Cochlear Implantation in the Elderly: Speech Performance, Associated Factor, Complication, and Surgical Safety.

BACKGROUND AND OBJECTIVES: The guidelines for cochlear implantation (CIs) are expanding, and the number of CI procedures performed on the elderly is increasing. The purpose of this study was to analyze the results and safety of cochlear implantation in the elderly, as well as to evaluate the predictive factors on CI outcomes. SUBJECTS AND METHODS: The study included 56 patients aged ≥40 years, who received CIs between 2009 and 2020. They were divided into two groups: 27 younger adults (40-64 years) and 29 elderly (>64 years). The study compared their pre- and postoperative speech perception and category of auditory performance (CAP) scores, surgical complications, and hospitalization periods. It also evaluated associated factors in the elderly group by examining categorical and continuous variables and postoperative CAP score. RESULTS: There was a significant improvement in speech recognition tests (both word and sentence) and CAP scores in both groups compared to the pre-implantation scores (p<0.001). Postoperative results were slightly lower in the elderly group than in younger adults for sentence recognition and CAP scores, except for word recognition. No significant associated factors were found on postoperative CAP scores, except for etiology. Postoperative CAP significantly improved in the sudden hearing loss group compared to the groups with other etiologies (p=0.045). The elderly group had more comorbidities than that in the younger adult group (p=0.026), but there were no significant differences in postoperative complications and hospitalization periods. CONCLUSIONS: While speech recognition and CAP scores were relatively lower in the elderly group compared to the younger adults, the elderly group showed significant improvements in audiological results after CI. Moreover, CI was safe and well tolerated in elderly patients.

Factors Affecting the Extrusion Rate and Complications After Ventilation Tube Insertion: A Multicenter Registry Study on the Effectiveness of Ventilation Tube Insertion in Pediatric Patients With Chronic Otitis Media With Effusion-Part II.

OBJECTIVES: The impacts of ventilation tube (VT) type and effusion composition on the VT extrusion rate and complications in children with otitis media remain unclear. This part II study evaluated the factors affecting the extrusion rate, recurrence rate, and complications of VT insertion. METHODS: A prospective study was conducted between June 2014 and December 2016 (the EVENT study [analysis of the effectiveness of ventilation tube insertion in pediatric patients with chronic otitis media]), with follow-up data collected until the end of 2017. Patients aged <15 years diagnosed with otitis media with effusion who received VT insertion were recruited at 15 tertiary hospitals. The primary outcomes were time to extrusion of VT, time to effusion recurrence, and complications. RESULTS: Data from 401 patients were analyzed. After excluding the. RESULTS: of long-lasting tubes (Paparella type II and T-tubes), silicone tubes (Paparella type I) exhibited a significantly longer extended time to extrusion (mean, 400 days) than titanium tubes (collar-button-type 1.0 mm: mean, 312 days; P<0.001). VT material (hazard ratio [HR], 2.117, 95% confidence interval [CI], 1.254-3.572; P=0.005), age (HR, 3.949; 95% CI, 1.239-12.590; P=0.02), and effusion composition (P=0.005) were significantly associated with the time to recurrence of middle ear effusion. Ears with purulent (mean, 567 days) and glue-like (mean, 588 days) effusions exhibited a shorter time to recurrence than ears with serous (mean, 846 days) or mucoid (mean, 925 days) effusions. The revision VT rates during follow-up were 3.5%, 15.5%, 10.4%, and 38.9% in ears with serous, mucoid, glue-like, and purulent effusions, respectively (P<0.001). The revision surgery rates were higher among patients aged <7 years than among those aged ≥7 years. CONCLUSION: Silicone tubes (Paparella type I) were less prone to early extrusion than titanium 1.0 mm tubes. VT type, patient age, and effusion composition affected the time to recurrence of effusion.

Differential Involvement of Lateral Semicircular Canal and Otolith Organs in Common Vestibular Disorders.

Semicircular canal and otolith functions came to be evaluated recently, but comprehensive and comparative analysis of canal and otolith dysfunction in common vestibular disorders is lacking. We aimed to analyze the abnormal rates of canal and otolith function in common vestibular disorders. We enrolled 302 patients who were managed for 2 months in a dizziness clinic. Results of caloric, video head impulse test (vHIT), and cervical and ocular vestibular evoked myogenic potential (cVEMP and oVEMP) tests were analyzed and compared among various diagnoses. Vestibular disorders diagnosed included recurrent vestibulopathy (RV, 27%), vestibular migraine (VM, 21%), benign paroxysmal positional vertigo (BPPV, 17%), Meniere's disease (MD, 11%), vestibular neuritis (VN, 10%), orthostatic dizziness (7%), and central lesions (3%). Lateral canal dysfunction was found most in VN (100%) and less commonly in definite MD (75%), RV (46%) and definite VM (29%). Abnormal caloric results were more common than abnormal vHIT in all disorders. Otolith dysfunction was found more frequently than lateral canal dysfunction in most vestibular disorders except VN. An abnormal cVEMP was more frequent in definite MD than the other disorders. Isolated otolith dysfunction without lateral canal dysfunction was the most found in BPPV, followed by definite VM, RV, and definite MD in decreasing order. Various patterns of involvement in canal and otoliths were revealed in vestibular disorders, suggesting different pathogenesis.

Postoperative results of ventilation tube insertion: a retrospective multicenter study for suggestion of grading system of otitis media with effusion.

BACKGROUND: In otitis media with effusion (OME), it is important to know when to surgically intervene and when careful monitoring is more appropriate. This study aimed to visualize and classify the clinical manifestations of OME and the correlation between the new grading system and postoperative results after ventilation tube insertion (VTI). METHODS: We classified the collective 1,012 ears from 506 patients into six groups: grade 0 (no effusion), grade I (scant effusion, but abnormal), grade II (effusion less than half of the tympanic cavity), grade III (effusion over half of the tympanic cavity, with air bubbles), grade IV (complete effusion), and grade V (retracted tympanic membrane or hemotympanum without air bubbles). RESULTS: The mean age at VTI was 5.2 (±2.9) years and mean duration between diagnosis and operation was 4.1 (±1.8) months. Between the grades, the nature of the middle ear effusion was also significantly different (p < 0.001). The duration of ventilation tube retention after VTI was significantly different when compared between two groups: grade I-IV and grade V (p = 0.019). Our results showed that the recurrence rate, as well as rate of revision VTI, increased as the grade increased (p < 0.001). CONCLUSIONS: The new grading system of OME using endoscopic otoscope evaluation had a significant correlation with the age at VTI, the nature of middle ear effusion, the recurrence rate of OME, and the rate of revision VTI.

Changes of Temporal Processing and Hearing in Noise after Use of a Monoaural Hearing Aid in Patients with Sensorineural Hearing Loss: A Preliminary Study.

BACKGROUND AND OBJECTIVES: The relationship between hearing aid (HA) use and improvement in cognitive function is not fully known. This study aimed to determine whether HAs could recover temporal resolution or hearing in noise functions. Materials and. METHODS: We designed a prospective study with two groups: HA users and controls. Patients older than 45 years, with a pure tone average threshold of worse than 40 dB and a speech discrimination score better than 60% in both ears were eligible. Central auditory processing tests and hearing in noise tests (HINTs) were evaluated at the beginning of the study and 1, 3, 6, and 12 months after the use of a monaural HA in the HA group compared to the control group. The changes in the evaluation parameters were statistically analyzed using the linear mixed model. RESULTS: A total of 26 participants (13 in the HA and 13 in the control group) were included in this study. The frequency (p<0.01) and duration test (p=0.02) scores showed significant improvements in the HA group after 1 year, while the HINT scores showed no significant change. CONCLUSIONS: After using an HA for one year, patients performed better on temporal resolution tests. No improvement was documented with regard to hearing in noise.

Prediction of hearing outcomes in chronic otitis media patients underwent tympanoplasty using ossiculoplasty outcome parameter staging or middle ear risk indices.

PURPOSE: Ossiculoplasty outcome parameter staging (OOPS) and middle ear risk index (MERI) are the most commonly used indices for predicting prognosis of patients with chronic otitis media (COM). This study aimed to verify the efficiency of OOPS and MERI scores in predicting outcomes of patients with COM who underwent tympanoplasty. METHODS: We retrospectively reviewed the data of patients who underwent tympanoplasty (n = 526). OOPS, and MERI scores were collected. Hearing data were measured 1 day preoperatively, and 3 and 12 months postoperatively. Operation success was defined according to the Korean Society of Otology guidelines. RESULTS: For calculation of success, the ROC values of MERI were 0.551 at 12 months. ROC values of OOPS were 0.637 at 12 months. There were no significant differences in hearing variables among the three groups according to MERI. There were significantly favorable outcomes in hearing variables in the low-risk group in OOPS. The mean OOPS score was greater in patients with success than those with non-success. Otorrhea, ossicle status, and status of mucosa as variables in both indices were associated with success. The type of mastoidectomy as a variable in OOPS alone was associated with success. Absence of hypertension, presence of ossiculoplasty, and use of incus as ossiculoplasty material were associated with poor success rate. CONCLUSION: Compared with MERI, the OOPS index was more closely associated with the hearing outcomes, which may be due to the extent of inflammation in the OOPS index.

Clinical outcomes of otogenic skull base osteomyelitis.

PURPOSE: Skull base osteomyelitis (SBO) is an uncommon and a potentially life-threatening condition if not promptly recognized and properly treated. The aim of our study was to present a 32-case series of patients diagnosed with SBO at a single center. METHODS: In this retrospective study, we reviewed the data of patients diagnosed with otogenic SBO between January 2011 and January 2020. 32 patients were enrolled in the study. SBO diagnosis was based on a combination of symptoms and physical examination, bone scan, brain magnetic resonance imaging, and pathologic examination findings. The following clinical data were collected during the follow-up period: types of antibiotics used, duration of antibiotic treatment, C-reactive protein level, presence of disease control, duration from the onset of symptoms to diagnosis, and patient survival. RESULTS: The mean follow-up period was 11 (1-110) months. The mean duration of antibiotic treatment was 115 (19-223) days. The mean C-reactive protein levels at the time of diagnosis and at the endpoint of follow-up were 3.05 (0.56-18.31) and 0.21 (0.03-33.61) mg/dL, respectively (P < 0.001). Disease control rate was 34.9% at 1-year and 83.7% at 5-year follow-up. Patient survival rate was 90.6% at 1- and 3-year follow-ups. At the endpoint of follow-up, three patients died. The mean durations from the onset of symptoms to diagnosis were 50 (5-360) and 90 (30-480) days in patients with the controlled disease and in those with the uncontrolled disease, respectively, at the endpoint of follow-up (P = 0.043). CONCLUSION: Comprehensive assessment and aggressive treatment of patients exhibiting symptoms suggestive of SBO would help in the rapid diagnosis of otogenic SBO, resulting in an improvement in prognosis.

Comparison of Ossiculoplasty Outcomes Using Different Materials in the Treatment of Chronic Otitis Media.

OBJECTIVE: This study aimed to evaluate success rates after ossicular chain reconstruction using different materials. STUDY DESIGN: Retrospective cohort study. SETTING: Tertiary referral center. PATIENTS: Four hundred forty-three participants who underwent ossiculoplasty at a tertiary medical center were included. INTERVENTION: Ossicular chain reconstruction using five materials: autologous malleus, incus, and cortical bone, as well as Hydroxyapatite (HA) and titanium. MAIN OUTCOME MEASURES: Hearing data were measured 1 day preoperatively and 6 months postoperatively. Successful hearing outcomes were defined by the fulfillment of more than one of the following criteria: postoperative air-bone gap of 20 dB or less, hearing air conduction (AC) gain of 15 dB or more, or postoperative AC hearing less than 30 dB. RESULTS: Preoperative median AC values (95% confidence interval) among participants with malleus, incus, cortical bone, HA, and titanium transplants or prostheses were 50 (39.6-54.6) dB, 51.3 (48.1-51.8) dB, 50 (45.2-52.2) dB, 56.3 (50.9-57.6) dB, and 54.3 (48.5-56.0) dB, respectively (p = 0.092). The success rates in malleus, incus, cortical bone, HA, and titanium were 53.3%, 60.3%, 51.7%, 61.6%, and 69.7%, respectively. Titanium had the highest success rate among the five materials, but the differences between the materials were not statistically significant (p = 0.283). Titanium had highest success rate among the participants with erosive stapes suprastructure or obstructed Eustachian tubes (p = 0.042 for erosive stapes suprastructure and p = 0.010 for obstructed Eustachian tubes). CONCLUSION: Our study demonstrated that titanium prostheses would be a good alternative for ossiculoplasty in cases wherein autologous material is unavailable, especially in association with unfavorable conditions, such as with the presence of cholesteatoma, erosive stapes suprastructure, edematous middle ear mucosa, and obstructed Eustachian tube.

Red cell distribution width is associated with hearing impairment in chronic kidney disease population: a retrospective cross-sectional study.

PURPOSE: Previous studies have shown that inflammatory markers are associated with hearing impairment in participants with inflammatory diseases. Therefore, screening for inflammatory status may have value in predicting the risk of hearing loss (HL) in participants with underlying inflammation. Therefore, red cell distribution width (RDW), an indirect indicator of inflammatory status, was used. The aim of the present study was to evaluate the clinical association between RDW and hearing impairment in a Korean population with chronic kidney disease (CKD). METHODS: In this cross sectional study, a total of 461 participants with estimated glomerular filtration rate (eGFR) < 60 ml/min/1.73 m2 were included. Participants were divided into three tertiles based on their RDW values. The threshold values at 0.5, 1, and 2 kHz were averaged to obtain the Low/Mid-Freq, and the values at 3, 4, and 6 kHz were averaged to obtain the High-Freq. The average hearing threshold (AHT) was calculated as the pure-tone average of the thresholds at 0.5, 1, 2, and 3 kHz. HL was defined as an AHT of > 40 dB. RESULTS: The numbers of participants in the Low, Middle, and High tertiles were 172, 154, and 135, respectively. The AUROCs of RDW and hs-CRP for HL were 0.644 and 0.522, respectively. In the multivariate analysis, the Low/Mid-Freq, High-Freq, and AHT values were lowest in the participants in the Low tertile compared with those in the Middle or High tertiles Multivariate logistic regression analyses showed that participants in the High tertile exhibited 2.32- and 1.78-fold higher odds for HL compared to those of the Low and Middle tertiles, respectively. There were positive associations between RDW and AHT values. CONCLUSION: High RDW was associated with increased odds of hearing impairment in the Korean population with CKD.

Clinical Characteristics and Treatment Outcomes of Congenital Cholesteatoma.

OBJECTIVES: Since its introduction in 2002, the staging system for congenital cholesteatoma, as defined by Potsic, has been used widely owing to its simplicity and predictability. The aim of the present study was to analyze the clinical characteristics and surgical treatment outcomes of congenital cholesteatoma and to correlate them with postoperative recurrence. MATERIALS AND METHODS: A retrospective chart review was performed for 38 patients who were diagnosed with congenital cholesteatoma and who underwent surgical resection between August 2007 and November 2014 at the Department of Otorhinolaryngology of our hospital. RESULTS: The mean age of the patients was 7.9±8.2 years, and the number of males and females was 20 and 18, respectively. The mean follow-up period was 30±26 months. Of the 38 patients, 9 (24%) had residual or recurrent cholesteatoma during follow-up examination after primary surgery. The results showed that the size (≥4 mm) of the lesion was significantly correlated with residual or recurrent disease (p=0.026). The disease extent (single vs. multiple quadrant involvement), type (closed vs. open type), and stage; applied surgical method (with mastoidectomy vs. without mastoidectomy); and preoperative hearing level (normal vs. abnormal) were not significantly correlated with residual or recurrent disease. CONCLUSION: The disease extent, type, and stage; applied surgical methods; and preoperative hearing level were not significantly correlated with residual or recurrent disease. The size (≥4 mm) of congenital cholesteatoma was significantly correlated with residual or recurrent disease.

Management of Ménière's Disease: How Does the Coexistence of Vestibular Migraine Affect Outcomes?

OBJECTIVE: To report the incidence of vestibular migraine (VM) in patients with Ménière's disease (MD) and investigate whether management outcomes of MD differ by the association of VM. STUDY DESIGN: Retrospective cohort study. SETTING: Tertiary care academic center. PATIENTS: MD patients (n = 251) with/without VM who were managed for 5 years in a dizziness clinic. MAIN OUTCOME MEASURES: Influence of VM on management outcomes and hearing at the latest follow-up in stepwise management options. RESULTS: Incidence of VM was 35% in MD patients. VM was more common in women than men (40 vs. 22%) and in probable MD than definite MD (43 vs. 29%). Bilateral MD was more frequent with coexistence of VM than without VM in definite MD (14 vs. 0%) as well as probable MD (24 vs. 7%). At the latest follow-up, preventive medications were effective in controlling vertigo in most (80%) patients (74%/90% in definite/probable MD). Additional intratympanic steroids were required in 16% (20%/10% in definite/probable MD) and intratympanic gentamicin or surgeries in 9 (6%) patients with intractable MD. The percentage of intractable MD did not differ with coexistence of VM, though definite MD showed a significantly higher percentage of intractable MD than probable MD (6 vs. 0%, respectively, p = 0.002). Worsening hearing was more frequent in definite MD than probable MD (19 vs. 4%), and association of VM did not influence the incidence of worsening hearing. CONCLUSIONS: Coexistence of VM was about 30 to 40% in definite and probable MD, especially frequent in bilateral MD (77%) and women with probable MD (50%), requiring identification of coexisting VM while managing MD patients. Management outcomes and worsening hearing in MD patients are not dependent on the coexistence of VM, when both are managed.

Direction-Changing and Direction-Fixed Positional Nystagmus in Patients With Vestibular Neuritis and Meniere Disease.

OBJECTIVES: Direction-changing positional nystagmus (PN) was considered to indicate the presence of benign paroxysmal positional vertigo involving lateral semicircular canal in most cases. We investigated the incidence of PN on the supine head-roll test and compared the characteristics of nystagmus in patients with vestibular neuritis (VN) and Meniere disease (MD). METHODS: A retrospective review of patients, who were diagnosed with unilateral VN or unilateral definite MD between September 2005 and November 2011, was conducted. Sixty-five VN patients and 65 MD patients were enrolled. Eye movements were recorded for 30-60 seconds at the positions of sitting, head roll to the right, and head roll to the left, and maximum slow-phase eye velocity was calculated. PN was classified as direction-fixed (paretic or recovery) and direction-changing (geotropic or apogeotropic). RESULTS: Spontaneous nystagmus was observed in 57 patients (87%, the slow-phase eye velocity of 7°/sec±5°/sec) with acute VN, 39 (60%, 2°/sec±1°/sec) with follow-up VN, and 32 (49%, 2°/sec±2°/sec) with MD. Direction-fixed PN was the most common type. Direction-fixed paretic type was most common in acute VN (80%) and follow-up VN (42%), and direction-fixed recovery type was most common in MD (31%). Paretic type was significantly more common in acute VN (80%) than in follow-up VN (42%) and MD (26%), and the recovery type was significantly more common in MD (31%) than in acute VN (3%) and follow-up VN (14%). Direction-changing PN was more common in MD (22%), followed by follow-up VN (14%) and acute VN (9%). CONCLUSION: Though direction-fixed paretic PN was most common in VN and MD patients, direction-changing PN could be observed in a few patients (9%-20%) with peripheral vestibular disorders regardless of the duration from the onset of dizziness, suggesting the presence of otolith-related dizziness.

Prognostic roles of preoperative CT findings and air-bone gaps in type 1 tympanoplasty.

BACKGROUND: Although CT has been used widely, the role of preoperative CT findings including other factors in tympanoplasty has not been elucidated comprehensively. AIMS/OBJECTIVES: To evaluate relationship of CT findings with other factors and audiological results in type 1 tympanoplasty. MATERIAL AND METHODS: A cohort of consecutive 175 patients with type 1 tympanoplasty was enrolled. Addition of mastoidectomy was based on the presence of soft tissue in antrum on CT. Postoperative air-bone gap (ABG) and reperforation rate were analyzed. RESULTS: Positive soft tissue in antrum on CT was found in 52 (29.7%) patients and showed larger preoperative ABG than the negative group. Successful ABG closure (≤20 dB) was obtained in 97% when preoperative ABG ≤20 dB, but it decreased as the preoperative ABG increased (83% with preoperative ABG of 21-30 dB, and 0% with preoperative ABG >30 dB). Postoperative reperforation rate was positively related to the preoperative ABG, but not the presence of soft tissue in the antrum, the size, or locations of preoperative perforations. CONCLUSIONS AND SIGNIFICANCE: Our findings showed that temporal bone CT was helpful in determining addition of mastoidectomy and the presence of soft tissue in the antrum was associated with large ABG.

Diagnostic Value of Gains and Corrective Saccades in Video Head Impulse Test in Vestibular Neuritis.

Objectives We investigated changes in video head impulse test (vHIT) gains and corrective saccades (CSs) at the acute and follow-up stages of vestibular neuritis to assess the diagnostic value of vHIT. Study Design Case series with chart review. Setting Tertiary medical center. Subjects and Methods Sixty-three patients with vestibular neuritis who underwent vHIT at an initial presentation and an approximately 1-month follow-up were included. vHIT gains, gain asymmetry (GA), peak velocities of CS, and interaural difference of CS (CSD) were analyzed. Results Mean vHIT gains increased significantly from the acute stage to the follow-up exam. The mean GA, peak velocities of CS, and CSD had decreased significantly at the follow-up. The incidence of CSs was also significantly decreased at the follow-up. The abnormal rate (87%) considering both gain and CS value was significantly higher than that (62%) considering vHIT gain only at the follow-up, although the abnormal rates did not differ at the acute stage (97% vs 87%). Conclusion The abnormal rates based on both vHIT gains and CS measurements are similar at the acute stage of VN but are considerably higher at the follow-up stage compared with the abnormal rates based on vHIT gains alone. It is thus advisable to check both CS and vHIT gain while performing vHIT to detect vestibular hypofunction.

Comparison of Video Head Impulse Test (vHIT) Gains Between Two Commercially Available Devices and by Different Gain Analytical Methods.

OBJECTIVES: To evaluate whether video head impulse test (vHIT) gains are dependent on the measuring device and method of analysis. STUDY DESIGN: Prospective study. METHODS: vHIT was performed in 25 healthy subjects using two devices simultaneously. vHIT gains were compared between these instruments and using five different methods of comparing position and velocity gains during head movement intervals. RESULTS: The two devices produced different vHIT gain results with the same method of analysis. There were also significant differences in the vHIT gains measured using different analytical methods. The gain analytic method that compares the areas under the velocity curve (AUC) of the head and eye movements during head movements showed lower vHIT gains than a method that compared the peak velocities of the head and eye movements. The former method produced the vHIT gain with the smallest standard deviation among the five procedures tested in this study. CONCLUSION: vHIT gains differ in normal subjects depending on the device and method of analysis used, suggesting that it is advisable for each device to have its own normal values. Gain calculations that compare the AUC of the head and eye movements during the head movements show the smallest variance.

Microbiological Results From Middle Ear Effusion in Pediatric Patients Receiving Ventilation Tube Insertion: Multicenter Registry Study on the Effectiveness of Ventilation Tube Insertion in Pediatric Patients With Chronic Otitis Media With Effusion: Part I.

OBJECTIVES: The aim of this multicenter registry study was to investigate the effectiveness of ventilation tube insertion and the microbiology of otitis media with effusion (OME) in children. This part I study was conducted to evaluate the microbiological profile of children with OME who needed ventilation tube insertion. METHODS: Patients <15 years old who were diagnosed as having OME and received ventilation tube insertion were prospectively enrolled in 16 tertiary hospitals from June 2014 to December 2016. After excluding patients with missing data, the data of 397 patients were analyzed among a total of 433 enrolled patients. The clinical symptoms, findings of the tympanic membrane, hearing level, and microbiological findings were collected. RESULTS: In 103 patients (25.9%), antibiotics were used within 3 weeks before surgery. Ventilation tube insertion was performed in a total of 710 ears (626 in both ears in 313 patients, 55 in the left ear only, and 29 in the right ear only). Culture of middle ear effusion was done in at least one ear in 221 patients (55.7%), and in a total of 346 ears. Only 46 ears (13.3%) showed positive results in middle ear effusion culture. Haemophilus influenzae (17.3%, followed by coagulase-negative Staphylococcus and Staphylococcus auricularis) was the most common bacteria detected. CONCLUSION: H. influenzae was the most commonly found bacteria in middle ear effusion. Relatively low rates of culture positivity were noted in middle ear effusion of patients with OME in Korea.

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.

A cadaver study of mastoidectomy using an image-guided human-robot collaborative control system.

Objective: Surgical precision would be better achieved with the development of an anatomical monitoring and controlling robot system than by traditional surgery techniques alone. We evaluated the feasibility of robot-assisted mastoidectomy in terms of duration, precision, and safety. Study Design: Human cadaveric study. Materials and Methods: We developed a multi-degree-of-freedom robot system for a surgical drill with a balancing arm. The drill system is manipulated by the surgeon, the motion of the drill burr is monitored by the image-guided system, and the brake is controlled by the robotic system. The system also includes an alarm as well as the brake to help avoid unexpected damage to vital structures. Experimental mastoidectomy was performed in 11 temporal bones of six cadavers. Parameters including duration and safety were assessed, as well as intraoperative damage, which was judged via pre- and post-operative computed tomography. Results: The duration of mastoidectomy in our study was comparable with that required for chronic otitis media patients. Although minor damage, such as dura exposure without tearing, was noted, no critical damage to the facial nerve or other important structures was observed. When the brake system was set to 1 mm from the facial nerve, the postoperative average bone thicknesses of the facial nerve was 1.39, 1.41, 1.22, 1.41, and 1.55 mm in the lateral, posterior pyramidal and anterior, lateral, and posterior mastoid portions, respectively. Conclusion: Mastoidectomy can be successfully performed using our robot-assisted system while maintaining a pre-set limit of 1 mm in most cases. This system may thus be useful for more inexperienced surgeons. Level of Evidence: NA.

Prevalence of hearing loss and associated factors in subjects with normal otoscopy: a national cross-sectional study.

OBJECTIVE: To report the prevalence of hearing loss (HL) and associated factors in a nationwide study. DESIGN: Cross-sectional study. STUDY SAMPLE: We investigated the prevalence of HL in 10,845 participants ≥12 years of age and analysed the associated factors with HL from 7434 participants ≥40 years of age. RESULTS: The prevalence of worse ear HL was 21.9% (1.2% in youngest and 81.9% in oldest) and that of better ear was 12.5% (none in youngest and 65.3% in oldest). Based on the worse ear HL, the prevalence of HL was more common in men, and related with low education and income. In univariable analysis, hypertension, smoking, diabetes, depressive mood, stroke or cardiac disease, anaemia, hypercholesterolaemia and underweight showed positive associations with HL, and alcohol consumption and regular walking showed negative associations with HL. There were five associated factors in multivariable analysis, including smoking (OR =1.36 for smokers with <20 pack years; OR =1.55 for smokers with ≥20 pack years), noise exposure at workplace (OR = 1.28), stroke (OR = 1.72), anaemia (OR = 1.36) and depressive mood (OR = 1.29). CONCLUSION: Prevention of smoking and reduction of noise, as well as awareness of the association with stroke, anaemia and depression would help to reduce the burden of HL.

In vivo assessment of hair cell damage and developmental toxicity caused by gestational caffeine exposure using zebrafish (Danio rerio) models.

The aim of the present study was to evaluate hair cell damage and associated developmental toxicity caused by gestational caffeine exposure. We exposed embryos to various caffeine concentrations (25µM, 125µM, 250µM, and 500µM) and evaluated developmental toxicity of the embryos at 72 and 120h and hair cell damage at 120h after fertilization. The average number of total hair cells within four neuromasts exposed to various concentrations of caffeine was compared with that of the control group. To seek the underlying mechanisms, TUNEL and DASPEI assay were carried out to evaluate hair cell apoptosis and mitochondrial damage, respectively. Morphologic abnormality, mortality, hatching rate, and heart rate were also evaluated. Caffeine induced significant hair cell damage compared with control group (p<0.01, control; 35.64±10.48 cells, 500µM caffeine; 23.32±12.14 cells, n=25-30). Significant increase in the hair cell apoptosis was confirmed in a dose-dependent manner (p<0.01, TUNEL assay) and the mitochondrial damage in high caffeine concentrations (250, 500µM) (p<0.01, DASPEI assay).Morphologic abnormalities were significantly increased in high caffeine concentrations (250 or 500µM) for body shape, notochord, and heart at both 3-, and 5-dpf. The control group exhibited 3.3% mortality which increased up to 11.6% at 500µM caffeine. Rapid hatching was present at 48h (control; 46.6%, 500µM caffeine; 100%). In conclusion, gestational caffeine exposure caused significant hair cell damage and developmental toxicities in zebrafish at early developmental stages.