Social distancing during the COVID-19 pandemic: Potential impact and correlation with asthma.

BACKGROUND: Non-pharmaceutical interventions have been implemented globally to control the COVID-19 pandemic and have been shown to alleviate both allergies and respiratory infections. Although mask-wearing is an accepted non-pharmaceutical intervention, the effects of social distancing have not been thoroughly evaluated. OBJECTIVES: To evaluate the effects of social distancing on asthma trends in Seoul, South Korea. METHODS: This study included data from the National Health Insurance Service of South Korea, covering approximately 10 million people in Seoul. Daily and monthly data of patients with asthma from 2018 to 2021 were examined, and the degree of social distancing performance was measured using the number of subway users as an index. Pearson's correlation coefficient was used to determine the relationship between the two indices. The change-point detection technique, cross-correlation, and Granger causality method were used to assess the temporal causality between social distancing and asthma. RESULTS: The number of patients with asthma decreased by 42.4 % from 2019 to 2020, while that of subway users decreased by 26.3 % during this period. Pearson's correlation analysis revealed significant positive correlations. Asthma and subway users showed a significant change in incidence following the implementation of social distancing; subway users showed a causal relationship with patients with asthma. CONCLUSION: Our results showed that the number of subway users decreased after the implementation of strict social distancing, coinciding with a decrease in the number of patients with asthma. These findings suggest that social distancing measures implemented to control COVID-19 may reduce the incidence and exacerbation of asthma.

Impact of COVID-19 Pandemic on the Incidence of Pediatric Acute Otitis Media in Seoul, South Korea.

OBJECTIVE: The implementation of nonpharmaceutical interventions (NPIs) for coronavirus disease 2019 (COVID-19) may affect the incidence of infectious diseases. This study aimed to evaluate the changes in the incidence of pediatric acute otitis media (AOM) after the COVID-19 outbreak in Seoul, South Korea. STUDY DESIGN: Retrospective cohort. SETTING: Tertiary referral center. PATIENTS: We ascertained the daily number of COVID-19 and pediatric AOM patients between January 20, 2020, and June 19, 2020. During the same period, the number of children using public transportation was used as an index for implementing NPIs. The same period 1 year ago was set as the control period. INTERVENTION: Diagnostic. MAIN OUTCOME MEASURE: The differences in the incidence of AOM and implementation of NPIs between the COVID-19 pandemic and control period were analyzed using segmented regression analyses. Negative values of difference meant that the number in the COVID-19 pandemic period declined compared with the control period. RESULTS: The study period was divided into two sections based on the change point of the COVID-19 cases. In the first period, the increased number of COVID-19 cases decreased, and in the second period, the number of COVID-19 cases increased again. Similar trends were observed in the incidence of AOM and NPI implementation. Before the change point, the study found a significant decreasing trend in the differences in pediatric AOM cases and children using public transportation. However, these trends changed after the change point, with a significant increase in both indices. CONCLUSION: Our findings indicate that NPIs for COVID-19 may influence the incidence of pediatric AOM.

Association of Central Auditory Processing Dysfunction With Preclinical Alzheimer's Disease.

OBJECTIVE: To investigate whether central auditory processing dysfunction measured by the dichotic digit test-1 digit (DDT1) is present in preclinical Alzheimer's disease (AD) individuals who are cognitively normal (CN) older adults with the cerebral beta-amyloid (Aß) deposition and to explore the potential of the DDT1 as a screening test for preclinical AD. STUDY DESIGN: Cross-sectional design. SETTING: A prospective observational cohort study. METHODS: CN older adults with a global clinical dementia rating score of 0 were included. The hearing test battery including pure-tone audiometry, speech audiometry, distortion product otoacoustic emission, and DDT1 was administered to participants. RESULTS: Fifty CN older adults were included. Among them, 38 individuals were included in the Aß deposition negative (AN) group and 12 were included in the Aß deposition positive (AP) group. The DDT1 scores of both the better and worse ears were significantly lower in the AP group than in the AN group (p = .008 and p = .015, respectively). No significant differences were observed between the groups in tests of the peripheral auditory pathways. In multivariable logistic regression analysis adjusted for apolipoprotein E4 positivity, the DDT1 better ear score predicted the AP group (p = .036, odds ratio = 0.892, 95% confidence interval: 0.780-0.985) with relatively high diagnostic accuracy. CONCLUSION: Our findings suggest that Aß deposition may affect the central auditory pathway even before cognitive decline appears. DDT1, which can easily be applied to the old-age population, may have the potential as a screening tool for preclinical AD.

Improved Prediction of Hearing Loss after Temporal Bone Fracture by Applying a Detailed Classification for Otic Capsule-Violating Fracture: A Wide Scope Analysis with Large Case Series.

INTRODUCTION: This study aimed to analyze the predictability of temporal bone (TB) fracture-associated hearing loss by applying a detailed classification separating individual injury of the cochlea, vestibule, and semicircular canals (SCC). METHODS: In this retrospective study, patients with otic capsule-violating (OCV) fractures were further classified as OCV-C(VS) when the cochlea was involved regardless of vestibule or SCC involvement, OCV-V(S) when the vestibule was involved regardless of SCC involvement, and OCV-S when the fracture only involved SCC. Hearing changes were compared by applying the above-mentioned classification, and TB fracture-induced facial palsy was also analyzed. RESULTS: A total of 119 patients were included. Patients with OCV fractures had significantly worse bone conduction (BC) and air conduction (AC) thresholds (59.1 ± 25.3 and 87.0 ± 29.5 dB) than those with otic capsule-sparing (OCS) fractures (20.1 ± 17.9 and 36.5 ± 21.9 dB; p < 0.001 for each comparison). The BC and the AC thresholds of OCV-C(VS) (77.5 ± 11.0 and 114.2 ± 14.3 dB) and OCV-V(S) (69.3 ± 27.7 and 98.0 ± 22.2 dB) were significantly higher than OCV-S (40.1 ± 22.9 and 62.1 ± 25.6 dB; p < 0.001 for each comparison). The BC hearing thresholds were not significantly improved in the last pure tone audiometry when compared for total, OCV, or OCS cases. The AC threshold significantly improved in OCS cases. In a considerable number of cases with facial palsy, causative fracture lines involved the geniculate ganglion or tympanic segment without the involvement of the otic capsule. Most cases showed significant improvement; however, recovery was limited in cases with obvious fallopian canal disruption. CONCLUSIONS: The cases with sole involvement of SCC had significantly better hearing thresholds than those with cochlear or vestibule involvement, even in OCV fracture cases.

LSTM model for predicting the daily number of asthma patients in Seoul, South Korea, using meteorological and air pollution data.

Asthma is a common respiratory disease that is affected by air pollutants and meteorological factors. In this study, we developed models that predict the daily number of patients receiving treatment for asthma using air pollution and meteorological data. A neural network with long short-term memory (LSTM) and fully connected (FC) layers was used. The daily number of asthma patients in the city of Seoul, the capital of South Korea, was collected from the National Health Insurance Service. The data from 2015 to 2018 were used as the training and validation datasets for model development. Unseen data from 2019 were used for testing. The daily number of asthma patients per 100,000 inhabitants was predicted. The LSTM-FC neural network model achieved a Pearson correlation coefficient of 0.984 (P < 0.001) and root mean square error of 3.472 between the predicted and original values on the unseen testing dataset. The factors that impacted the prediction were the number of asthma patients in the previous time step before the predicted date, type of day (regular day and day after a holiday), minimum temperature, SO2, daily changes in the amount of cloud, and daily changes in diurnal temperature range. We successfully developed a neural network that predicts the onset and exacerbation of asthma, and we identified the crucial influencing air pollutants and meteorological factors. This study will help us to establish appropriate measures according to the daily predicted number of asthma patients and reduce the daily onset and exacerbation of asthma in the susceptible population.

Machine Learning Models for Predicting the Occurrence of Respiratory Diseases Using Climatic and Air-Pollution Factors.

OBJECTIVES: Because climatic and air-pollution factors are known to influence the occurrence of respiratory diseases, we used these factors to develop machine learning models for predicting the occurrence of respiratory diseases. METHODS: We obtained the daily number of respiratory disease patients in Seoul. We used climatic and air-pollution factors to predict the daily number of patients treated for respiratory diseases per 10,000 inhabitants. We applied the relief-based feature selection algorithm to evaluate the importance of feature selection. We used the gradient boosting and Gaussian process regression (GPR) methods, respectively, to develop two different prediction models. We also employed the holdout cross-validation method, in which 75% of the data was used to train the model, and the remaining 25% was used to test the trained model. We determined the estimated number of respiratory disease patients by applying the developed prediction models to the test set. To evaluate the performance of each model, we calculated the coefficient of determination (R2) and the root mean square error (RMSE) between the original and estimated numbers of respiratory disease patients. We used the Shapley Additive exPlanations (SHAP) approach to interpret the estimated output of each machine learning model. RESULTS: Features with negative weights in the relief-based algorithm were excluded. When applying gradient boosting to unseen test data, R2 and RMSE were 0.68 and 13.8, respectively. For GPR, the R2 and RMSE were 0.67 and 13.9, respectively. SHAP analysis showed that reductions in average temperature, daylight duration, average humidity, sulfur dioxide (SO2), total solar insolation amount, and temperature difference increased the number of respiratory disease patients, whereas increases in atmospheric pressure, carbon monoxide (CO), and particulate matter ≤2.5 µm in aerodynamic diameter (PM2.5) increased the number of respiratory disease patients. CONCLUSION: We successfully developed models for predicting the occurrence of respiratory diseases using climatic and air-pollution factors. These models could evolve into public warning systems.

CS-VIBE accelerates cranial nerve MR imaging for the diagnosis of facial neuritis: comparison of the diagnostic performance of post-contrast MPRAGE and CS-VIBE.

OBJECTIVE: We aimed to compare the diagnostic performance of post-contrast 3D compressed sensing volume-interpolated breath-hold examination (CS-VIBE) and 3D T1 magnetization-prepared rapid-acquisition gradient-echo (MPRAGE) in detecting facial neuritis. MATERIALS AND METHODS: Between February 2019 and September 2019, 60 patients (30 facial palsy patients and 30 controls) who underwent contrast-enhanced cranial nerve MRI with both conventional MPRAGE and CS-VIBE (scan time: 6 min 8 s vs. 2 min 48 s) were included in this retrospective study. All images were independently reviewed by three radiologists for the presence of facial neuritis. In patients with facial palsy, signal-to-noise ratio (SNR) of the pons, enhancement degree and contrast-to-noise ratio (CNRnerve-CSF) of the facial nerve were measured. The overall image quality, artifacts, and facial nerve discrimination were analyzed. The sensitivity and specificity of both sequences were calculated with the clinical diagnosis as a reference. RESULTS: CS-VIBE had comparable performance in the detection of facial neuritis to that of MPRAGE (sensitivity and specificity, 97.8% and 99.4% vs. 100.0% and 99.4% in pooled analysis; 97.8% and 98.9% vs. 100.0% and 98.9% in patents with facial palsy, p value > 0.05 for all). CS-VIBE showed significantly lower SNR (p value < 0.001 for all), but significantly higher CNRnerve-CSF (p value < 0.05 for all) than MPRAGE. CS-VIBE also performed better in the overall image quality, artifacts, and facial nerve discrimination than MPRAGE (p value < 0.001 for all). CONCLUSION: CS-VIBE achieved comparable diagnostic performance for facial neuritis compared to the conventional MPRAGE, with the scan time being half of that of MPRAGE. KEY POINTS: • Post-contrast 3D CS-VIBE MRI is a reliable method for the diagnosis of facial neuritis. • CS-VIBE reduces the scan time of cranial nerve MRI by more than half compared to conventional T1-weighted image. • CS-VIBE had better performance in contrast-to-noise ratio and favorable image quality compared with conventional T1-weighted image.

Development of prediction models for the incidence of pediatric acute otitis media using Poisson regression analysis and XGBoost.

Otitis media has profound health and economic impact, and its occurrence is known to be influenced by air pollution and climate. The purpose of this study was to develop prediction models using climate and air pollution indicators for the occurrence of acute otitis media (AOM). The study was conducted from January 1, 2014, to December 31, 2019, and included pediatric patients (age < 12 years) diagnosed on their emergency room visit in our tertiary medical institution. We obtained data on the weekly number of AOM patients and the weekly average values of air pollution and climate indicators. Poisson regression analysis and eXtreme Gradient Boosting (XGBoost) were used to develop prediction models for the overall pediatric patients and for the patients classified according to sex (male and female) and age (< 2 years and ≥ 2 years). For the overall population, the correlation coefficients between the original and estimated data in the testing set were 0.441 (p < 0.001) and 0.844 (p < 0.001) for the models developed using Poisson regression analysis and XGBoost, respectively. The root-mean-square errors in the testing set were 3.094 and 1.856, respectively. For patients classified according to sex and age, the prediction models developed using XGBoost showed better performance than the models developed using Poisson regression analysis. In conclusion, this study successfully developed prediction models with air pollution and climate indicators for the incidence of pediatric AOM, using XGBoost. This model can be further developed to prevent pediatric AOM.

Changes in respiratory diseases in South Korea during the COVID-19 pandemic: an interrupted time series study.

INTRODUCTION: In South Korea, non-pharmaceutical interventions such as mask-wearing, hand washing and social distancing were strictly implemented to prevent the spread of COVID-19 after a national crisis alert was raised to the highest level early in the pandemic (23 February 2020). We aimed to investigate changes in the occurrence of respiratory diseases at the national level after the COVID-19 outbreak. METHODS: The study period was from 1 January to 1 August 2019 (213 days) and from 1 January to 31 July 2020 (213 days). Based on the National Health Insurance Service data, we analysed changes in the numbers of patients treated for respiratory diseases. The changes in the numbers of individuals using public transportation and visiting the theatre were investigated to assess the effect of social distancing after the national crisis alert was raised. Differences in daily cumulative numbers (DDCNs) in 2020 were calculated as follows: (daily cumulative number in 2020)-(cumulative number for that day in 2019). A change over time in DDCNs of <0 was taken as indication that the numbers decreased from 2019 to 2020. Segmented regression analyses were performed using generalised least squares method to identify changes in trends of DDCNs of patients treated for respiratory diseases and individuals using public transportation and visiting the theatre. RESULTS: After the national crisis alert was raised to the highest level, DDCNs of patients treated for respiratory diseases, individuals using public transportation, and those visiting the theatre exhibited a significant daily decline by 53.18 per 10 000 inhabitants (95% CI -65.86 to -40.49), 48.19 per 1000 inhabitants (95% CI -62.05 to -34.32) and 25.30 per 5000 inhabitants (95% CI -36.30 to -14.30), respectively, compared with before the national crisis alert was raised. CONCLUSION: Non-pharmaceutical interventions to prevent the spread of COVID-19 significantly reduce the incidence of respiratory diseases.

Is the posterior cingulate cortex an on-off switch for tinnitus?: A comparison between hearing loss subjects with and without tinnitus.

As the human brain works in a Bayesian manner to minimize uncertainty toward external stimuli, the deafferented brain may generate tinnitus in an attempt to fill in missing auditory information, e.g. due to hearing loss. However, not everybody with hearing loss develops tinnitus. Understanding the differences between people with hearing loss who develop tinnitus versus those who do not offers a unique opportunity to unravel critical brain areas involved in the generation of a phantom sound. In this study, we compared resting-state quantitative electroencephalography between hearing loss patients with (HL-T) and without tinnitus (HL-NT) to identify cortical oscillatory signatures that may reveal prerequisites for the selective development of tinnitus in subjects with hearing loss. We enrolled 65 subjects with HL-NT and 65 subjects with HL-T whose tinnitus handicap inventory scores were <16 (grade 1) to minimize the bias induced by distress-induced cortical activity changes. Subjects in the HL-T and HL-NT groups were matched in terms of the bilateral hearing threshold (0.25-8 kHz) using nearest neighbor method. Compared to the HL-NT group, the HL-T group showed significantly higher activity in the right parahippocampus for the beta 1 frequency band, in the left inferior parietal lobule (IPL) for the beta 2 frequency band, and in the right IPL for the beta 3- and gamma frequency bands. Functional connectivity analyses revealed that the HL-T group had significantly higher connectivity than the HL-NT group between both parahippocampal gyri and the right IPL for the delta frequency band, and between the left posterior cingulate cortex (PCC) and right IPL for the beta 2 frequency band. These results suggest that tinnitus may be perceived only if auditory memory stored in the parahippocampus is actively linked to the IPL-based "circuit breaker" system and the circuit breaker signal is connected to the PCC-based default mode network (DMN). Thus, when the circuit breaker system regards tinnitus secondary to peripheral deafferentation as a salient event and then the DMN regards tinnitus as a norm, subjects with hearing loss may consciously perceive tinnitus. The results of this study further refine the recently proposed Bayesian model and decipher the neurobiological mechanism of the selective development of tinnitus in subjects with hearing loss.

Role of microRNA­375­3p­mediated regulation in tinnitus development.

Changes in the dorsal cochlear nucleus (DCN) following exposure to noise play an important role in the development of tinnitus. As the development of several diseases is known to be associated with microRNAs (miRNAs/miRs), the aim of the present study was to identify the miRNAs that may be implicated in pathogenic changes in the DCN, resulting in tinnitus. A previously developed tinnitus animal model was used for this study. The study consisted of four stages, including identification of candidate miRNAs involved in tinnitus development using miRNA microarray analysis, validation of miRNA expression using reverse transcription­quantitative PCR (RT­qPCR), evaluation of the effects of candidate miRNA overexpression on tinnitus development through injection of a candidate miRNA mimic or mimic negative control, and target prediction of candidate miRNAs using mRNA microarray analysis and western blotting. The miRNA microarray and RT­qPCR analyses revealed that miR­375­3p expression was significantly reduced in the tinnitus group compared with that in the non­tinnitus group. Additionally, miR­375­3p overexpression via injection of miR­375­3p mimic reduced the proportion of animals with persistent tinnitus. Based on mRNA microarray and western blot analyses, connective tissue growth factor (CTGF) was identified as a potential target for miR­375­3p. Thus, it was inferred that CTGF downregulation by miR­375­3p may weaken with the decrease in miRNA expression, and the increased pro­apoptotic activity of CTGF may result in more severe neuronal damage, contributing to tinnitus development. These findings are expected to contribute significantly to the development of a novel therapeutic approach to tinnitus, thereby bringing about a significant breakthrough in the treatment of this potentially debilitating condition.

Impact of air pollution on benign paroxysmal positional vertigo incidence: a retrospective study of the citizens of Seoul, South Korea.

Benign paroxysmal positional vertigo (BPPV) is among the most common inner ear diseases. Although BPPV is one of the most common causes of dizziness, its pathogenesis remains unknown. Air pollutants might reach the middle ear through the eustachian tube and be absorbed into the inner ear through the round window membrane, increasing the risk of BPPV. We investigated the relationship between air pollution and BPPV risk. Data were extracted from the Korean Health Insurance Review and Assessment Service database, which contains health claims information of the entire South Korean population. Variables of interest included the number of patients diagnosed with BPPV in Seoul, South Korea, patients' clinical and demographic characteristics, and osteopenia status. Seoul's daily air pollution indicators, including SO2, CO, O3, NO2, PM10, and PM2.5, were obtained from the Korea Environment Corporation website. Overdispersed Poisson regression analysis was performed. In the multivariable analysis, NO2 air concentration (ppb) was associated with increased incidence of BPPV. In analysis stratified by gender, levels of NO2 were associated with increased incidence of BPPV in both men and women. In the analysis stratified by age, NO2 air concentration was associated with increased incidence of BPPV among all adults over the age of 19 years. In the analysis stratified by osteopenia status, NO2 was associated with increased incidence of BPPV in patients with and without osteopenia. Air levels of NO2 were associated with increased incidence of BPPV in the present study. This finding contributes toward a better understanding of BPPV pathogenesis and improved prevention and management of this condition.

MicroRNAs Related to Cognitive Impairment After Hearing Loss.

OBJECTIVES: Our research group has previously demonstrated that hearing loss might be a risk factor for synaptic loss within the hippocampus and impairment of cognition using an animal model of Alzheimer disease. In this study, after inducing hearing loss in a rat model of Alzheimer disease, the associations of various microRNAs (miRNAs) with cognitive impairment were investigated. METHODS: Rats were divided randomly into two experimental groups: the control group, which underwent sham surgery and subthreshold amyloid-ß infusion and the deaf group, which underwent bilateral cochlear ablation and subthreshold amyloid-ß infusion. All rats completed several cognitive function assessments 11 weeks after surgery, including the object-in-place task (OPT), the novel object recognition task (NOR), the object location task (OLT), and the Y-maze test. After the rats completed these tests, hippocampus tissue samples were assessed using miRNA microarrays. Candidate miRNAs were selected based on the results and then validated with quantitative reverse transcriptionpolymerase chain reaction (qRT-PCR) analyses. RESULTS: The deaf group showed considerably lower scores on the OPT, OLT, and Y-maze test than the control group. The microarray analysis revealed that miR-29b-3p, -30e-5p, -153-3p, -376a-3p, -598-3p, -652-5p, and -873-3p were candidate miRNAs, and qRT-PCR showed significantly higher levels of miR-376a-3p and miR-598-3p in the deaf group. CONCLUSION: These results indicate that miR-376a-3p and miR-598-3p were related to cognitive impairment after hearing loss.

The effects of climate on the incidence of benign paroxysmal positional vertigo.

Benign paroxysmal positional vertigo (BPPV) is one of the most common vestibular disorders. An investigation into the factors related to BPPV could contribute to its prevention and appropriate management. We investigated the association between climatic factors and incidence of BPPV in this study. A total of 365 patients who were diagnosed with idiopathic BPPV in the emergency room of our hospital in 2015 were included. The number of patients diagnosed with BPPV per week was calculated (every week). Climatic factors, including daily average humidity, temperature, atmospheric pressure, cloud amount, sunshine amount, and daylight time, were documented daily. The weekly mean climatic value in each week was calculated. Simple correlation analysis and multivariate regression analyses were performed to identify climatic factors associated with the number of patients diagnosed with BPPV. Simple correlation analysis revealed a significant association between the humidity (r = 0.276, p = 0.048), temperature (r = 0.275, p = 0.049), and cloud amount (r = 0.293, p = 0.035) and the number of BPPV patients diagnosed per week. Multivariate regression analysis revealed that only the cloud amount was a statistically significant factor associated with the number of BPPV patients diagnosed every week. A significant positive association was discovered between the cloud amount and BPPV incidence. Cloud amount can therefore have an association with the incidence of BPPV.

Can Osteopenia Induce Residual Dizziness After Treatment of Benign Paroxysmal Positional Vertigo?

OBJECTIVE: This study aimed to determine whether there is an association between osteopenia and residual dizziness after successful treatment of benign paroxysmal positional vertigo (BPPV). METHODS: In all, 62 patients with canalolithiasis-type BPPV were included in the study. Patients were divided into two groups according to the presence of residual dizziness after resolution of BPPV. Univariate and multivariate analyses were performed to determine the factors associated with residual dizziness. Patients were analyzed based on age, sex, affected semicircular canal, affected side, BPPV duration, and presence of hypertension, diabetes mellitus, hyperlipidemia, and osteopenia. RESULTS: In univariate analysis, BPPV duration and osteopenia showed a relatively significant association (p < 0.20) with the development of residual dizziness. On subsequent multivariate analysis using these factors, osteopenia remained a statistically significant factor in association with residual dizziness (p = 0.012, odds ratio, 9.916). CONCLUSION: Osteopenia is associated with the development of residual dizziness. BPPV patients with osteopenia more frequently suffer from residual dizziness after successful treatment of BPPV than those without osteopenia.

Axonal sprouting in the dorsal cochlear nucleus affects gap­prepulse inhibition following noise exposure.

One of the primary theories of the pathogenesis of tinnitus involves maladaptive auditory­somatosensory plasticity in the dorsal cochlear nucleus (DCN), which is assumed to be due to axonal sprouting. Although a disrupted balance between auditory and somatosensory inputs may occur following hearing damage and may induce tinnitus, examination of this phenomenon employed a model of hearing damage that does not account for the causal relationship between these changes and tinnitus. The present study aimed to investigate changes in auditory­somatosensory innervation and the role that axonal sprouting serves in this process by comparing results between animals with and without tinnitus. Rats were exposed to a noise­inducing temporary threshold shift and were subsequently divided into tinnitus and non­tinnitus groups based on the results of gap prepulse inhibition of the acoustic startle reflex. DCNs were collected from rats divided into three sub­groups according to the number of weeks (1, 2 or 3) following noise exposure, and the protein levels of vesicular glutamate transporter 1 (VGLUT1), which is associated with auditory input to the DCN, and VGLUT2, which is in turn primarily associated with somatosensory inputs, were assessed. In addition, factors related to axonal sprouting, including growth­associated protein 43 (GAP43), postsynaptic density protein 95, synaptophysin, α­thalassemia/mental retardation syndrome X­linked homolog (ATRX), growth differentiation factor 10 (GDF10), and leucine­rich repeat and immunoglobulin domain­containing 1, were measured by western blot analyses. Compared to the non­tinnitus group, the tinnitus group exhibited a significant decrease in VGLUT1 at 1 week and a significant increase in VGLUT2 at 3 weeks post­exposure. In addition, rats in the tinnitus group exhibited significant increases in GAP43 and GDF10 protein expression levels in their DCN at 3 weeks following noise exposure. Results from the present study provided further evidence that changes in the neural input distribution to the DCN may cause tinnitus and that axonal sprouting underlies these alterations.

Hearing loss as a risk factor for cognitive impairment and loss of synapses in the hippocampus.

Although epidemiological studies have identified an association between hearing loss and cognitive impairment, there is a lack of biological evidence detailing the mechanisms underlying this association. The present study investigated the effects of hearing loss on cognitive impairment using an at-risk model. In this animal model, amyloid-ß (Aß) was administered to the brain to such an extent that it did not cause cognitive impairments but made the brain vulnerable to risk factors. This study included four experimental groups based on hearing level and Aß administration. Behavioral tests were conducted to evaluate cognitive function, and synaptic protein levels were measured in the hippocampus and prefrontal cortex. The group with hearing loss and Aß administration showed significantly greater deficits on cognitive tests associated with the hippocampus than the other three groups (only Aß administration, only hearing loss, and without hearing loss or Aß administration). The hearing loss and Aß administration group also had significantly lower levels of synaptic proteins in the hippocampus than the other groups. The present results suggest that hearing loss may act as a risk factor for cognitive impairment in Alzheimer's disease. Additionally, the present findings indicate hearing loss may cause hippocampal synapses to be more vulnerable to Aß-induced damage.

Impact of control of blood glucose level during treatment of sudden deafness in diabetics: relationship with prognosis.

The objective of this study is to investigate the impact of control of blood glucose level during treatment of sudden deafness. A retrospective study was performed involving 197 patients from January, 2011 to September, 2015. All patients were administrated prednisolone (Pharmaprednisolone tab®, 5 mg/T; KoreaPharma) p.o under the following regimen: 60 mg/day for 4 days, 40 mg/day for 2 days, 30 mg/day for 1 day, 20 mg/day for 1 day, and 10 mg/day for 2 days. During treatment, pure tone audiometry and blood glucose level were investigated for each patient and the results were statistically analyzed. Mean hearing improvement was 19.2 dB for the non-diabetes group and 24.8 dB for the diabetes group. The greater improvement for diabetics was not statistically significant (p = 0.146). Hearing improvement was 25.1 dB for subjects with mean blood glucose <200 mg/dl and 24.6 dB for subjects with mean blood glucose >200 mg/dl; the difference was not statistically significant (p = 0.267). Mean blood glucose level was 200.8 mg/dl for subjects with hearing improvement >20 dB and 181.8 mg/dl for subjects with hearing improvement <20 dB; the difference was not statistically significant (p = 0.286). Control of blood glucose level during treatment of sudden deafness does not have a direct effect on prognosis.

A novel wedge technique to correct the curved deviation of the cartilaginous nasal septum.

OBJECTIVE: To introduce a novel wedge technique in endonasal septoplasty to correct the curved deviation of the cartilaginous septum and describe the surgical procedure and results. METHODS: A retrospective analysis was performed on 17 patients who had septoplasty using the wedge technique to correct the curved deviation of their cartilaginous septum. A 2-2.5-cm-long wedge made of either septal cartilage or ethmoid/vomer bone was inserted through an incision located 1.5-2 cm caudal to the bony-cartilaginous junction near the dorsum. Materials used for the wedge, objective evaluation of the surgical results, subjective symptom improvement and surgical complications were investigated. RESULTS: The degree of deviation was moderate to severe in all patients. Bony septum was used as the wedge material in 9 patients and septal cartilage in 8 patients. Among 17 patients, 15 had a completely straight septum while 2 had a minimal curvature remaining. Subjective symptoms of nasal obstruction evaluated by the Visual Analog Scale score and Nasal Obstructive Symptom Evaluation scale improved in all patients. In acoustic rhinometry, minimal cross-sectional area and nasal volume change showed some improvement without statistical significance. There were no major complications including saddle nose and revision surgery. CONCLUSION: Our novel wedge technique can be an effective and safe technique to straighten the curved deviations of the cartilaginous septum in selected patients.

Post-intubation tracheoesophageal fistula with posterior glottic web.

Tracheoesophageal fistula (TEF) after prolonged intubation could present as chronic aspiration and could be mistaken as unilateral or bilateral vocal fold palsy, especially when there was combined posterior glottic synechia. We present a case of post-intubation TEF which was successfully treated with tracheal resection and anastomosis with primary esophageal closure. The accompanying posterior glottic web was treated by endoscopic technique of web lysis, with topical application of mitomycin C solution.