Viral and epidemiologic studies of idiopathic sudden hearing loss

Natural History of Untreated Idiopathic Sudden Sensorineural Hearing Loss

OBJECTIVE

Although corticosteroids and other treatments for idiopathic sudden sensorineural hearing loss (ISSNHL) have been described, understanding its prognosis without intervention provides valuable information for patient management. The objective of this study is to provide a comprehensive, quantitative statistical analysis of the natural history of untreated idiopathic sudden sensorineural hearing loss (ISSNHL).

STUDY TYPE AND DESIGN

A systematic review and meta-analyses.

METHODS

Two independent searches of PubMed, Scopus, Web of Science, and Cochrane Library databases up to June 30, 2022, were performed. Adults with idiopathic sudden sensorineural hearing loss who received placebo or were untreated and had audiometric outcome measures in all study types were reviewed. These data indicative of the natural history of ISSNHL were analyzed, as were study characteristics related to risk of bias. Heterogeneity as assessed via I2 and random effects analyses were performed.

RESULTS

Six studies meeting the inclusion criteria yielded 319 untreated patients whose natural history could be assessed. Heterogeneity among studies was moderate, with a variety of reported outcomes. A hearing improvement of at least 30 dB HL was observed in 36% (95% CI 0.28-0.44) of untreated patients, and of at least 10 dB HL was observed in 70% (95% CI 0.57-0.82) of untreated patients at 3 months. The mean hearing gain among untreated patients was 24.0 dB HL (95% CI 2.65-45.37) at 2-3 months.

CONCLUSIONS

The observed natural history of ISSNHL suggests that patients can regain some hearing without active treatment. In the absence of future studies collecting prospective natural history data from untreated or placebo-treated ISSNHL patients, the data presented here provide the best available historical control data for reconsideration of results in past ISSNHL studies, as well as a roadmap for design and interpretation of future ISSNHL treatment clinical trials. Furthermore, knowing there is a statistically significant mean hearing gain of 24.0 dB HL in the untreated/placebo group provides an ethical basis for future placebo study of ISSNHL. The current status on ISSNHL management calls for a multi-institutional, randomized, double-blind placebo-controlled trial with validated outcome measures to provide science-based treatment guidance. Laryngoscope, 134:S1-S15, 2024.

Association between air pollution and sudden sensorineural hearing loss (SSHL): A systematic review and meta-analysis

Recent studies have indicated that air pollution (AP) has harmful effects on hearing and ear diseases such as Sudden Sensorineural Hearing Loss (SSHL). The purpose of this study was to evaluate the impact of exposure to AP on SSHL incidence. Valid electronic databases were searched to retrieve studies published until December 1, 2022, using appropriate keywords. The result of the search was 1146 studies, and after screening according to the defined criteria, in total 8 studies were obtained. The risk of bias (ROB) in the studies and their quality were assessed. Finally, the meta-analysis with a significance level of 5% was performed. The findings revealed that the mean level of SO2, CO, NO2, and PM10 in the patient group was more than that of the control group, and p-values were 0.879, 0.144, 0.077, and 0.138, respectively. There was an indirect relation between air pollutants and SSHL, and PM2.5 showed a significant effect (p < 0.05). Given the limited research and the use of different statistical methods, more research is suggested to confirm this association and to determine the mechanisms by which AP exposure may cause SSHL.

High Cardio-Ankle Vascular Index Values in Idiopathic Sudden Sensorineural Hearing Loss Patients Indicate Better Prognosis

OBJECTIVE

Vascular disorders and viral infections are the presumed etiologies of idiopathic sudden sensorineural hearing loss (ISSNHL) and acute sensorineural hearing loss, with no identifiable cause. However, no clinical test for estimating the extent of vascular involvement in ISSNHL has been reported despite its potential impact on prognosis and treatment. We investigated the correlation between the cardio-ankle vascular index (CAVI), which reflects arterial stiffness and elasticity, and hearing improvement to ascertain its usefulness as an additional indicator of ISSNHL prognosis and etiology.

METHODS

We enrolled 182 patients diagnosed with definite ISSNHL. The percentage of mild ISSNHL patients and that of patients experiencing no change were compared between the high-CAVI and low-CAVI groups. Age, initial and final pure-tone average (PTA) values, CAVI, presence or absence of vertigo, and medical histories were retrospectively reviewed and included in univariate and multivariate analyses.

RESULTS

The percentage of mild ISSNHL patients was smaller in the high-CAVI group than in the low-CAVI group, whereas the percentage of patients experiencing no change was smaller in the high-CAVI group than in the low-CAVI group, although patients in the high-CAVI group were significantly older than those in the low-CAVI group. The Cox proportional hazard model revealed that high CAVI, hypertension, younger age, and initial PTA <90 dB were associated with hearing improvement.

CONCLUSIONS

ISSNHL in patients with high CAVI was more severe but had a better prognosis than that in those with low CAVI. CAVI may help evaluate diseases of vascular and other etiologies, as well as ISSNHL.

Intra-Tympanic Dexamethasone Therapy via Grommet Insertion for Improved Auditory Outcome in Sudden Sensorineural Hearing Loss

Idiopathic sudden-sensorineural hearing loss (ISSHL) is an emergent otological condition needing prompt treatment for better recovery. In our study we aimed to determine the efficacy of intra-tympanic dexamethasone therapy after inserting a grommet in postero-inferior quadrant of the tympanic membrane for dexamethasone instillation. This is a prospective cohort study of 31 patients of ISSHL, in whom grommet was inserted and dexamethasone drops were instilled for 5 days. Several factors such as time of initiation of therapy, age of patient was considered, and inferences were drawn. Auditory outcomes were divided into low, mid and high frequency and the results were tabulated. Paired t tested was applied for all frequencies for both pre-test and post-test. P-value was (< 0.05) in all the three ranges of frequencies. Also, statistical significance was found between early treatment from onset of disease and auditory outcome. The earlier the therapy was initiated, better were the results.

Is There an Association between Concurrent Epstein-Barr Virus Infection and Sudden Hearing Loss?-A Case-Control Study in an East Asian Population

Viral infection serves as the crucial etiology for the development of sudden sensorineural hearing loss (SSNHL). We aimed to investigate whether there is an association between concurrent Epstein-Barr virus (EBV) infection and SSNHL in an East Asian population. Patients who were older than 18 years of age and met the criteria of sudden hearing loss without an identifiable etiology were enrolled from July 2021 until June 2022, followed by the serological testing of IgA antibody responses against EBV-specific early antigen (EA) and viral capsid antigen (VCA) with an indirect hemagglutination assay (IHA) and real-time quantitative polymerase chain reaction (qPCR) of EBV DNA in serum before the treatment was initiated. After the treatment for SSNHL, post-treatment audiometry was performed to record the treatment response and degree of recovery. Among the 29 patients included during enrollment, 3 (10.3%) had a positive qPCR result for EBV. In addition, a trend of poor recovery of hearing thresholds was noted for those patients with a higher viral PCR titer. This is the first study to use real-time PCR to detect possible concurrent EBV infection in SSNHL. Our study demonstrated that approximately one-tenth of the enrolled SSNHL patients had evidence of concurrent EBV infection, as reflected by the positive qPCR test results, and a negative trend between hearing gain and the viral DNA PCR level was found within the affected cohort after steroid therapy. These findings indicate a possible role for EBV infection in East Asian patients with SSNHL. Further larger-scale research is needed to better understand the potential role and underlying mechanism of viral infection in the etiology of SSNHL.

The Incidence of Sudden Sensorineural Hearing Loss (SSNHL) in COVID-19 Patients in Tertiary Care Referral Units

COVID-19 is a new pandemic infectious disease that emerged in Wuhan, China, at the end of 2019. We aimed to evaluate the sudden sensorineural hearing loss (SSNHL) prevalence after COVID-19 infection or even vaccination. This is a two-center retrospective, observational cross-sectional study performed at tertiary care referral Audiovestibular Medicine Units at the period between August 1, 2020, and October 31, 2021. All SSNHL patients diagnosed in a period of a month with COVID-19 or vaccinated with a COVID-19 vaccine were included in this study. Fifty-three cases with confirmed COVID-19 and one patient vaccinated with a COVID-19 vaccine 1 week before, who reported sudden sensory neural hearing loss, were included in this study. Forty-eight patients had unilateral hearing loss and 6 patients had bilateral hearing loss. Forty-nine patients had typical COVID-19 symptoms; one patient discovered them after complaining of anosmia and ageusia and one patient after COVID-19 vaccination; and three patients were complaining only from hearing loss and had a PCR test for nasopharyngeal swabs to prove infection. Different degrees of SSNHL ranged from mild to severe and most of the patients had severe hearing loss. With more patients, COVID-19 may be a potential factor in sudden sensorineural hearing loss. It should be kept in mind that SSNHL may be the only indicator used to identify COVID-19 cases.

Standardization of Outcome Measures for Intratympanic Steroid Treatment for Idiopathic Sudden Sensorineural Hearing Loss

OBJECTIVE

To identify variability in reported hearing outcomes for intratympanic (IT) steroid treatment of idiopathic sudden sensorineural hearing loss (ISSNHL) by comparing outcomes using the American Academy of Otolaryngology-Head and Neck Surgery (AAO-HNS) guideline with other published criteria.

STUDY DESIGN

Retrospective chart review.

SETTING

Tertiary otology practice.

PATIENTS

Patients with ISSNHL treated with IT steroid between April 2003 and December 2020.

INTERVENTIONS

IT steroid injection and audiometric evaluation.

MAIN OUTCOME MEASURES

1) Rates of full, partial, or no recovery using the AAO-HNS guideline versus other reported criteria, and 2) correlation analyses of demographic and clinical variables with response to IT steroid.

RESULTS

Using AAO-HNS reporting criteria, full recovery of the pure-tone average was noted in 25.68% of patients. Applying eight other published outcomes criteria to this patient cohort classified full recovery in 14.87 to 40.54% of patients. Similarly, AAO-HNS criteria classified "no recovery" in 51.35% of our patients, whereas applying the other reported criteria showed an average rate of 62.16% no recovery and as high as 82.43% of patients without recovery. Younger age ( p = 0.003; effect size, 0.924) and IT injection within a week of onset ( p < 0.001; effect size, 1.099) positively correlated with full recovery. There was no impact of prior or concurrent oral steroids, or number of steroid injections on outcome.

CONCLUSION

Great variability exists in the literature for assessment of IT steroid outcomes in ISSNHL. Standard reporting of outcomes as per the AAO-HNS SSNHL guideline is recommended to consistently characterize IT steroid efficacy and allow comparison across studies.

Understanding Immune Responses to Lassa Virus Infection and to Its Candidate Vaccines

Lassa fever (LF) is a deadly viral hemorrhagic fever disease that is endemic in several countries in West Africa. It is caused by Lassa virus (LASV), which has been estimated to be responsible for approximately 300,000 infections and 5000 deaths annually. LASV is a highly pathogenic human pathogen without effective therapeutics or FDA-approved vaccines. Here, we aim to provide a literature review of the current understanding of the basic mechanism of immune responses to LASV infection in animal models and patients, as well as to several of its candidate vaccines.

Study of Hearing Status in COVID-19 Patients: A Multicentered Review

To evaluate the hearing status of COVID-19 patients and compare with control group. Prospective study carried out in 9 institutes. The pure tone audiogram and impedance audiometry of COVID-19 patients performed initially and at 3 months follow up. The control group consisted COVID-19 negative individuals with no history of ear related diseases. The average of air and bone conduction threshold (AC and BC) were compared between the COVID-19 patients and control group using independent t-test with a p value of less than 0.05 considered significant. Total of 331 patients, age 32 ± 4.3 years, 66.7% males and 33.3% females were included in the study. There were 80 individuals in the control group. Aural symptoms were, tinnitus in 1.8%, aural fullness in 1.4%, hearing loss in 3. 9%, and ear ache in 1.8% were present initially, resolved at 3 months follow up. The impedance audiometry demonstrated type B and type C curve in 5.1% and 1.15% ears, and out of these 64.7% and 40% improved at 3 months follow up respectively. No significant difference observed between the average AC and BC of the COVID-19 patients and control group. The COVID-19 infection may present with aural symptoms; however, it was concluded that there was no significant difference in the hearing status of the COVID-19 positive patients in comparison to the control group. The presence of some changes in the normal functioning of the eustachian tube and middle ear in the COVID-19 infection was also highlighted.

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.

Bilateral Sudden Sensorineural Hearing Loss: A Distinct Phenotype Entity

OBJECTIVE

To investigate the clinical phenotype and hearing prognosis of patients with unilateral and bilateral (simultaneous and nonsimultaneous) sudden sensorineural hearing loss (SSNHL).

STUDY DESIGN

Retrospective cohort.

SETTING

Otology outpatient clinic of a tertiary university hospital.

PATIENTS

Three hundred eighty-five medical records from patients with SSNHL.

MAIN OUTCOME MEASURES

Comparison of demographic, clinical, and audiometric (pretreatment and posttreatment) data of patients with unilateral and bilateral SSNHL.

RESULTS

Our final analysis comprised of 239 medical records of patients with SSNHL. Most patients had unilateral SSNHL (186, 77.82%). We identified a potential underlying cause for the SSNHL in 105 (43.9%) of the cases, being more frequent in cases of bilateral simultaneous SSNHL (100%) as compared with unilateral (45.6%) and nonsimultaneous bilateral SSNHL (22.7%). Cases of simultaneous bilateral SSNHL presented more frequently with severe or profound hearing loss (89%; unilateral SSNHL 50.5%; nonsimultaneous bilateral SSNL, 59.1%) and had a significantly worse hearing recovery prognosis as compared with unilateral or nonsimultaneous bilateral SSNHL (p = 0.002).

CONCLUSION

We observed a high heterogeneity of clinical presentations of SSNHL, the most common being unilateral SSNHL. Our results demonstrate that the clinical and audiological prognosis of simultaneous bilateral SSNHL differed significantly from unilateral and nonsimultaneous bilateral SSNHL, suggesting that simultaneous cases of bilateral SSNHL may be a part of a different disease process. The presence of a simultaneous, bilateral SSNHL indicates the need to investigate the presence of an underlying systemic disease.

Pathogenicity and virulence mechanisms of Lassa virus and its animal modeling, diagnostic, prophylactic, and therapeutic developments

Lassa fever (LF) is a deadly viral hemorrhagic disease that is endemic to West Africa. The causative agent of LF is Lassa virus (LASV), which causes approximately 300,000 infections and 5,000 deaths annually. There are currently no approved therapeutics or FDA-approved vaccines against LASV. The high genetic variability between LASV strains and immune evasion mediated by the virus complicate the development of effective therapeutics and vaccines. Here, we aim to provide a comprehensive review of the basic biology of LASV and its mechanisms of disease pathogenesis and virulence in various animal models, as well as an update on prospective vaccines, therapeutics, and diagnostics for LF. Until effective vaccines and/or therapeutics are available for use to prevent or treat LF, a better level of understanding of the basic biology of LASV, its natural genetic variations and immune evasion mechanisms as potential pathogenicity factors, and of the rodent reservoir-vector populations and their geographical distributions, is necessary for the development of accurate diagnostics and effective therapeutics and vaccines against this deadly human viral pathogen.

Biomarkers Suggesting Favorable Prognostic Outcomes in Sudden Sensorineural Hearing Loss

Sudden sensorineural hearing loss (SSNHL) is a medical emergency, making detailed examination to determine possible causes and early treatment important. However, etiological examinations in SSNHL do not always reveal a cause, and several factors have been found to affect treatment outcomes. Various studies are being performed to determine the prognosis and effects of treatment in patients who experience sudden hearing loss, and to identify biomarkers associated with this condition. Embase, PubMed, and the Cochrane database were searched using the key words SSNHL, prognostic, and biomarker. This search identified 4 articles in Embase, 28 articles in PubMed, and 36 in the Cochrane database. Of these 68 articles, 3 were duplicates and 37 were unrelated to the research topic. After excluding these articles, the remaining 28 articles were reviewed. Factors associated with SSNHL were divided into six categories: metabolic, hemostatic, inflammatory, immunologic, oxidative, and other factors. The associations between these factors with the occurrence of SSNHL and with patient prognosis were analyzed. Low monocyte counts, low neutrophil/lymphocyte ratio (NLR) and monocyte/high-density lipoproteins (HDL) cholesterol ratio (MHR), and low concentrations of fibrinogen, platelet glycoprotein (GP) IIIa, and TNF-α were found to be associated with good prognosis. However, these factors alone could not completely determine the onset of and recovery from SSNHL, suggesting the need for future basic and clinical studies.

Comparisons among vestibular examinations and symptoms of vertigo in sudden sensorineural hearing loss patients

OBJECTIVES

Vertigo in sudden sensorineural hearing loss (SSNHL) is hypothesized as an extension of the disease caused by the anatomical proximity of the cochlea and vestibule. The present study aimed to demonstrate the association of vestibular function test (VFT) results with SSNHL disease severity and prognosis.

MATERIALS AND METHODS

This study assessed clinical records of 263 SSNHL patients admitted to our hospital, between January 2010 and October 2017. Steroid treatment comprised high-dose intravenous dexamethasone (16 mg/d) or oral methylprednisolone (64 mg/d) for 4 days and tapered oral methylprednisolone for 8 days after discharge. Caloric tests were performed in all patients, and cervical vestibular-evoked myogenic potential (c-VEMP) and ocular VEMP (o-VEMP) tests were performed in 209 and 144 patients, respectively.

RESULTS

Ninety six patients had vertigo, and caloric abnormalities were observed in 119 patients. Initial PTA in patients with vertigo were worse than in those without vertigo (63.0 dB vs 72.7 dB, P = .002). Initial PTA in patients with abnormal o-VEMP was worse than in those with normal o-VEMP (61.4 dB vs 73.0 dB, P = .004). PTA improvement after steroid treatment in patients with vertigo was lower than in those without vertigo (25.0 dB vs 20.9 dB, P = .028). PTA improvement after treatment in patients with abnormal caloric results was lower than in those with normal caloric results (26.0 dB vs 18.4 dB, P = .013).

CONCLUSION

The functions of vestibular organs, particularly the utricle and lateral semicircular canal, are associated with disease severity and hearing outcome in SSNHL patients.

Early Magnetic Resonance Imaging for Patients With Idiopathic Sudden Sensorineural Hearing Loss in an Emergency Setting

OBJECTIVE

The role of magnetic resonance (MR) imaging in idiopathic sudden sensorineural hearing loss (ISSHL) is controversial due to the inhomogeneity of clinical and MR protocols. The aim of this work is to relate early MR findings obtained immediately after the admission, with the clinical presentation, the audiological findings, and the outcomes of treatment.

STUDY DESIGN

Prospective observational study.

SETTING

Tertiary referral university center.

PATIENTS

Forty-seven patients (22 M, 25 F; age: 54.4 ± 17.5 yr) consecutively referred to the Department of Emergency for ISSHL.

INTERVENTIONS

All patients underwent the diagnostic and therapeutic work-up for ISSHL, and MR imaging within 72 hours from the admission, independently of the symptoms onset. All patients received the same treatment (systemic steroid therapy, intratympanic steroid injection, and hyperbaric oxygen therapy).

MAIN OUTCOME MEASURE(S)

MR patterns, clinical, and laboratory findings.

RESULTS

MR imaging was positive in 25 of 47 cases (53%), with a perfect agreement between clinical and MR examinations (Cohen K = 1) upon the affected ear. Three different radiological patterns were observed: labyrinthine haemorrhage (n = 5), acute inflammatory process (n = 14), isolated blood-labyrinth barrier breakdown (n = 6). By binary logistic regression, only vertigo was associated with a positive MR imaging [B = 2.8; p = 0.011; OR = 9.5 (95% CI: 2.2-40.8)] and the latter was the only variable associated with an unfavorable outcome [(B = 2.8; p = 0.02 OR = 12.8 (95% CI: 2.9-56.7)].

CONCLUSION

Patients affected by ISSHL with associated vertigo show a higher likelihood of having a positive MR imaging, which, in turn, seems to predict an unfavorable outcome.

Sudden sensorineural hearing loss (SSHL) following a local anesthetic dental procedure

Acute sensorineural hearing loss is an uncommon phenomenon in dentistry. We describe the case of a 79-year-old male who presented with acute sensorineural hearing loss occurring 2 days after a tooth extraction procedure under local anesthesia. Possible mechanisms are discussed. He was treated with vasodilators (Ginaton and Alprostadil Injection) and Mecobalamin injection with benefit. High dose oral steroids (1 mg/kg) and low molecular weight dextran were used.

Time and geographic clustering of adult patients with unilateral idiopathic sudden sensorineural hearing loss

For the preponderance of patients with unilateral idiopathic sudden sensorineural hearing loss (SSNHL), the etiology is unknown. The pathogenesis of disease and a definitive mechanism for this abrupt hearing loss has not yet been elucidated. We hypothesize that there is a time-clustered presentation for idiopathic SSNHL; from an epidemiological standpoint, this suggests an environmental or infectious etiology. At a tertiary referral center in the northeast United States, we have observed that adult patients with SSNHL present in clusters with interspersed intervals of time with no presentations.

MR evaluation of encephalic leukoaraiosis in sudden sensorineural hearing loss (SSNHL) patients

Epidemiological evidence suggests a strict correlation between sudden sensorineural hearing loss (SSNHL) and cerebrovascular disorders. Leukoaraiosis represents a diffuse alteration of the periventricular and subcortical white matter. The aim of our study was to verify if the presence of white matter hyperintensity (WMH) was higher in patients affected by SSNHL compared to controls and evaluate the correlation between WMH and the cardiovascular risk factors, hearing level, and the response to therapy in SSNHL patients. The study group included 36 subjects affected by unilateral SSNHL. Thirty-six age- and sex-matched normal subjects with a negative history of SSNHL were used as controls. All patients underwent magnetic resonance imaging (MRI) (1.5 Tesla GE Signa) and the extent of leukoaraiosis was assessed with the Fazekas scale. The results of the present study demonstrate a high prevalence of WMH in SSNHL patients compared to controls confirming the hypothesis of a vascular impairment in SSNHL patients. The higher recovery rate in patients with greater periventricular white matter hyperintensity (PWMH) may suggest a vascular etiology that is still responsive to medical treatment. We aim to expand both the number of patients and the controls to avoid the limitation of the still small number to warrant solid scientific conclusions.

Intratympanic glucocorticosteroid therapy for idiopathic sudden hearing loss: Meta-analysis of randomized controlled trials

BACKGROUND AND OBJECTIVE

Glucocorticoids are the standard treatment for idiopathic sudden sensorineural hearing loss (ISSNHL), but whether intratympanic or systemic therapy is superior remains controversial. Previous meta-analyses of this question have omitted key clinical trials or included observational studies.

METHODS

English-language randomized controlled trials in OvidSP, PubMed, Embase, CINAHL, and the Cochrane Library comparing intratympanic versus systemic glucocorticoid therapy for ISSNHL were meta-analyzed using RevMan 5.3. The primary outcome of interest was improvement in pure tone average (PTA) threshold.

RESULTS

Six trials involving 248 patients receiving intratympanic steroids and 236 receiving systemic steroids were meta-analyzed. PTA thresholds were similar between the 2 groups at 3 months after therapy initiation (mean difference, 0.24; 95% confidence interval [CI] -2.43 to 2.91, P = .86; I = 54%, P = .07, random-effects model). PTA thresholds were also similar at 6 months (mean difference, 4.69, 95% CI -5.84 to 15.22, P = .38), although the results showed extremely high heterogeneity (I = 98%). Sensitivity analysis indicated that a single trial containing 250 patients provided the strongest evidence for equivalence between the 2 types of therapy. Rates of recovery within 3 months (defined as PTA improvement >10 dB) were similar between the 2 types of therapy (odds ratio 0.92, 95% CI 0.59-1.43, P = .70), with no significant heterogeneity in the pooled data (I = 1%, P = .40).

CONCLUSION

Intratympanic and systemic steroids' therapies appear to show similar short-term efficacy for restoring hearing in patients with ISSNHL. Intratympanic therapy may reduce systemic side effects associated with steroid use.

Evaluation of Procalcitonin and hs-CRP Levels in Sudden Sensorineural Hearing Loss

OBJECTIVE

The aim of this study was to evaluate procalcitonin and high sensitive c-reactive protein (hs-CRP) levels in idiopathic sudden sensorineural hearing loss (ISSNHL) patients and assess their correlations with the clinical prognosis.

MATERIALS AND METHODS

Twenty-three ISSNHL patients were included in the study (group A). The control group was consisted of 19 patients (group B). Procalcitonin and hs-CRP levels were compared between the groups. The relationship between procalcitonin and hs-CRP levels and the configuration of the audiogram, degree of hearing loss [partial or total ( > 90 dB)], and status of improvement (improvement of > 15 dB in the first month PTA) were evaluated.

RESULTS

The mean age was 47.91±15.73 years (range 21-73 years) and 35.16±15.67 years (range 19-79 years) in groups A and B, respectively. Seven patients (30.4%) had underlying cardiovascular risk factors. Mean procalcitonin levels were 0.057±0.025 µg/L and 0.041±0.016 µg/L in groups A and B, respectively. Mean hs-CRP levels were 0.461±1.335 mg/dL and 0.129±0.125 mg/dL in groups A and B, respectively. Procalcitonin levels were significantly higher in group A than in group B (p=0.018). Procalcitonin levels were significantly lower (0.035±0.013 µg/L vs. 0.061±0.025 µg/L) in patients with low-frequency hearing loss (p=0.04). ROC analysis of procalcitonin values revealed that area under the curve was 0.80 (p=0.005). A cut-off procalcitonin level of 0.45 µg/L yielded a sensitivity of 90% and specificity of 56.2%.

CONCLUSION

In conclusion, as a proinflammatory marker, procalcitonin levels were higher in ISSNHL patients than in healthy controls. The procalcitonin level was significantly lower in upsloping-type hearing loss patients. This finding could be regarded as an indirect indicator of pathogenesis.

Comparative Analysis of the Combined Therapeutic Effects of Lipoprostaglandin E1 on Sudden Idiopathic Sensorineural Hearing Loss

Background and Objectives

Viral and vascular disorders are considered to be a major cause of idiopathic sudden sensorineural hearing loss (ISSNHL). Lipoprostaglandin E₁ (lipo-PGE₁) has vasodilating activity and has been used to treat ISSNHL. The purpose of this study was to determine the specific therapeutic effects of lipo-PGE₁ and compare them to other treatment modalities for ISSNHL.

Subjects and Methods

The study group had 1,052 patients diagnosed with ISSNHL. All were treated with steroid, carbogen inhalation, stellate ganglion block (SGB), or PGE₁. The CP group (steroid, carbogen inhalation, and PGE1 injection; 288 patients) was treated with lipo-PGE₁ and carbogen inhalation, the CS group (steroid, carbogen inhalation, and stellate ganglion block; 232 patients) with steroid, carbogen inhalation, and SGB, the C group (steroid and carbogen inhalation; 284 patients) with steroid and carbogen, and the control group (steroid only; 248 patients) with steroid only. Patients in the groups receiving lipo-PGE₁ received a continuous infusion of 10 µL lipo-PGE₁.

Results

The overall recovery rate after treatment was 52.2%, and recovery rates by group were 67.7% in the CP group, 54.3% in the CS group, 52.1% in the C group, and 32.2% in the control group. Therefore, the therapeutic results in groups treated with lipo-PGE₁ were better than results in other groups. The difference was statistically significant.

Conclusions

The study results suggested that the CP group received effective treatment modalities for ISSNHL. The combined therapy of lipo-PGE₁ with carbogen inhalation in patients with ISSNHL was more beneficial than other treatment modalities.

Improvement in word recognition following treatment failure for sudden sensorineural hearing loss

Objectives

Patients with sudden sensorineural hearing loss (SSNHL) may have word recognition scores (WRS) that correlate with pure tone average (PTA). We hypothesize that there is a subset of patients with SSNHL who have improved WRS despite stable PTA.

Methods

Retrospective case review at a tertiary otolaryngology practice.

Results

We identified 13 of 113 patients with SSNHL whose WRS increased despite overall stable pure tone averages. There was an observed average improvement in WRS by 23.8 points in this patient cohort at follow-up, with mean initial PTA in the affected ear at 48.7 dB.

Conclusions

We identify a novel cohort of SSNHL patients that have failed treatment as measured by PTA, but who have increased WRS over time. These data have implications for patient counseling and lend insight into the pathophysiology of SSNHL.

Sudden Sensorioneural Hearing Loss and Autoimmune Systemic Diseases

Introduction  Several authors have demonstrated the relationship between sudden sensorineural hearing loss (SNHL) and systemic autoimmune diseases (SAD). Immune-mediated SNHL can rarely present as unilateral sudden SNHL and manifests itself in the contralateral ear only after years. It presents clinical relevance for being one of the few SNHL that may be reversible given that early and appropriate treatment is applied. Objective  The objective of this study is to describe the clinical presentations and audiological findings from patients with idiopathic sudden SNHL and SAD associated with a probable diagnosis of immune-mediated SNHL. Furthermore, we strive to estimate the prevalence of SAD in patients with sudden SNHL. Methods  This is an observational retrospective cohort. We have selected and studied patients with SAD. Revision of available literature on scientific repositories. Results  We evaluated 339 patients with sudden SNHL. Among them, 13 (3.83%) patients suffered from SAD. Three patients had bilateral involvement, a total of 16 ears. We evaluate and describe various clinical, epidemiological, and audiological aspects of this sample. Conclusion  In our sample of patients with sudden SNHL, the prevalence of SAD was found relevant. The majority had tinnitus and dizziness concomitant hearing loss, unilateral involvement and had experienced profound hearing loss at the time of the installation. In spite of instituted treatment, most cases showed no improvement in audiometric thresholds. Apparently, patients with sudden SNHL and SAD have a more severe initial impairment, higher percentage of bilateral, lower response to treatment, and worse prognosis than patients with sudden SNHL of unknown etiology.

Prognostic Factors in Sudden Sensorineural Hearing Loss: Our Experience and a Review of the Literature

Objectives:

We investigated prognostic factors in sudden sensorineural hearing loss (SSNHL).

Methods:

Our study group consisted of 133 patients with SSNHL who were treated at our department between 1980 and 2000. Eighty-one of them (group B) were treated between 1980 and 1996; they received vasodilators and small doses of steroids. The others (52 patients; group A) were treated between 1997 and 2000; they received vasodilators, steroids at high doses, and hyperbaric oxygen. A multivariate stepwise linear regression was used to identify the prognostic factors that were related to hearing improvement as measured by objective change of gain in the overall average (0.5, 1, 2, 4, 6, 8 kHz), the pure tone average (0.5, 1, 2 kHz), the high tone average (4, 6, 8 kHz), and the pure middle tone average (0.5, 1, 2, 4 kHz). The following factors were included in the analysis: group (method of treatment), age, gender, seasonal occurrence of disease, presence of tinnitus and vestibular symptoms, time delay before first visit, type of initial audiogram, and type of caloric reaction. In group A, an additional analysis was conducted to include the results of certain laboratory tests: blood morphology parameters, erythrocyte sedimentation rate, glucose level, coagulogram, lipidogram, thyroid-stimulating hormone, autoantibodies (antimitochondrial antibodies, smooth muscle antibodies, and anti-brush border antibodies), and immunoglobulins G, A, and M. Values for p of less than .05 were considered significant.

Results:

Our analysis suggests the presence of the following prognostic factors for SSNHL: method of SSNHL treatment (better results in group A); time delay before the start of treatment (better results when treatment started within 10 days of the first symptoms of SSNHL); and type of caloric reactions (worse results in patients with canal paresis). In group A, the factors for poor prognosis for absolute hearing improvement were as follows: delayed treatment, labyrinth responsiveness disorders, and decreased level of thyroid-stimulating hormone. In group A, better hearing improvement was observed in those patients in whom SSNHL was diagnosed in the spring.

Conclusions:

A short time delay before starting treatment (within 10 days), treatment with high doses of steroids and hyperbaric oxygen, preserving complete caloric function of the labyrinths, normal function of the thyroid, and seasonal occurrence of the disease in the spring were positive prognostic factors for hearing recovery in SSNHL.

Bilateral versus unilateral sudden sensorineural hearing loss

OBJECTIVES: To analyze the clinical characteristics and treatment results between bilateral (bi-) and unilateral (uni-) sudden sensorineural hearing loss (SSNHL).

STUDY DESIGN AND SETTING: A retrospective study.

METHODS: Three hundred twenty-four patients with SSNHL were classified into two groups; simultaneous bi-SSNHL (n = 16) and uni-SSNHL (n = 308). We compared clinical characteristics, medical history, hearing level, and treatment results between the 2 groups.

RESULTS: The incidence of bi-SSNHL was 4.9 percent of overall patients with SSNHL. Bi-SSNHL occurs more commonly in patients of older age, with preexisting diabetes mellitus, and lipid panel abnormalities compared with uni-SSNHL. Ten patients (62.5%) in the bi-SSNHL group showed hearing recovery in 1 or both ears compared with 56.5 percent of patients with uni-SSNHL. Only 12 (37.5%) of all 32 ears recovered in bi-SSNHL, which was significantly lower than in uni-SSNHL.

CONCLUSION: Bi-SSNHL has a very low incidence and lower recovery rate than uni-SSNHL. Recognition of similarities and differences between bilateral and unilateral SSNHL can help in counseling and managing the patients.

© 2007 American Academy of Otolaryngology–Head and Neck Surgery Foundation. All rights reserved.

Intratympanic dexamethasone for profound idiopathic sudden sensorineural hearing loss

OBJECTIVES: To determine hearing recovery by using intratympanic dexamethasone for profound, idiopathic sudden sensorineural hearing loss (ISSNHL).

STUDY DESIGN AND SETTING: A prospective, clinical study was performed of 25 consecutive patients seen with profound ISSNHL. Patients received 4 intratympanic treatments of dexamethasone over the course of 2 weeks. Complete hearing recovery was defined as the final pure-tone average (PTA) within 10 dB of baseline. Partial recovery was defined as a final PTA with >50% hearing. The hearing in the contralateral ear was used as baseline.

RESULTS: The average time to treatment was 28 days. Two patients had significant hearing recovery, and 1 additional patient had partial recovery. The 2 patients with significant hearing recovery were treated within 9 days of onset of hearing loss.

CONCLUSIONS: By using the treatment protocol and definition of hearing recovery of this study, intratympanic dexamethasone does not result in significant hearing improvement for patients with profound ISSNHL. There is a possible trend for improved hearing results if intratympanic treatment is performed within 11 days of onset of hearing loss.

The efficacy of combination therapy for idiopathic sudden sensorineural hearing loss

OBJECTIVES/HYPOTHESIS

The aim of this study was to compare the hearing results of patients with idiopathic sudden sensorineural hearing loss (ISSNHL) who initially were treated with either a combination therapy of systemic steroids (SS) and intratympanic steroid injection (IT-S) or SS only.

METHODS

The study followed a retrospective case-control design. One-hundred five patients who were diagnosed with ISSNHL and required treatment via admission were enrolled in this study. The control group (n = 53) was treated with SS, and the study group (n = 52) received SS as well as IT-S. We divided the patients according to pretreatment hearing levels. The outcome measured was improvement after the treatment audiology data at pretreatment were compared with those at day 10 and > 90 days after the treatment. Outcome data were analyzed using the t test, Pearson's χ(2) test, Fisher's exact test, and multivariate analyses of covariance with adjustment for pretreatment hearing levels.

RESULTS

After more than 90 days, the average pure tone audiometry (PTA) in the control and study groups were 54.8 ± 31.4 dB and 43 ± 31.2 dB, respectively (P = 0.013). Hearing recovery rate was 57.7% in the control group and 69.8% in the study group. The hearing gain of the study group was higher than that of the control group at high frequencies within the 10 days of the treatment period. Analysis between subgroups, divided according to the severity of pretreatment hearing level, showed that the recovery rate was higher at all frequencies in the study group than in the control group in patients with mild to moderate hearing loss (pretreatment PTA < 70 dB). However, in patients with severe to profound hearing loss (pretreatment PTA ≥ 70 dB), the hearing outcomes of the study and control groups were not significantly different, except at a low frequency.

CONCLUSION

The results of this study suggest that the treatment of ISSNHL with combination therapy results in higher hearing recovery rates when compared to treatment with SS alone, even in patients with severe hearing loss.

LEVEL OF EVIDENCE

3b. Laryngoscope, 126:1871-1876, 2016.

Potential Benefits of Combination Therapy as Primary Treatment for Sudden Sensorineural Hearing Loss

Objective

We analyzed the effectiveness of combination therapy (CT) for idiopathic sudden sensorineural hearing loss (ISSNHL) and the utility of intratympanic dexamethasone injection (ITDI) reapplication as salvage treatment for ISSNHL refractory to CT.

Study Design

Case series with chart review.

Setting

Academic university hospital.

Subjects and Methods

We reviewed 229 patients with ISSNHL and divided these patients into 2 groups according to treatment: systemic steroid therapy (SST) and CT groups. The SST group received prednisolone therapy. The CT group also received ITDI daily. Patients who demonstrated no recovery (<10 dB) after initial treatment were defined as refractory and received salvage ITDI therapy: ITDI reapplication in the CT group and ITDI application in the SST group.

Results

Hearing recovery rates were 77.8% (77/99) in the CT group and 60.8% (79/130) in the SST group. The difference was statistically significant ( P = .011). Initial pure-tone audiometry and vertigo were affective factors on hearing recovery rates in the CT group. After salvage therapy, hearing improvement of 10 dB or greater was noted in 6 of the 22 (27.3%) patients in the CT group and 16 of the 51 (31.4%) patients in the SST group. The difference in efficacy of salvage therapy between the CT and SST groups was simply not significant ( P = .612).

Conclusions

Combination therapy was more effective for ISSNHL in achieving hearing gain than SST alone. Furthermore, ITDI reapplication for ISSNHL refractory to CT was as effective as salvage ITDI for ISSNHL refractory to SST.

Expression of toll-like receptor genes in leukocytes of patients with sudden sensorineural hearing loss

OBJECTIVES/HYPOTHESIS

Sudden sensorineural hearing loss (SNNHL) is a disease entity that could be caused by multiple etiologies in which the innate immunity status of the patients might be involved. The aim of this study is to investigate the expression of Toll-like receptor (TLR) genes in peripheral blood leukocytes of SNNHL patients.

STUDY DESIGN

Basic research.

METHODS

We examined the expression of six TLR genes in the peripheral blood leukocytes of SNNHL patients and normal controls using real-time quantitative reverse transcriptase-polymerase chain reaction.

RESULTS

We found significantly higher expression of TLR2, TLR3, TLR4, TLR7, TLR8, and TLR9 genes in SNNHL patients as compared with normal controls (P < 0.05). Higher expression of the TLR2 gene was found in patients with profound hearing loss compared with those with less severe hearing loss (P < 0.05). The result was validated by the positively stained leukocytes for TLR2 protein in SNNHL patients using the immunocytochemical study. In addition, the percentage of CD14(+) monocytes expressing TLR2 in SNNHL patients was higher than in normal controls assessed by flow cytometry and significantly correlated with the hearing thresholds of the affected ear (P < 0.05).

CONCLUSION

Our study implies a role for TLRs in SNNHL. The expression of TLR2 in particular correlates with the severity of the disease.

LEVEL OF EVIDENCE

N/A.

Association between the prothrombin G20210A mutation and sudden sensorineural hearing loss in European population: a meta-analysis

PURPOSE

Epidemiological studies have reported inconsistent findings on the association between the prothrombin G20210A mutation and sudden sensorineural hearing loss (SSNHL) in European population. The aim of this meta-analysis was to clarify the association of this polymorphism with SSNHL in European population.

METHODS

PubMed, Embase, and the China National Knowledge Infrastructure (CNKI) were searched up to August 1, 2014. We used STATA12.0 to calculate summary odds ratios (ORs) with 95% confidence intervals (CIs).

RESULTS

Eight studies including 1972 patients were identified. Pooled data showed no significant association between the prothrombin G20210A mutation and risk of SSNHL in European population : A vs. G (OR =1.645, 95% CI:0.78-3.49,POR =0.194); AG vs.GG (OR =1.660, 95% CI:0.77-3.60,POR=0.199).

CONCLUSIONS

The present meta-analysis suggests that the prothrombin G20210A mutation is not significantly associated with an increased risk of SSNHL in European population.

A clinical analysis of sudden sensorineural hearing loss cases

BACKGROUND AND OBJECTIVES

High-dose systemic steroid therapy is the mainstay treatment for sudden sensorineural hearing loss (SSNHL). Recovery rates from SSNHL range are about 47-63% and are influenced by various prognostic factors. To evaluate the prognostic value of specific clinical parameters, we reviewed 289 cases by clinical and statistical analysis.

SUBJECTS AND METHODS

This study included 289 patients with SSNHL who visited the Department of Otolaryngology at Soonchunhyang University Hospital from January 2005 to December 2012. The cases were reviewed retrospectively based on clinical charts. Hearing improvement was evaluated in relation to pure-tone audiogram results, duration between SSNHL onset and time of initial treatment, seasonal incidence, dizziness, patient age, degree of hearing loss, patterns of initial pure-tone audiogram and presence of underlying disease.

RESULTS

Hearing improvement was observed in 196 of 289 (67.8%) patients; such improvement began within 7 days in most patients, followed by rapid hearing recovery. Cases that failed to show improvement within 14 days were unlikely to achieve hearing recovery. The more severe the hearing loss during the early stage, the lower the hearing recovery rates. Patients aged less than 60 years appear to have better prognosis of hearing improvement compared to those who are over 60 years.

CONCLUSIONS

Important prognostic factors for recovery in patients with SSNHL include the time of initiating treatment after symptom onset, the degree of early-stage hearing loss, and the age of the affected patient.

Glucocorticoid influence on prognosis of idiopathic sudden sensorineural hearing loss

Introduction

Idiopathic Sudden Sensorineural Hearing Loss (ISSHL) is defined when a loss of at least 30 dB occurs in over 3 continuous frequencies, in up to 72 hours, of which etiology is not established, despite adequate investigation. Different types of treatment regimens have been proposed, but only glucocorticoids have shown some evidence of benefit in the literature.

Objective

To analyze whether the type of treatment or time of treatment with glucocorticoids have any influence on hearing recovery in ISSHL.

Methods

Observational retrospective cohort study. One hundred twenty-seven patients with ISSHL, treated at outpatient clinics between the years 2000 and 2010, were studied. We evaluated the prognostic correlation of the type of treatment and time to treatment with glucocorticoids and ISSHL.

Results

The absolute hearing gain and the relative hearing gain was as follows: 23.6 dB and 37.2%. Complete recovery was observed in 15.7% of patients, significant recovery in 27.6% and recovery in 57.5%.

Conclusion

In this study, there was no difference between the use and nonuse of glucocorticoids in hearing improvement. However, when started within seven days after onset, the use of glucocorticoids was a factor of better prognosis.

Investigation of seasonal variability of vestibular neuronitis

Objective:

To determine if the incidence of vestibular neuronitis displays seasonal variation.

Methods:

A retrospective case review was performed to determine the monthly and quarterly incidence of vestibular neuronitis over a 36-month period. Incidence values were compiled, and the chi-square test and Rayleigh test for circular means were used to assess for uneven distribution and seasonality, respectively.

Results:

Fifty-two patients were diagnosed with vestibular neuronitis during the study period. The 2009–2010 study year showed uneven distribution and evidence of seasonality (R = 7.211, p < 0.001). However, the other two study years did not show statistical significance using either the chi-square test or Rayleigh test. In addition, when incidence values were aggregated across all three years of the study, neither the chi-square test nor Rayleigh test showed statistical significance.

Conclusion:

The present study found minimal evidence of seasonality in the incidence of vestibular neuronitis. These findings are consistent with studies of seasonality observed for other inner-ear disorders thought to be virally mediated.

Efficacy of intratympanic steroid therapy for idiopathic sudden sensorineural hearing loss: comparison with systemic steroid therapy and combined therapy

CONCLUSION

Intratympanic steroid therapy (IT-S) was as effective as systemic steroid therapy (SST) or combined therapy (CT) and could be considered a first-line therapeutic modality for idiopathic sudden sensorineural hearing loss (SSNHL). Due to its known safety and efficacy, IT-S will be particularly suitable for patients with SSNHL who have chronic diseases such as diabetes mellitus, hypertension, or chronic renal failure.

OBJECTIVES

Systemic high dose steroid therapy is the main therapeutic modality for SSNHL. Comparable therapeutic efficacies for IT-S and CT with SST and IT-S for SSNHL have been reported recently. We compared the efficacy of IT-S, SST, and CT for treating SSNHL.

METHODS

A retrospective, multicenter study investigating the therapeutic efficacy of SST, IT-S, and CT for SSNHL was designed and involved 735 patients with idiopathic SSNHL who were diagnosed and treated at seven tertiary referral medical centers of the Catholic University of Korea between 2007 and 2011. Patients were divided into three groups according to the treatment methods they received: IT-S group, SST group, and CT group (SS plus IT-S). Hearing was evaluated by pure tone audiogram performed before initial treatment and at 4 weeks following the final treatment. More than a 10 dB HL decrease in average air conduction threshold of hearing at 500, 1000, 2000, and 3000 Hz was defined as improved hearing.

RESULTS

Among 735 patients with SSNHL, 94 were included in the IT-S group, 444 in the SST, and 197 in the CT group. Age, gender, interval from disease onset to start of treatment, and initial hearing level were not different among the three groups. Patients who had concomitant medical disorders such as diabetes mellitus, hypertension, or chronic renal failure were more frequently treated with IT-S. No difference in the level of hearing gain or ratio of hearing improvement was observed among the three groups (p = 0.147 and p = 0.067, respectively).

Virus-induced expression of retinoic acid inducible gene-I and melanoma differentiation-associated gene 5 in the cochlear sensory epithelium

The inner ear has been regarded as an immunoprivileged site because of isolation by the blood-labyrinthine barrier. Several reports have indicated the existence of immune cells in the inner ear, but there are no reports showing immunocompetence of the cochlear tissue. In this report, we examined the potential involvement of retinoic acid inducible gene-I (RIG-I) and melanoma differentiation-associated gene 5 (MDA5), which are critical for initiating antiviral innate immune responses. We found that RIG-I and MDA5 are expressed in the mouse cochlear sensory epithelium, including Hensen's and Claudius' cells. Ex vivo viral infection using Theiler's murine encephalomyelitis virus revealed that the virus replicates in these cells and that protein levels of RIG-I and MDA5 are up-regulated. Furthermore, the critical antiviral transcription factor, interferon (IFN) regulatory factor-3, is activated in the infected cells as judged by its nuclear translocation and the accumulation of type I IFN transcripts. These results strongly suggest that RIG-I and MDA5 participate in innate antiviral responses in cochlear tissue.

Acute-phase inflammatory response in idiopathic sudden deafness: pathogenic implications

The acute-phase inflammatory response in the peripheral bloodstream can be an expression of transient cerebral ischaemia in idiopathic sudden deafness. For this, a neurological and otorhinolaryngological examination of each patient, performing tests on audiometry, and tympanometry, haemogram, and cranial magnetic resonance were performed. The acute-phase inflammatory response manifests as an increased neutrophil/lymphocyte ratio that is detected 48–72 hours after the appearance of sudden deafness. This study shows that there is an acute-phase response in the peripheral bloodstream with an increased neutrophil/lymphocyte ratio as an expression of an inflammatory process that can be caused by transient cerebral ischaemia in sudden deafness. In addition, the increased neutrophil/lymphocyte ratio can rule out a viral origin of sudden deafness, since a viral infection lowers the neutrophil count and increases the lymphocyte count, thus reducing the neutrophil/lymphocyte ratio. These findings aid in understanding the pathogenic mechanisms involved in sudden deafness and offer better treatment to the patient.

Analysis of frequency loss as a prognostic factor in idiopathic sensorineural hearing loss

CONCLUSION

The combination of systemic steroids with intratympanic dexamethasone injection (ITDI) did not result in significantly different outcomes from steroid treatment only and did not have any additional beneficial effects.

OBJECTIVE

To evaluate hearing recovery in idiopathic sudden sensorineural hearing loss (ISSNHL) according to frequency and to compare treatment responses between patients treated with systemic steroids and systemic steroids with ITDI.

METHODS

Ninety-nine patients with ISSNHL were selected to participate in the study by a retrospective medical chart review. Patients were divided into two groups, systemic steroid treatment only and systemic steroid with adjunctive ITDI. Hearing recovery was evaluated by pure tone audiometry (PTA). All patients underwent PTA examination before treatment and after 3 months. Thresholds were analyzed by frequency along with other factors.

RESULTS

Low frequency hearing loss responded better than high frequency loss to PTA. When we analyzed pure tone audiogram patterns, all patterns except for the descending type showed better improvement in patients with lower frequency hearing loss than in patients with higher frequency 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).

[Sudden onset hearing loss: imaging work-up]

Sudden onset hearing loss is idiopathic. It occurs in less than 24 h and spontaneously resolves within 15 days in two thirds of cases. Imaging is performed to exclude other causes of sudden onset hearing loss (vestibular schwannoma, vertebral artery dissection, stroke) and evaluate the inner ear structures. A few anatomical anomalies have been associated with an increased risk of hearing loss. Morphological anomalies involved the following structures in decreasing order of frequency: lateral semicircular canal (hypoplasia and dilatation), superior semicircular canal, posterior semicircular canal, vestibule and cochlea. Enlargement of the vestibular aqueduct also is frequently observed.

Sudden sensorineural hearing loss: a review of diagnosis, treatment, and prognosis

Sudden sensorineural hearing loss (SSNHL) is commonly encountered in audiologic and otolaryngologic practice. SSNHL is most commonly defined as sensorineural hearing loss of 30 dB or greater over at least three contiguous audiometric frequencies occurring within a 72-hr period. Although the differential for SSNHL is vast, for the majority of patients an etiologic factor is not identified. Treatment for SSNHL of known etiology is directed toward that agent, with poor hearing outcomes characteristic for discoverable etiologies that cause inner ear hair cell loss. Steroid therapy is the current mainstay of treatment of idiopathic SSNHL in the United States. The prognosis for hearing recovery for idiopathic SSNHL is dependent on a number of factors including the severity of hearing loss, age, presence of vertigo, and shape of the audiogram.