.0001) and decreased the Terminal deoxynucleotidyl transferase (TdT)-mediated dUTP-biotin nick end labeling (TUNEL) reaction. Structures of mitochondria and hair cell within neuromasts in ultrastructural analysis were preserved in zebrafish exposed to 1000 μM cisplatin and 750 μM edaravone for 4h.

CONCLUSIONS

Edaravone attenuated cisplatin-induced hair cell damage in zebrafish. The results of the current study suggest that cisplatin induces apoptosis, and the apoptotic cell death can be prevented by treatment with edaravone in zebrafish.

Role of nicotinic acetylcholine receptor on efferent inhibition in cochlear hair cell

The α9α10 nicotinic acetylcholine receptors (nAChRs) mediates efferent inhibition of hair cell function within the auditory sensory organ. Gating of the nAChRs leads to activation of calcium-dependent potassium channels to hyperpolarize the hair cell. In efferent system, main calcium providers to SK channel are nAChR and synaptic cistern, which contribution to efferent inhibition is different between avian and mammalian species. Calcium permeation is more effective in nAChRs of mammalian cochlea than avian cochlea, and mammalian calcium permeability of nAChRs is about 3 times more than avian hair cell. Thus, mammalian nAChRs is a main component of efferent inhibition in cochlear hair cell system.

Analysis of frequency loss as a prognostic factor in idiopathic sensorineural hearing loss

CONCLUSION

The combination of systemic steroids with intratympanic dexamethasone injection (ITDI) did not result in significantly different outcomes from steroid treatment only and did not have any additional beneficial effects.

OBJECTIVE

To evaluate hearing recovery in idiopathic sudden sensorineural hearing loss (ISSNHL) according to frequency and to compare treatment responses between patients treated with systemic steroids and systemic steroids with ITDI.

METHODS

Ninety-nine patients with ISSNHL were selected to participate in the study by a retrospective medical chart review. Patients were divided into two groups, systemic steroid treatment only and systemic steroid with adjunctive ITDI. Hearing recovery was evaluated by pure tone audiometry (PTA). All patients underwent PTA examination before treatment and after 3 months. Thresholds were analyzed by frequency along with other factors.

RESULTS

Low frequency hearing loss responded better than high frequency loss to PTA. When we analyzed pure tone audiogram patterns, all patterns except for the descending type showed better improvement in patients with lower frequency hearing loss than in patients with higher frequency hearing loss.