Sex differences in associated factors for age-related hearing loss.

The prevalence and age of onset of hearing loss differ according to sex. This study aimed to identify associated factors for age-related hearing loss (ARHL) and determine whether there are differences between males and females regarding associated factors for ARHL. This cross-sectional study used data from adults who underwent medical examinations including hearing tests from 2011 to 2021. A total of 2,349 individuals were included. The study conducted sex-specific analyses using both univariate and multiple regression. Univariate analysis employed logistic regression, while multiple regression involved variable selection through the augmented backward elimination method. Separate multiple logistic regression analyses were conducted for each sex. In the univariate analysis, among males, age, underweight, alcohol consumption, weight, and height exhibited statistical significance. Among females, age, hypertension, diabetes, dyslipidemia, obesity, sarcopenia, weight, height, age at menarche, and duration of hormone exposure were found to be significant factors. However, in the multiple logistic regression model for males, underweight, and smoking emerged as significant, while in females, age, weight, obesity, and age at menarche retained their significance. We found that there are different associated factors for ARHL in each sex. Assessment and counseling for smoking, obstetric history, underweight, and obesity may be beneficial in managing patients with ARHL.

Transcriptomic analysis reveals prolonged neurodegeneration in the hippocampus of adult C57BL/6N mouse deafened by noise.

Introduction: Several studies have reported a significant correlation between noise-induced hearing loss and cognitive decline. However, comprehensive analyses of this relationship are rare. This study aimed to assess the influence of hearing impairment on cognitive functions by analyzing organ samples in the afferent auditory pathway of deafened mice using mRNA sequencing. Methods: We prepared 10 female 12-week-old C57BL/6N mice as the experimental and control groups in equal numbers. Mice in the experimental group were deafened with 120 dB sound pressure level (SPL) wideband noise for 2 h. Cochlea, auditory cortex, and hippocampus were obtained from all mice. After constructing cDNA libraries for the extracted RNA from the samples, we performed next-generation sequencing. Subsequently, we analyzed the results using gene ontologies (GOs) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway databases for differentially expressed genes (DEGs) of each organ. Results: Our results revealed 102, 89, and 176 DEGs for cochlea, auditory cortex, and hippocampus, respectively. We identified 294, 203, and 211 GOs; 10, 7, and 17 KEGG pathways in the cochlea, auditory cortex, and hippocampus, respectively. In the long term (12 weeks) from noise-induced hearing loss, GOs and KEGG pathways related to apoptosis or inflammation persisted more actively in the order of hippocampus, auditory cortex, and cochlea. Discussion: This implies that the neurodegenerative effects of noise exposure persist more longer time in the central regions.

Sleep disturbance and dysregulation of circadian clock machinery in sudden sensorineural hearing loss.

BACKGROUND: The cochlea contains a robust biological clock associated with auditory function, exhibiting diurnal sensitivity to noise or ototoxicity. OBJECTIVES: We examined the relationship between disrupted circadian rhythm and altered expression of circadian clock genes in patients with sudden sensorineural hearing loss (SSNHL) and explored whether the circadian clock genes serve as prognostic biomarkers. MATERIAL AND METHODS: Twelve patients with SSNHL were enrolled study group. Twelve people with normal hearing were enrolled voluntarily for comparison. Audiological evaluation was performed to evaluate hearing thresholds. Korean version of the Pittsburgh Sleep Quality Index Questionnaire was performed to evaluate sleep quality and patterns. Circadian clock genes including for PERI, PER2, PER3, CRYI, CRY2, CLOCK, ARNTL, CSNKIE, and TIMELESS expression in blood were evaluated using real-time quantitative PCR method. RESULTS: Compared with healthy controls without hearing loss, most of the circadian clock genes were markedly downregulated, coupled with low sleep quality and disturbing patterns, in patients with SSNHL. Intriguingly, a weak correlation between hearing improvement following steroid treatment and altered levels of circadian clock genes was observed. CONCLUSIONS AND SIGNIFICANCE: This study provides an additional basis for the relevance of disrupted circadian rhythm to SSNHL and suggests a possible prognostic biomarker for SSNHL treatment.

Management of External Auditory Canal Anterior Wall Defect: A Case Series and Literature Review.

OBJECTIVES: Although rare in etiology, anterior bony wall defects of the external auditory canal (EAC) accompanied by temporomandibular joint herniation may cause various otologic symptoms. Surgical treatment can be considered based on symptom severity because many previous case reports have highlighted its efficacy. This study aimed to review the long-term results of surgical treatment of EAC anterior wall defect and to suggest a stepwise approach when creating a treatment plan. METHODS: We performed a retrospective review of 10 patients who underwent surgical management to address the EAC anterior wall defect and its associated symptoms. Medical records, temporal bone computed tomography scans, audiometry, and endoscopic examination findings were analyzed. RESULTS: The primary repair of the EAC defect was the first to be surgically addressed in most cases, excluding one case with a severe combined infection. Of the 10 cases, 3 patients exhibited either postoperative complications or symptom recurrence. Six patients had resolved symptoms consequent to primary surgical repair, and four patients underwent revision surgery undergoing a more invasive procedure, such as canalplasty or mastoidectomy. CONCLUSION: Primary repair of the anterior wall defect of the EAC seems to be overpromoted for lasting results but is not as promising as previously noted. We therefore propose to create a novel treatment flowchart regarding the surgical treatment of anterior wall defects of the EAC based on clinical experience. LEVEL OF EVIDENCE: IV.

Increased Resting-State Positron Emission Tomography Activity After Cochlear Implantation in Adult Deafened Cats.

OBJECTIVES: Cochlear implants are widely used for hearing rehabilitation in patients with profound sensorineural hearing loss. However, Cochlear implants have variable. RESULTS: and central neural plasticity is considered to be a reason for this variability. We hypothesized that resting-state cortical networks play a role in conditions of profound hearing loss and are affected by cochlear implants. To investigate the resting-state neuronal networks after cochlear implantation, we acquired 18F-fluorodeoxyglucose (FDG)-positron emission tomography (PET) images in experimental animals. METHODS: Eight adult domestic cats were enrolled in this study. The hearing threshold of the animals was within the normal range, as measured by auditory evoked potential. They were divided into control (n=4) and hearing loss (n=4) groups. Hearing loss was induced by co-administration of ethacrynic acid and kanamycin. FDG-PET was performed in a normal hearing state and 4 and 11 months after the deafening procedure. Cochlear implantation was performed in the right ear, and electrical cochlear stimulation was performed for 7 months (from 4 to 11 months after the deafening procedure). PET images were compared between the two groups at the three time points. RESULTS: Four months after hearing loss, the auditory cortical area's activity decreased, and activity in the associated visual area increased. After 7 months of cochlear stimulation, the superior marginal gyrus and cingulate gyrus, which are components of the default mode network, showed hypermetabolism. The inferior colliculi showed hypometabolism. CONCLUSION: Resting-state cortical activity in the default mode network components was elevated after cochlear stimulation. This suggests that the animals' awareness level was elevated after hearing restoration by the cochlear implantation.

Update on CD164 and LMX1A genes to strengthen their causative role in autosomal dominant hearing loss.

Novel hearing loss (HL) genes are constantly being discovered, and evidence from independent studies is essential to strengthen their position as causes of hereditary HL. To address this issue, we searched our genetic data of families with autosomal dominant HL (ADHL) who had been tested with high-throughput DNA sequencing methods. For CD164, only one pathogenic variant in one family has so far been reported. For LMX1A, just two previous studies have revealed its involvement in ADHL. In this study we found two families with the same pathogenic variant in CD164 and one family with a novel variant in LMX1A (c.686C>A; p.(Ala229Asp)) that impairs its transcriptional activity. Our data show recurrence of the same CD164 variant in two HL families of different geographic origin, which strongly suggests it is a mutational hotspot. We also provide further evidence for haploinsufficiency as the pathogenic mechanism underlying LMX1A-related ADHL.

Clinicoradiologic Characteristics of Temporal Bone Meningioma: Multicenter Retrospective Analysis.

OBJECTIVES/HYPOTHESIS: Meningioma is a neoplasm arising from cells related to the arachnoid villi. The aim of the present study was to explore the clinical and radiological characteristics of temporal bone meningioma (TBM) in a multicenter cohort. STUDY DESIGN: Retrospective cohort study. METHODS: Thirteen patients diagnosed with TBM at eight medical institutes between 1998 and 2018 were retrospectively enrolled. The clinical procedures, symptoms, signs, and images that led to the diagnosis of TBM were investigated for all patients. RESULTS: The most common symptom at the initial visit was hearing loss (n = 12/13, 92.3%). All patients exhibited unilateral TBMs with varied symptom durations (1-60 months). Four patients presented masses occupying the external auditory canal; the tympanic membrane (TM) could not be evaluated. The other nine patients did not show TM perforation despite the presence of inflammatory signs. The majority of patients exhibited unilateral conductive or mixed hearing loss. A retrospective review of temporal bone computed tomography (TBCT) images revealed findings suggestive of a tumor in all patients. However, three patients had been misdiagnosed with chronic otitis media and were subjected to tympanomastoidectomy (n = 3/7, 42.9%). TBCT findings that suggested TBM included diffuse trabecular hyperostosis in the middle and posterior cranial fossae and widening and destruction of the temporal bone in the jugular bulb area. CONCLUSIONS: TBM should be suspected if patients exhibit persistent inflammatory symptoms or signs involving intact TM or unilateral conductive or mixed hearing loss with trabecular hyperostosis or destruction of the temporal bone on computed tomography images. LEVEL OF EVIDENCE: 4 Laryngoscope, 131:173-178, 2021.

Conductive Hearing Loss Aggravates Memory Decline in Alzheimer Model Mice.

The study of cognitive impairment associated with hearing loss has recently garnered considerable interest. Epidemiological data have demonstrated that hearing loss is a risk factor for cognitive decline as a result of aging. However, no previous study has examined the effect of hearing loss in patients with cognitive problems such as Alzheimer's disease. Therefore, we investigated the effect of conductive hearing loss in an Alzheimer's mouse model. Positron emission tomography (PET) and magnetic resonance imaging (MRI) were used to evaluate changes in glucose metabolism and gray matter concentrations in the 5xFAD Alzheimer's Disease (AD) transgenic mouse model with and without conductive hearing loss (HL). Conductive hearing loss was induced using chronic perforation of the tympanic membrane. Behavioral data from the Y-maze and passive avoidance tests revealed greater memory deficits in the AD with HL (AD-HL) group than in the AD group. Following induction of hearing loss, lower cerebral glucose metabolism in the frontal association cortex was observed in the AD-HL group than in the AD group. Although lower glucose metabolism in the hippocampus and cerebellum was found in the AD-HL group than in the AD group at 3 months, the gray matter concentrations in these regions were not significantly different between the groups. Furthermore, the gray matter concentrations in the simple lobule, cingulate/retrosplenial cortex, substantia nigra, retrosigmoid nucleus, medial geniculate nucleus, and anterior pretectal nucleus at 7 months were significantly lower in the AD-HL group than in the AD group. Taken together, these results indicate that even partial hearing loss can aggravate memory impairment in Alzheimer's disease.

Influence of Cochlear Dead Regions on Hearing Outcome in Sudden Sensorineural Hearing Loss.

OBJECTIVE: The aims of this multicenter study were to prospectively evaluate the prevalence of dead regions (DRs) in sudden sensorineural hearing loss (SSNHL) and compare the clinical characteristics and hearing outcomes of SSNHL according to the presence of DRs. STUDY DESIGN: Prospective study. SETTING: Multicenter study. PATIENTS AND METHODS: The threshold-equalizing noise (TEN) test was prospectively performed on a total of 130 patients diagnosed with SSNHL. All patients received systemic steroid therapy and/or intratympanic steroid injection within 1 month after onset. Pure-tone audiograms and the TEN test were conducted before and after steroid treatment. Age, sex, side of affected ear, recurrence, onset of symptoms, presence of dizziness, and comorbid diseases were also collected. The prevalence of DRs in SSNHL and clinical factors related to the DRs were assessed. Hearing outcomes for SSNHL according to DRs were evaluated in 68 patients who followed a pure-tone audiogram. RESULTS: The overall prevalence of one or more DRs in SSNHL evaluated using the TEN test was 20.8% (27/130 subjects) and the overall frequency-specific prevalence of DR was 6.7% (61/910 DRs). Although the DRs (+)and DR (-) groups had similar initial pure-tone thresholds, the DRs (+) group had significantly worse initial WRS compared to the DRs (-) group (p = 0.015). The presence of DRs was not associated with hearing recovery in a multivariate logistic regression model, but it was significantly associated with the degree of hearing gain in a multivariate linear regression model (p = 0.018). CONCLUSIONS: The presence of DRs can be considered one of the poor prognostic factors for SSNHL and the TEN test may contribute to assess the prognosis of SSNHL in clinical settings.

Transcriptome Analysis of Deafness: Intracellular Signal Transduction Signaling Pathways Regulate Neuroplastic Changes in the Auditory Cortex.

HYPOTHESIS AND BACKGROUND: Hearing loss leads to synaptic changes in auditory neurons and their networks, and functions as a consequence of the interplay between genes and proteins. However, cellular and molecular mechanisms leading to deafness-induced plasticity in the auditory cortex (AC) remain unclear. Here, we examined the changes in gene expression and key signaling pathways that regulate differentially expressed genes (DEGs) in the AC following auditory deafferentation using RNA-sequencing (RNA-Seq) analysis. METHODS: Cochlear ablation-induced bilaterally deafened Sprague-Dawley rats were maintained for 12 weeks and their ACs were harvested. RNA-seq analysis was performed on each sample to identify which genes were expressed. This information was then used for comparative analysis of DEGs between samples. The statistical significance of DEGs was determined by fold change (|FC| > 1.5) and independent t test (p < 0.05). RESULTS: RNA-seq analysis identified 72 DEGs, of which 19 were upregulated and 53 were down-regulated after bilateral deafening in the ACs. Gene ontology (GO) analysis revealed the potential involvement of mitogen-activated protein kinase, tumor necrosis factor, and cyclic adenosine 3',5'-monophosphate (e.g., Bdnf, Gli1, and c-Fos) signaling pathways in regulating changes in the expression of the genes listed herein. The DEGs of interest-including c-Fos, Arc, Ntf3, and Gli1-from the RNA-seq analysis were consistent with result of quantitative reverse transcriptase polymerase chain reaction. CONCLUSION: RNA-seq analysis revealed that auditory deprivation in adult rats elicited changes in gene expression, transcription factor levels, and their complex interaction at specific gene promoters in the AC. Particularly, activation of intracellular signal transduction signaling pathways may be key to neuronal plasticity in deafness.

Clinical Characteristics of Patients with Cochlear Fistulas Caused by Chronic Otitis Media with Cholesteatoma.

OBJECTIVES: To analyze the clinical characteristics of cochlear fistulas (CFs) and propose a new fistula classification system with regard to the cochlea. MATERIALS AND METHODS: A retrospective chart review was conducted between January 2008 and December 2015 to identify patients who had undergone surgery for cholesteatoma with an associated CF. The following data were collected: preoperative symptoms, findings of temporal bone computed tomography (TBCT), fistula stage, cholesteatoma classification, surgical technique, and pre- and postoperative pure-tone audiometry. RESULTS: We analyzed a total of 159 patients, out of which 9 (5.7%) were diagnosed with a CF. The average duration of the chronic otitis media was 19.8 years. Cholesteatomas that induced CF rarely existed in the nonaggressive state; recurrent otorrhea was observed in all but one of our subjects. All the patients with CF had a distinct origin of cholesteatoma that developed from the retraction of posterior pars tensa; further, 88.9% cholesteatomas extended to and filled the sinus tympani. Preoperative audiometry revealed total hearing loss in 4 (44.4%) patients. Further, five patients with residual hearing before surgery had stage I fistulas, and the bone conduction thresholds remained stable after surgery. CONCLUSION: Cochlear fistulas were often detected in patients with (1) a history of chronic otitis media (exceeding 10 years), (2) frequently recurring otorrhea, and (3) pars tensa cholesteatomas that extended to the posterior mesotympanum and filled the sinus tympani. Such patients can suffer from potentially severe and irreparable sensorineural hearing loss.

Clinical Implications of Intralesional Steroid Injections in the Management of Otohematoma.

OBJECTIVES/HYPOTHESIS: To evaluate the long-term effects of intralesional steroid injections (ILSIs) in patients with otohematoma and to suggest the clinical implications, especially with regard to the duration of otohematoma. STUDY DESIGN: Retrospective analysis. METHODS: Fifty-six patients were enrolled and classified into short-term otohematoma (n = 30) and long-term otohematoma (n = 26) groups according to the period of time after auricular trauma. After the first ILSI, all patients underwent weekly examinations during the 21-day observational period to determine the treatment outcomes and were then followed up for reevaluation for a maximum of 36 months. We considered ILSIs to be ineffective if the otohematoma persisted after the third ILSI, and we opted to perform surgical treatment in such cases. In addition, we evaluated early recurrence, late recurrence, and ILSI-related complications. RESULTS: After up to three ILSIs, 29 out of 30 cases (96.7%) with short-term otohematoma and 20 out of 26 cases (76.9%) with long-standing otohematoma were treated without complications. Three patients with long-term otohematoma, however, experienced late recurrences at 4, 15, and 18 months, respectively. Seven patients who showed no response after ILSIs underwent surgical treatment. The duration of otohematoma (P = .043) and a higher initial aspirated fluid volume (P = .014) were shown to significantly increase the risk of treatment failure after ILSIs. CONCLUSIONS: Multiple and immediate ILSIs in patients with otohematoma appear to be an effective treatment approach with no complications. Patients with short-term otohematoma showed better outcomes following ILSIs. The treatment approach may be optimized based on the duration and degree of otohematoma. LEVEL OF EVIDENCE: 4 Laryngoscope, 129:459-465, 2019.

Neuroplastic change of cytoskeleton in inferior colliculus after auditory deafferentation.

Neural plasticity is a characteristic of the brain that helps it adapt to changes in sensory input. We hypothesize that auditory deafferentation may induce plastic changes in the cytoskeleton of the neurons in the inferior colliculus (IC). In this study, we evaluated the dynamic status of neurofilament (NF) phosphorylation in the IC after hearing loss. We induced auditory deafferentation via unilateral or bilateral cochlear ablation in rats, aged 4 weeks. To evaluate cytoskeletal changes in neurons, we evaluated mRNA fold changes in NF heavy chain expression, non-phosphorylated NF protein fold changes using SMI-32 antibody, and the ratio of SMI-32 immunoreactive (SMI-32-ir) neurons to the total neuronal population in the IC at 4 and 12 weeks after deafness. In the bilateral deafness (BD) group, the ratios of SMI-32-ir neurons significantly increased at 4 weeks after ablation in the right and left IC (6.1 ±â€¯4.4%, 5.0 ±â€¯3.4%, respectively), compared with age-matched controls (P < 0.01, P < 0.01). At 12 weeks after ablation, the ratio of SMI-32 positive neurons was higher (right, 3.4 ±â€¯2.0%; left, 3.2 ±â€¯2.3%) than that in the age-matched control group, albeit not significant in the right and left side (P = 0.38, P = 0.24, respectively). Consistent with the results of the ratio of SMI-32-ir neurons, SMI-32-ir protein expression was increased at 4 weeks after BD, and the changes at 12 weeks after bilateral ablation were not significant in the right or left IC. The age-matched control fold changes of NF mRNA expression after bilateral deafness were not significant at 4 and 12 weeks after deafness in right and left IC. Unilateral deafness did not induce significant change of NF mRNA expression, SMI-32-ir protein expression, and the ratio of SMI-32-ir neurons in the IC at 4 and 12 weeks after hearing loss. Bilateral auditory deafferentation induces structural changes in the neuronal cytoskeleton within the IC, which is prominent at 4 weeks after BD. The structural remodeling of neurons stabilized at 12 weeks after BD. Unlike BD, unilateral auditory deafferentation did not affect the dynamic status of NFs in the IC.

Characteristics of tinnitus found in anemia patients and analysis of population-based survey.

OBJECTIVE: This study analyzed the characteristics of tinnitus identified in anemia patients with cohort- and population-based studies in a single institute and suggests a management algorithm. METHODS: Fifty patients who were treated for anemia and referred for tinnitus treatment were included in a single institute retrospective study. Characteristics of tinnitus were investigated in a correlation analysis with demographic and audiologic parameters. For the population-based study, data from the Korea National Health and Nutrition Examination Survey collected between 2010 and 2011 were analyzed. The study population consisted of 11,402 individuals aged 20-97 years with complete tinnitus-related data. The prevalence of tinnitus in anemia patients was investigated using the questionnaire, and associations between tinnitus and blood/urine parameters were evaluated by binary logistic regression analysis. RESULTS: In a single-institute study, patients with non-pulsatile tinnitus were significantly older and their initial hemoglobin was higher than those with pulsatile tinnitus (p=0.001, 0.008, respectively). In pulsatile tinnitus, age and difference between initial and post-treatment hemoglobin were significantly associated with a subjective improvement in tinnitus (p=0.002, 0.016, respectively). There were no significant audiologic or hematologic parameters associated with the improvement of non-pulsatile tinnitus. In the population-based study, there was no significant correlation between anemia and tinnitus (p=0.064). In a multivariate analysis, age was the only parameter associated with tinnitus in participants with anemia. CONCLUSION: The therapeutic strategy and prognosis of tinnitus in anemia patients differ according to the characteristics of tinnitus and the severity of anemia.

Sudden sensorineural hearing loss in children and adolescents: Clinical characteristics and age-related prognosis.

OBJECTIVE: Although many studies have investigated sudden sensorineural hearing loss (SSNHL) in adults, there were few studies on SSNHL in the pediatric population; especially research on treatment and prognosis of pediatric SSNHL was limited. The aim of this study was to evaluate clinical characteristics, treatment outcomes and prognostic factors in children and adolescents with SSNHL. METHODS: A retrospective review of medical records of 67 pediatric patients (67 ears) who had diagnosed with SSNHL at our hospitals was performed to analyze patients' clinical manifestations and audiograms. All patients were treated with high-dose systemic prednisolone (1mg/kg), and 17 of them underwent intratympanic steroid injection therapy. Audiological evaluation was carried out before and after treatment, and hearing recovery was defined as complete recovery and partial recovery according to Siegel's criteria. Patients were divided into two groups: childhood group (ages between 4 and 12 years old) and adolescence group (age>12years), and clinical characteristics and treatment outcomes were investigated. In addition, patients were divided into two groups according to degree of hearing recovery, and evaluation was made regarding possible prognostic factors. RESULTS: The recovery rate in total 67 patients was 55.2%. The recovery rate of the childhood group was significantly lower than that of the adolescence group (p=0.038). While the presence of vertigo did not significantly correlate with prognosis (p=0.219), the presence of tinnitus was significantly associated with hearing recovery (p=0.005). Audiological assessment revealed that a low initial hearing threshold, high speech discrimination score, and descending type of audiogram were positively associated with hearing recovery (p=0.002, p=0.003, and p=0.029, respectively). CONCLUSION: The childhood group had worse treatment outcomes than the adolescence group. High initial hearing threshold and absence of tinnitus were poor prognostic factors of hearing recovery. Active treatment is required for patients with these poor prognostic factors and childhood patients with SSNHL.

The effect of systemic lipoic acid on hearing preservation after cochlear implantation via the round window approach: A guinea pig model.

The present study aimed to evaluate the effects of systemic lipoic acid on hearing preservation after cochlear implantation. Twelve Dunkin-Hartley guinea pigs were randomly divided into two groups: the control group and the lipoic acid group. Animals in the lipoic acid group received lipoic acid intraperitoneally for 4 weeks. A sterilised silicone electrode-dummy was inserted through the round window to a depth of approximately 5 mm. The hearing level was measured using auditory brainstem responses (ABRs) prior to electrode-dummy insertion, and at 4 days and 1, 2, 3 and 4 weeks after electrode-dummy insertion. The threshold shift was defined as the difference between the pre-operative threshold and each of the post-operative thresholds. The cochleae were examined histologically 4 weeks after electrode-dummy insertion. Threshold shifts changed with frequency but not time. At 2kHz, ABR threshold shifts were statistically significantly lower in the lipoic acid group than the control group. At 8, 16 and 32kHz, there was no significant difference in the ABR threshold shift between the two groups. Histologic review revealed less intracochlear fibrosis along the electrode-dummy insertion site in the lipoic acid group than in the control group. The spiral ganglion cell densities of the basal, middle and apical turns were significantly higher in the lipoic acid group compared with the control group. Therefore, systemic lipoic acid administration appears to effectively preserve hearing at low frequencies in patients undergoing cochlear implantation. These effects may be attributed to the protection of spiral ganglion cells and prevention of intracochlear fibrosis.

Optimal use of CT imaging in pediatric congenital cholesteatoma.

OBJECTIVE: This study aimed to determine the radiation dose of temporal bone computed tomography (TBCT) to detect pediatric congenital cholesteatoma (CC), and suggests strategy for lowering perioperative radiation dose. METHODS: Fifty-three CC patients followed up for more than 12 months after surgery. Perioperative clinical findings and the effective radiation dose (ERD) of TBCT were investigated. Patients' mean age at initial TBCT was 60 months; the mean follow-up period was 43 months. RESULTS: In 33 (62.3%) of 53 patients, only one TBCT was performed postoperatively. Postoperative CT imaging was performed to evaluate before second-stage ossiculoplasty, due to suspicion of CC recurrence on examinations, or as part of follow-up. When TBCT was performed on more than two occasions after surgery as a part of follow-up, there was no difference in the distribution of stage or type of CC compared to patients subjected to TBCT on less than three occasions (p=0.093 and p=0.744, respectively). During the most-recent follow-up of these 53 cases, there was no CC recurrence. The mean ERD of a single TBCT was 1.2mSv, and the mean cumulative ERD of TBCT was 2mSv per patient. CONCLUSION: Mean and cumulative ERD of TBCT performed in CC cases was not too high to consider radiation hazard. However, efforts to minimize the number of CT scans should be taken basically.

Difference of Type 3 secretion system (T3SS) effector gene genotypes (exoU and exoS) and its implication to antibiotics resistances in isolates of Pseudomonas aeruginosa from chronic otitis media.

OBJECTIVE: Type 3 secretion system (T3SS) is the most important virulence factor in Pseudomonas aeruginosa infection. Of the various T3SS effector genes, exoS and exoU showed mutually exclusive distributions, and these two genes showed varied virulence. In many pseudomonal infections, the distribution of these genes showed different pattern and it influenced severity of infection. This study was aimed to evaluate differences of virulence factors and antibiotics resistance between chronic otitis media and other body infection caused by P. aeruginosa. METHODS: To estimate the prevalence of effector genes of T3SS, especially the distributions of exoS and exoU genes and their association with antibiotic resistance in COM, we compared the prevalence of T3SS genes in isolates from COM with those from lower respiratory infection and bacteremia. Other virulence genes, including groEL, pilA, ndvB, lasB, rhlI, and apr, were also studied to evaluate prevalence. These isolates were tested for antibiotic susceptibility, and we examined the association between antibiotic susceptibility and the prevalence of T3SS effector genes. RESULTS: The COM group showed a significantly higher exoU-positive rate than the control group (70.6% vs. 6.7%; P<0.01). Furthermore, COM patients with exoU showed significant antibiotic resistance to ciprofloxacin and tobramycin (P=0.035), whereas there was no significant difference in the control group. CONCLUSIONS: The high incidence of exoU-positive P. aeruginosa and ciprofloxacin resistance can explain the chronicity and intractability of infection in COM. Elucidation of this pathogenicity will facilitate the development of new treatment options for COM patients.

Clinical features of recurrence and osteoporotic changes in benign paroxysmal positional vertigo.

OBJECTIVE: Several previous studies have demonstrated that comorbidities, secondary causes, physical inactivity, and osteoporosis may cause recurrence of benign paroxysmal positional vertigo (BPPV). However, there has also been some controversy over the clinical course(s) and cause(s) of recurrent BPPV (rBPPV). We identified clinical features and associated factors, including decreased bone mineral density, in the recurrence of BPPV. METHODS: In total, 198 patients with idiopathic BPPV, diagnosed at the otolaryngology clinics of Seoul National University Boramae Medical Center, were enrolled. The medical data of these patients were reviewed retrospectively. Recurrent BPPV was defined as the recurrence of BPPV after at least 1 month of a symptom-free interval following previous successful treatment. RESULTS: Of the BPPV patients, 67 (33.8%) were classified as rBPPV. Among them, about 16% showed changes in the involved semicircular canals and about 6% showed multiple semicircular canal involvement. rBPPV was more common in patients with comorbidities (P<0.001). Involved semicircular canals showed no statistically significant difference according to the recurrence of BPPV. The mean symptom-free interval of the rBPPV group varied from 1 to 50.2 (mean, 11.6) months; however, 90% of BPPV recurrence occurred within 24 months. Bone mineral density in dual-energy X-ray absorptiometry (DEXA) was markedly decreased in BPPV patients versus normal controls, but there were no significant differences according to BPPV recurrence. CONCLUSION: The incidence of rBPPV in idiopathic BPPV patients was 33.8% in the present study. The mean period of recurrence after a symptom-free interval was about 11.6 months; most patients showed recurrence within 2 years after the first attack of BPPV. Furthermore, about 16% of patients suffered from rBPPV at a different kind or type of canal from the semicircular canal of the initial BPPV attack. Comorbidities, but not age, gender, or the involved semicircular canal, might be correlated with BPPV recurrence. Decreased bone mineral density did not show significant association with BPPV recurrence, but showed a significant relation with BPPV occurrence.