Idiopathic sudden sensorineural hearing loss: temporal bone histopathologic study

Importance of small vessel disease as a possible cause of sudden sensorineural hearing loss

OBJECTIVE

Vascular disease like small-vessel disease (SVD) is the most likely cause among the potential causes of Sudden sensorineural hearing loss (SSNHL). Understanding the relationship between SVD and SSNHL is crucial for developing effective prevention and treatment strategies. To confirm the relationship between SVD and SSNHL, the effect of SVD is confirmed by focusing on the duration and recurrence of SSNHL.

METHODS

This article reports a retrospective observational study that investigated the relationship between SVD and SSNHL using the South Korea Health Insurance Review and Assessment Service (HIRA) database from 2010 to 2020. This retrospective observational study included 319,569 SSNHL patients between 2010 and 2020.

RESULTS

Participant demographics were controlled using Propensity Score Matching. The hazard ratios (HR) for the effect of SVD on the duration of SSNHL were 1.045 for the group with SVD before the onset of SSNHL and 1.234 for the group with SVD after the onset of SSNHL. SVD was statistically significant for the recurrence of SSNHL, with an odds ratio of 1.312 in the group with SVD compared to the group without SVD. The HR for the period until a recurrence in the group with SVD was 1.062.

CONCLUSIONS

The study identified SVD as a possible cause of SSNHL and found that the duration of SSNHL increased only in the presence of SVD. SVD also affected the recurrence of SSNHL, with the recurrence rate being 1.312 times higher in the group with SVD.

Can Cochlear Nerve Size Assessment With Magnetic Resonance Enhance the Understanding of Idiopathic Sudden Sensorineural Hearing Loss?

BACKGROUND AND OBJECTIVES

Idiopathic sudden sensorineural hearing loss (ISSHL) is a rapid loss of hearing, exceeding 30 dB in at least 3 consecutive frequencies within 3 days, without any identifiable cause despite thorough investigations. Currently, the etiology and pathogenesis of ISSHL have not been fully elucidated. This study aimed to assess the size of the cochlear nerve in patients with ISSHL and explore its relationship with pretreatment audiograms and treatment response. Subjects and.

METHODS

A total of 125 patients (59 [47.2%] women; mean age 47.7±13.8 years [minimum-maximum: 21-76]) and 60 healthy participants (27 [45%] women; mean age 45.7±16.8 years [minimum-maximum: 20-76]) as a control group were included in this study. The size of the cochlear nerve was assessed on the affected side, compared to the control group, as well as on the unaffected side. Pretreatment and posttreatment audiological values were also analyzed.

RESULTS

The cross-sectional area (CSA), vertical diameter (VD), and horizontal diameter (HD) of the CN were found to be smaller on the affected side of ISSHL patients compared to the control group (p<0.01; p=0.04; p=0.02, respectively). In the study group (affected side of ISSHL patients), there were no significant differences in VD, HD, and CSA values between pretreatment audiogram types (p=0.23; p=0.53; p=0.39, respectively), and initial hearing levels (p=0.16; p=0.22; p=0.23, respectively). Furthermore, there were no significant differences in VD, HD, and CSA values between the recovery groups according to Furuhashi criteria (p=0.18; p=0.37; p=0.27, respectively).

CONCLUSIONS

The size of the CN may be a risk factor for ISSHL, but it does not affect the type of audiogram curves and was not prognostic in terms of treatment response.

Advanced Magnetic Resonance Imaging Sheds Light on the Distinct Pathophysiology of Various Types of Acute Sensorineural Hearing Loss

OBJECTIVE

To compare the findings of magnetic resonance imaging (MRI) with advanced protocols in patients with various types of acute sensorineural hearing loss (ASNHL).

STUDY DESIGN

Retrospective case review.

SETTING

Tertiary referral center.

PATIENTS

Two hundred eighty-seven patients with ASNHL.

INTERVENTIONS

All patients underwent MRI scanning, including heavily T2-weighted three-dimensional fluid-attenuated inversion recovery before and 4 hours after the intravenous administration of gadolinium contrast medium (delayed 3D-FLAIR). A hybrid of the reversed image of the positive endolymph signal and the native image of the perilymph signal image was constructed to visualize the endolymphatic space.

RESULTS

The detection rates of abnormal MRI findings vary significantly among different types of ASNHL. A hyperintense signal on delayed 3D-FLAIR was observed in all patients with intralabyrinthine schwannoma or vestibular schwannoma and 20.5% of patients with idiopathic sudden sensorineural hearing loss (ISSNHL) but was rarely observed in definite Ménière's disease (MD, 2.6%). In contrast, endolymphatic hydrops (EH) was frequently observed in patients with definite MD (79.5%) but was observed much less frequently in patients with ISSNHL (11.0%). In patients with cochlear MD and ALHL, detection rates of cochlear EH were similar to those with definite MD, whereas detection rates of vestibular EH were significantly lower than in patients with definite MD.

CONCLUSIONS

The significantly different detection rates of abnormal MRI findings among various types of ASNHL shed light on the distinct pathophysiology of each disorder. A diagnosis based on MRI findings with advanced protocols may help select treatment strategies and provide prognostic information for patients.

Idiopathic sudden sensorineural hearing loss: A critique on corticosteroid therapy

Idiopathic sudden sensorineural hearing loss (ISSNHL) is a condition affecting 5-30 per 100,000 individuals with the potential to significantly reduce one's quality of life. The true incidence of this condition is not known because it often goes undiagnosed and/or recovers within a few days. ISSNHL is defined as a ≥30 dB loss of hearing over 3 consecutive audiometric octaves within 3 days with no known cause. The disorder is typically unilateral and most of the cases spontaneously recover to functional hearing within 30 days. High frequency losses, ageing, and vertigo are associated with a poorer prognosis. Multiple causes of ISSNHL have been postulated and the most common are vascular obstruction, viral infection, or labyrinthine membrane breaks. Corticosteroids are the standard treatment option but this practice is not without opposition. Post mortem analyses of temporal bones of ISSNHL cases have been inconclusive. This report analyzed ISSNHL studies administering corticosteroids that met strict inclusion criteria and identified a number of methodologic shortcomings that compromise the interpretation of results. We discuss the issues and conclude that the data do not support present treatment practices. The current status on ISSNHL calls for a multi-institutional, randomized, double-blind trial with validated outcome measures to provide science-based treatment guidance.

Delayed Recovery in Idiopathic Sudden Sensorineural Hearing Loss

Sudden hearing loss is an easily encountered disease in clinics, but its prognosis has not been completely elucidated. In the present study, we investigated the long-term prognosis of sudden hearing loss with 130 patients who were diagnosed based on strict criteria and provided uniform treatment. The patients with incomplete recovery were reevaluated after 2 months without receiving additional treatment. Hearing levels at different time points were compared. Moreover, the associated factors affecting the degree of hearing improvement over time were evaluated using stepwise multiple linear regression. After treatment, 73 out of the 130 (56.1%) patients attained incomplete recovery and were reevaluated after 2 months. Seventeen out of the seventy-three (23.3%) patients showed a grade promotion, fifty-four (74%) were constant, and two (2.7%) were aggravated. The mean interaural hearing differences (IHDs) showed significant improvement. Old age, poor initial IHD, and poor recovery grade were significantly associated with a profitable delayed hearing gain. Poorer hearing level at the time of onset might be a sign for slower recovery rather than a poorer prognostic factor. The treatment outcome of idiopathic sudden sensorineural hearing loss (ISSNHL) should be evaluated at least 2 months after treatment completion, and counseling is required due to the need for long-term follow-up in patients with ISSNHL.

CD4 T-cell depletion prevents Lassa fever associated hearing loss in the mouse model

Lassa virus (LASV) is the causative agent of Lassa fever (LF), which presents as a lethal hemorrhagic disease in severe cases. LASV-induced hearing loss in survivors is a huge socioeconomic burden, however, the mechanism(s) leading to hearing loss is unknown. In this study, we evaluate in a mouse LF model the auditory function using auditory brainstem response (ABR) and distortion product otoacoustic emissions (DPOAE) to determine the mechanisms underlying LASV-induced hearing loss. In the process, we pioneered measures of ABR and DPOAE tests in rodents in biosafety level 4 (BSL-4) facilities. Our T cell depletion studies demonstrated that CD4 T-cells play an important role in LASV-induced hearing loss, while CD8 T-cells are critical for the pathogenicity in the acute phase of LASV infection. Results presented in this study may help to develop future countermeasures against acute disease and LASV-induced hearing loss.

Association Between the BNT162b2 Messenger RNA COVID-19 Vaccine and the Risk of Sudden Sensorineural Hearing Loss

IMPORTANCE

Identification of adverse events after vaccination increases awareness of vaccine-associated complications, leading to early diagnosis and treatment. Evidence remains scarce on the association between the BNT162b2 messenger RNA (mRNA) COVID-19 vaccine (Pfizer-BioNTech) and sudden sensorineural hearing loss (SSNHL).

OBJECTIVE

To assess the association between the BNT162b2 mRNA COVID-19 vaccine and SSNHL.

DESIGN, SETTING, AND PARTICIPANTS

This retrospective, population-based cohort study was performed from December 20, 2020, to May 31, 2021, using data from the largest health care organization in Israel. Patients 16 years or older who received the first vaccine dose between December 20, 2020, and April 30, 2021, and the second vaccine dose between January 10, 2021, and April 30, 2021, were included.

EXPOSURES

Receipt of first and second BNT162b2 mRNA COVID-19 vaccine doses.

MAIN OUTCOMES AND MEASURES

The main outcome was SSNHL based on International Classification of Diseases, Ninth Revision (ICD-9) codes in conjunction with concurrent prednisone dispensing. Observed cases of SSNHL, occurring within 21 days after each of the first and second vaccine doses, were compared with the expected cases based on the experience of the population in 2018 and 2019. Standardized incidence ratios (SIRs) and attributable risks were computed.

RESULTS

Overall, 2 602 557 patients (mean [SD] age, 46.8 [19.6] years; 51.5% female) received the first dose of BNT162b2 mRNA COVID-19 vaccine, with 91 cases of SSNHL reported. Of these patients, 2 441 719 (93.8%) received the second vaccine dose, with 79 cases of SSNHL reported. The age- and sex-weighted SIRs were 1.35 (95% CI, 1.09-1.65) after the first vaccine dose and 1.23 (95% CI, 0.98-1.53) after the second vaccine dose. After the first vaccine dose, the estimated SIRs were more pronounced in female patients aged 16 to 44 years (SIR, 1.92; 95% CI, 0.98-3.43) and female patients 65 years or older (SIR, 1.68; 95% CI, 1.15-2.37). After the second vaccine dose, the highest estimated SIR was observed in male patients 16 to 44 years (SIR, 2.45; 95% CI, 1.36-4.07). The attributable risks were generally small, and the results were similar when 2019 was used as a reference to estimate the expected number of SSNHL cases.

CONCLUSIONS AND RELEVANCE

This study suggests that the BNT162b2 mRNA COVID-19 vaccine might be associated with increased risk of SSNHL; however, the effect size is very small. Further studies are warranted to establish this possible association.

Utilizing Single Cell RNA-Sequencing to Implicate Cell Types and Therapeutic Targets for SSNHL in the Adult Cochlea

OBJECTIVE

To identify genes implicated in sudden sensorineural hearing loss (SSNHL) and localize their expression in the cochlea to further explore potential pathogenic mechanisms and therapeutic targets.

STUDY DESIGN

Systematic literature review and bioinformatics analysis.

DATA SOURCES

The following sources were searched from inception through July 2, 2020: PubMed-NCBI, MEDLINE, Embase, CINAHL, Cochrane Library, ClinicalTrials.gov, OpenGrey, GreyNet, GreyLiterature Report, and European Union Clinical Trials Registry. PubMed-NCBI and MEDLINE were additionally searched for human temporal bone histopathologic studies related to SSNHL.

METHODS

Literature review of candidate SSNHL genes was conducted according to PRISMA guidelines. Existing temporal bone studies from SSNHL patients were analyzed to identify the most commonly affected inner ear structures. Previously published single-cell and single-nucleus RNA-Seq datasets of the adult mouse stria vascularis, as well as postnatal day 7 and 15 mouse cochlear hair cells and supporting cells, were utilized for localization of the SSNHL-related genes curated through literature review.

CONCLUSIONS

We report 92 unique single nucleotide polymorphisms (SNPs) in 76 different genes that have been investigated in relation to SSNHL in the literature. We demonstrate that a subset of these genes are expressed by cell types in the adult mouse stria vascularis and organ of Corti, consistent with findings from temporal bone studies in human subjects with SSNHL. We highlight several potential genetic targets relevant to current and possible future SSNHL treatments.

Sensorineural hearing loss and risk of stroke: a systematic review and meta-analysis

The aim of this systematic review and meta-analysis study was to clarify the effects of sensorineural hearing loss (SNHL) on the incidence of stroke. In line with this, PubMed, Scopus, Web of Science, and ScienceDirect databases were searched using related keywords and MeSH terms from inception to March 1, 2020. Out of the 1961 initial records, eight cohort studies comprising 4,564,202 participants were included, and their qualities were assessed using the Newcastle-Ottawa Scale (NOS). Then, the random-effects model was used to pool HR (95% CI) for risk of stroke; and heterogeneity was presented with I2 index. Subgroup analysis and publication bias tests were performed, and the pooled HR (95% CI) of stroke in SNHL was estimated as 1.31 (1.08, 1.53) for the unadjusted model and 1.33 (1.18, 1.49) for the adjusted model. Subgroup analysis indicates a significantly higher risk of stroke in patients with sudden SNHL (SSNHL) in comparison to age-related HL (ARHL) both in the unadjusted model, [HR = 1.46; 95% CI (1.08, 1.63)] versus [HR = 1.14; 95% CI (0.64, 1.65)], and in the adjusted model, [HR = 1.44; 95% CI (1.15, 1.74)] versus [HR = 1.29; 95% CI (1.24, 1.34)]. Our study showed that patients with SNHL face a higher risk of stroke than those without SNHL. It is necessary to perform hematologic and neurological examinations to help clinicians detect patients who are potentially at risk for stroke.

Analysis of the relationship between changes in the auditory brainstem response and prognosis in patients with sudden hearing loss

Objective

To analyse how the auditory brainstem response changes in patients with sudden sensorineural hearing loss.

Method

Data were collected via retrospective medical chart review.

Results

Forty-three patients were included in this study. The mean latency of auditory brainstem response wave 1 was significantly longer for the affected side than for the unaffected side (p = 0.003). The mean latency of auditory brainstem response wave 1 was significantly shorter, and the mean amplitude of auditory brainstem response wave 1 was significantly larger, in the good response group compared to the poor response group. In forward conditional logistic regression analysis, auditory brainstem response wave 1 latency was an independent predictor of a good response (odds ratio = 34.37, 95 per cent confidence interval = 1.56–757.15, p = 0.025).

Conclusion

In patients with sudden sensorineural hearing loss, the latency of wave 1 of the auditory brainstem response was significantly increased and was related to prognosis.

Association of Sudden Sensorineural Hearing Loss With Risk of Cardiocerebrovascular Disease: A Study Using Data From the Korea National Health Insurance Service

Importance

The interruption of vascular supply to the cochlea has been proposed as a major etiological factor for sudden sensorineural hearing loss (SSNHL), and several risk factors for cardiocerebrovascular disease (CCVD) are associated with SSNHL, including heavy smoking, alcohol consumption, and thromboembolic events. However, the link between SSNHL and CCVD has not been fully evaluated.

Objective

To investigate the association between SSNHL and CCVD.

Design, Setting, and Participants

A retrospective propensity score-matched cohort study was conducted using a nationwide representative sample from the National Sample Cohort 2002 through 2013 data from the Korea National Health Insurance Service. The SSNHL group (n = 154) included certain patients who were diagnosed with SSNHL between January 2003 and December 2005. The comparison group was selected (4 patients for every 1 patient with SSNHL; n = 616) using propensity score matching, according to sociodemographic factors and the year of enrollment. Each patient was monitored until 2013.

Main Outcomes and Measures

Survival analysis, the log-rank test, and Cox proportional hazards regression models were used to calculate the incidence, survival rate, and hazard ratio of CCVD for each group.

Results

Among the 770 patients, 385 (50.0%) were female and 370 (48.1%) were aged between 45 and 64 years. Of the total study population, 66 patients developed CCVD, such as stroke and acute myocardial infarction, during the 11-year follow-up period: 18 patients in the SSNHL group (incidence, 13.5 cases per 1000 person-years) and 48 from the comparison group (incidence, 7.5 cases per 1000 person-years). After adjustment for other factors, the hazard ratio of CCVD during the 11-year follow-up period was 2.18 times (95% CI, 1.20-3.96) greater for patients with SSNHL. An increased risk of stroke was associated with SSNHL (HR, 2.02; 95% CI, 1.16-3.51); however, there was no relation between SSNHL and risk of myocardial infarction (HR, 1.18; 95% CI, 0.25-5.50).

Conclusions and Relevance

This observational study using nationwide data suggests that SSNHL is associated with an increased incidence of CCVD, specifically stroke. Therefore, patient surveillance for signs of CCVD should be considered for patients who receive a diagnosis of SSNHL.

Comparison of Different Treatment Methods for Idiopathic Sudden Sensorineural Hearing Loss

Objective

To evaluate the effectiveness of different therapies for idiopathic sudden sensorineural hearing loss and prognostic factors, and determine the most successful treatment according to the audiogram type and time from onset to treatment.

Methods

A total of 90 cases from February 2009 to January 2015 were classified under Group I oral treatment (methylprednisolone, acyclovir, betahistine-dihydrochloride, and vitamin B12); Group II oral treatment + intratympanic steroids (ITS); Group III oral treatment + hyperbaric oxygen; and Group IV only ITS. A pure tone average (PTA) improvement of less than 10 dB was assessed as "no improvement," a PTA of 10 dB or more or a 10% or more increase in the speech discrimination score (SDS) as "partial improvement," and a hearing threshold within 10 dB and SDS within 5%-10% of the unaffected ear as "full improvement."

Results

Overall, 32.2% patients showed full and 28.9% showed partial improvement, whereas 38.9% showed no improvement. There was no significant difference in terms of mean hearing gain between the different treatment methods. As the degree of hearing loss and time from onset to treatment increased, improvement worsened (p<0.05). Descending audiogram had lower mean hearing gains compared to other groups (p=0.014). There was no significant effect of age, sex, tinnitus and/or vertigo, and systemic disease on treatment success (p>0.05).

Conclusion

The most important factors affecting prognosis were the time from onset to treatment, hearing loss severity, and audiogram type. Only ITS avoided side effects and reduced hospitalization. ITS in the first two weeks, followed by hyperbaric oxygen were considered as the treatment priority.

[The etiopathogenetic aspects of idiopathic sensorineural impairment of hearing]

The objectives of the present work were the overview of the results of the modern investigations concerning etiology of idiopathic sensorineural impairment of hearing as well as the analysis of the theory of microthrombus formation and its role in pathogenesis of hearing impairment.

Does Herpes Virus Reactivation Affect Prognosis in Idiopathic Sudden Sensorineural Hearing Loss?

Objectives

Several etiologies have been proposed to underlie idiopathic sudden sensorineural hearing loss (ISSNHL), including viral infection, vascular disturbance, and immune-mediated mechanisms. However, none of these mechanisms are conclusive. Should ISSNHL be caused by reactivation of a viral infection, antiviral treatment would be an important option. Thus, in this study, we reported the prognosis according to serologic test results of herpes viruses in patients with ISSNHL. We also evaluated treatment response with acyclovir and corticosteroids versus corticosteroids alone in herpes simplex virus (HSV) seropositive ISSNHL patients.

Methods

We compared hematologic examinations and the results of audiometry testing in 232 patients with ISSNHL. Statistical analyses for initial hearing impairment, progression of hearing impairment, recovery of hearing loss, and laboratory results were performed in all patients. All statistical analyses were performed using SPSS software.

Results

The 232 ISSNHL patients were divided into two subgroups according to HSV immunoglobulin M (IgM) serologic results (seropositive or seronegative). When the seropositive group was compared to the seronegative group, age, gender, body mass index (BMI), white blood cell, absolute neutrophil count, absolute monocyte count, and platelet count were not significantly different. Initial hearing level, final recovery hearing level, and recovery time were also not significantly different between the two groups (P>0.05). Though there were no significant differences in age, gender, BMI, or viral HSV IgM titer, the two groups had similar initial hearing level, final recovery hearing level, and recovery time. The difference in hearing threshold before and after treatment was larger (18.7±37.1) in the group receiving antiviral medication than in the corticosteroids group (11.0±44.5), but this difference was not significant (P=0.619).

Conclusion

There was no significant difference of prognosis between the patients with and without reactivation of HSV. In addition, there seems to be no benefit for the treatment of acyclovir combined with the corticosteroids in the patients with ISSNHL.

Prognosis of Inner Ear Periphery and Central Vestibular Plasticity in Sudden Deafness with Vertigo

Objectives:

We sought to elucidate the clinical problems and otopathology of patients with sudden deafness with vertigo (SDV).

Methods:

In 24 patients with SDV who had significant canal paresis (CP) at their first visit to our hospital between 1997 and 2001, we examined pure tone audiograms, caloric tests, and several questionnaires twice, at the first visit within 5 days after the onset and around 2 years after steroid therapy.

Results:

These examinations revealed that improvements of auditory and vestibular function in patients with SDV tended to be correlated with one another. Sixteen of the 24 patients (66.7%) still had CP. This rate in SDV was significantly worse than that reported previously for vestibular neuritis (VN). On the other hand, patients with SDV with long-lasting CP had a faster reduction of head-shaking afternystagmus and of handicaps in their everyday life due to dizziness than did patients with VN and CP.

Conclusions:

These findings suggest that SDV may deteriorate the inner ear function more severely but accelerate the central vestibular compensation more effectively than VN after the lesion. It is well known that vestibular neurectomy causes much more severe motion-induced dizziness after surgery than does labyrinthectomy. Taken together, these findings suggest different regions of damage in SDV (mainly the labyrinth, as in labyrinthectomy) and VN (mainly the ganglion, as in vestibular neurectomy).

Risk of depressive disorders following sudden sensorineural hearing loss: A nationwide population-based retrospective cohort study

BACKGROUND

Sudden sensorineural hearing loss (SSNHL) occurs as an unexplained, rapid loss of hearing that can cause significant stress in the affected individual. This study aims to assess the risk of depressive disorders in SSNHL patients.

METHODS

From the National Health Insurance Research Database (NHIRD) in Taiwan, we identified new SSNHL patients diagnosed by an otolaryngologist between January 01, 2000, and December 31, 2008. A control group was composed of individuals who had never suffered from SSNHL. A total of 1717 SSNHL patients and 6868 individuals without SSNHL who were matched by sex, age and index date were followed until December 31, 2009, unless otherwise diagnosed with depressive disorders by a psychiatrist or deceased.

RESULTS

The results found that after adjusting for patients' age, sex, comorbidities, urbanization, and monthly income, SSNHL patients are 2.17 times more at risk (95% confidence interval [CI], 1.51-3.08, p<.001) for depressive disorders then control patients, especially in younger age groups (<60 years old).

CONCLUSIONS

Our study indicated an increased risk of developing depressive disorders in patients with SSNHL, particularly for younger patients. Symptoms of depression should be regularly evaluated in patients with SSNHL.

Sudden sensorineural hearing loss is associated with chronic rhinosinusitis: population-based study

BACKGROUND

This study aimed to evaluate the association of chronic rhinosinusitis with sudden sensorineural hearing loss using a population-based database.

METHODS

Sampled subject data were obtained from the Taiwan Longitudinal Health Insurance Database 2000. A total of 3325 patients with sudden sensorineural hearing loss were identified and 9975 controls were randomly selected. A conditional logistic regression was used to calculate the odds ratio for having been previously diagnosed with chronic rhinosinusitis, for cases and controls.

RESULTS AND CONCLUSION

The adjusted odds ratio of having prior chronic rhinosinusitis among cases compared to controls was 1.36 (95 per cent confidence interval = 1.16-1.60). The significant relationship between sudden sensorineural hearing loss and chronic rhinosinusitis was most pronounced among those patients aged 44 years or less (compared to controls) (odds ratio = 2.18; 95 per cent confidence interval = 1.63-2.92). However, the significant relationship between sudden sensorineural hearing loss and prior chronic rhinosinusitis was not sustained for patients older than 60 years compared to controls.

Investigation of neutrophil-to-lymphocyte ratio and mean platelet volume in sudden hearing loss

Introduction

Several theories attempt to explain the pathophysiology of sudden hearing loss.

Objective

The objective of this study was to investigate the possible role of inflammation and atherothrombosis in sudden hearing loss patients through the neutrophil-to-lymphocyte ratio and mean platelet volume.

Methods

Study design – retrospective cross-sectional historical cohort. This study was conducted on two groups: one with 59 individuals diagnosed with sudden hearing loss, and other with 59 healthy individuals with the same characteristics of gender and age distribution, neutrophil-to-lymphocyte ratio and mean platelet volume levels were measured in patients diagnosed with sudden hearing loss as well as in the control group, and it was verified whether these results interfered for a better or worse prognosis with treatment of sudden deafness.

Results

Neutrophil-to-lymphocyte ratio levels are much higher in patients diagnosed with sudden hearing loss compared to the control group. Similarly, mean levels of neutrophil-to-lymphocyte ratio are higher in non-recovered versus recovered patients (p = 0.001). However, we could not find a correlation with mean platelet volume levels (p > 0.05).

Conclusion

Neutrophil-to-lymphocyte ratio is a quick and reliable indicator regarding diagnosis and prognosis of sudden hearing loss; on the other hand, mean platelet volume may be considered a less important indicator in this aspect.

Sudden sensorineural hearing loss: Is antiviral treatment really necessary?

OBJECTIVES

It was aimed to investigate the necessity of antiviral agents in the ISSHL treatment.

METHODS

In this study, the patients, diagnosed with sudden hearing loss and admitted in the first 7 days of hearing loss were divided into two groups; a combination therapy was administered to one of the groups, and famciclovir was administered to the other group as an antiviral treatment in addition to the combined therapy. Both groups were compared in terms of levels of recovery.

RESULTS

No statistically significant difference was found in the recovery rates between the two groups (p=0.7).

CONCLUSION

In this study, the additional antiviral treatment was found to have no effect on the remission rates in patients with ISSHL treated with combined therapy.

A clinical study of sudden deafness

CONCLUSIONS

Sudden Sensorineural Hearing Loss (SSHL) was commonly seen in middle aged people. Tinnitus was reported by 87.2% of the patients, and dizziness or vertigo were reported by 48.5%. The most common concomitant disorder of SSHL was hyperlipidemia.

OBJECTIVE

A retrospective register study with SSHL was performed in Xi'an, China, from 2000-2009.

RESULTS

Of 617 inpatients, the right ear was affected in 267 cases, the left ears in 282 cases, and both ears in 68 cases. The most common age of patients was 41-50 years. There were 20.4% SSHL patients with hypertension, coronary artery disease, or diabetes, and 49.6% patients with hyperlipidemia. Auditory Brainstem Responses (ABR) were performed in 460 patients (504 ears) before treatment, and the ABR threshold of 56.4% ears was > 90 dB. The constituent ratio of patients with an ABR threshold over 90 dB was greater in the vertigo group than the other group. CT and/or MRI scans were available in 277 cases, of which 40 cases (14.4%) were abnormal.

Transient auditory dysfunction: a description and study of prevalence

Transient auditory dysfunction (TAD) is a previously undescribed symptom complex of unknown cause. It is characterized by short-lasting sensorineural hearing loss (unilateral or bilateral), it is associated with tinnitus, it resolves completely within minutes, and it is not accompanied by vestibular symptoms. We conducted a cross-sectional prospective study to define TAD, find its prevalence, and discuss its significance. Two hundred healthy subjects between the ages of 16 and 49 years were surveyed using a questionnaire. Of these subjects, 41 (20.5%) reported experiencing symptoms of TAD. The mean number of episodes was 5.9 times per month, the mean duration was 41 seconds, and 80% experienced concomitant tinnitus. We conclude that TAD is a common finding in a healthy population. This may have implications for the pathogenesis of sudden-onset sensorineural hearing loss. Further longitudinal studies and detailed audiologic evaluation of patients with TAD are required to ascertain the significance, etiology, and pathophysiology of this condition.

Mean platelet volume: is it a predictive parameter in the diagnosis of sudden sensorineural hearing loss?

The mean platelet volume (MPV) is associated with increased platelet reactivity and increased atherothrombosis. High MPV values are a risk factor for thrombotic vascular diseases. Our aim was to investigate whether a relationship exists between sudden sensorineural hearing loss (SSHL) and a high MPV value. The records of 46 patients who were admitted to the ENT (ear nose throat) ward for SSHL and received medical treatment and 46 patients in a control group were retrospectively screened. The correlation among the levels of the MPV, the number of platelets, and SSHL were evaluated in the two groups. The ages, genders, and the platelet count values of the patients showed a normal distribution in both groups. No significant difference was found for the MPV values between the groups. The MPV is not a predictive parameter in the diagnosis of SSHL.

Migraine is a risk factor for sudden sensorineural hearing loss: a nationwide population-based study

BACKGROUND

The pathophysiology of idiopathic sudden sensorineural hearing loss (SSNHL) is poorly understood. Few case reports have proposed a possible link between migraine and SSNHL.

OBJECTIVES

This study aimed to explore the risk of idiopathic SSNHL in patients with migraine in a nationwide, population-based cohort study.

METHODS

We identified patients with migraine from the Taiwan National Health Insurance Research Database (NHIRD) between 2000 and 2009. Each migraine patient was matched with four randomly selected subjects without migraine for age, sex, and comorbidities. Both cohorts were followed up until the end of 2009. We compared the incidence rates of SSNHL in the two cohorts and identified the risk factors.

RESULTS

A total of 10,280 migraine patients and 41,120 matched controls were enrolled with a median follow-up of five years. The migraine cohort had a greater risk of developing SSNHL than the matched cohort (81.6 vs. 45.7 per 100,000 person-years, incidence rate ratio (IRR) = 1.8; 95% confidence interval (CI) 1.22-2.61, p = 0.002). The Cox proportional hazards analysis revealed that among migraine subjects, comorbidity with hypertension was associated with a trend of developing SSNHL (hazard ratio (HR) = 1.92, 95% CI 0.97-3.79, p = 0.06).

CONCLUSIONS

This population-based study demonstrates that migraine is associated with an increased risk of idiopathic SSNHL, which, however, is a rare condition.

Treatment Outcome of Additional Dextran to Corticosteroid Therapy on Sudden Deafness

Objective

This study aimed to investigate whether adding low-molecular-weight dextran to oral steroids in patients with idiopathic sudden sensorineural hearing loss resulted in better hearing outcomes than those in patients receiving oral corticosteroids alone.

Study Design

Historical cohort study.

Setting

Tertiary teaching hospital.

Subjects and Methods

The authors reviewed the clinical records of 166 patients with idiopathic sudden sensorineural hearing loss. Therapeutic effectiveness was measured by the gain of pure-tone averages and 4 categories of hearing outcome (complete recovery, marked recovery, mild improvement, or no improvement). To manage potential confounding factors associated with treatment allocation, the authors matched the subjects from each group according to the propensity score (ie, the predicted probability that they would receive a specific treatment).

Results

The authors identified 50 pairs of propensity score–matched subjects (n = 100) without significant difference of all clinical factors ( P > .05). Subsequent analyses demonstrated that the average hearing gain in subjects receiving additional dextran to oral steroid was 31.7 ± 21.5 dB, which did not differ from 33.0 ± 21.8 dB in subjects receiving steroids alone ( P = .76). Difference of hearing outcomes between the 2 groups was also nonsignificant ( P = .92).

Conclusion

Matching propensity scores successfully balanced the heterogeneity between the dextran and steroid groups. Analytical results demonstrated that adding low-molecular-weight dextran to oral corticosteroids was not associated with greater hearing gain or better hearing outcome in idiopathic sudden sensorineural hearing loss.

No increased risk of sudden sensorineural hearing loss following recent herpes zoster: a nationwide population-based study

CONCLUSION

There is no increased risk for sudden sensorineural hearing loss (SSNHL) among people who have experienced a recent herpes zoster attack, compared with a matching population.

OBJECTIVE

The pathogenesis of SSNHL remains unknown, but viral infection is considered to be one of the main causes. The objective of this case-cohort study was to investigate the frequency and risk for SSNHL following a recent herpes zoster attack in the general population.

METHODS

We extracted 313 612 patients with herpes zoster from a nationwide health registry in Taiwan, and also randomly selected 313 612 matched control subjects. Each participant was individually tracked for 2 months from their index ambulatory care visit to identify those who developed SSNHL. Stratified Cox proportional hazard regressions were conducted to analyze the risk of SSNHL for the sampled patients.

RESULTS

Of the sample of 627 224 patients, 121 (0.02%) had SSNHL during the 2-month follow-up period, 59 from the study group (0.02% of the herpes zoster patients) and 62 from the comparison group (0.02% of patients without herpes zoster). Regression analysis revealed no increased adjusted hazard of SSNHL during the 2-month follow-up period for patients with herpes zoster as compared to those without (hazard ratio = 0.89, 95% confidence interval (CI) = 0.63-1.28, p = 0.540).

Systematic review and meta-analysis of the risk factors for sudden sensorineural hearing loss in adults

OBJECTIVES/HYPOTHESIS

To review the medical literature evidence of potential risk factors for sudden sensorineural hearing loss (SSNHL) in the adult general population.

STUDY DESIGN

Systematic review of prospective and retrospective studies; meta-analysis of case-controlled studies.

METHODS

Three researchers independently reviewed MEDLINE (January 1, 1950-November 30, 2010), Embase (January 1, 1980-November 30, 2010), and Evidence-Based Medicine Reviews databases in addition to conducting a manual reference search. Randomized controlled trials, prospective cohort studies, consecutive/nonconsecutive case series, and retrospective reviews in which a clear definition of SSNHL was stated were included in the study. Researchers individually extracted data regarding patient information and the presumed risk factors. Discrepancies were resolved by mutual consensus.

RESULTS

Twenty-two articles met the inclusion criteria. Cardiovascular risk factors (smoking, increased alcohol consumption) appeared to be associated with a higher risk of developing SSNHL. A low level of serum folate may also be implicated as a risk factor. Factor V Leiden and MTHFR gene polymorphisms were found to occur more frequently in patients with SSNHL in several studies, suggesting these inherited prothrombophilic mutations could be independent risk factors of SSNHL.

CONCLUSIONS

Acquired and inherited cardiovascular risk factors appeared to be associated with an increased risk of developing SSNHL.

Sudden sensorineural hearing loss increases the risk of stroke: a 5-year follow-up study

BACKGROUND AND PURPOSE

No previous study has investigated the incidence or risk of cerebrovascular diseases developing after the sudden sensorineural hearing loss (SSNHL). This study sets out to estimate the risk of stroke development among SSNHL patients during a 5e-year follow-up period after hospitalization for acute episodes of SSNHL.

METHODS

Our study design features a study cohort and a comparison cohort. The study cohort consists of all patients hospitalized with a principal diagnosis of sudden hearing loss (n=1,423), whereas the control cohort comprised all patients hospitalized for an appendectomy in 1998 (n=5692) as a surrogate for the general population. Each patient was tracked from hospitalization in 1998 until the end of 2003. Cox proportional hazard regressions were performed as a means of computing the 5-year stroke-free survival rates after adjustment for possible confounding factors.

RESULTS

Of the total sample, 621 patients (8.7%) had strokes during the 5-year follow-up period: 180 (12.7% of the SSNHL patients) from the study cohort and 441 (7.8% of patients undergoing an appendectomy) from the control cohort. After adjusting for other factors, the hazard of stroke during the 5-year follow-up period was 1.64-times (95% CI, 1.31 to 2.07; P<0.001) greater for SSNHL patients than for appendectomy patients.

CONCLUSIONS

Our findings suggest that SSNHL can be an early warning sign of impending stroke. We suggest that SSNHL patients should undergo a comprehensive hematologic and neurological examination to help clinicians identify those potentially at risk for stroke developing in the near future.

Sudden deafness: is it viral?

A number of theories have been proposed to explain the etiopathogenesis of idiopathic sudden sensorineural hearing loss (ISSHL), including viral infection, vascular occlusion, breaks of labyrinthine membranes, immune-mediated mechanisms and abnormal cellular stress responses within the cochlea. In the present paper, we provide a critical review of the viral hypothesis of ISSHL. The evidence reviewed includes published reports of epidemiological and serological studies, clinical observations and results of antiviral therapy, morphological and histopathological studies, as well as results of animal experiments. The published evidence does not satisfy the majority of the Henle-Koch postulates for viral causation of an infectious disease. Possible explanations as to why these postulates remain unfulfilled are reviewed, and future studies that may provide more insight are described. We also discuss other mechanisms that have been postulated to explain ISSHL. Our review indicates that vascular occlusion, labyrinthine membrane breaks and immune-mediated mechanisms are unlikely to be common causes of ISSHL. Finally, we review our recently proposed theory that abnormal cellular stress responses within the cochlea may be responsible for ISSHL.

[Dynamic vestibular compensation in vestibular peripheral diseases]

Vestibular compensation, or neuronal plasticity in the central vestibular system, is quite an important process in patients with acute unilateral peripheral vestibular disease, allowing them to lead a comfortable daily life when medical treatments fail to cure the peripheral vestibular function. Is the residual unilateral vestibular input from damaged vestibular endo-organs a positive or negative factor for the development of dynamic vestibular compensation in the central nervous system? To elucidate the true mechanism of vestibular compensation, we examined the ENG findings and dizziness handicap inventory questionnaire in patients with vestibular neuronitis (VN), sudden deafness with vertigo (SDV), Meniere's disease (MD) and acoustic tumor (AT) during remission of the vertigo attacks. We obtained neuro-otological findings from caloric tests and head shaking after nystagmus using ENG and information on motion-evoked dizziness in daily life using the questionnaire. There were no significant differences in the sex, age or canal paresis % (CP%) among the four groups. The results of the present study showed that dynamic vestibular compensation processes developed progressively in the order of patients with SDV, VN, MD and AT (Kruskal-Wallis : p < 0.05). This finding suggests that processes of dynamic vestibular compensation could be accelerated in patients with fixed vestibular lesions caused by SDV and VN more than in those with fluctuating vestibular functions caused by MD and AT. In patients with fixed vestibular lesions caused by SDV and VN, patients with lower CP% showed dynamic vestibular compensation (i.e. disappearance of head shaking after nystagmus (chi-square: p < 0.05) and motion-evoked dizziness (Mann-Whitney: p < 0.0005)) more rapidly than those with higher CP%. In patients with fluctuating vestibular functions caused by MD and AT, patients with lower CP% did not always develop dynamic vestibular compensation more smoothly than those with higher CP%.

Surdez súbita idiopática: aspectos etiológicos e fisiopatogênicos

Vários fatores têm sido postulados como causa da surdez súbita idiopática. Por meio de uma revisão bibliográfica foi feita uma análise crítica quanto aos aspectos etiológicos e fisiopatogênicos desta manifestação clínica. Estudos atuais sugerem que os distúrbios vasculares, a ruptura de membranas da orelha interna e as doenças auto-imunes são possíveis causas, mas a afecção viral tem recebido maior atenção nos últimos anos, embora ainda pouco se conheça sobre os mecanismos da surdez súbita idiopática. Os vírus podem causar a perda súbita da audição na infecção aguda, mas a forma latente, com uma possível reativação viral, também tem sido considerada no mecanismo de agressão à cóclea. Apesar de uma alteração da viscosidade sangüínea poder explicar a perda auditiva, estudos experimentais e clínicos não mostram sinais de ossificação e de fibrose na cóclea ou de ruptura de membranas do labirinto. Estes fatos contrapõem, respectivamente, a teoria vascular e a da fístula labiríntica. A eventual presença de anticorpos contra a orelha interna sugere que a surdez súbita idiopática possa ser de natureza auto-imune, fato este também não confirmado pela falta de relação entre os aspectos clínicos e morfológicos da doença auto-imune e da perda auditiva. A surdez súbita idiopática é, ainda, um tema controverso e obscuro em diversos aspectos.

Idiopathic sudden sensorineural hearing loss: etiopathogenic aspects

Several factors have been postulated to elicit the etiology of idiopathic sudden sensorineural hearing loss. Through a bibliographic review, we made a critical analysis of the different etiopathogenic aspects of its clinical manifestation. The most recent studies concerning the possible causes of sudden hearing loss suggest vascular disorders, rupture of the inner ear membrane and autoimmune diseases; however, viral infections have received a great deal of attention in recent years. Little is known about the mechanism of sudden hearing loss. Viruses can cause sudden hearing loss in an acute infection, however the latent form, and its possible reactivation have also been considered as explanations of the cochlear injury mechanism. Even though hearing loss can be explained by a blood viscosity change, experimental and clinical studies do not show any evidence of labyrinthine fibrosis and new bone formation, or labyrinthine membrane breaks. These findings are not in agreement with vascular and rupture membrane factors, respectively. The eventual presence of antibodies against the inner ear suggests that sudden hearing loss pathogenesis may be of autoimmune nature, but the difficulty in establishing the correlation of its morphological and clinical aspects to the hearing loss also do not help to support this statement. Sudden hearing loss is still a controversial and obscure subject in several aspects.

Paget disease and sensorineural hearing loss associated with spiral ligament degeneration

HYPOTHESIS

Previously unreported cystic degeneration of the spiral ligament in cases of Paget disease.

BACKGROUND

About 70% of cases of Paget disease involve the skull, with hearing affected in approximately 50% of these. The hearing impairment may be sensorineural, mixed, or, rarely, only conductive. The etiology and pathogenesis of the hearing loss are not yet understood, and reports in the literature are inconsistent regarding the pathologic changes responsible for sensorineural hearing loss. Of six pairs of temporal bones from patients with Paget disease in the temporal bone collection of a research institution, two pairs have abnormalities not previously associated with sensorineural hearing loss or Paget disease. We report the histopathologic findings in these temporal bones.

METHODS

The temporal bones were fixed in formalin, decalcified in ethylenediaminetetraacetic acid, embedded in celloidin, and sectioned in the horizontal plane at a thickness of 20 microm. Every 10th section was stained with hematoxylin-eosin and mounted on glass slides. The sections were examined by light microscopy.

RESULTS

Cystic degeneration of the spiral ligament, primarily in the basal segment, was found in both cases. Endolymphatic hydrops and a small endolymphatic sac with calcification of the perisaccular tissue were found in one case.

CONCLUSIONS

Cystic degeneration of the spiral ligament has not been previously reported and may be unique to Paget disease. This is consistent with recent literature showing a previously unsuspected role of the spiral ligament in sensorineural hearing loss.

Ressonância magnética em surdez súbita

A surdez súbita é um sintoma cuja etiologia nem sempre é elucidada mesmo dispondo-se de toda propedêutica atual. Neste estudo avaliaremos as alterações encontradas em ressonância magnética de pacientes portadores de surdez súbita. FORMA DE ESTUDO: coorte transversal. MATERIAL E MÉTODO: Estudo prospectivo com realização de RM em 49 dos 61 pacientes com surdez súbita atendidos no pronto socorro de Otorrinolaringologia do Hospital São Paulo, no período de abril de 2001 a maio de 2003. Doze pacientes abandonaram ou não foram submetidos à ressonância magnética por outros motivos. RESULTADOS: 23 (46,9%) pacientes apresentaram alterações à ressonância magnética. Foram encontrados dois tumores sugestivos de meningioma e três schwannomas do oitavo par craniano. Lesões subcorticais e periventriculares esparsas e hiperintensas em FLAIR foram encontradas em 13 pacientes. Cinco (21,7%) pacientes apresentaram alterações periféricas. CONCLUSÃO: A surdez súbita deve ser abordada como um sintoma comum a diferentes doenças. A presença de tumores do ângulo pontocerebelar em 10,2% dos nossos casos, entre outras causas tratáveis, justifica o uso da ressonância magnética com contraste tanto para o estudo do sistema auditivo periférico quanto para o estudo das vias auditivas centrais, incluindo o cérebro.

Magnetic resonance imaging in sudden deafness

The etiology of sudden deafness can remain undetermined despite extensive investigation. This study addresses the value of magnetic resonance imaging in the analysis of sudden deafness patients. Study design: transversal cohort. Material and Method: In a prospective study, 49 patients attended at otolaryngology emergency room of Federal University of Sao Paulo - Escola Paulista de Medicina, from April 2001 to May 2003, were submitted to magnetic resonance imaging. Results: Magnetic Resonance abnormalities were seen in 23 (46.9%) patients and revealed two tumors suggestive of meningioma, three vestibular schwannomas, thirteen microangiopathic changes of the brain and five (21.7%) pathological conditions of the labyrinth. Conclusion: Sudden deafness should be approached as a symptom common to different diseases. The presence of cerebellopontine angle tumors in 10.2% of our cases, among other treatable causes, justifies the recommendation of gadolinium-enhanced magnetic resonance use, not only to study the auditory peripheral pathway, but to study the whole auditory pathway including the brain.

Pathology and Pathophysiology of Idiopathic Sudden Sensorineural Hearing Loss

BACKGROUND

The cause and pathogenesis of idiopathic sudden sensorineural hearing loss remain unknown. Proposed theories include vascular occlusion, membrane breaks, and viral cochleitis.

AIMS

To describe the temporal bone histopathology in 17 ears (aged 45-94 yr) with idiopathic sudden sensorineural hearing loss in our temporal bone collection and to discuss the implications of the histopathologic findings with respect to the pathophysiology of idiopathic sudden sensorineural hearing loss.

METHODS

Standard light microscopy using hematoxylin and eosin-stained sections was used to assess the otologic abnormalities.

RESULTS

Hearing had recovered in two ears and no histologic correlates were found for the hearing loss in both ears. In the remaining 15 ears, the predominant abnormalities were as follows: 1) loss of hair cells and supporting cells of the organ of Corti (with or without atrophy of the tectorial membrane, stria vascularis, spiral limbus, and cochlear neurons) (13 ears); 2) loss of the tectorial membrane, supporting cells, and stria vascularis (1 ear); and 3) loss of cochlear neurons only (1 ear). Evidence of a possible vascular cause for the idiopathic sudden sensorineural hearing loss was observed in only one ear. No membrane breaks were observed in any ear. Only 1 of the 17 temporal bones was acquired acutely during idiopathic sudden sensorineural hearing loss, and this ear did not demonstrate any leukocytic invasion, hypervascularity, or hemorrhage within the labyrinth, as might be expected with a viral cochleitis.

DISCUSSION

The temporal bone findings do not support the concept of membrane breaks, perilymphatic fistulae, or vascular occlusion as common causes for idiopathic sudden sensorineural hearing loss. The finding in our one case acquired acutely during idiopathic sudden sensorineural hearing loss as well as other clinical and experimental observations do not strongly support the theory of viral cochleitis.

CONCLUSION

We put forth the hypothesis that idiopathic sudden sensorineural hearing loss may be the result of pathologic activation of cellular stress pathways involving nuclear factor-kappaB within the cochlea.

Surdités brusques idiopathiques

Idiopathic Sudden Sensorineural Hearing Loss (ISSHL) remains one of the major unsolved otologic emergencies. It is characterized by the onset of an unilateral sensorineural hearing loss developing within 24 hours, and averaging on pure tone audiogram at least 30 dB HL for three subsequent octave steps, with no marked vestibular symptoms and no identifiable cause. ISSHL is a syndrome covering several heterogeneous entities resulting from different pathogenetic mechanisms. At this time, the audiogram is the unique tool which may help clinicians to identify these entities and provide a classification based on 5 types of hearing loss. Numerous experimental and clinical studies have investigated the mechanisms by which infectious, ischemic, mechanic or immunologic insults may induce cochlear dysfunction. However, extrapolation to humans and rationale therapeutic approaches to ISSHL remain uncertain. SSHL being a diagnosis of exclusion, retrocochlear and neurologic etiologies should be eliminated. No argument allows to consider ISSHL a therapeutic emergency. More precisely, the experimental data presently available on cochlear physiology suggests that a treatment could have some chance to be effective if undertaken within minutes following the onset of ISSHL, a condition never encountered in daily practice. Conversely, it is not justifiable to impute the absence of hearing recovery to a delay in therapy. The various therapeutic strategies currently recommended are highly empirical and should be questionned in terms of cost-effectiveness, the most common being high-dose corticosteroids. New investigation tests are required for improving our approach to ISSHL.

Platelet GPIaC807T polymorphism is associated with negative outcome of sudden hearing loss

To determine the relevance of inherited prothrombotic risk factors in sudden hearing loss, we investigated 85 patients with sudden hearing loss of >/= 60 dB for the presence of inherited prothrombotic risk factors. The FV G1691A, FII G20210A, GPIa C807T, GPIIIa PIA1/A2, PAI-1 4G/5G, t-PA Alu repeat ID, MTHFR C677T and CBS 844ins68 genotypes were investigated. Allele frequencies found in patients were compared to those of 85 healthy control subjects of the same ethnic background using Chi-squared and odds-ratio analysis. The frequency of the GPIa807T allele was significantly elevated in patients compared to controls. In addition, allele frequency and genotype distribution of GPIa was significantly elevated in the patient group without recovery after 3 months of sudden hearing loss onset. Allele frequencies of all other prothrombotic risk factors investigated here did not differ from those of the control subjects. The single-nucleotide polymorphism of GPIa C807T seems to play a role as a prognostic factor in recovery from sudden hearing loss.

Treatment of idiopathic sudden sensorineural hearing loss with antiviral therapy: a prospective, randomized, double-blind clinical trial

A subclinical viral labyrinthitis has been postulated in the literature to elicit idiopathic sudden sensorineural hearing loss (ISSHL). An etiologic role for the herpes family is assumed. Corticosteroids possess a limited beneficial effect on hearing recovery in ISSHL. In this study, we evaluated the therapeutic value of the antiherpetic drug acyclovir (Zovirax) on hearing recovery in 91 patients with ISSHL who received prednisolone in a prospective, randomized, double-blind, placebo-controlled, multicenter trial. The audiometric parameters included pure tone and speech audiometry. Subjective parameters studied included hearing recovery, a pressure sensation in the affected ear, vertigo, and tinnitus. A 1-year follow-up was obtained. Hearing recovery for the whole group averaged about 35 dB and was independent of the severity of the initial hearing loss or vestibular involvement. Speech audiometry improved from 49% to 75%. After 12 months, pressure sensation and vertigo decreased to 15.6% (acyclovir) and 10.3% (placebo) and 12.5% (acyclovir) and 10.7% (placebo), respectively. Tinnitus decreased slightly, to 46.9% (acyclovir) and 55.2% (placebo), in the same period (p > .05 for all parameters). We conclude that no beneficial effect from combining acyclovir with prednisolone can be established in patients with ISSHL.

Acyclovir in the Treatment of Idiopathic Sudden Sensorineural Hearing Loss

BACKGROUND: Idiopathic sudden sensorineural hearing loss (ISSNHL) is a vexing problem that continues to pose a diagnostic and therapeutic enigma for the otologist. The aim of the study, adopting the viral theory, was to discover whether patients with ISSNHL would benefit from early treatment with acyclovir and hydrocortisone compared with patients treated by hydrocortisone alone.

METHODS: Sixty patients with ISSNHL were treated in a prospective controlled randomized manner. Patients were seen within 7 days of onset and were divided randomly into 2 groups. The study group patients were treated with acyclovir and hydrocortisone, whereas those in the control group were treated with hydrocortisone alone.

RESULTS: We compared the 2 groups before and after treatment regarding SRT, mean hearing level at each frequency, speech reception threshold improvement, gender, age, tinnitus, and balance complaints. The overall improvement was 78%.

CONCLUSION: We conclude that there probably is no benefit from the addition of acyclovir in the treatment of ISSNHL.

Autoimmunity in sudden sensorineural hearing loss: possible role of anti-endothelial cell autoantibodies

In order to verify whether anti-endothelial cell autoantibodies (AECAs) can be used as serological markers of inner ear vasculitis in sudden sensorineural hearing loss (SSHL), 32 patients affected by idiopathic SSHL were investigated. All patients underwent a routine general physical examination and extensive audiovestibular, microbiological and immunological investigations. Fourteen normal subjects without a history of HL, autoimmune or metabolic disease served as controls. Detection of AECAs was performed using an indirect immunofluorescence technique. AECA-positive patients were treated with methylprednisone, while AECA-negative patients were treated with a combined regimen of steroids, plasma expander and aspirin. The average hearing recovery for 5 frequencies (0.25-4 kHz) was analyzed in each subject 1 month after treatment and every 3 months thereafter; median follow-up was 12 months (range 9-18 months). A total of 15/32 patients (46.8%; 11/19 females, 4/13 males) were AECA-positive and thus differed significantly from the normal population in whom only 2/14 tested cases were positive (p = 0.03). Severe hearing loss was associated with being AECA-positive in 8/11 cases. During follow-up, 25/32 patients improved their hearing and 17 of these patients were AECA-negative. The seven cases without hearing improvement were all AECA-positive. In patients with SSHL, immune-mediated vascular damage may have a pathogenetic role and AECAs may represent a serological marker of vasculitis even if they are not inner ear-specific and even if they represent an epi-phenomenon rather than the only cause of SSHL.

Analysis of spiral ganglion cell populations in children with normal and pathological ears

This study analyzed features of total and segmental spiral ganglion cell populations in children with normal ears and those with various pathological conditions. Sixty-three human temporal bone specimens, obtained from 43 children 4 days to 9 years of age, were studied histopathologically. These specimens were divided into 5 diagnostic groups: group 1, normal ears (13 ears); group 2, congenital infectious diseases (13 ears); group 3, chromosomal aberrations (11 ears); group 4, multiple craniofacial anomalies with hereditary or genetic causes (21 ears); and group 5, perinatal and postnatal asphyxia (5 ears). Eighteen of the 63 ears had documented profound deafness. In either normal ears (group 1) or those with various pathological conditions (groups 2 through 5), the total number of ganglion cells did not change as a function of age during the first 10 years. The total number of ganglion cells was significantly larger in group 1 (33,702) than in each of groups 2, 3, 4, and 5 (p < .01), and the number was significantly larger in group 2 than in each of groups 4 and 5 (p < .01 and p < .05, respectively). The ratio of basal to apical ganglion cell populations remained constant in both normal and pathological ears. Each ratio of the number of basal and apical ganglion cells in groups 2, 3, 4, and 5 to the mean number in group 1 (basal and apical survival ratios) was at least approximately 40%. There was no statistical difference between these two ratios in groups 2, 3, 4, and 5. The mean (+/-SD) total number of ganglion cells in ears with documented profound deafness was 15,417 +/- 5,944, which is approximately 40% of those present in normal ears. Our results suggest that normally, cochlear neurons are completely present at birth and minimally regress during the first decade of life. In addition, although intergroup differences among various pathological groups were present, the majority of pathological ears had more than 10,000 spiral ganglion cells present. Cochlear implantation has gradually been recognized as an effective and reliable tool for rehabilitation of children who have profound deafness, even congenitally or prelingually deafened children. On the basis of the results obtained in this study, we discuss the implications for cochlear implantation in children.

Dextran-induced pulmonary edema in patients with sudden deafness

OBJECTIVE

Pulmonary complication in cases of sudden deafness after dextran treatment is rarely reported. This study discusses the management of two cases and reviews the current literature.

PATIENTS

Two (1%) of 204 patients with sudden deafness patients had fever, cough, and dyspnea after intravenous dextran infusion. Pulmonary edema was diagnosed after chest radiographic examination.

RESULTS

After interruption of dextran, subsequent supportive treatment relieved chest discomfort and fever without any sequelae. The results of chest radiograph and laboratory studies, including hemogram, renal function, and arterial blood oxygen saturation, were normal.

CONCLUSIONS

Patients receiving dextran treatment should have their clinical symptoms, renal function, chest radiographs, hemogram, and coagulation profiles monitored. If fever, bleeding, cough, or dyspnea occurs during treatment, dextran must be immediately stopped. Subsequent treatment should focus on dextran clearance to prevent further cascade complications.