Determinants of Conductive Hearing Loss in Tympanic Membrane Perforation

ObjectivesTympanic membrane perforations are common, but there have been few studies of the factors determining the extent of the resulting conductive hearing loss. The aims of this study were to determine whether the size of tympanic membrane perforation, pneumatization of middle ear & mastoid cavity, and location of perforation were correlated with air-bone gap (ABG) of patients.MethodsForty-two patients who underwent tympanoplasty type I or myringoplasty were included and preoperative audiometry were analyzed. Digital image processing was applied in computed tomography for the estimation of middle ear & mastoid pneumatization volume and tympanic membrane photograph for the evaluation of perforation size and location.ResultsPreoperative mean ABG increased with perforation size (P=0.018), and correlated inversely with the middle ear & mastoid volume (P=0.005). However, perforations in anterior versus posterior locations showed no significant differences in mean ABG (P=0.924).ConclusionThe degree of conductive hearing loss resulting from a tympanic membrane perforation would be expected with the size of perforation and pneumatization of middle ear and mastoid

The Risk of BPPV, Meniere’s Disease, and Vestibular Neuronitis in Patients with Gout: A Longitudinal Follow-Up Study Using a National Health Screening Cohort

This study evaluated the impact of pre-existing gout on the occurrence of benign paroxysmal positional vertigo (BPPV), Meniere’s disease, and vestibular neuronitis, with the goal of identifying novel associations of gout with other comorbid diseases. The 2002–2019 Korean National Health Insurance Service Health Screening Cohort data were retrospectively analyzed. 23,827 patients with gout were matched to 95,268 controls without gout for age, sex, income, region of residence, and index date. The occurrence of BPPV, Meniere’s disease, and vestibular neuronitis was evaluated in both groups. The hazard ratios (HRs) of gout for BPPV, Meniere’s disease, and vestibular neuronitis were calculated using a stratified Cox proportional hazard model. Participants with gout demonstrated a 1.13-fold higher risk of BPPV (95% CI, 1.06–1.21, p p p = 0.391). A previous history of gout was related to a higher risk of BPPV and Meniere’s disease. Additional studies are necessary to elucidate the mechanism underlying the relationship between gout and comorbid diseases such as BPPV and Meniere’s disease

Effectiveness of Intratympanic Dexamethasone Injection for Tinnitus Treatment: A Systematic Review and Meta-Analysis

Objectives. Intratympanic dexamethasone injection (ITDI) has been introduced as a treatment option for subjective tinnitus. However, the effects of ITDI on patients with tinnitus remain unclear. In the present systematic review and meta analysis, we evaluated the effectiveness of ITDI for tinnitus treatment. Methods. We searched Medline, the Cochrane Central Register of Controlled Trials, and Embase. Four double-blind randomized controlled trials that tested the efficacy of ITDI compared with a placebo were deemed eligible for a quantitative meta-analysis, while four prospective studies and seven retrospective studies reporting the effectiveness of ITDI on tinnitus treatment were included in a qualitative synthesis. Results. In the four studies included in the quantitative meta-analysis, ITDI did not show evidence of tinnitus improvement compared with placebo (odds ratio [OR], 1.38; 95% confidence interval, 0.53-3.61). In the 11 studies included in the qualitative synthesis, seven retrospective studies without controls reported rates of tinnitus improvement after ITDI ranging from 35.9% to 91.3%. In the four prospective studies with controls, ITDI seemed to be effective when combined with other drugs for tinnitus treatment. Conclusion. ITDI alone did not show a significant effect for treating tinnitus compared with placebo. However, the potential of combination treatment of ITDI with other drugs for tinnitus therapy should be further studied in more systematic research.N

Cochlear Damage Caused by the Striking Noise of Titanium Head Golf Driver

Objectives. To investigate how mouse cochleae are affected by the striking noise of titanium head golf driver. Methods. Thirty-two BALB/c mice (20–22 g) with normal hearing were used. The impact acoustic stimulus generated by the striking of titanium golf driver head was centered around 4.5 kHz with 120.5 dB sound pressure level. The recorded impact noise was provided to mice in two ways with the same exposure time of 288 seconds: 1,440 repetitions and an impact duration of 0.2 seconds for 2 hours (repetitive noise) or serially connected impact noise for 288 seconds (continuous noise). Auditory brainstem responses were measured at baseline, day 7, and day 14 after exposure. The mice were then sacrificed for histology. Results. Both groups showed statistically significant threshold shifts immediately after noise exposure. Mice in the continuous exposure group, except for those exposed to 32 kHz noise, recovered from threshold shifts 1–2 weeks after noise exposure. However, in the repetitive exposure group, threshold shifts remained for 2 weeks after exposure. The repetitive exposure group had greater hair cell damage than did the continuous exposure group. Structural changes in the stria vascularis were observed in the repetitive exposure group. Conclusion. Overexposure to impact noise caused by hitting of titanium head golf driver may be hazardous to the cochlea, and repetitive exposure may induce greater damage than continuous exposure

A Novel Voltage Control Scheme for Low-Voltage DC Distribution Systems Using Multi-Agent Systems

Low-voltage direct current (LVDC) distribution systems have been evolving into interesting ways of integrating distributed energy resources (DERs) and power electronics loads to local distribution networks. In LVDC distribution systems, voltage regulation is one of the most important issues, whereas AC systems have concerns such as frequency, power factor, reactive power, harmonic distortion and so on. This paper focuses on a voltage control method for a LVDC distribution system based on the concept of multi-agent system (MAS), which can deploy intelligence and decision-making abilities to local areas. This paper proposes a distributed power flow analysis method using local information refined by local agents and communication between agents based on MAS. This paper also proposes a voltage control method by coordinating the main AC/DC converter and multiple DERs. By using the proposed method, we can effectively maintain the line voltages in a pre-defined normal range. The performance of the proposed voltage control method is evaluated by case studies and compared to conventional methods

Association between Osteoporosis and Meniere’s Disease: Two Longitudinal Follow-Up Cohort Studies

A high rate of Meniere’s disease (MD) in patients with osteoporosis has been suggested. This research intended to estimate the bidirectional association of MD with osteoporosis. The ≥40-year-old population in the Korean National Health Insurance Service-Health Screening Cohort 2002–2019 was examined. In study I, 9529 patients with MD and 38,116 control I participants were analyzed for a previous history of osteoporosis. In study II, 65,858 patients with osteoporosis and 65,858 control II participants were analyzed for a previous history of MD. Stratified Cox proportional hazard models were applied to calculate the hazard ratios (HRs) and 95% confidence intervals (CIs) of MD for osteoporosis in study I and of osteoporosis for MD in study II. The rate of a prior history of osteoporosis was 13.3% for the MD group and 11.3% for the control I group. The patients with MD had a 1.12 times higher HR for previous osteoporosis (95% CI = 1.04–1.20). In study II, the rate or a prior history of MD was 3.7% for patients with osteoporosis and 2.0% for the control II group. The patients with osteoporosis had a 1.50 times higher HR for previous MD (95% CI = 1.40–1.61). Most subgroups according to age, sex, and comorbid conditions demonstrated consistent bidirectional associations between MD and osteoporosis. Adult patients with MD had a greater risk of osteoporosis. In addition, adult patients with osteoporosis also showed a higher risk of MD

The Analysis of A Frequent TMPRSS3 Allele Containing P.V116M and P.V291L in A Cis Configuration among Deaf Koreans

We performed targeted re-sequencing to identify the genetic etiology of early-onset postlingual deafness and encountered a frequent TMPRSS3 allele harboring two variants in a cis configuration. We aimed to evaluate the pathogenicity of the allele. Among 88 cochlear implantees with autosomal recessive non-syndromic hearing loss, subjects with GJB2 and SLC26A4 mutations were excluded. Thirty-one probands manifesting early-onset postlingual deafness were sorted. Through targeted re-sequencing, we detected two families with a TMPRSS3 mutant allele containing p.V116M and p.V291L in a cis configuration, p.[p.V116M; p.V291L]. A minor allele frequency was calculated and proteolytic activity was measured. A p.[p.V116M; p.V291L] allele demonstrated a significantly higher frequency compared to normal controls and merited attention due to its high frequency (4.84%, 3/62). The first family showed a novel deleterious splice site variant—c.783-1G>A—in a trans allele, while the other showed homozygosity. The progression to deafness was noted within the first decade, suggesting DFNB10. The proteolytic activity was significantly reduced, confirming the severe pathogenicity. This frequent mutant allele significantly contributes to early-onset postlingual deafness in Koreans. For clinical implication and proper auditory rehabilitation, it is important to pay attention to this allele with a severe pathogenic potential

The Reciprocal Relationship between Osteoporosis and Renal Stones

Previous studies have proposed an association between osteoporosis and renal stones. The current analyses intended to investigate the bidirectional relationship between osteoporosis and renal stones. The ≥40-year-old population in the National Health Insurance Service-Health Screening cohort (2002–2015) was analyzed. In study I, 67,811 patients with osteoporosis and 67,811 control I participants were matched. The hazard ratio (HR) of osteoporosis for renal stones was calculated using stratified Cox proportional hazard models. In study II, 25,261 patients with renal stones and 101,044 control II participants were matched. The HR of renal stones for osteoporosis was estimated using stratified Cox proportional hazard models. In study I, 3.4% (2276/67,811) of osteoporosis patients and 2.5% (1696/67,811) of control I participants had renal stones. Osteoporosis patients had a 1.36 times higher HR for renal stones than control I participants (95% confidence intervals [CI] = 1.28–1.45). In study II, 9.2% (2319/25,261) of renal stone patients and 7.6% (7658/101,044) of control II participants had osteoporosis. Renal stone patients had a 1.26 times higher HR for osteoporosis than control II participants (95% CI = 1.21–1.32). Adults with osteoporosis had a higher risk of renal stones. Moreover, adults with renal stones had a higher risk of osteoporosis