Pcolce2 overexpression promotes supporting cell reprogramming in the neonatal mouse cochlea.

Hair cell (HC) damage is a leading cause of sensorineural hearing loss, and in mammals supporting cells (SCs) are unable to divide and regenerate HCs after birth spontaneously. Procollagen C-endopeptidase enhancer 2 (Pcolce2), which encodes a glycoprotein that acts as a functional procollagen C protease enhancer, was screened as a candidate regulator of SC plasticity in our previous study. In the current study, we used adeno-associated virus (AAV)-ie (a newly developed adeno-associated virus that targets SCs) to overexpress Pcolce2 in SCs. AAV-Pcolce2 facilitated SC re-entry into the cell cycle both in cultured cochlear organoids and in the postnatal cochlea. In the neomycin-damaged model, regenerated HCs were detected after overexpression of Pcolce2, and these were derived from SCs that had re-entered the cell cycle. These findings reveal that Pcolce2 may serve as a therapeutic target for the regeneration of HCs to treat hearing loss.

Association Between Hearing Loss, Asymmetric Hearing, and Postural Instability.

OBJECTIVES: Recent studies have suggested that older adults with hearing loss (HL) are at a greater risk of postural instability than those with normal hearing. However, little is known regarding this association in middle-aged individuals. The relationships between HL laterality, asymmetric hearing, and posture control are similarly unclear. The purpose of this study was to investigate the effects of hearing status on postural control and to explore the dose-response relationship between the hearing threshold and postural instability risk in middle-aged adults. DESIGN: This cross-sectional study included 1308 participants aged 40 to 69 years with complete audiometric and standing balance function data from the 2001-2004 National Health and Nutrition Examination Survey. Speech-frequency HL was defined as a pure-tone average at 0.5, 1, 2, and 4 kHz of >25 dB in the better-hearing ear; high-frequency HL was defined as a pure-tone average at 3, 4, and 6 kHz of >25 dB. Asymmetric hearing was defined as a difference in the pure-tone average >15 dB between ears. Postural instability was defined as participants ending the modified Romberg test in condition 4. RESULTS: After adjustment for sociodemographic variables, lifestyle, and comorbidities, speech-frequency HL, except for unilateral HL, was associated with increased postural instability (mild HL: odds ratio [OR], 2.33; 95% confidence interval [CI], 1.25-4.35; moderate-to-severe HL: OR, 3.59; 95% CI, 1.61-8.03). Compared with individuals with normal bilateral hearing, participants with bilateral HL also showed a higher risk of postural instability (OR, 2.88; 95% CI, 1.61-5.14). The OR for postural instability among participants with asymmetric hearing compared with those with symmetric hearing was 2.75 (95% CI, 1.37-5.52). Furthermore, each 10 dB increase in the speech-frequency hearing threshold was associated with a 44% higher risk of postural instability. CONCLUSIONS: Hearing loss is associated with poorer postural control. Individuals with asymmetric hearing have a higher postural instability risk compared with those with symmetric hearing. Further studies are needed to confirm these findings and the causality. Moreover, future studies are warranted to assess whether hearing aids are beneficial for the restoration of impaired balance functions.

Global, regional, and national prevalence of hearing loss from 1990 to 2019: A trend and health inequality analyses based on the Global Burden of Disease Study 2019.

As a severe public health issue, hearing loss has caused an increasingly disease burden, especially in the elderly population. Hearing loss may inevitably induce asymmetric hearing, which makes it difficult for elderly individuals to locate sound sources, therefore resulting in increased postural instability and falling risk. To emphasize the public health emergence of hearing loss, we investigated the temporal trend of prevalence of hearing loss over the last 30 years and further predicted its changes in the next 20 years, decomposed the trend according to demographic factors and epidemiological changes, and quantified the cross-country healthy inequalities, using the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2019. In 2019, there were more than 140 million cases of hearing loss worldwide, a 93.89% increase from 70 million cases in 1990. The age-standardized rate (ASR) also increased with an estimated annual percentage change of 0.08% per year. Population growth and aging are the major drivers contributing to the changes, accounting for 60.83% and 35.35%. Of note, the contribution of aging varies showing a gradual increasing trend with sociodemographic index (SDI) elevating. Also notable, there were significant health inequalities across 204 countries and territories, with slope index of inequality rising over time. Projection of the global burden of hearing loss from 2020 to 2040 indicated progressive increases in both case number and ASR. These reflect the heavy disease burden of hearing loss that needed more targeted and efficient strategies in its prevention and management.

Comorbidities and laboratory changes of sudden sensorineural hearing loss: a review.

Sudden sensorineural hearing loss (SSNHL) is defined as an abrupt hearing loss of more than 30 dB in three contiguous frequencies within 72 h. It is an emergency disease requiring immediate diagnosis and treatment. The incidence of SSNHL in Western countries' population is estimated between 5 and 20 per 1,00,000 inhabitants. The etiology of SSNHL remains unknown. Due to the uncertainty of the cause of SSNHL, at present, no specific treatment targets the cause of SSNHL, resulting in poor efficacy. Previous studies have reported that some comorbidities are risk factors for SSNHL, and some laboratory results may provide some clues for the etiology of SSNHL. Atherosclerosis, microthrombosis, inflammation, and the immune system may be the main etiological factors for SSNHL. This study confirms that SSNHL is a multifactorial disease. Some comorbidities, such as virus infections, are suggested to be the causes of SSNHL. In summary, by analyzing the etiology of SSNHL, more targeting treatments should be used to achieve a better effect.

State of the art: non-invasive electrical stimulation for the treatment of chronic tinnitus.

Subjective tinnitus is the perception of sound in the absence of external stimulation. Neuromodulation is a novel method with promising properties for application in tinnitus management. This study sought to review the types of non-invasive electrical stimulation in tinnitus to provide the foothold for further research. PubMed, EMBASE, and Cochrane databases were searched for studies on the modulation of tinnitus by non-invasive electrical stimulation. Among the four forms of non-invasive electrical modulation, transcranial direct current stimulation, transcranial random noise stimulation, and transauricular vagus nerve stimulation yielded promising results, whereas the effect of transcranial alternating current stimulation in the treatment of tinnitus has not been confirmed. Non-invasive electrical stimulation can effectively suppress tinnitus perception in some patients. However, the heterogeneity in parameter settings leads to scattered and poorly replicated findings. Further high-quality studies are needed to identify optimal parameters to develop more acceptable protocols for tinnitus modulation.

Etiological analysis of patients with sudden sensorineural hearing loss: a prospective case-control study.

Sudden sensorineural hearing loss (SSNHL) is a multifactorial emergency disease. Until now, the etiology of SSNHL is still unknown. Previous studies regarding the etiology of SSNHL are clinical studies depending on clinical data collection and analysis. Due to the insufficient sample size or various selective bias in clinical studies, the results of these studies may be inaccurate. This prospective case-control study aimed at exploring the possible etiology and risk factors of SSNHL. We enrolled 255 SSNHL patients and 255 sex-, age- and residence-matched non-SSNHL subjects in the control group. Our study shows that there was no significant difference in the prevalence of comorbidities including hypertension and diabetes, as well as the incidence of smoking and drinking habits between the case and control groups (P > 0.05). In addition, the peripheral blood white blood cell count, neutrophil count, platelet-to-lymphocyte ratio (PLR) and fibrinogen level of the case group were significantly higher than those in the control group (P < 0.05). These findings suggest smoking, drinking, hypertension and diabetes may not be related to the onset of SSNHL. However, hypercoagulable state and inner ear vascular microthrombosis related to an elevated fibrinogen level might be the risk factors of the disease. In addition, inflammation play an important role of SSNHL onset.Trial Registration: Chinese Clinical Trial Registry. Registration number: ChiCTR2100048991.

Associations Between Physical Activity, Tinnitus, and Tinnitus Severity.

OBJECTIVES: To examine the associations between physical activity and tinnitus development and physical activity and tinnitus severity in a large representative sample of US adults. DESIGN: Data were obtained from 3826 eligible participants (20 to 69 years) in the National Health and Nutrition Examination Survey between 2015 and 2016. Physical activity was assessed using a Global Physical Activity Questionnaire. We used multivariable logistic regression to test the associations of physical activity (without physical activity, with physical activity) and amount of physical activity (min/week, in quartiles) with tinnitus symptoms. Adults with depressive symptoms were excluded, and the models were controlled for relevant sociodemographic, lifestyle, and health-related covariates. A restricted cubic spline was used to explore the dose-response relationship between the amount of physical activity and tinnitus. RESULTS: Overall, 12.8% of the population who engaged in physical activity reported tinnitus, compared with 18.5% of the population who did not ( p = 0.005). Subgroup analysis based on the amount of physical activity showed that participants who performed physical activity (150 to 300, 310 to 540, and 550 to 4800 min/week) had lower risks of tinnitus than those with no physical activity (odds ratio = 0.72, 0.56, and 0.62, respectively), after adjusting for covariates. However, no correlation was observed between physical activity and tinnitus severity in the present study. The dose-response analysis showed a nonlinear relationship (P for nonlinearity = 0.04) between the amount of physical activity and the risk of tinnitus. CONCLUSIONS: Physical activity may be associated with a reduced risk of tinnitus. Further research using a longitudinal design is required to confirm these findings and clarify the direction of causation.

Characteristics of tinnitus and factors influencing its severity.

Background and Objectives: There is a wealth of information regarding the treatment methods for tinnitus; however, the treatment available is unsatisfactory because of the following reasons: first, tinnitus has various etiologies and second, it has distinct heterogeneity among different individuals. Numerous studies have focused on understanding the causes of tinnitus severity, but the conclusions have been inconsistent. The purpose of the present study was to define factors that differentially influence subjectively perceived tinnitus severity. Methods: Clinical data of patients with chronic tinnitus who visited our outpatient clinic from April 2020 to April 2021 were collected. Tinnitus Handicap Inventory (THI) and Tinnitus Evaluation Questionnaire (TEQ) were used to evaluate tinnitus severity among patients, and the independent factors influencing the severity of tinnitus were investigated by performing univariate and multivariate stepwise regression analyses. Results: Eleven variables were associated with THI and TEQ scores, of which nine were identical. Multiple regression analyses results revealed that five variables had a significantly unique predictive effect on tinnitus severity based on THI and the TEQ scores. Three factors including Self-Rating Scale of Sleep (SRSS), change in loudness, and Self-Rating Anxiety Scale (SAS) were identical. Conclusion: Sleep status, anxiety level, and change in loudness in patients with chronic tinnitus were significantly correlated with severity of tinnitus. Follow-up studies should investigate the causal relationship between these factors and tinnitus severity.

Identification of a novel CNV at the EYA4 gene in a Chinese family with autosomal dominant nonsyndromic hearing loss.

BACKGROUND: Hereditary hearing loss is a heterogeneous class of disorders that exhibits various patterns of inheritance and involves many genes. Variants in the EYA4 gene in DFNA10 are known to lead to postlingual, progressive, autosomal dominant nonsyndromic hereditary hearing loss. PATIENTS AND METHODS: We collected a four-generation Chinese family with autosomal-dominant nonsyndromic hearing loss (ADNSHL). We applied targeted next-generation sequencing (TNGS) in three patients of this pedigree and whole-genome sequencing (WGS) in the proband. The intrafamilial cosegregation of the variant and the deafness phenotype were confirmed by PCR, gap-PCR and Sanger sequencing. RESULTS: A novel CNV deletion at 6q23 in exons 8-11 of the EYA4 gene with a 10 bp insertion was identified by TNGS and WGS and segregated with the ADNSHL phenotypes. CONCLUSIONS: Our results expanded the variant spectrum and genotype‒phenotype correlation of the EYA4 gene and autosomal dominant nonsyndromic hereditary hearing loss in Chinese Han individuals. WGS is an accurate and effective method for verifying the genomic features of CNVs.

Study on the effects of desloratadine citrate disodium on the postoperative complications and inflammatory response in patients with chronic sinusitis undergoing endoscopic sinus surgery.

OBJECTIVE: To explore the effects of desloratadine citrate disodium on the postoperative complications and inflammatory markers in patients with chronic sinusitis undergoing endoscopic sinus surgery. METHODS: From June 2019 to December 2020, the patients with chronic sinusitis who received treatment in our hospital were selected and divided into the control group (CG) and experimental group (EG). In both groups, patients were given endoscopic sinus surgery. On this basis, patients were treated with desloratadine citrate disodium in the EG. The total effective rate of the operation and the incidence of complications were compared between the two groups, and the VAS scores of clinical symptoms were compared between the two groups after treatment. Meanwhile, the changes of serum TIgE, ECP and inflammatory factors were compared between the two groups, and the nasal mucociliary clearing function was compared between the two groups before and after treatment. RESULTS: After treatment, the total effective rate was 94.9% in the EG, which was significantly higher than that in the CG (82.2%). The levels of serum interleukin-6 (IL-6), interleukin-8 (IL-8), high-sensitivity C-reactive protein (hs-CRP) and tumor necrosis factor-α (TNF-α) in the EG were significantly lower than those in the CG, and the levels of serum TIgE and ECP were also significantly lower than those in the CG. After treatment for 3 months, the mucociliary clearance rate and mucociliary clearance rate in the EG were significantly higher than those in the CG, while the saccharin clearance time was significantly shorter than that in the CG. The incidence of complications in the EG was significantly lower than that in the CG (all P < 0.05). CONCLUSION: Desloratadine citrate disodium combined with endoscopic sinus surgery can improve the clinical efficacy, reduce the level of inflammatory factors and effectively reduce the incidence of complications in patients with chronic sinusitis.

Efficacy of Various Corticosteroid Treatment Modalities for the Initial Treatment of Idiopathic Sudden Hearing Loss: A Prospective Randomized Controlled Trial.

OBJECTIVE: To evaluate the efficacy of systemic and intratympanic steroid treatment in patients with idiopathic sudden sensorineural hearing loss (ISSNHL). METHODS: Ninety patients who met the inclusion criteria were randomly divided into 3 groups (n = 30 per group). Group I patients were given oral methylprednisolone (MEPD) tablets, group II received intravenous MEPD injection, and group III received intratympanic MEPD injection. Pure-tone average (PTA) hearing threshold was recorded before and after treatment as well as 1 month later. The general efficacy rate was the ratio of patients whose hearing improved by >10 dB in each group. RESULTS: Thirty-two of the 60 patients (53.3%) in groups I and II together showed a hearing improvement of >10 dB hearing level (HL) in the pure-tone audiogram, compared to 21 patients (70%) in group III, respectively. The mean improvements were 16.1, 14.3, and 21.6 dB HL measured in Groups I, II, and III, respectively. Both the general efficacy rate and hearing improvement were significantly greater in group III than in groups I and II. CONCLUSIONS: Our study showed that intratympanic injection rendered better treatment efficacy than systemic administration.

Comparison of Therapeutic Results with/without Additional Hyperbaric Oxygen Therapy in Idiopathic Sudden Sensorineural Hearing Loss: A Randomized Prospective Study.

OBJECTIVE: To assess the efficacy of the combination of hyperbaric oxygen (HBO) and pharmacological treatment in patients with idiopathic sudden sensorineural hearing loss (ISSNHL) and define patients amenable for HBO therapy. METHODS: Prospective, randomized, trial involving 136 cases with unilateral ISSNHL that were randomly divided into 2 groups: the pharmacological treatment (P) group and HBO + pharmacological treatment (HBO+P) group, which received additional HBO for 14 days besides the pharmacological treatments. Pure tone audiometry gain larger than 15 dBHL was defined as success, and the success rate of each group was calculated. RESULTS: The overall success rate of the HBO+P group and the P group is 60.6% (40/66) and 42.9% (30/70), respectively (p < 0.05). Furthermore, patients with mild-moderate baseline hearing loss, aged ≤50 years, receiving treatment in ≤14 days, or without accompanied dizziness/vertigo in the HBO+P group had higher success rate than the P group (p < 0.05). CONCLUSIONS: HBO combined with pharmacological treatments leads to better hearing recovery than pharmacological treatments alone.

Cochlear implantation in prelingually deaf children with white matter lesions.

OBJECTIVE: White matter lesions (WMLs) are the most common central nervous system changes observed during cochlear implant evaluation. However, its clinical significance in cochlear implantation (CI) remains unclear. The purpose of this study is to explore the effects of WMLs on hearing and speech rehabilitation of prelingually deaf children after CI. METHODS: The data of forty-five children with WMLs who received CI from 2011 to 2014 were retrospectively reviewed. All patients underwent magnetic resonance imaging examination preoperatively. The categories of auditory performance (CAP) and speech intelligibility rating (SIR) scales were used to evaluate changes in the auditory and speech abilities of the patients, and the Fazekas scale was adopted to assess the extent of WMLs. The degree of WMLs was divided into four grades (none, mild, moderate, severe). We assessed hearing and speech abilities at the following time points: 6, 12, 24, 36, 48 and 60-months post-operation. RESULTS: No significant differences in CAP scores were observed between WMLs groups and the control group at 12 months post-CI (p = 0.099), but marked between-group differences were found at 6, 24, 48- and 60-months post-CI. (p < 0.05). Similarly, no significant differences in the SIR scores were observed at 6 months post-CI (p = 0.087), but marked between-group differences were found at 12, 24, 48- and 60- months post-CI. (p < 0.05). Analysis of stratified group results revealed improvements in hearing and speech development for all the subgroups, including the severe WMLs subgroup following CI. However, hearing and speech ability of the severe WMLs subgroup was much slower than that of other groups. CONCLUSIONS: The auditory and speech abilities of prelingually deaf children with WMLs and those without WMLs can improve after CI. Therefore, WMLs should not be considered a contraindication for CI. However, the decision to perform CI in such patients needs a comprehensive evaluation because the post-surgery effects on children with severe WMLs are not ideal.

Treatment of pulsatile tinnitus caused by anomalies of the sigmoid sinus wall via combined internal and external sigmoid sinus wall reconstruction with 3D temporal bone CT guidance.

PURPOSE: The present analysis aims to describe a surgical approach wherein pulsatile tinnitus (PT) arising due to sigmoid sinus wall anomalies (SSWA) can be treated via combination internal and external sigmoid sinus wall reconstruction. We further evaluated the utility of temporal bone 3D-CT imaging during both the pre- and post-operative assessments of all treated patients. METHODS: Data pertaining to 11 patients that had undergone sigmoid sinus wall reconstruction were retrospectively analyzed. All of these patients underwent preoperative 3D-CT imaging assessment. These patients were additionally subjected to sigmoid sinus wall reconstruction via a combined internal and external layer approach. Postoperatively, all patients underwent a radiological assessment of auricular cartilage and autologous bone powered displacement. Patients were additionally asked about any subjective changes in PT or associated symptoms at follow-up time points. RESULTS: SSWA in the 3D-CT imaging from these patients were all distinct. In 10/11 patients, PT fully resolved following reconstruction of the sinus wall. The remaining patients exhibited significant improvements in symptoms postoperatively, with PT fully resolving within a 1-month follow-up period. No patients suffered any major complications. CONCLUSIONS: Temporal bone 3D-CT imaging allow for effective visualization of SSWA, enabling effective pre- and post-operative assessments of treated patients. A combined internal and external layer approach to sigmoid sinus wall reconstruction can be implemented safely and effectively, yielding high rates of satisfactory outcomes and achieving rigid reconstruction of this surface. As such, there is clear value in the consideration of this approach when treating individuals suffering from PT as a result of SSWA.

Myringotomy and tube insertion combined with balloon eustachian tuboplasty for the treatment of otitis media with effusion in children.

OBJECTIVE: This study aimed to clarify the role and safety of balloon eustachian tuboplasty (BET) in the treatment of otitis media with effusion (OME) in children. METHODS: This retrospective study was performed between January 2017 and February 2018. The study covered 25 OME patients treated with BET combined with myringotomy and tube insertion (MTI), designated as the BET group, and 24 OME patients treated with MTI during the same period considered as the controls. In addition, all patients received adenoidectomy if found with adenoid hypertrophy. The air-bone conduction gap (ABG) and curative effect were compared between the two groups. Tubomanometry (TMM) results were recorded preoperatively to confirm existence of eustachian tube dysfunction (ETD). Otologic history and examination results of all patients were carefully recorded before the operation, at 6, 12 and 18 months postoperatively. RESULTS: Six months after surgery, ABG difference between the two groups was less than 1 dB HL. At 12 months after the operation, ABG in the BET group was smaller than that in the control group. There was a marked ABG deterioration (from 10.1 to 15.9 dB HL) in the control group compared to that in BET. Statistically significant differences in ABG difference between the two groups were observed 18 months after surgery with cured and total effective rates of BET at 76.1 and 93.5%, respectively. In the control group, these rates were 60.9 and 89.1% respectively. No serious complications and tympanic perforations were found in all subjects. CONCLUSION: MTI combined with BET is effective and safe in the treatment of children with OME. Compared to simple MTI, application of BET can effectively extend improvement period and increase cured rate, especially after removal of the ventilation tube. Directly benefit from the ventilation tube, the curative effect was close during the period of tube retention. Considering the sample size and follow-up time of this study, related studies targeting large cohorts are needed in the future to validate the benefits of BET in children with OME.

Options of medical treatment and laryngeal function preservation in elderly patients with medial wall pyriform sinus cancer.

OBJECTIVE: To retrospectively investigate the clinical efficacy and larynx preservation of two different treatments: radiotherapy followed by surgery (R+S) and surgery followed by radiotherapy (S+R), in elderly patients with medial wall pyriform sinus cancer. MATERIALS AND METHODS: Medical records from 48 patients over 70 years old with medial wall pyriform sinus cancer who underwent different treatments between 2001 and 2010 were analyzed. Twenty-one patients underwent radiotherapy first followed by surgery (R+S), and the other 27 patients underwent surgery first followed by radiotherapy (S+R). A Kaplan-Meier method was used to calculate the survival rate. RESULTS: Overall 3-year and 5-year survival rates were 60.4% and 35.4%, respectively. The 5-year survival rates in R+S group and S+R group were 38.1% and 33.3%, respectively, without a statistically significant difference between the two groups (P>0.05). Also, comparisons of the decannulation rates (64.3% for R+S group vs 50.0% for S+R group) and postoperative complication rates (42.9% for R+S group vs 37.0% for S+R group) between the two groups of patients did not show obvious differences. However, the laryngeal preservation rates in R+S group and S+R group were 66.7% and 37.0%, respectively, with significantly statistical difference between the two groups (P<0.05). CONCLUSION: Based on the data analysis of 48 patients, the survival rates of elderly patients who underwent R+S or S+R were comparable, but R+S treatment could improve the laryngeal preservation rate of patients. Further study on large-scale sample pool should be performed to confirm this conclusion.

Mechanisms of Hearing Loss in a Guinea Pig Model of Superior Semicircular Canal Dehiscence.

Defective acoustic transmission in the cochlea is closely related with various auditory and vestibular symptoms. Among them, semicircular canal dehiscence (SCD) with a defective semicircular bone is typical. Currently, the pathogenesis of SCD is usually explained by the third window hypothesis; however, this hypothesis fails to explain the variability in the symptoms and signs experienced by superior SCD (SSCD) patients. We evaluated the mechanism of hearing loss in a guinea pig model of bony dehiscence with various sizes and locations along the superior semicircular canal. Auditory brainstem responses (ABRs) and laser Doppler velocimetry were used to measure hearing loss and vibration changes before and after fenestration, as well as after restorative patching. ABR thresholds at low frequencies (e.g., 1000 Hz) increased after fenestration and decreased back to the normal range after we repaired the defect. Energy leakage from the surgically introduced third window was detected in the range of 300-1500 Hz, accompanied by increased vibration at the umbo, stapes head, and the dehiscence site, while decreased vibration was observed at the round window membrane in the same frequency range. After the patching procedure, the deviant vibrations were recovered. The degree of postfenestration energy leakage was proportional to the size of fenestration and the proximity of the fenestration site to the oval window. These results suggest that the bony fenestration of the superior semicircular canal mimics the hearing loss pattern of patients with SSCD. The decrease in perilymph wave impedance likely accounts for the auditory changes.

Analysis of Pressure Distribution During Direct Microlaryngoscopy.

OBJECTIVE: This study aimed to investigate the pressure distribution during direct microlaryngoscopy and its relation with the positioning of the patient. STUDY DESIGN: This is a prospective study in cadavers. MATERIALS AND METHODS: The pressure distribution during direct microlaryngoscopy was investigated in five adult fresh cadavers by using matrix-based piezoresistive thin-film sensors. The pressure among three head and neck positions (extension-extension, neutral, and flexion-extension) was studied. RESULTS: The real-time pressure and its distribution were recorded as 3-D contours. The map commonly showed two peak pressure points, with one focused on the middle of the laryngoscope (peak pressure 1) and the other one focused on the distal part of the laryngoscope (peak pressure 2). The mean average pressure in this study was 38 ± 13 kPa, and the flexion-extension position had the lowest average pressure and peak pressure. However, the average pressure and peak pressure 1 showed no significant difference among the three positions (P > 0.05); peak pressure 2 in the flexion-extension position was significantly lower than that in the extension-extension position (P = 0.024) and the neutral position (P = 0.020). CONCLUSIONS: The results of this study indicate that the flexion-extension position induced lower pressure exerted on the laryngoscope and is an optimal position for direct microlaryngoscopy. Hyoid bone may play an important role in the pressure exerted.

Effect of Endolymphatic Hydrops on Sound Transmission in Live Guinea Pigs Measured with a Laser Doppler Vibrometer.

Objective. This study aimed at describing the mechanism of hearing loss in low frequency and the different dynamic behavior of the umbo, the stapes head, and the round window membrane (RWM) between normal guinea pigs and those with endolymphatic hydrops (EH), using a laser Doppler vibrometer (LDV). Methods. Cochlear sections were stained with hematoxylin and eosin (HE) to evaluate the hydropic ratio (HR). Auditory brainstem responses (ABR) and whole-mount immunostaining were measured. Displacement of the umbo, stapes head, and RWM in response to ear-canal sound was evaluated using a LDV. Results. Mean HR values in EH model of all the turns are larger than the control group. The ABR threshold of the EH group was significantly higher than that of the control. Strong positive correlation was found between HR at apical turn and ABR threshold elevation at 1000 Hz and at subapical turn and ABR threshold elevation at 2000 Hz. FITC-phalloidin immunostaining of the cochlear basilar membrane in the apical, subapical, and suprabasal turns showed missing and derangement stereocilia of third-row outer hair cells. The umbo, stapes head, and RWM displacement in ears with EH was generally lower than that of normal ears. The EH-induced differences in stapes head and RWM motion were significant at 0.5 kHz. Conclusion. The LDV results suggested that the higher inner ear impedance in EH affected the dynamic behavior of the two opening windows of the cochlea and then reduced the vibration of the ossicular chain by increasing the afterload, resulting in acoustic dysfunction. The vibration reduction mainly occurred at low frequencies, which has related with the morphology changes of the apical and subapical turns in EH model.

A comparison of effects of systemic and intratympanic steroid therapies for sudden sensorineural hearing loss: A meta-analysis.

OBJECTIVE: To evaluate the efficacy and safety of intratympanic and systemic steroid therapies in the initial treatment of Sudden Sensorineural Hearing Loss (SSNHL) patients. METHODS: A comprehensive search of PubMed, Wanfang database and CNKI (China National Knowledge Infrastructure) was performed covering the period from January 1990 to July 2014. A meta-analysis was conducted after filtering by the criteria of Cochrane Collaboration. Three hundred fifty six subjects in nine studies allocated to the group of intratympanic steroid therapies and 343 controls receiving systemic steroid therapies met the criteria for meta-analysis. The data were extracted and analyzed using the RevMan 5.3 meta-analysis software. RESULTS: The total effectiveness rate in SSNHL patients receiving intratympanic steroid therapies did not differ statistically from patients receiving systemic therapies (RR = 1.08, 95％CI = 0.99-1.99, P = 0.10), although the rate of full hearing recovery in this group differed significantly from patients receiving systemic therapies (RR = 1.29, 95％CI = 1.00-1.66, P = 0.05). CONCLUSION: Local steroid therapy appears to generate higher rate of complete hearing recovery than systemic steroid treatment as an initial treatment for SSNHL, which may be especially useful for patients in whom systemic steroids are contraindicated.