Prognosis of sudden deafness with special reference to risk factors of microvascular pathology

Efficacy of high dose systemic versus combined (systemic and intratympanic) corticosteroid therapy in idiopathic sudden sensorineural hearing loss: A prospective randomized trial and risk factor analysis

The pathophysiology and the proper treatment of idiopathic sudden sensorineural hearing loss (ISSNHL) are an ongoing subject of debate. Locally or systemic administered corticosteroids are the most accepted drugs of treatment in reference to ISSNHL (idiopathic sudden sensorineural hearing loss), however, no strong evidence nor guidelines regarding their effectiveness yet exists. In our prospective, randomized, controlled trial 78 participants were enrolled. Patients were randomly assigned based on the day of admission to two groups according to treatment: group SS (n = 43) received intravenous systemic methylprednisolone alone, and group CT (n = 35) received intratympanic dexamethasone + systemic methylprednisolone. The primary outcome was to compare the hearing outcomes between the treatment groups based on different, widely accepted categories (Siegel, Kanzaki, modified Siegel and PTA4 gain). In consideration of the secondary outcome, we examined the effect of the various risk factors on the hearing improvement. No differences were detected regarding hearing improvement between the two groups, based on any criteria [Siegel's criteria (p = 0.604); Kanzaki's criteria (p = 0.720); modified Siegel's criteria (p = 0.524) and PTA 4 gain (p = 0.569)]. However, several clinical factors such as vertigo (p = 0.039), or cardiovascular comorbidity (p = 0.02) and the severity of initial hearing loss (p = 0.033) were found to bear a significant impact upon the hearing outcome. To the best of our knowledge, this is the first randomized controlled trial comparing high dose systemic and combination corticosteroid therapy in ISSNHL patients. Our findings suggest coexisting cardiovascular comorbidity, vertigo and severity of the initial hearing loss may bear a significantly higher impact upon hearing improvement, than the additional intratympanic steroid administration. The presented trial was registered in the European Union Drug Regulating Authorities Clinical Trials Database (name: Combinated systemic and intratympanic steroid therapy in idiopathic sudden sensorineural hearing loss, No.: 2017-000658-20) and with the ethical approval of The National Institute of Pharmacy and Nutrition (OGYÉI) (protocol No.: 7621, on 2017.02.16.).

Positive horizontal-canal head impulse test is not a benign sign for acute vestibular syndrome with hearing loss

Background

Diagnosis of acute vestibular syndrome (AVS) with hearing loss is challenging because the leading vascular cause—AICA territory stroke—can appear benign on head impulse testing. We evaluated the diagnostic utility of various bedside oculomotor tests to discriminate imaging-positive and imaging-negative cases of AVS plus hearing loss.

Method

We reviewed 13 consecutive inpatients with AVS and acute unilateral hearing loss. We compared neurologic findings, bedside and video head impulse testing (bHIT, vHIT), and other vestibular signs (including nystagmus, skew deviation, and positional testing) between MRI+ and MRI– cases.

Results

Five of thirteen patients had a lateral pontine lesion (i.e., MRI+); eight did not (i.e., MRI–). Horizontal-canal head impulse test showed ipsilateral vestibular loss in all five MRI+ patients but only in three MRI– patients. The ipsilesional VOR gains of horizontal-canal vHIT were significantly lower in the MRI+ than the MRI– group (0.56 ± 0.11 vs. 0.87 ± 0.24, p = 0.03). All 5 MRI+ patients had horizontal spontaneous nystagmus beating away from the lesion (5/5). One patient (1/5) had direction-changing nystagmus with gaze. Two had skew deviation (2/5). Among the 8 MRI– patients, one (1/8) presented as unilateral vestibulopathy, four (4/8) had positional nystagmus and three (3/8) had isolated posterior canal hypofunction.

Conclusion

The horizontal-canal head impulse test poorly discriminates central and peripheral lesions when hearing loss accompanies AVS. Paradoxically, a lateral pontine lesion usually mimics unilateral peripheral vestibulopathy. By contrast, patients with peripheral lesions usually present with positional nystagmus or isolated posterior canal impairment, risking misdiagnosis as central vestibulopathy.

Association between Serum Lipid Levels and Sensorineural Hearing Loss in Korean Adult Population

Background

Hearing loss (HL) has been suggested to be associated with impaired microcirculation of the inner ear. This cross-sectional study aimed to evaluate an association between HL and serum lipid levels.

Methods

The study comprised 10,356 Korean adults who participated in the fifth Korea National Health and Nutrition Examination Survey (2010–2012). We defined HL as the average hearing thresholds exceeding 25 dB at predetermined frequency levels by pure tone audiometry. Serum lipid levels were measured using an enzymatic assay. The associations between lipid levels and HL were evaluated using a multiple logistic regression model after adjusting for covariates including age, sex, hypertension, diabetes, smoking status, alcohol, physical activity, educational level, household income, and noise exposure. Stratified analyses were performed to examine the effect of the covariates on the association between lipid levels and HL.

Results

The high-density lipoprotein cholesterol (HDL-C) level was inversely associated with high-frequency (HF)-HL, with an odds ratio (95% confidence interval) of 0.78 (0.64–0.96) for 1-mmol/L increase in the HDL-C level. Neither the triglyceride nor the low-density lipoprotein cholesterol level was associated with HF-HL. For low-frequency HL, association with any of the serum lipid components was absent. A stratified analysis showed that the inverse association between HDL-C levels and HF-HL was evident (P trend <0.05) in some subjects with specific characteristics such as older age (≥65 years), female sex, non-hypertensive state, and non-regular physical activity. However, a significant interaction between HDL-C levels and all of the stratified variables was absent (P for interaction >0.05).

Conclusion

The HDL-C level has a linear inverse association with the risk of HF-HL. Given the known protective role of HDL-C against atherosclerotic changes, this finding seems to support the concept of impaired microcirculation in the inner ear as a mechanism for HF-HL.

Prediction of hearing recovery in unilateral sudden sensorineural hearing loss using artificial intelligence

Despite the significance of predicting the prognosis of idiopathic sudden sensorineural hearing loss (ISSNHL), no predictive models have been established. This study used artificial intelligence to develop prognosis models to predict recovery from ISSNHL. We retrospectively reviewed the medical data of 453 patients with ISSNHL (men, 220; women, 233; mean age, 50.3 years) who underwent treatment at a tertiary hospital between January 2021 and December 2019 and were followed up after 1 month. According to Siegel's criteria, 203 patients recovered in 1 month. Demographic characteristics, clinical and laboratory data, and pure-tone audiometry were analyzed. Logistic regression (baseline), a support vector machine, extreme gradient boosting, a light gradient boosting machine, and multilayer perceptron were used. The outcomes were the area under the receiver operating characteristic curve (AUROC) primarily, area under the precision-recall curve, Brier score, balanced accuracy, and F1 score. The light gradient boosting machine model had the best AUROC and balanced accuracy. Together with multilayer perceptron, it was also significantly superior to logistic regression in terms of AUROC. Using the SHapley Additive exPlanation method, we found that the initial audiogram shape is the most important prognostic factor. Machine/deep learning methods were successfully established to predict the prognosis of ISSNHL.

Clinical Profile of Patients With Unilateral Sudden Sensorineural Hearing Loss: Correlation With Hearing Prognosis

OBJECTIVE

To characterize, with a standard systematic protocol, the clinical and audiometric profile of patients with idiopathic sudden sensorineural hearing loss (ISSNHL) and to correlate the findings with hearing recovery prognosis.

STUDY DESIGN

Retrospective cohort of patients with ISSNHL.

SETTING

Outpatients of a tertiary referral center followed for 20 years.

METHODS

We collected clinical information, including the presence of tinnitus, vertigo, and comorbidities, as well as initial pure tone averages, degree of hearing loss, audiogram curves, and time between hearing loss onset and treatment. These variables were statistically analyzed for their impact on hearing recovery prognosis. All patients were treated with oral corticosteroids, following a standard treatment protocol. Hearing recovery was defined according to the criteria of the American Academy of Otolaryngology-Head and Neck Surgery Foundation, and hearing outcomes were reported via a standardized method (scattergrams).

RESULTS

Our final study group comprised 186 patients. Most patients were between 41 and 60 years of age. Univariate analysis revealed that vertigo; presence of severe or profound initial hearing loss; flat, U-shaped, and descending audiogram curves; and initiating treatment ≥15 days were correlated with worse hearing recovery. However, the multivariate logistic model revealed that only the presence of severe or profound hearing loss (odds ratio, 6.634; 95% CI, 2.714-16.216; P < .001) and initiating treatment ≥15 days (odds ratio, 0.250; 95% CI, 0.102-0.610; P = .008) were independent risk factors for worse hearing recovery prognosis.

CONCLUSION

This study demonstrated that the presence of severe or profound hearing loss at the first audiogram and initiating treatment after 14 days from ISSNHL onset were independent risk factors associated with a worse hearing recovery prognosis.

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.

Efficacy of the additional effect of hyperbaric oxygen therapy in combination of systemic steroid and prostaglandin E1 for idiopathic sudden sensorineural hearing loss

PURPOSE

The efficacies of hyperbaric oxygen therapy (HBO), systemic steroid, prostaglandin E₁, or the combination of any two modalities have been reported in patients with idiopathic sudden sensorineural hearing loss (ISSNHL). However, little is known about the combined efficacy of HBO, systemic steroid, and prostaglandin E₁ for this disorder. We aimed to investigate the efficacy of HBO combined with systemic steroids and prostaglandin E₁ as triple therapy in patients with ISSNHL.

MATERIALS AND METHODS

We retrospectively evaluated the records of 67 patients with ISSNHL who were treated with systemic steroid and prostaglandin E₁, with (n = 38) or without (n = 29) HBO. The inclusion criteria included a diagnosis of ISSNHL within 14 days of symptom onset, age ≥15 years, treatment according to the protocol, and clinical follow-up of at least 1 month. The patients' hearing levels were evaluated 1 month after hearing loss onset. The primary outcome was hearing improvement on pure tone audiometry. We also evaluated the demographic profiles of patients.

RESULTS

Patients treated with triple therapy showed significantly greater hearing improvement (p < 0.01) than those treated without HBO, despite some differences between the two treatment groups. Multivariate logistic regression analysis revealed a significant positive correlation between pure tone audiometry improvement and hyperbaric oxygen therapy, after adjustment for confounding factors (odds ratio = 7.42; 95% and confidence interval = 2.37-23.3; p = 0.001).

CONCLUSION

HBO with systemic steroid and prostaglandin E₁ administration conferred significant therapeutic benefits for ISSNHL. Therefore, routine use of triple therapy is recommended for patients with ISSNHL.

Effect of Diabetes on the Prognosis of Sudden Sensorineural Hearing Loss: Propensity Score Matching Analysis

Objective

The aim of this study was to investigate the clinical implications of diabetes for the management of idiopathic sudden sensorineural hearing loss (ISSNHL).

Study Design

Retrospective study.

Setting

Tertiary referral center.

Subjects and Methods

ISSNHL patients (N = 403) who received inpatient management between January 2015 and December 2018 were analyzed. All were managed by a uniform treatment protocol of high-dose steroid therapy and salvage intratympanic steroid injections. Treatment results were evaluated according to the American Academy of Otolaryngology—Head and Neck Surgery’s criteria 3 months after the start of treatment. We compared the clinical parameters and treatment outcomes of ISSNHL with and without diabetes. We also evaluated the influence of diabetes on the prognosis of ISSNHL by propensity score matching.

Results

Overall, of the 403 ISSNHL patients, 94 (23.3%) had diabetes, and 11 were newly diagnosed with diabetes. The patients with diabetes were older than those without diabetes ( P < .001), and their initial hearing threshold was significantly higher ( P < .001). The diabetic patients were hospitalized for a longer period, and their hearing recovery rate was lower. However, when age, sex, and initial hearing level were adjusted by propensity score matching, the diabetic patients and matched controls yielded similar treatment results.

Conclusions

ISSNHL with diabetes usually presents with severe hearing loss and requires longer hospitalization. However, diabetes itself may not influence the prognosis of ISSNHL. Proper management must be provided in ISSNHL with diabetes.

Characteristics and prognosis of idiopathic sudden sensorineural hearing loss in aged people: a retrospective study

Background: Few studies focused on the prognosis of sudden sensorineural hearing loss (ISSHL) of aged people. Objectives: The aim of this study is to analyze the characteristics, treatment, and prognostic factors of ISSHL in aged people. Material and methods: A total of 278 patients diagnosed of ISSHL in aged people from 2014 to 2019 were retrospectively analyzed. Univariates were analyzed by univariate and multivariate logistic analysis. Results: Among the 13 univariates, the patients' age was younger in the overall recovery group ORG (p = .018), while onset days was shorter in ORG (p = .000). The percentage of DM and HTN comorbidities were higher in ORG (p = .026 and .038). Meanwhile differences were significant in audiogram configurations (p = .037), the degree of hearing loss (p = .033), and types of lipid treatment (p = .020). Then these seven independent risk factors were included in the multivariate analysis, final results indicated that hypertension (p = .028), lipid control groups (p = .009), age (p = .000), and onset days (p = .001) were related to the treatment outcome of ISSHL. Conclusions: The prognosis of ISSHL in aged patients was closely related to age, the onset days of treatment, and good control of complications such as hypertension and hyperlipidemia, so vascular factors were considered as the main causes of morbidity.

Diabetes in the practice of otolaryngology

Diabetes mellitus is the most common endocrine disease, characterized by chronic hyperglycemia. The hyperglycemic milieu leads to endothelial injury in blood vessels of variant size, which results in microangiopathy and macroangiopathy (atherosclerosis). Consequential ischemia of nerves and hyperglycemia by itself lead to nerve degeneration and generalized neuropathy, affecting most often the sensory peripheral nerves and the autonomic nervous system. Auditory, vestibular and olfactory sensorium may be compromised by DM. People with DM have an increased susceptibility to infection, as a result of neutrophil dysfunction and impaired humoral immunity. Therefore DM predisposes to certain infectious diseases, such as fungal sinusitis or malignant otitis externa, which are rare in general population. Recovery from infections or from injuries may be compromised by coexisting DM. In this review we discuss complications of DM in the head and neck region. Otolaryngologists and general practitioners should be alert to specific conditions related to DM and be minded of the relevant complications and consequences.

Is Sensorineural Hearing Loss Related to Chronic Rhinosinusitis Caused by Outer Hair Cell Injury?

Background

Sensorineural hearing loss is caused by defects in the inner ear. In the present study, associations between chronic rhinosinusitis, outer hair cell injury, and sensorineural hearing loss were investigated.

Material/Methods

A total of 103 patients who met the inclusion criteria were recruited and allocated into a chronic rhinosinusitis group (n=82) and a simple deviated nasal septum group (n=21). Degree and type of hearing loss, including distortion product otoacoustic emissions, were used to assess the status of cochlear outer hair cells.

Results

The rate of hearing loss in the simple deviated nasal septum group was significantly lower than in the chronic rhinosinusitis group (4.76%, 1/21 vs. 24.39%, 20/82, P<0.05), among which 15 chronic rhinosinusitis patients (75%, 15/20) had hearing loss in the high frequency range. Acoustic stapedial reflexes were elicited in all patients of the 2 groups, while positive Metz was found in 3 chronic rhinosinusitis patients (15%, 3/20). The pass rate of distortion product otoacoustic emissions (DPOAEs) for chronic rhinosinusitis patients was significantly lower than in simple deviated nasal septum patients (88.10% vs. 70.73%, P<0.05). Moreover, the signal-to-noise ratio of DPOAE test results at 704 Hz, 3991 Hz, and 5649 Hz in the chronic rhinosinusitis group were significantly lower than in the simple deviated nasal septum group (P<0.05). Logistic regression analysis revealed a correlation between severity of chronic rhinosinusitis and sensorineural hearing loss (OR=1.39, P<0.05).

Conclusions

Outer hair cell injury and sensorineural hearing loss may have a common cause in chronic rhinosinusitis patients.

The Effect of the Cholesterol Levels on Noise-Induced Hearing Loss

Introduction  Noise-induced hearing loss (NIHL), which is one of the most common occupational diseases among industrialized populations, is associated with longstanding exposure to high levels of noise. The pathogenesis of NIHL is not clear, but some genes and their activity at the tissue level have been investigated. Hypercholesterolemia, which can disturb the microcirculation, can be one of the underlying pathologies in hearing loss. Objective  To investigate the relationship between NIHL and hypercholesterolemia. Methods  The study group was selected among workers who had an occupational exposure of 85 dB of noise for at least 10 years. The audiologic assessment was recorded at seven frequencies (500 Hz, 1,000 Hz, 2,000 Hz, 3,000 Hz, 4,000 Hz, 6,000 Hz and 8,000 Hz). A total of 456 workers were included in the study and divided into two groups: the control group (252 patients) and the NIHL group (204 patients). After the audiologic measurement, blood samples were taken and investigated for blood cholesterol levels. According to these results, the groups were compared. Results  Both groups were similarly distributed regarding age and occupational exposure time ( p  > 0.05). We could not detect any association between cholesterol levels and noise-induced hearing loss ( p  < 0.05). According to logistic regression analyses, the odds ratios are not significant for both hypercholesterolemia and hypertriglyceridemia ( p  > 0.05). Conclusion  Noise-induced hearing loss is still a common occupational problem that can be prevented by hearing conservation programs and occupational health and safety training. Still, we know little about the relationship between NIHL and hypercholesterolemia. According to our findings, we cannot detect any relationship. Controlled studies and studies with human individuals can be made possible in the future with diagnostic innovations in tissue imaging and tissue microcircular sampling.

Sudden Sensorineural Hearing Loss after Rapid Reduction of Blood Pressure in Malignant Hypertension

Although circulatory impairment of the cochlea would be intuitively a possible cause of sudden sensorineural hearing loss (SSHL), definite proof is lacking. A 46-year-old man developed bilateral SSHL immediately after rapid reduction of the blood pressure in malignant hypertension. Vertigo and left-sided hearing impairment and tinnitus resolved spontaneously a few hours after onset. The right-sided hearing loss and tinnitus persisted, and the hearing loss improved only 17 dB after 3 months of treatment. This case may provide an in vivo human model of SSHL caused by ischemia. Bilateral involvement is possible in SSHL if the circulatory disturbance is systemic. In addition, a poorer prognosis is anticipated on the side with the more severe initial attack.

Sudden Sensorineural Hearing Loss: Long-term Follow-up Results

OBJECTIVE: This study describes the long-term outcome of patients suffering from sudden sensorineural hearing loss (SSHL) after an initial combined therapy of steroids with vasodilators.

STUDY DESIGN AND SETTING: Eighty cases were retrospectively reviewed to evaluate the long-term audiometric data and to statistically assess the value of specific clinical parameters. The persistent long-term otoneurologic manifestations associated with SSHL were also reported.

RESULTS: In the long-term period, hearing level remained stable 2 months after the onset of SSHL. Patients complained of persistent tinnitus (36%), fluctuant hearing loss (8.7%), dizziness (8.7%), and classical Meniere's triad in 2.5% of cases. Profound and total SSHL associated with vertigo are poor prognostic indicators.

CONCLUSIONS: In terms of cost-effectiveness, a steroid-vasodilator therapy for SSHL for >2 months is not recommended because no additional effect was evidenced. Persistent otoneurologic manifestations, mainly tinnitus or dizziness are relatively common, particularly in patients with severe to total SSHL.

EBM rating: C-4

Analysis of Predisposing Factors for Hearing Loss in Adults

We aimed to estimate the effects of various risk factors on hearing level in Korean adults, using data from the Korea National Health and Nutrition Examination Survey. We examined data from 13,369 participants collected between 2009 and 2011. Average hearing thresholds at low (0.5, 1, and 2 kHz) and high frequencies (3, 4, and 6 kHz), were investigated in accordance with various known risk factors via multiple regression analysis featuring complex sampling. We additionally evaluated data from 4,810 participants who completed a questionnaire concerned with different types of noise exposure. Low body mass index, absence of hyperlipidemia, history of diabetes mellitus, low incomes, low educational status, and smoking were associated with elevated low frequency hearing thresholds. In addition, male sex, low body mass index, absence of hyperlipidemia, low income, low educational status, smoking, and heavy alcohol consumption were associated with elevated high frequency hearing thresholds. Participants with a history of earphone use in noisy circumstances demonstrated hearing thresholds which were 1.024 dB (95% CI: 0.176 to 1.871; P = 0.018) higher, at low-frequencies, compared to participants without a history of earphone use. Our study suggests that low BMI, absence of hyperlipidemia, low household income, and low educational status are related with hearing loss in Korean adults. Male sex, smoking, and heavy alcohol use are related with high frequency hearing loss. A history of earphone use in noisy circumstances is also related with hearing loss.

Role of Obesity on the Prognosis of Sudden Sensorineural Hearing Loss in Adults

OBJECTIVE

To investigate the role of obesity/overweight on the prognosis of sudden sensorineural hearing loss (SSHL).

STUDY DESIGN

Retrospective cohort study.

SETTING

Outpatient department of a community hospital.

SUBJECTS AND METHODS

We collected 254 adult patients with SSHL from a community hospital. The odd ratios of body mass index (BMI) or obesity/overweight (BMI ≥25 kg/m(2)) on the recovery of SSHL were evaluated with multivariate logistic regression analysis.

RESULTS

There were 120 (47.2%) patients in the nonobesity group (BMI <25 kg/m(2)) and 134 (52.8%) patients in the obesity/overweight group (BMI ≥25 kg/m(2)). The complete and partial recovery rates were 10.0% and 49.2% in the nonobesity group and 9.7% and 47.0% in the obesity/overweight group, respectively. Univariate logistic regression showed that BMI had no significant association with recovery of SSHL (odds ratio [OR] of complete and partial recovery versus no recovery = 1.04, 95% confidence interval [CI] = 0.965-1.113, P = .327). Multivariate logistic regression analysis also showed that BMI (OR = 1.04, 95% CI = 0.964-1.131, P = .292) was not significantly associated with the recovery of SSHL for all subjects, after adjusting for all considered variables. Also, obesity/overweight (BMI ≥25 kg/m(2)) had no significant association with the recovery of SSHL.

CONCLUSION

Obesity/overweight would appear to have no significant effect on the prognosis of SSHL.

Effect of comorbid diabetes and hypercholesterolemia on the prognosis of idiopathic sudden sensorineural hearing loss

OBJECTIVES

We tested the hypothesis that comorbid diseases significantly affect the prognosis of sudden sensorineural hearing loss (ISSNHL).

STUDY DESIGN

A retrospective cohort study.

METHODS

The records of patients newly diagnosed with ISSNHL and treated with steroid prednisolone in a tertiary referral center between January 2003 and December 2013 were retrospectively reviewed. Pretreatment and posttreatment hearing levels were evaluated using pure-tone average (PTA) and word recognition score (WRS). The comorbidities of diabetes, hypertension, coronary artery disease, hypercholesterolemia, cerebrovascular disease, chronic kidney disease, and anemia were identified. We examined the effects of these comorbid diseases on the prognosis of ISSNHL 2 months posttreatment.

RESULTS

Regression analyses adjusted for gender, age, pretreatment hearing, treatment delay time, and all the comorbidities showed that the probability of major improvement in the PTA was significantly higher in patients without diabetes compared to those with diabetes (univariate odds ratio [OR], 1.90; 95% confidence interval (CI), 1.25-2.90; multivariate OR, 1.69; 95% CI, 1.03-2.77). Major (≥ 90%) and moderate (50%-89% improvement of the PTA, but with a remaining hearing loss of > 10 dB) improvement in the PTA was significantly higher in patients without hypercholesterolemia compared to those with hypercholesterolemia (univariate OR, 1.78; 95% CI, 1.13-2.80; multivariate OR, 1.70; 95% CI, 1.02-2.84). There was, however, no significant difference in the distribution of major (≥ 90%), moderate (50%-89%), and minor (< 50%) improvement in the posttreatment WRS for these comorbid diseases.

CONCLUSIONS

Comorbid diabetes or hypercholesterolemia may indicate a smaller probability of major or moderate PTA improvement for patients with ISSNHL.

Platelet glycoproteins and fibrinogen in recovery from idiopathic sudden hearing loss

Background

The pathomechanism and location of idiopathic sudden sensorineural hearing loss (ISSHL) is unclear. In a previous case-control study, we found elevated fibrinogen concentrations and a higher prevalence of T allele carriers of the glycoprotein (Gp) Ia C807T polymorphism in ISSHL patients.

Methodology

127 patients with ISSHL (mean age 53.3 years, 48.8% females), who underwent a standard therapy with high dose steroids, pentoxifyllin and sterofundine over 8 days were included. We examined the influence of GpIa genotype and fibrinogen (BclI-, A312-, HaeIII-) genotype and fibrinogen plasma levels on hearing recovery after 8 weeks (change from baseline: 0 dB  =  no recovery, >0 to 10 dB = moderate recovery, >10 dB = good recovery). In a subsample of 59 patients with ISSHL, we further studied the association of platelet glycoprotein GpIa, Ib and IIIa densities on hearing recovery as well as the possible effect-modification of platelet glycoproteins on hearing recovery by plasma fibrinogen.

Results

In univariate analysis, neither the GpIa genotype nor fibrinogen genotype (all p>0.1) but lower fibrinogen levels (p = 0.029), less vertigo (p = 0.002) and lower GpIIIa receptor density (p = 0.037, n = 59) were associated with hearing recovery. In multivariate analysis, fibrinogen significantly modified the effect of GPIa receptor density on good hearing recovery (effect-modification on multiplicative scale OR = 0.45 (95% confidence interval (0.21–0.94)), p = 0.03). GPIb receptor density below the mean was associated with a 2-fold increase in good hearing recovery both in patients with fibrinogen levels above (p = 0.04) as well as in patients with fibrinogen levels below the mean (p = 0.06). There was no indication for an effect-modification (p = 0.97).

Conclusions

The findings suggest a vascular/rheological origin of ISSHL with unique features of thrombosis in the inner ear artery that may include complex interrelationships among platelet glycoproteins and plasma fibrinogen.

Neuromagnetic index of hemispheric asymmetry predicting long-term outcome in sudden hearing loss

The neuromagnetic index of hemispheric asymmetry in terms of ipsilateral/contralateral ratio at acute stage was previously revealed to prognosticate the 1-month hearing outcome of acute unilateral idiopathic sudden sensorineural hearing loss (ISSNHL), showing a dynamic relationship between top- and down-levels of auditory pathway. However, the prognostic effect of reorganization pattern for the long-term results remained elusive. This study aimed to probe the prognosticating relevance of hemispheric asymmetry to the hearing at chronic stage of ISSNHL. Using magnetoencephalography (MEG), inter-hemispheric differences in peak dipole of N100m responses to monaural tones were evaluated in 21 controls and 21 ISSNHL patients at initial and final (12 months later) stages. Predictive value of hemispheric asymmetry was assessed by correlating hearing level and ipsilateral/contralateral ratio (I/C) of N100m latency and amplitude. Healthy-side dominance of N100m was observed in ISSNHL initially, and remained in three final prognostic subgroups (complete, partial, and no recovery) of ISSNHL. The initial I/C(amplitude) on affected-ear stimulation strongly correlated with the hearing level of final stage in ISSNHL. However, there was no prognostic effect of hemispheric asymmetry pattern for the 12-month hearing improvement. The heterogeneity between neuromagnetic index and hearing levels possibly echoed different pathogeneses of ISSNHL. Since a restored hearing status did not necessarily lead toward a normal functional organization, the dynamics of hemispheric asymmetry could actually index a central resilient reorganization in the brain for sound processing in ISSNHL. Our finding showed not only a clinically relevant measure to predict final hearing of ISSNHL, but also a linkage between central plasticity and cochlear lesion. This finding suggests a new perspective, and perhaps new interventions, to diagnose and treat unilateral ISSNHL.

Neuromagnetic index of hemispheric asymmetry prognosticating the outcome of sudden hearing loss

The longitudinal relationship between central plastic changes and clinical presentations of peripheral hearing impairment remains unknown. Previously, we reported a unique plastic pattern of “healthy-side dominance” in acute unilateral idiopathic sudden sensorineural hearing loss (ISSNHL). This study aimed to explore whether such hemispheric asymmetry bears any prognostic relevance to ISSNHL along the disease course. Using magnetoencephalography (MEG), inter-hemispheric differences in peak dipole amplitude and latency of N100m to monaural tones were evaluated in 21 controls and 21 ISSNHL patients at two stages: initial and fixed stage (1 month later). Dynamics/Prognostication of hemispheric asymmetry were assessed by the interplay between hearing level/hearing gain and ipsilateral/contralateral ratio (I/C) of N100m latency and amplitude. Healthy-side dominance of N100m amplitude was observed in ISSNHL initially. The pattern changed with disease process. There is a strong correlation between the hearing level at the fixed stage and initial I/C_amplitude on affected-ear stimulation in ISSNHL. The optimal cut-off value with the best prognostication effect for the hearing improvement at the fixed stage was an initial I/C_latency on affected-ear stimulation of 1.34 (between subgroups of complete and partial recovery) and an initial I/C_latency on healthy-ear stimulation of 0.76 (between subgroups of partial and no recovery), respectively. This study suggested that a dynamic process of central auditory plasticity can be induced by peripheral lesions. The hemispheric asymmetry at the initial stage bears an excellent prognostic potential for the treatment outcomes and hearing level at the fixed stage in ISSNHL. Our study demonstrated that such brain signature of central auditory plasticity in terms of both N100m latency and amplitude at defined time can serve as a prognostication predictor for ISSNHL. Further studies are needed to explore the long-term temporal scenario of auditory hemispheric asymmetry and to get better psychoacoustic correlates of pathological hemispheric asymmetry in ISSNHL.

Multivariate analysis of hearing outcomes in patients with idiopathic sudden sensorineural hearing loss

CONCLUSIONS

Contralateral hearing loss is significantly correlated with poor hearing outcomes in patients with idiopathic sudden sensorineural hearing loss (ISSNHL).

BACKGROUND

The hearing outcome in patients with ISSNHL was analyzed using multiple variables.

METHODS

A retrospective chart review was conducted using 89 patients with ISSNHL. Patients within 40 dB HL of average hearing levels and/or patients whose hearing loss was restricted to low frequencies were excluded. The influence of pre-existing conditions on hearing outcome was analyzed using a polytomous universal model. Pre-existing conditions analyzed included hyperglycemia, hypercholesterolemia, hypertension, and contralateral hearing loss. In addition, the severity of hearing loss, age group, and the existence of vertigo were analyzed concomitantly.

RESULTS

Hearing recovery was significantly reduced in patients with a past history of contralateral hearing loss.

A prospective study of cardiovascular risk factors and incident hearing loss in men

OBJECTIVES/HYPOTHESIS

Hearing loss is the most common sensory disorder in the United States, affecting more than 36 million people. Cardiovascular risk factors have been associated with the risk of hearing loss in cross-sectional studies, but prospective data are currently lacking.

STUDY DESIGN

Prospective cohort study.

METHODS

We prospectively evaluated the association between diagnosis of hypertension, diabetes mellitus, hypercholesterolemia, smoking, or body mass index (BMI) and incident hearing loss. Participants were 26,917 men in the Health Professionals Follow-up Study, aged 40 to 74 years at baseline in 1986. Study participants completed questionnaires about lifestyle and medical history every 2 years. Information on self-reported professionally diagnosed hearing loss and year of diagnosis was obtained from the 2004 questionnaire, and cases were defined as hearing loss diagnosed between 1986 and 2004. Multivariable-adjusted hazard ratios (HRs) were calculated using Cox proportional hazards regression models.

RESULTS

A total of 3,488 cases of hearing loss were identified. History of hypertension (HR 0.96; 95% confidence interval [CI], 0.88-1.03), diabetes mellitus (HR 0.92; 95% CI, 0.78-1.08), or obesity (HR 1.02; 95% CI, 0.90-1.15 for BMI >or=30 compared to normal range of 19-24.9) was not significantly associated with hearing-loss risk. Hypercholesterolemia (HR 1.10; 95% CI, 1.02-1.18) and past smoking history (HR 1.09; 95% CI, 1.01-1.17) were associated with a significantly increased risk of hearing loss after multivariate adjustment.

CONCLUSIONS

A history of hypertension, diabetes mellitus, or obesity is not associated with increased risk of hearing loss; a history of past smoking or hypercholesterolemia has a small but statistically significant association with increased risk of hearing loss in adult males.

Methylenetetrahydrofolate reductase C677T gene mutation as risk factor for sudden sensorineural hearing loss: association with plasma homocysteine, folate and cholesterol concentrations

Objective:

Impaired cochlear perfusion appears to be the most important event in the development of sudden sensorineural hearing loss. Methylenetetrahydrofolate reductase gene mutations at nucleotide 677 cause reduced methylenetetrahydrofolate reductase enzyme activity, resulting in vascular impairment.

Methods:

Thirty-three patients and 68 control subjects underwent audiological and haematological investigation.

Results:

No statistically significant association was found between sudden sensorineural hearing loss and the methylenetetrahydrofolate reductase C677T gene mutation. Mean homocysteine and cholesterol concentrations were significantly higher in patients than in controls. Mean folate levels were significantly lower in patients than in controls. Amongst patients with sudden sensorineural hearing loss, no significant differences in mean cholesterol, homocysteine or folate concentration were found, comparing patients with methylenetetrahydrofolate reductase C677T mutation genotypes with those without.

Conclusion:

No statistically significant association was found between the methylenetetrahydrofolate reductase C677T gene mutation and sudden sensorineural hearing loss. There was a statistically significant difference between the homocysteine, folate and cholesterol concentrations of sudden sensorineural hearing loss patients, compared with controls. However, there was no statistically significant difference in these levels, comparing patients with and without the methylenetetrahydrofolate reductase C677T mutation.

Prothrombotic Gene Mutations in Patients with Sudden Sensorineural Hearing Loss and Cardiovascular Thrombotic Disease

Objectives:

Impaired cochlear perfusion seems to be an important event in sudden sensorineural hearing loss. Prothrombotic gene mutations have been related to vascular disorders and sudden hearing loss. We assessed the prothrombotic risk in 10 patients with sudden sensorineural hearing loss who had previously experienced cardiovascular events to support its vascular pathogenesis.

Methods:

Ten patients underwent hematologic tests (MTHFR C677T/A1298C, prothrombin G20210A, platelet GlyIIIaA1/A2, and V Leiden G1691A genotyping; fibrinogenemia; cholesterolemia; homocysteinemia; folatemia). The results were compared with those of 100 previously investigated patients with sudden hearing loss alone and those of 200 healthy controls. DNA was isolated from peripheral blood leukocytes, and the gene mutations were investigated by polymerase chain reaction and a LightCycler DNA analyzer.

Results:

Two patients had 2 mutant alleles, 6 had 3, and 2 had 4. The mean homocysteine, cholesterol, and fibrinogen levels were above the upper limit of normal; the mean folate levels were slightly above the lower limit of normal. Multiple mutations were more frequent in the patient group than in the previously analyzed patients and healthy controls.

Conclusions:

The association between inherited and acquired prothrombotic factors in patients with sudden sensorineural hearing loss and thrombotic diseases in other sites suggests that a multifactorial mechanism may underlie microvascular cochlear impairment. Hematologic investigation, including MTHFR, prothrombin, platelet, and V Leiden genotyping, may help to detect patients at potential risk of recurrent hearing loss and multiple microvascular diseases, and could be usefully performed in otherwise idiopathic sudden sensorineural hearing loss.

Urografin in the treatment of sudden sensorineural hearing loss

The present study was conducted to find out whether combined treatment of intravenous urografin and corticosteroid has a therapeutic advantage over oral corticosteroid therapy in the treatment of Sudden Sensorineural Hearing Loss (SSNHL). The design of the study was an interventional and controlled clinical trial. Between 2003 and 2005, patients with SSNHL were treated in our center in Tabriz, Iran. Patients were selected if they had a hearing loss of at least 30 dB in at least 3 frequencies on audiometric testing. Audiograms were performed before admission, 1 and 2 weeks and 1 and 2 months after treatment. Patients who were put on bed rest and received intravenous urografin and hydrocortisone were compared with outpatients treated with oral steroid alone. Various descriptive analytical calculations and both Chi-square and t-test were used to analyze the data. Sixty patients were included in this study. Fifty-one patients referred to the otological clinics for the appropriate treatment within the first two weeks after the onset of hearing loss. The overall improvement of both groups was 53.3%. Seventeen (56.6%) of 30 patients treated in the inpatient group who received intravenous urografin and intravenous corticosteroid had hearing improvement, while half of the outpatient group received oral corticosteroid responded positively to the treatment (p > 0.05). This study revealed no significant difference in hearing improvement between the hospitalized patients who received intravenous urografin and corticosteroid and the patients who received oral corticosteroid alone.

Hyperlipidemia in noise-induced hearing loss

OBJECTIVES

To assess the influence of hyperlipidemia on the development of noise-induced hearing loss (NIHL).

STUDY DESIGN

This case-control study analyzed data from the Department of Preventive Medicine at one academic medical center in southern Taiwan.

SUBJECTS AND METHODS

We collected the laboratory data from routine health examinations administered to workers who were exposed to noise greater than 85 dBA over a one-year period. We analyzed the relationships of cholesterol and triglyceride levels with NIHL.

RESULTS

A total of 4071 cases were analyzed. After adjusting for age and gender, hypertriglyceridemia was found to be related to NIHL (aOR = 1.281; 95% CI, 1.088-1.507), but hypercholesterolemia was not (aOR = 0.951; 95% CI, 0.795-1.138).

CONCLUSIONS

This study, one of the largest to date to study the relationship between hyperlipidemia and NIHL, found that individuals with hypertriglyceridemia are at greater risk of NIHL. On the basis of this finding, workers exposed to high noise levels should be educated on control of triglyceride levels to help reduce their risk of NIHL.

Thirty-year trends in sudden deafness from four nationwide epidemiological surveys in Japan

CONCLUSIONS

The estimated annual number of patients with sudden deafness treated in Japan has increased during the last 30 years, especially in the elderly population. Hypertension and diabetes mellitus could contribute to the etiology of this disorder.

OBJECTIVES

To investigate the epidemiological trends of sudden deafness in Japan over the past 30 years by analyzing data from national surveys.

MATERIALS AND METHODS

Nationwide epidemiological surveys on sudden deafness were conducted four times by the Research Committee of the Ministry of Health and Welfare in Japan. The first, second, third, and fourth surveys were performed in 1972, 1987, 1993, and 2001, respectively.

RESULTS

The estimated annual numbers of patients with sudden deafness treated in Japan were 4000 in 1972; 16,700 in 1987; 24,000 in 1993, and 35,000 in 2001. The average ages of patients at onset were 39.1, 45.4, 49.3, and 51.3 years, respectively. Thus, both the number of patients and the average age of patients with sudden deafness have increased during the past 30 years. Patients with sudden deafness in the fourth survey exhibited hypertension and diabetes mellitus more frequently than did patients in the first survey; this trend was particularly noticeable among elderly patients.

WITHDRAWN: [Effects of atorvastatin on presbyacusis and tinnitus : A prospective, randomized, double-blind clinical trial.]

Ahead of Print article withdrawn by publisher

Impact of prognostic factors on recovery from sudden hearing loss

Objective:

To define the impact of patient-related and audiovestibular parameters on the prognosis of sudden hearing loss.

Methods:

Eighty-three patients were included in this retrospective study. All were treated medically. We recorded the patients' demographic parameters, systemic diseases, time elapsed between onset of sudden hearing loss and initiation of treatment, tinnitus, vestibular symptoms, type of initial audiogram, pure tone averages and speech discrimination scores. For all patients, audiological measurements were performed on initial admission and at the completion of treatment on the 10th day.

Results:

There was no correlation between the hearing gain and recovery rate scores and patients' gender or age (p>0.05). However, a correlation was found between gender and relative hearing gain. Vertigo was not correlated with hearing gain and recovery rate scores (p<0.05). However, relative hearing gain correlated negatively with the presence of vertigo (−r=0.05, 81 degrees of freedom,p=0.043). Patients with <40 dB hearing loss on admission showed a better relative hearing gain (r=0.55, 81 degrees of freedom,p=0.03). Relative hearing gain correlated positively with better pre-treatment speech discrimination scores (r=0.82, 81 degrees of freedom,p=0.009) and negatively with poorer pre-treatment pure tone averages (−r=0.082, 81 degrees of freedom,p=0.009). There was no correlation between the scores for hearing gain, relative hearing gain and recovery rate and: systemic diseases (p>0.05); time elapsed between onset of sudden hearing loss and initiation of treatment (p>0.05); type of audiogram on initial admission (p>0.05), except for midfrequency type of audiogram; and tinnitus (p>0.05).

Conclusions:

The outcome of sudden hearing loss was unaffected by systemic disease, tinnitus or type of audiogram (except for midfrequency type). The following were poor prognostic factors in the outcome of sudden hearing loss: female gender, presence of vertigo, initiation of treatment more than seven days after onset of hearing loss, and >40 dB hearing loss on admission.

Sudden hearing impairment combined with diabetes mellitus or hyperlipidemia

The objective of this study was to delineate whether the presence of the risk factors of microvascular disorder (MD) contribute to the prognostic outcome in patients with idiopathic sudden deafness (ISD). Retrospective clinical record review was conducted with 106 patients of ISD. Pure tone hearing thresholds were compared among the groups with or without hyperglycemia and hypercholesterolemia. Significantly better hearing recoveries were observed in cases with hyperglycemia as compared with controls. There was a tendency that the magnitude of hearing recovery in hypercholesterolemia was greater than that of controls although there was no statistical difference. The presence of the risks in MD could be an indicator of better hearing prognosis of ISD if we choose appropriate treatments. Heterogeneity of the ISD makes the establishment of the relationship between the risk factors of MD and etiology of some cases of ISD. We may have to choose the treatments for ISD considering whether the patient has any risk factor of MD.

Apheresis for idiopathic sudden hearing loss: Reviewing the evidence

Plasmapheresis has been used for various conditions for a number of years. Recently, its application for idiopathic sudden hearing loss (ISHL) has met with increasing interest. ISHL affects about 10-20 per 100,000 persons per year, impairing not only their hearing but also their ability to interact socially and their quality of life. ISHL is thought to be a sequela of an underlying microvascular disorder caused by a local hyperviscosity syndrome in the cochlear vessels. Plasmapheresis can effectively lower plasma and whole blood viscosity, improve erythrocyte elasticity, and reduce aggregability. Thus, it may be effectively employed in the treatment of ISHL. This article will briefly outline the background against which apheresis procedures are used in the treatment of ISHL and review studies done to date. Furthermore, a broader basis for the use of apheretic applications in the treatment of ISHL will be suggested, correlating age-adjusted ISHL incidence and age-adjusted levels of macromolecular plasma proteins such as fibrinogen. In conclusion, plasmapheresis is a promising new treatment for ISHL but more basic data on ISHL, and on apheresis applications for ISHL, are needed to safely assess treatment outcomes and possible future applications.

Methylenetetrahydrofolate reductase gene mutations as risk factors for sudden hearing loss

Sudden hearing loss (SHL) can be caused by vascular disorders favoring impaired cochlear perfusion. Several inherited prothrombotic risk factors have been considered in the pathogenesis of vascular impairment, and the possible role of genetic alterations has recently been suggested. Methylenetetrahydrofolate reductase (MTHFR) gene mutations at nucleotides 677 and 1298 cause reduced MTHFR enzyme activity, which leads to increased homocysteine and reduced serum folate levels that are known to be involved in vascular impairment. We studied the relationship between SHL and MTHFR C677T and A1298C gene polymorphisms in 67 patients with SHL and 134 controls. Wild-type MTHFR CC677/AA1298 was significantly more frequent in the controls (P = .05), and gene mutations were significantly more frequent in the patients (P = .001; P = .001 for trend). Fifty-three patients (79.1%) and 56 controls (41.8%) (P = .012) had a double mutation (homozygosis 677TT or 1298CC; compound heterozygosis for both polymorphisms). Homocysteine levels were significantly higher and serum folate levels significantly lower in the patients than in the controls (P < .0001). These data suggest that MTHFR gene polymorphisms may be involved in the pathogenesis of SHL.

Sudden hearing loss and MTHFR 677C>T/1298A>C gene polymorphisms

PURPOSE

Sudden hearing loss (SHL) can be caused by vascular disorders favoring impaired cochlear perfusion. A number of inherited prothrombotic risk factors have been considered in the pathogenesis of vascular impairment and the possible role of genetic alterations has recently been suggested. We aimed to investigate the relationship between SHL and MTHFR 677 and 1298 gene polymorphisms.

METHODS

DNA genotyping was performed on peripheral blood leukocytes in 45 SHL patients and 135 controls.

RESULTS

Wild-type MTHFR (677CC/1298AA) was significantly more frequent in the controls (P=0.01), and gene polymorphisms (677CT, 677TT, 1298AC, 1298CC, compound 677CT/1298AC) were significantly more frequent in the patients (P=0.005; Ptrend=0.001).

CONCLUSION

These data suggest that MTHFR gene polymorphisms may be considered as risk factors for SHL and participate on vascular impairment related to this disorder. Further studies, based on large series of patients, are needed to definitely assess the role of this prothrombotic factor in the etiopathogenesis of SHL.

Idiopathic sudden hearing loss in patients with type 2 diabetes

The aim of the present study was to identify clinical and audiologic characteristics of idiopathic sudden hearing loss (ISHL) in patients with type 2 diabetes. We retrospectively investigated 148 cases of ISHL, whose age was more than 40 years, comparing clinical and audiologic valuables between diabetic and non-diabetic patients. Twenty-four patients (16.2%) had type 2 diabetes (16 male, 8 female). Prevalence of hypertension and hyperlipidemia were significantly greater in diabetic patients. Hearing in the affected ear was more impaired in diabetic than non-diabetic patients, although hearing in the unaffected ear and degree of recovery did not differ significantly. Mean BMI, duration of diabetes, HbA1c values, and ultrasonographically determined carotid intima-media thickness (IMT) and plaque scores in diabetic patients with ISHL were 24.0+/-3.7 kg/m(2), 9.8+/-7.8 years, 7.8+/-1.5%, 0.83+/-0.16 mm, and 3.8+/-2.8, respectively. Of 17 diabetic patients whose ISHL was treated with steroids, 12 required insulin for glycemic control during treatment. Compared with diabetic patients without ISHL, HbA1c value was significantly higher in diabetic patients with ISHL (7.2+/-1.2% versus 7.8+/-1.5%, P=0.0202). In conclusion, nearly 16% of our patients with ISHL had type 2 diabetes, and this subgroup was associated with more severe hearing loss. Further studies are needed to determine which subgroups of diabetic patients are most likely to develop ISHL, which patients are predisposed to more severe hearing loss, and how various factors and treatments influence outcome.

[Neurosensory sudden deafness, blood hyperviscosity syndrome, and diabetes mellitus]

Diabetes mellitus is considered a risk factor for sensorineural sudden deafness. Its pathogenesis remains unknown. However, the physiopathological implication of a hyperviscosity syndrome in diabetics and patients bearing of sudden deafness can mean the nexus between the two entities. Total blood viscosity and erythrocyte adhesion were haemorheological parameters significatively higher in blood of diabetics with sudden deafness than in normal hearing controls. Moreover, erythrocyte filterability and deformability were lower in diabetics, but it was not statistically significative. These findings help to guide therapy in these patients towards specific measures to improve blood viscoelastic properties.

Does the addition of hyperbaric oxygen therapy to the conventional treatment modalities influence the outcome of sudden deafness?

OBJECTIVE

To investigate the therapeutic effects of the addition of hyperbaric oxygen (HBO) therapy to the conventional therapies in sudden deafness (SD) and to investigate the influence of patient age on the effectiveness of HBO therapy.

STUDY DESIGN AND SETTING

We undertook a retrospective review of 50 cases of SD treated at a tertiary university hospital. Twenty-five patients (group 1) were treated with betahistine hydrochloride, prednisone, and daily stellate ganglion block. A second group (group 2) of 25 patients received the same basic treatment with the addition of HBO therapy.

RESULTS

The mean hearing gain was 20.0 dB in group 1 and 37.9 dB in group 2 (P < 0.05). In group 2 patients, the mean gains were 51.4 and 23.3 dB for those younger and older than 50 years (P < 0.05) and 48.9 and 14.5 dB for those younger and older than 60 years (P < 0.001), respectively. In patients older than 60 years, the mean gains were 14.5 and 14.4 dB in group 2 and group 1, respectively (P > 0.05).

CONCLUSIONS

The addition of HBO therapy to the conventional treatment significantly improves the outcome of SD, especially in patients younger than 50 years. Additional HBO therapy provides limited benefit in patients older than 50 years and no benefit in patients older than 60 years.

Clinicoepidemiologic features of sudden deafness diagnosed and treated at university hospitals in Japan

Nationwide epidemiologic surveys were done 3 times by the Research Committee of the Ministry of Health and Welfare in Japan to investigate the number of patients and clinical manifestations of idiopathic sudden sensorineural hearing loss (sudden deafness). The first, second, and third surveys were carried out during the 1970s, 1980s, and 1990s, respectively. For each patient, we have compiled data regarding age, sex, onset day, presence or absence of vertigo, and hearing ability, including initial and final audiograms, in a computer in the Nagoya University Computer Center. Regarding patients who visited university hospitals, complete data were collected for 421 subjects (age: 40.2+/-15.4 years, female: 203, male: 218) between July 1973 and June 1974, for 813 subjects (age: 45.1+/-15.4 years, female: 407, male: 406) in 1987, and for 1112 subjects (age: 49.1+/-16.0 years, female: 591, male: 521) in 1993. The number of patients with sudden deafness treated in university hospitals in Japan has increased, especially in the elderly population. This increase is associated with population increase and age-adjusted incidence rates per 100,000 in the elderly population. The initial and final hearing levels in the first survey were worse than those in the second and third surveys; there was no significant difference in hearing between the second and third surveys. The hearing levels were worse in children and elderly patients than in the other age groups.

Rheopheresis: rheologic, functional, and structural aspects

Rheopheresis is a specific application of membrane differential filtration, synonymous with double filtration plasmapheresis for extracorporeal hemorheotherapy, eliminating an exactly defined spectrum of high molecular weight proteins from human plasma (e.g.: fibrinogen, alpha-2-macroglobulin, low-density lipoprotein cholesterol, IgM). This results in the improvement of blood flow and microcirculation initiated by lowering blood and plasma viscosity, and erythrocyte aggregation. In this context, microcirculation stands not only for the patency of small blood vessels, but for the complete interactive network between plasma, blood cells, the vessel wall, and cellular and extracellular compartments of the surrounding tissue. Insufficient tissue oxygenation leads to tissue damage, e.g., a microcirculatory disorder develops, creating acute as well as chronic symptoms. Therefore, impaired microcirculation has a rheologic, functional, and structural dimension with respect to involved organs or tissues. Rheopheresis represents a specific therapeutic approach with an acute rheologic as well as chronic functional and structural effects, which was confirmed in pilot and controlled clinical studies for several organ systems. Data from 2 controlled clinical trials are available for the safe and effective treatment in patients with age-related macular degeneration.