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.

Clonazepam Usage Improves Chronic Tinnitus and Sleep Quality: A Prospective Cohort Study / 대한이비인후과학회지

Background and Objectives@#Tinnitus, although being a common chronic disease, can be an intractable disease that causes depression and insomnia. This study aimed to analyze the results of the Tinnitus Handicap Inventory (THI), Beck Depression Inventory (BDI), and Pittsburgh Sleep Quality Index (PSQI) questionnaire surveys before and after clonazepam therapy. In addition, we analyzed the association of three pre-treatment questionnaires and evaluated whether pre-treatment factors could predict the post-treatment THI index.Subjects and Method Patients were selected from those who visited a tertiary hospital from 2019 to 2021 for the treatment of chronic tinnitus they had for more than 3 months and who were over 20 years old. Patients were excluded from the study if they were diagnosed with acute sudden hearing loss, Meniere’s disease, brain/internal auditory canal tumors, or muscular/vascular tinnitus. The questionnaire surveys of THI, BDI, PSQI were conducted before and after 3 months of clonazepam therapy (Rivotril [Roche Inc.] 0.25 or 0.5 mg). Questionnaire scores were compared using the paired t-test. Multiple regression analysis was used to determine the relationships among the three questionnaires. @*Results@#A total of 76 patients (38 males and 38 females) with the mean age of 57.2±9.01 years was analyzed. The average hearing threshold was 30.4±20.67 dB HL on the right and 31.7±17.06 dB HL on the left. The pre-treatment THI, BDI, and PSQI scores were 44.3±23.4, 7.96±2.36, and 6.85±4.68, respectively. The relationships between the THI and BDI and the THI and PSQI were significant (p=0.0027 and p<0.0001, respectively). The pre-THI score showed no significant association with age, sex, or hearing threshold (p=0.91, 0.85, and 0.23, respectively). The post-treatment THI score was 33.6±17.1, which was significantly lower than the pre-THI scores (p<0.0001). Post-BDI and post-PSQI were 7.38±2.25 and 4.04±3.20, respectively. Post-PSQI also significantly decreased compared with pre-PSQI (p=0.0002), but post-BDI did not significantly decrease (p=0.1231). In the THI survey, Question 7 (sleep disturbance) showed decrease the most, followed by Question 25 (unstable mood). The post-treatment THI could be predicted by using the formula, 0.7673+0.6947×pre-THI+0.3572×pre-PSQI. @*Conclusion@#The appropriate/optional use of clonazepam at low doses (0.25-0.5 mg) can significantly improve chronic tinnitus and sleep quality. Tinnitus was significantly associated with the scores of THI, BDI, PSQI and the usage of Clonazepam significantly reduced the THI and PSQI scores. However, clonazepam did not affect the BDI score.

Update on Clinical Manifestation in Acute Low-Tone Hearing Loss / 대한이비인후과학회지

Background and Objectives@#Acute low-tone hearing loss (ALHL) is gaining attention as an independent disease identity with close association with endolymphatic hydrops and early stage Meniere’s disease (MD). This study aims to compare patients of ALHL with patients exhibiting low-tone hearing loss and ear fullness without vertigo in various audio-vestibular assessments and in progression to overt MD.Subjects and Method A total of 249 patients with low-tone hearing loss with ear fullness without vertigo was enrolled in this study. Of these patients, 58 patients met criteria for ALHL, which was defined as having an average hearing loss of ≥30 dB at 125, 250, and 500 Hz and ≤20 dB at 2, 4, and 8 kHz. Demographics, electrocochleography (ECoG) abnormality, rate of hearing improvement, vestibular functions, and progression to MD were analyzed. @*Results@#An average low-tone hearing loss of ALHL patients was 42.8 dB, which recovered to 18.9 dB following a combined treatment of diuretics and oral steroid therapy. The hearing recovery rate of this group was 87.9% and the ECoG abnormality ratio was 42.5%. Also, 15.5% of ALHL patients eventually progressed to MD. @*Conclusion@#This study described demographics and characteristics of ALHL, demonstrating a successful response to the combined treatment of diuretics and oral steroid. Also, this report demonstrated a close relationship between the degree of low-tone hearing loss and ECoG abnormality and observed the progression to MD in ALHL patients. These data can be usefully applied in clinical setting to explain clinical outcomes of ALHL.

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.

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.

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.

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.

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.

Analysis of Electrocochleography: According to the Position of Summating Potential Peak / 대한이비인후과학회지

BACKGROUND AND OBJECTIVES: The aim of this study was to analyze the summating potential (SP)/action potential (AP) ratio of electrocochleography (ECoG) recorded from the position of SP peak. We compared the SP/AP ratios of negative polarity and positive polarity graphs from the same ECoG of each patient by assuming different the position of SP peak. In addition, we attempted to evaluate the utility of two different manners of recording the ECoG graph in the diagnosis of Meniere's disease. SUBJECTS AND METHOD: Retrospectively, we analyzed the results of ECoG in 67 patients with unilateral definite Meniere's disease. ECoG was analyzed in two different manners. From the AP peak, the SP peak was determined close when positioned in the negative polarity; on the other hand, SP peak was considered distant when positioned in the positive polarity. The SP/AP ratio was interpreted with reference to the base line value. The ratio of two different ECoG values from each patient of Meniere's disease was calculated. RESULTS: In the abnormal side, the negative polarity ECoG showed significantly greater value of SP/AP ratio (mean: 0.334±0.10) than the positive polarity ECoG (mean: 0.283±0.09) (p<0.001). In the normal side, the negative polarity ECoG, showed significantly greater value of SP/AP ratio (mean: 0.250±0.09) than the positive polarity ECoG (mean: 0.204±0.06), as well as in the abnormal cases (p<0.001). CONCLUSION: The standard SP/AP ratio for the diagnosis of Meniere's disease can be variable according to the manner of determining the SP peak.

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.

Protective Effect of Metformin on Gentamicin-Induced Vestibulotoxicity in Rat Primary Cell Culture

OBJECTIVES: One of the antidiabetic drugs, metformin, have shown that it prevented oxidative stress-induced death in several cell types through a mechanism involving the opening of the permeability transition pore and cytochrome c release. Thus, it is possible that the antioxidative effect of metformin can also serve as protection against gentamicin-induced cytotoxicity related to reactive oxygen species (ROS). The aim of this study was to examine the protective effect of metformin on gentamicin-induced vestibulotoxicity in primary cell culture derived from rat utricle. METHODS: For vestibular primary cell culture, rat utricles were dissected and incubated. Gentamicin-induced cytotoxicity was measured in both the auditory and vestibular cells. To examine the effects of metformin on gentamicin-induced cytotoxicity in the primary cell culture, the cells were pretreated with metformin at a concentration of 1 mM for 24 hours, and then exposed to 2.5 mM gentamicin for 48 hours. The intracellular ROS level was measured using a fluorescent dye, and also measured using a FACScan flow cytometer. Intracellular calcium levels in the vestibular cells were measured with calcium imaging using Fura-2 AM. RESULTS: Vestibular cells were more sensitive to gentamicin-induced cytotoxicity than auditory hair cells. Metformin protects against gentamicin-induced cytotoxicity in vestibular cells. Metformin significantly reduced a gentamicin-induced increase in ROS, and also reduced an increase in intracellular calcium concentrations in gentamicin-induced cytotoxicity. CONCLUSION: Metformin significantly reduced a gentamicin-induced increase in ROS, stabilized the intracellular calcium concentration, and inhibited gentamicin-induced apoptosis. Thus, Metformin showed protective effect on gentamicin-induced cytotoxicity in vestibular primary cell culture.

Analysis of 4 kHz Notch Audiogram as a Sign of Noise Induced Hearing Loss / 대한이비인후과학회지

BACKGROUND AND OBJECTIVES: In this study, we tried to study the criteria and characteristics of patients with noise-induced hearing loss by analyzing the pure tone audiogram such as "C5 dip" or "4 kHz notch". SUBJECTS AND METHOD: Out of 553 patients who complained of tinnitus and hearing loss, medical examination by interview, physical examination, hearing test, brain MRI and survey of tinnitus were performed from January 2010 to December 2012, targeting 81 patients who underwent pure tone hearing test. We analyzed the clinical characteristics of 81 patients with the exception of systemic disease or a history of otologic disease, conductive hearing loss, and vestibular schwannomas. Patients consisted of 70 men and 11 women (34 persons on both sides, 31 persons on right side, and 16 persons on left side), with an average of 48.1+/-12.9 years. 4 kHz notch-type sensorineural hearing loss was compared with contralateral hearing. RESULTS: The audiogram of 4 kHz notch was analyzed, and the results were as follows; 0.5 kHz (11.2+/-9.9 dB HL), 1 kHz (13.2+/-9.9 dB HL), 2 kHz (19.4+/-15.4 dB HL), 3 kHz (38.1+/-18.7 dB HL), 4 kHz (49.3+/-16.2 dB HL), 8 kHz (27.2+/-16.2 dB HL). Among all frequencies of 4 kHz notch audiogram, there was no significant hearing loss in 0.5 kHz and 1 kHz, but significant hearing loss was noted in higher frequencies (paired t-test, p>0.05). The contralateral ear showed a ski-slope hearing loss in about half of the patients. CONCLUSION: Remarkable points of the 4 kHz notch audiogram analysis, known as a typical characteristic of noise-induced hearing loss, were as follows; First, there was hearing loss of about 50 dB HL at 4 kHz. Second, the hearing threshold was improved to about 30 dB HL at 8 kHz. Third, the 4 kHz-notch audiogram showed a significant hearing loss in a high-pitched tone of over 2 kHz, but otherwise there were no significant hearing loss observed in 0.5 kHz and 1 kHz. Fourth, even if there were no symptoms, contralateral ear can still show the ski-slope type of hearing loss.

Protective Role of Trimetazidine Against Neomycin-induced Hair Cell Damage in Zebrafish

OBJECTIVES: Trimetazidine (TMZ) is known to reduce the generation of oxygen-derived free radicals. The objective of the present study was to evaluate the effects of TMZ on neomycin-induced ototoxicity in transgenic zebrafish (Brn3C: EGFP). METHODS: Five-day, postfertilization zebrafish larvae were exposed to 125 microM neomycin and one of the following TMZ concentrations for 1 hour: 10 microM, 100 microM, 500 microM, 1,000 microM, 1,500 microM, or 2,000 microM. Hair cells within the neuromasts of the supraorbital (SO1 and SO2), otic (O1), and occipital (OC1) lateral lines were analyzed using fluorescence microscopy and confocal microscopy (n=10). Hair cell survival was calculated as a percentage of hair cells in the control group that were not exposed to neomycin. Ultrastructural changes were evaluated using scanning electron microscopy. RESULTS: TMZ protected against neomycin-induced hair cell loss in the neuromasts (TMZ 1,000 microM, 11.2+/-0.4 cells; 125 microM neomycin only, 4.2+/-0.5 cells; n=10; P<0.05) and decreased the terminal deoxynucleotidyl transferase (TdT)-mediated dUTP-biotin nick end labeling (TUNEL) reaction. In the ultrastructural analysis, structures of mitochondria and hair cells within the neuromasts were preserved in zebrafish exposed to 125 microM neomycin and 1,000 microM TMZ. CONCLUSION: TMZ attenuated neomycin-induced hair cell loss in zebrafish. The results of this study suggest that neomycin induces apoptosis, and that apoptotic cell death can be prevented by treatment with tremetazidine.

Candidates for Tumor Markers of Cervical Cancer Discovered by Proteomic Analysis

Cervical cancer is the second most common gynecological cancer among Korean women. While nationwide screening program has developed, the pathogenesis of cervical cancer is unknown. The aim of this study was to compare the protein expression profiles between cervical squamous carcinomas and normal cervical tissues in order to identify proteins that are related to the cancer. Three cervical cancer tissue samples and three normal cervical tissue samples were obtained and protein expression was compared and was identified in the samples with the use of matrix assisted laser desorption/ionization-time of flight mass spectrometry (MALDI-TOF-MS). A total of 20 proteins that showed up-regulated expression in the cervical cancer tissue samples were selected and identified. Seven proteins were matched to allograft inflammatory factor 1 (AIF-1), actine-like protein 2 (ALP2), brain type fatty acid-binding protein (B-FABP), NCK adaptor protein 1 (NCK-1), islet cell autoantigen 1 (ICA69), cationic trypsinogen (PRSS1), and cyclin-dependent kinase 4 (CDK4), but the remaining 13 proteins were unidentifiable. After confirmation by RT-PCR, Western blotting and immunohistochemistry, we found that B-FABP, NCK-1, and CDK4 were related to the pathogenesis of cervical cancer. These proteins are suggested as candidates of new pathological tumor markers for cervical cancer.

Nasopharynx as a Microbiologic Reservoir in Chronic Suppurative Otitis Media: Preliminary Study

OBJECTIVES: The present study was designed to identify the correlations of bacterial strains of the middle ear and the nasopharynx in chronic suppurative otitis media (CSOM) patients who were scheduled for operations. METHODS: Sixty-three patients with CSOM were enrolled in the study. Culture specimens were collected from the middle ear and nasopharynx of patients who were admitted for operation. Samples collections were performed 3 times; from the middle ear and nasophaynx at the admission day, from the middle ear during the operation, and from the external auditory canal post-operatively. Bacteria were identified by gram staining and biochemical tests. The correspondence rate of organisms which simultaneously exist in the middle ear and the nasopharynx was measured. RESULTS: Sixty-eight organisms were isolated from the middle ear and 57 organisms from the nasopharynx among 63 patients. Of 68 bacteria identified in middle ear, 26.52% (18 bacteria) corresponded with those of nasopharynx. MRSA had the high correspondence rate, and of 18 methicillin-resistant Staphylococcus aureus (MRSA) isolated from middle ear, 33.3% (6 bacteria) corresponded with nasophaynx. Meanwhile, 3 organisms of MRSA were detected from the external auditory canal post-operatively, although they were only found in nasopharynx pre-operatively. CONCLUSION: The current trend of middle ear swab alone for bacterial detection would be insufficient to identify the potent MRSA and impede early antibiotic intervention for the effective middle ear surgery. Therefore, it is necessary to perform nasopharynx cultures together with conventional middle ear culture to control potent risk for infection pre-operatively.

Anti-Adhesive Effect of GUARDIX-SL(R) after Intact Canal Wall Mastoidectomy: Preliminary Study

BACKGROUND AND OBJECTIVES: Adhesion of middle ear and mastoid cavity after mastoidectomy represents a potential source of surgical failure. GUARDIX-SL(R), absorbable anti-adhesive material, which is composed of sodium hyaluronate and sodium carboxymethyl cellulose, is an effective agent that widely used as a surgical adjuvant to decrease adhesion in the surgery. Therefore, we evaluated the clinical efficacy of the GUARDIX-SL(R) for the prevention of adhesion after mastoidectomy. SUBJECTS AND METHODS: This study was randomized and double-blinded. Conventional intact canal wall mastoidectomy was conducted in both control (n=14) and study group (n=10). To avoid bias because of different surgeons, we only included patients who were operated on by one surgeon. In the study group, 1.5 g GUARDIX-SL(R) was applied in the mastoid cavity at the end of mastoidectomy. To evaluate anti-adhesive effect of GUARDIX-SL(R), the volume of aerated area in the mastoid cavity was calculated and compared with temporal bone computed tomography performed at preoperatively and postoperatively. Besides, to assess the success of operation, pure tone audiometry was also performed at preoperatively and postoperatively. RESULTS: The volume of aerated area of mastoid cavity after mastoidectomy was more increased in GUARDIX-SL(R) group, but was not statistically significant in the GUARDIX-SL(R) group than the control. And all results of pure tone audiometry satisfied the criteria of successful operation which has been suggested by Otological Society of Korea. CONCLUSION: The results suggest that GUARDIX-SL(R) may be an efficacious and safe material in decreasing the incidence of adhesion after mastoidectomy.

Expression of Insulin-like Growth Factors in a Mouse Model of Salicylate Ototoxicity

OBJECTIVES: Insulin-like growth factors (IGFs) are known to be neurotrophic factors, and they efficiently signal to cells to grow, differentiate and survive. The purpose of study was to identify the expressions of IGFs in mice with salicylate ototoxicity, which is a typical reversible hearing loss model. METHODS: The mice were given intraperitoneal injections of salicylate (400 mg/kg) and about a 30 dB threshold shift was achieved at 3 hours. The expressions of IGF-1 and 2 were confirmed by semi-quantitative reverse transcription polymerase chain reaction (RT-PCR) and Western blotting. Localization of IGFs was confirmed using confocal immunofluorescence imaging. For in-vitro study on the HEI-OC1 auditory cells, the cell viability was calculated and the apoptotic features of the nuclei were observed with Hoechst staining. RESULTS: The expressions of the IGFs mRNA and protein were significantly increased in the salicylate ototoxicity groups compared with that of the normal control group. Salicylate induced apoptosis and decreased viability of the HEI-OC1 auditory cells in a time- and dose-dependent manner. The expressions of IGFs were localized in the stria vascularis, and these IGFs play a protective role in the in-vivo condition of salicylate ototoxicity. CONCLUSION: IGFs were highly expressed in the mice with salicylate ototoxicity, and this expression was mainly focused in the stria vascularis in the salicylate intoxicated mice. The systemic action of IGFs, which were expressed in the vascular-rich stria vascularis, can act as a major protective mechanism in a mouse model of salicylate ototoxicity.

A Case of Hyperkeratotic Seborrheic Keratosis of the External Auditory Canal / 대한이비인후과학회지

A seborrheic keratosis is a very common benign lesion of the skin in elderly people. However, the incidence of seborrheic keratosis in the external auditory canal is very rare and there have been only a few reports of it in the literature. We have experienced a case of hyperkeratotic seborrheic keratosis of the external auditory canal in a 47-year-old male, who first presented with a dome-like brownish mass with a greasy surface and a bloody discharge from right external auditory canal. Because seborrheic keratosis partly mimics malignant lesions such as basal cell carcinoma and squamous cell carcinoma macroscopically, the correct diagnosis should be required. The biopsy and surgical resection were necessary steps in correct diagnosis and treatment.

Osteosarcoma of the Temporal Bone / 대한이비인후과학회지

Osteosarcoma is a highly malignant bone tumor that is rarely found in the facial and cranial bones. It may be found in the mandible and maxilla but is very rare in the temporal bone. Surgery with adequate margins seems to be the procedure of choice and postoperative chemotherapy and radiotherapy is recommended as well as a long term follow up. The authors experienced a case of osteosarcoma of the temporal bone in a 39 years-old male. The patient underwent a tumor removal with open craniotomy and simple mastoidectomy; then, the mastoid was obliterated by temporalis muscle rotation flap. After operation, the patient received chemotherapy. The patient has been free of local recurrence or metastasis for 2 postoperative years.