High Total Cholesterol in Peripheral Blood Correlates with Poorer Hearing Recovery in Idiopathic Sudden Sensorineural Hearing Loss

Traditional and non-traditional lipid parameters as risk factors for sudden sensorineural hearing loss

OBJECTIVE

The purpose was to explore the effects of traditional and non-traditional lipid parameters on Sudden Sensorineural Hearing Loss (SSNHL).

METHODS

The study included 452 patients diagnosed with SSNHL, among whom 206 patients had a level of hearing improvement ≥10 dB after one month of follow-up. A propensity score-matched (2:1) control group was used. Conditional and unconditional logistic regression were used to analyze the risk factors for SSNHL.

RESULTS

Patients with SSNHL had a higher risk of concomitant hypertension and elevated atherosclerogenic lipid levels, with apolipoprotein B and apolipoprotein E identified as independent risk factors for the onset of SSNHL. Additionally, the Lipid Comprehensive Index (LCI) was an independent risk factor for the degree of hearing loss. A positive linear correlation was revealed between triglyceride, non-high-density lipoprotein cholesterol, atherogenic index, Castelli risk index, atherogenic index of plasma, LCI and hearing loss. However, no linear relationship was observed between hearing gain and any lipid parameters. When Total Cholesterol (TC) was in the range of borderline high, the treatment effect was the best. However, the statistical significance disappeared upon adjusting for confounding factors.

CONCLUSION

Patients with SSNHL exhibited markedly dysregulated lipid metabolism. Elevated serum lipid levels may be a causative factor in auditory impairment and can influence the extent of hearing loss. Promptly improving cochlear microcirculation may benefit patients with borderline elevated TC.

LEVEL OF EVIDENCE: 4

Contemporary Review of Idiopathic Sudden Sensorineural Hearing Loss: Management and Prognosis

Sudden sensorineural hearing loss (SSNHL) is a rapid decline in auditory function that needs urgent medical management. Although etiologic factors, including viral infections, autoimmune diseases, and vascular issues, contribute to the understanding of SSNHL, the condition remains unclear in most cases. Systemic steroids are often used as the first-line treatment because they reduce inner ear inflammation; however, there remains numerous discussions about the effectiveness of alternative treatments. To predict hearing recovery is crucial in patients' counseling with factors, including delayed treatment, vertigo, and other health conditions, which indicate poor prognosis. Herein, we review contemporary research on the treatment approaches and outcome predictions of SSNHL to establish important guidelines for physicians in evaluating and treating patients with SSNHL.

Recovery From Idiopathic Sudden Sensorineural Hearing Loss: Association With Cardiovascular Disease Risk

PURPOSE

The purpose of this study is to investigate the association between cardiovascular disease (CVD) risk factors and idiopathic sudden sensorineural hearing loss (ISSNHL) disease severity and recovery.

METHOD

A retrospective medical chart review was performed on 90 patients (n = 48 men; Mage = 59.8 years, SD = 15.8) evaluated for ISSNHL. Major CVD risk factors (current tobacco smoking, diabetes, total cholesterol ≥ 240 mg/dl or treatment, and hypertension [systolic blood pressure [BP]/diastolic BP ≥ 140/ ≥ 90 mmHg or treatment]) determined two CVD risk groups: lower (no major risk factors) and higher (one or more risk factors). Two pure-tone averages (PTAs) were computed: PTA0.5,1,2 and PTA3,4,6,8. Complete recovery of ISSNHL was defined as PTAinitial - PTAfollow-up ≥ 10 dB. Logistic regression estimated the odds of ISSNHL recovery by CVD risk status adjusting for age, sex, body mass index, noise exposure, and treatment.

RESULTS

Most patients (67.8%) had one or more CVD risk factors. Severity of initial low- and high-frequency hearing loss was similar between CVD risk groups. Recovery was 53.2% for PTA0.5,1,2 and 32.9% for PTA3,4,6,8. With multivariable adjustment, current/former smoking was associated with lower odds of PTA0.5,1,2 recovery (OR = 0.27; 95% CI [0.08, 0.92]). Neither higher CVD risk status nor individual CVD risk factors had a significant association with recovery. For every one-unit increase in Framingham Risk Score, odds of PTA3,4,6,8 recovery were 0.95 times lower (95% CI [0.90, 1.00]) after accounting for age, sex, body mass index, noise exposure, and treatment/time-to-treatment grouping (p = .056).

CONCLUSIONS

The prognosis of low-frequency ISSNHL recovery is worse among current/former smokers than nonsmokers. Other CVD risk factors and aggregate risk are not significantly related to recovery.

Bidirectional Association Between Sudden Sensorineural Hearing Loss and Glaucoma: A Cohort Study

OBJECTIVES

To investigate the bidirectional association between sudden sensorineural hearing loss (SSNHL) and open-angle glaucoma (OAG) over a 12-year follow-up period using nationwide, population-based data.

METHODS

The study was conducted using the National Health Information Database of the National Health Insurance Service (NHIS-NHID), which covered 3.5 million individuals from 2008 to 2019. In Study 1, we evaluated the effect of OAG on SSNHL, and in Study 2, we evaluated the effect of SSNHL on OAG. Participants of the control group were enrolled through "greedy nearest-neighbor" 1:1 propensity score matching.

RESULTS

In Study 1, 26,777 people were included in each group. The hazard ratio (HR) for SSNHL of the OAG group was 1.27 (95% confidence interval [CI], 1.15-1.39). In subgroup analysis, there was significant HR value regarding (old age: 1.17, hyperlipidemia: 1.19). In Study 2, 15,433 people were included in each group. The HR for OAG of the SSNHL group was 1.18 (95% CI, 1.07-1.30). In subgroup analysis, the HRs were significant for old age (2.31), hypertension (1.17), diabetes (1.39), and hyperlipidemia (1.26).

CONCLUSION

Over the 12-year follow-up, we found a bidirectional association between SSNHL and OAG, suggesting a shared pathogenesis.

LEVEL OF EVIDENCE

N/A. Laryngoscope, 133:3169-3177, 2023.

Assessment of prognostic biomarkers in sudden sensorineural hearing loss: A systematic review and meta-analysis

Sudden sensorineural hearing loss (SSNHL) is defined as hearing loss of more than 30 dB in less than 72 h. SSNHL is a frequent complaint and an emergency in otolaryngology. Various biomarkers have been used to determine the prognosis of SSNHL. This systematic review and meta-analysis aims to evaluate the relationship between the different biomarkers and the prognosis of SSNHL. We searched English-language literature up to October 2022 in four databases, including PubMed, Google Scholar, Cochrane, and Science Direct. This search was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. This study was reported in the International Prospective Register of Systematic Reviews (PROSPERO) database (ID = CRD42022369538). All studies examining the role of neutrophil to lymphocyte ratio (NLR) concluded that higher NLR is associated with a worse prognosis. The results of studies regarding the relationship between platelet to lymphocyte ratio (PLR) and tumor necrosis factor (TNF) are controversial. Other factors shown to be associated with SSNHL include Glycated hemoglobin (HbA1C), blood glucose, iron levels, serum endocan, salusin-beta, and bone turnover biomarkers. This meta-analysis showed that PLR, NLR, and neutrophils were significantly different between recovered and non-recovered patients. PLR, NLR, and neutrophil count are reliable tools to assess the prognosis of patients with SSNHL.

Clinical Profiles and Prognoses of Adult Patients with Full-Frequency Sudden Sensorineural Hearing Loss in Combination Therapy

We aimed to characterize the clinical profiles and short-term outcomes of adult patients with full-frequency idiopathic sudden sensorineural hearing loss (ISSNHL) treated uniformly with combination therapy, and to determine the prognostic predictors for the combination therapy. A total of 131 eligible cases hospitalized in our department from January 2018 to June 2021 were retrospectively reviewed. All enrolled cases received a standardized combination therapy employing intravenous methylprednisolone, batroxobin, and Ginkgo biloba extract during the 12 days of hospitalization. The clinical and audiometric profiles were compared between recovered patients and their unrecovered counterparts. The overall recovery rate was 57.3% in the study. Accompanying vertigo (odds ratio = 0.360, p = 0.006) and body mass index (BMI, odds ratio = 1.158, p = 0.016) were two independent predictors of hearing outcomes of the therapy. The male gender and cigarette-smoking history were marginally associated with good hearing prognosis (p = 0.051 and 0.070, respectively). Patients with BMI ≥ 22.4 kg/m² had a better chance of hearing recovery (p = 0.02). Conclusions: Accompanying vertigo and low BMI (<22.4 kg/m²) were independently associated with poor prognosis for full-frequency ISSNHL in combination therapy. Male gender and cigarette-smoking history might be considered positive effects on hearing prognosis.

Prognosis of Idiopathic Sudden Sensorineural Hearing Loss: The Nomogram Perspective

OBJECTIVE

The aim of this study is to create a nomogram for accurately predicting the prognosis of idiopathic sudden sensorineural hearing loss (ISSNHL) and provide a reference for clinical treatment.

METHODS

Three hundred and twenty-three patients with ISSNHL were admitted from September 2014 to November 2020. The clinical data were retrospectively reviewed. Prognostic factors for ISSNHL were assessed based on univariate and multivariate logistic regression analysis and used to create a nomogram. Nomogram performance in terms of predictive and discriminatory ability was evaluated by calculating the concordance index (C-index) and generating calibration plots.

RESULTS

The overall hearing improvement rate was 41.4%, comprising complete recovery (13.3%), marked recovery (17.0%), and slight recovery (11.1%). Multivariate logistic regression analysis showed that age, symptoms of vertigo, interval between onset and treatment, low-density lipoprotein, and type of hearing loss were independent predictors of ISSNHL. A nomogram based on these 5 factors had a C index of 0.798 (95% confidence interval 0.750-0.845).

CONCLUSIONS

Age, vertigo, interval between onset and treatment, low-density lipoprotein level, and type of hearing loss are closely associated with hearing recovery. The nomogram may enable prediction of the prognosis of ISSNHL and facilitate clinical decision-making.

Serum Albumin Levels as a Potential Marker for the Predictive and Prognostic Factor in Sudden Sensorineural Hearing Loss: A Prospective Cohort Study

Objectives: As a common otology emergency, sudden sensorineural hearing loss (SSNHL) has a great impact on quality of life. The diagnosis and treatment of SSNHL remain challenging. This study aims to identify and investigate the association of liver functions with SSNHL.

Methods: A total of 135 SSNHL patients and 135 sex- and age-matched controls were prospectively enrolled. The baseline and clinical characteristics, along with liver function levels of participators, were collected. Linear correlation, logistic regression, and receiving operator characteristic curve analysis tests were applied to examine the association between liver function levels and SSNHL.

Results: There were no differences in baseline characteristics between SSNHL and control groups. The albumin (ALB) level of the SSNHL group was significantly lower than that in the control group (p < 0.001). The logistic regression showed that the low ALB level may be a predictive factor of SSNHL with an adjusted OR of 0.809 (95% CI, 0.742–0.882, p < 0.001). By comparing the indicators of different prognosis groups, we found that the effective group had a significantly lower hearing impair onset and higher ALB (p = 0.001) and AGR (p = 0.003) levels than the ineffective group. Logistic regression revealed that the hearing level onset (OR, 0.976; 95% CI, 0.956–0.997; p = 0.026) and ALB level (OR, 1.181; 95% CI, 1.071–1.301; p = 0.001) showed strong associations with treatment outcome.

Conclusions: Lower ALB levels, within the normal ranges, were associated with the occurrence and unfavorable outcome of SSNHL. However, further research on the underlying mechanisms needs to be conducted.

Identification of dyslipidemia as a risk factor for sudden sensorineural hearing loss: A multicenter case-control study

Background

Recently, several studies have reported an association between lipid profiles and sudden sensorineural hearing loss (SSNHL), yet there is considerable variability between the individual studies in defining the precise association between serum lipids levels and SSNHL. This study sought to identify a possible relationship between dyslipidemia and the prevalence and prognosis of SSNHL.

Methods

A case‐control study was carried out at two independent medical centers, including 2,288 SSNHL patients and 2,288 healthy controls. Clinical characteristics and serum lipid parameters were assessed, including total cholesterol (CHOL), high‐density lipoprotein (HDL), low‐density lipoprotein (LDL), triglycerides (Trig), apolipoprotein AI (ApoAI), apolipoprotein B (ApoB), and lipoprotein a (Lpa). Multivariate logistic regression analysis was performed to assess the relationship between lipid profiles and SSNHL in the 4,576 subjects.

Results

Significant differences were identified in several conventional serum lipid markers including CHOL, Trig, HDL, LDL, ApoAI, ApoB, and Lpa, between SSNHL patients and healthy controls. Serum ApoAI levels were significantly lower in patients with bilateral SSNHL compared to unilateral SSNHL. Binary logistic regression analysis revealed that higher levels of ApoB, LDL, Trig, and lower levels of ApoAI and HDL were all associated with an increased risk of SSNHL. After clinical characterization, multivariate analysis showed that only low levels of ApoB predicted likelihood of a recovery of more than 30 dB among patients with SSNHL.

Conclusions

Serum lipids are associated with the incidence and prognosis of SSNHL. Identification of dyslipidemia may improve early evaluation and management of SSNHL risks.

LDLR expression in the cochlea suggests a role in endolymph homeostasis and cochlear amplification

There is now growing evidence that hypercholesterolemia and high serum levels of low-density lipoproteins (LDL) predispose to sensorineural hearing loss. Circulating LDL-cholesterol is delivered to peripheral tissues via LDL receptor (LDLR) -mediated endocytosis. Recently, it has been shown that LDLR gene polymorphisms are associated with higher susceptibility to sudden deafness. These findings suggested that we should investigate the expression of LDLR from the postnatal maturation of the mouse cochlea until adulthood. In the cochlea of newborn mice, we observed that LDLR is mostly expressed in the lateral wall of the cochlea, especially in a band of cells directly facing the cochlear duct. Moreover, LDLR is expressed in the inner and outer hair cells, as well as in the adjacent greater epithelial ridge. In early postnatal stages, LDLR is expressed in the marginal cells of the immature stria vascularis, in the root cells of the spiral ligament, and in the adjacent outer sulcus cells. At the same time, LDLR begins to be expressed in the pillar cells of the immature organ of Corti. From the onset of hearing, LDLR is expressed in the marginal cells of the stria vascularis, in the outer sulcus cells, and in the capillaries of the adjacent spiral ligament. In the organ of Corti, LDLR is expressed in outer pillar cells and Deiters' cells, i.e. in the non-sensory supporting cells that directly surround the outer hair cells. These cells are believed to provide a mechanical coupling with the outer hair cells to modulate electromotility and cochlear amplification. In the stria vascularis of three-month-old mice, LDLR is further expressed in both marginal and intermediate cells. Overall, our results suggest that LDLR is mostly present in cochlear cells that are involved in endolymph homeostasis and cochlear amplification. Further functional studies will be needed to unravel how LDLR regulates extracellular and intracellular levels of cholesterol and lipoproteins in the cochlea, and how it could influence cochlear homeostasis.

Evaluation of Oxidative-Stress Pathway and Recovery of Sudden Sensorineural Hearing Loss

Introduction  Although the pathogenesis of sudden sensorineural hearing loss (SSNHL) has been discussed in the literature, many unclear points remain. Several authors have hypothesized that oxidative stress plays a role in the pathogenesis of noise-related hearing loss, as well as in drug- and aging-related hearing loss. Reactive oxygen species (ROS) may contribute to the pathogenesis of SSNHL in a similar way as in cases of ototoxicity, noise-induced hearing loss and presbyacusis. Objective  The aim of the present study was to find potential peripheral biomarkers to show the levels of oxidative stress in samples of peripheral blood collected from SSNHL patients with and withouth metabolic disease. Methods  In total, 80 consecutive patients with SSNHL were evaluated in the otolaryngology emergency room and outpatient clinic of a tertiary hospital between May 2017 and May 2019. All patients underwent detailed anamnesis, physical examination, audiometry, magnetic resonance imaging (MRI) of the inner ears, and blood tests for serum lipids and plasma activity of thiobarbituric acid reactive species (TBARS). Results  No significant effect of malondialdehyde (MDA) activity was observed regarding the hearing recovery of patients who developed SSNHL. Conclusion  We did not observe a significant correlation between the concentration of TBARs in the peripheral blood or the presence of arterial hypertension and the severity of the initial hearing loss or the prognosis of hearing recovery in patients with SSNHL. The concentration of TBARs in the peripheral blood may not adequately represent the abnormalities that occur in the intracoclear environment.

Association of the prognosis and severity of idiopathic sudden sensorineural hearing loss with cervical ultrasonographic findings

OBJECTIVE

The aim of this study was to investigate the association of the prognosis and severity of idiopathic sudden sensorineural hearing loss (ISSNHL) with cervical ultrasonographic findings suggestive of cardiovascular risk.

METHODS

Seventy-four inpatients with ISSNHL were included in our study. Cervical ultrasonography was performed to evaluate the common carotid artery (CCA), internal carotid artery (ICA), and vertebral artery (VA). The peak systolic velocity, end diastolic velocity, intima-media thickness, pulsatility index (PI), and resistance index (RI) were evaluated. We investigated the relationship of these variables with the severity and prognosis of ISSNHL.

RESULTS

ICA-PI, ICA-RI, and CCA-RI were significantly higher in patients with poor hearing prognosis than in those with good prognosis. The variables of VA were not related to the prognosis of ISSNHL. There were no statistically significant differences between ISSNHL severity and cervical ultrasonographic findings.

CONCLUSIONS

We found that PI and RI might be prognostic factors for ISSNHL.

Metabolic syndrome and idiopathic sudden sensori-neural hearing loss

The purpose of this study was to evaluate the association between the presence of Metabolic Syndrome (MetS) and idiopathic sudden sensorineural hearing loss (ISSHL) and the impact of MetS on recovery of patients with ISSHL. 39 Patients with ISSHL and 44 controls were enrolled in this study. Demographic, clinical characteristics and hearing recovery were evaluated. MetS was defined according to the diagnostic criteria of International Diabetes Federation (IDF) consensus definition. Patients affected by ISSHL presented a body mass index (BMI), waist circumference, waist hip ratio (WHR), fasting glucose and blood pressure significantly higher compared to controls. Considering patients with central obesity, 5 controls and 15 ISSHL patients met the criteria of MetS. According to Siegel criteria, a complete or partial recovery was observed in 60% of patients with MetS and in 91,66% of patients without MetS. MetS was associated with ISSHL and this association negatively influenced the hearing recovery of these patients.

Association between routine hematological parameters and sudden sensorineural hearing loss: A meta-analysis

Objective

Recent studies have shown that chronic inflammation contributes to the development of sudden sensorineural hearing loss (SSNHL). Some hematologic parameters have also been linked to the prognosis of SSNHL. However, the prognostic value of such hematological factors is not conclusive. This study explored the association of routine hematological parameters with SSNHL.

Methods

A systematic literature search was conducted in PubMed, Cochrane Library, Web of Science and Embase to identify eligible studies. Standardized mean deviation (SMD) and the 95% confidence interval (CI) were retried from relevant studies for analysis. Heterogeneity, subgroup, and publication bias analyses were performed.

Results

A total of 18 studies involving 1505 SSNHL patients and 1466 healthy persons were enrolled in the final analysis. The study population included 699 responders and 458 non-responders to treatment. Pooled results revealed that the neutrophil/lymphocyte ratio (NLR) and platelet/lymphocyte ratio (PLR) value in the SSNHL patient group were higher than in the healthy group (SMD = 1.05, 95% CI: 0.86,1.24, p < 0.001, SMD = 0.52, 95% CI: 0.26,0.78, p < 0.001, respectively). However, there was no significant difference in the mean platelet volumes (MPV) between the groups (SMD = 0.03, 95% CI: 0.44, 0.49, p = 0.91). Notably, NLR and PLR values were evidently higher in the unrecovered group than in the recovered group (SMD = −0.63, 95% CI: 1.02, −0.23, p = 0.002, SMD = −0.4, 95% CI: 0.76, −0.03, p = 0.03, respectively). However, the MPV value was similar in both groups (SMD = −0.35, 95% CI: 1.14,0.44, p = 0.38).

Conclusions

Our results show that NLR and PLR values can predict the onset and prognosis of SSNHL.

Sudden sensorineural hearing loss: What factors influence the response to therapy?

The standard treatment of Sudden Sensorineural Hearing Loss is based on oral steroids. In addition, intratympanic steroid is currently used in patients who fail to respond to oral treatment. The aim of the present study was to evaluate, in patients affected by SSHL, factors that influence the response to systemic and intratympanic steroid treatment. A retrospective analysis was conducted on 149 patients, all treated with systemic steroids. Moreover, patients not responsive to systemic therapy were treated with intratympanic steroids as salvage therapy. Auditory gain was assessed through the recovery rate at the discharge and after 30 days. Statistical analysis demonstrated that patients with delayed treatment and down-sloping auditory curve presented a poor recovery. Linear and stepwise regression showed that hypertriglyceridemia and hyperglycemia were negative prognostic factors. The prognosis of SSHL is affected by hyperglycemia and hypertriglyceridemia suggesting that a microvascular dysfunction within the cochlea could impair hearing recovery. Intratympanic steroid treatment was used as salvage treatment, however in patients with poor prognostic factors or at risk for side effects, it could be used in association with systemic treatment.

Serum Bilirubin Level as a Potential Marker for the Hearing Outcome in Severe-Profound Bilateral Sudden Deafness

Supplemental Digital Content is available in the text

Objective:

To investigate the association of serum bilirubin level with hearing outcomes in bilateral sudden sensorineural hearing loss (BSSHL) patients.

Participants:

One hundred thirteen in-patient BSSHL patients were consecutively enrolled between July 2008 and December 2015 in a tertiary center.

Main Outcome Measures:

Multivariable linear regression, generalized estimating equations (GEE), and stratified analyses were applied to examine the association between serum bilirubin level and hearing outcome measures such as final hearing threshold and absolute and relative hearing gains in BSSHL.

Results:

After full adjustment for potential confounders, total bilirubin levels (TBIL) were observed to be positively and independently associated with hearing outcomes as measured by final hearing (β [95% confidence interval {CI}]: −1.5 [−2.7, −0.2] dB HL per 1 μmol/L increase in TBIL) and absolute and relative hearing gains (β [95% CI]: 1.4 [0.2, 2.7] dB and 1.6 [0.2, 3.1] dB, respectively) in the severe to profound hearing loss subpopulation.

Conclusions:

Higher TBIL levels, within the normal or mildly elevated ranges, were independently and significantly associated with better hearing outcome in BSSHL patients with severe to profound hearing loss. Given bilirubin elevation treatments exist, our finding suggests a novel pharmacological strategy for this specific subpopulation.

The Influence of Metabolic Syndrome on the Prognosis of Idiopathic Sudden Sensorineural Hearing Loss

OBJECTIVES

We aimed to verify the hypothesis that metabolic syndrome (MetS) and its components affect the prognosis of idiopathic sudden sensorineural hearing loss (ISNNHL).

STUDY DESIGN

A retrospective cohort study.

SETTING

Tertiary otology referral center.

PATIENTS

We divided patients who were diagnosed with ISSNHL between January 2015 and January 2018 into a MetS group and a Non-MetS group according to the diagnostic criteria of MetS.

INTERVENTIONS

We diagnosed ISSNHL patients by using pure-tone audiometry and treated them with oral steroids, blood flow promoting agents, and hyperbaric oxygen therapy.

MAIN OUTCOME MEASURES

We used multivariate logistic analysis to identify prognostic factors of ISSNHL.

RESULTS

The MetS group comprised 94 patients, and the Non-MetS group comprised 162 subjects. Despite the rate of hypertension, diabetes mellitus, hyperlipidemia, and BMI, no significant difference was observed between the two groups (p > 0.05). The rates of complete recovery and partial recovery of the MetS group were significantly lower than those of the Non-MetS group (p < 0.05). According to the multivariate analysis, MetS was significantly correlated with a poor prognosis (OR = 2.912, p = 0.008), and the OR increased with an increase in the number of MetS components. Late onset of treatment, high initial hearing threshold, and presence of diabetes mellitus and hyperlipidemia were associated with a poor prognosis (p < 0.05).

CONCLUSIONS

The presence of MetS may negatively affect the recovery of Chinese patients with ISSNHL, and the prognosis was poorer with an increase in the number of MetS components. Early onset of treatment, low initial hearing threshold and absence of diabetes mellitus, and hyperlipidemia are associated with favorable hearing recovery.

Clinical Practice Guideline: Sudden Hearing Loss (Update)

OBJECTIVE

Sudden hearing loss is a frightening symptom that often prompts an urgent or emergent visit to a health care provider. It is frequently but not universally accompanied by tinnitus and/or vertigo. Sudden sensorineural hearing loss affects 5 to 27 per 100,000 people annually, with about 66,000 new cases per year in the United States. This guideline update provides evidence-based recommendations for the diagnosis, management, and follow-up of patients who present with sudden hearing loss. It focuses on sudden sensorineural hearing loss in adult patients aged ≥18 years and primarily on those with idiopathic sudden sensorineural hearing loss. Prompt recognition and management of sudden sensorineural hearing loss may improve hearing recovery and patient quality of life. The guideline update is intended for all clinicians who diagnose or manage adult patients who present with sudden hearing loss.

PURPOSE

The purpose of this guideline update is to provide clinicians with evidence-based recommendations in evaluating patients with sudden hearing loss and sudden sensorineural hearing loss, with particular emphasis on managing idiopathic sudden sensorineural hearing loss. The guideline update group recognized that patients enter the health care system with sudden hearing loss as a nonspecific primary complaint. Therefore, the initial recommendations of this guideline update address distinguishing sensorineural hearing loss from conductive hearing loss at the time of presentation with hearing loss. They also clarify the need to identify rare, nonidiopathic sudden sensorineural hearing loss to help separate those patients from those with idiopathic sudden sensorineural hearing loss, who are the target population for the therapeutic interventions that make up the bulk of the guideline update. By focusing on opportunities for quality improvement, this guideline should improve diagnostic accuracy, facilitate prompt intervention, decrease variations in management, reduce unnecessary tests and imaging procedures, and improve hearing and rehabilitative outcomes for affected patients.

METHODS

Consistent with the American Academy of Otolaryngology-Head and Neck Surgery Foundation's "Clinical Practice Guideline Development Manual, Third Edition" (Rosenfeld et al. Otolaryngol Head Neck Surg. 2013;148[1]:S1-S55), the guideline update group was convened with representation from the disciplines of otolaryngology-head and neck surgery, otology, neurotology, family medicine, audiology, emergency medicine, neurology, radiology, advanced practice nursing, and consumer advocacy. A systematic review of the literature was performed, and the prior clinical practice guideline on sudden hearing loss was reviewed in detail. Key Action Statements (KASs) were updated with new literature, and evidence profiles were brought up to the current standard. Research needs identified in the original clinical practice guideline and data addressing them were reviewed. Current research needs were identified and delineated.

RESULTS

The guideline update group made strong recommendations for the following: (KAS 1) Clinicians should distinguish sensorineural hearing loss from conductive hearing loss when a patient first presents with sudden hearing loss. (KAS 7) Clinicians should educate patients with sudden sensorineural hearing loss about the natural history of the condition, the benefits and risks of medical interventions, and the limitations of existing evidence regarding efficacy. (KAS 13) Clinicians should counsel patients with sudden sensorineural hearing loss who have residual hearing loss and/or tinnitus about the possible benefits of audiologic rehabilitation and other supportive measures. These strong recommendations were modified from the initial clinical practice guideline for clarity and timing of intervention. The guideline update group made strong recommendations against the following: (KAS 3) Clinicians should not order routine computed tomography of the head in the initial evaluation of a patient with presumptive sudden sensorineural hearing loss. (KAS 5) Clinicians should not obtain routine laboratory tests in patients with sudden sensorineural hearing loss. (KAS 11) Clinicians should not routinely prescribe antivirals, thrombolytics, vasodilators, or vasoactive substances to patients with sudden sensorineural hearing loss. The guideline update group made recommendations for the following: (KAS 2) Clinicians should assess patients with presumptive sudden sensorineural hearing loss through history and physical examination for bilateral sudden hearing loss, recurrent episodes of sudden hearing loss, and/or focal neurologic findings. (KAS 4) In patients with sudden hearing loss, clinicians should obtain, or refer to a clinician who can obtain, audiometry as soon as possible (within 14 days of symptom onset) to confirm the diagnosis of sudden sensorineural hearing loss. (KAS 6) Clinicians should evaluate patients with sudden sensorineural hearing loss for retrocochlear pathology by obtaining magnetic resonance imaging or auditory brainstem response. (KAS 10) Clinicians should offer, or refer to a clinician who can offer, intratympanic steroid therapy when patients have incomplete recovery from sudden sensorineural hearing loss 2 to 6 weeks after onset of symptoms. (KAS 12) Clinicians should obtain follow-up audiometric evaluation for patients with sudden sensorineural hearing loss at the conclusion of treatment and within 6 months of completion of treatment. These recommendations were clarified in terms of timing of intervention and audiometry and method of retrocochlear workup. The guideline update group offered the following KASs as options: (KAS 8) Clinicians may offer corticosteroids as initial therapy to patients with sudden sensorineural hearing loss within 2 weeks of symptom onset. (KAS 9a) Clinicians may offer, or refer to a clinician who can offer, hyperbaric oxygen therapy combined with steroid therapy within 2 weeks of onset of sudden sensorineural hearing loss. (KAS 9b) Clinicians may offer, or refer to a clinician who can offer, hyperbaric oxygen therapy combined with steroid therapy as salvage therapy within 1 month of onset of sudden sensorineural hearing loss.

DIFFERENCES FROM PRIOR GUIDELINE

Incorporation of new evidence profiles to include quality improvement opportunities, confidence in the evidence, and differences of opinion Included 10 clinical practice guidelines, 29 new systematic reviews, and 36 new randomized controlled trials Highlights the urgency of evaluation and initiation of treatment, if treatment is offered, by emphasizing the time from symptom occurrence Clarification of terminology by changing potentially unclear statements; use of the term sudden sensorineural hearing loss to mean idiopathic sudden sensorineural hearing loss to emphasize that >90% of sudden sensorineural hearing loss is idiopathic sudden sensorineural hearing loss and to avoid confusion in nomenclature for the reader Changes to the KASs from the original guideline: KAS 1-When a patient first presents with sudden hearing loss, conductive hearing loss should be distinguished from sensorineural. KAS 2-The utility of history and physical examination when assessing for modifying factors is emphasized. KAS 3-The word "routine" is added to clarify that this statement addresses nontargeted head computerized tomography scan that is often ordered in the emergency room setting for patients presenting with sudden hearing loss. It does not refer to targeted scans, such as temporal bone computerized tomography scan, to assess for temporal bone pathology. KAS 4-The importance of audiometric confirmation of hearing status as soon as possible and within 14 days of symptom onset is emphasized. KAS 5-New studies were added to confirm the lack of benefit of nontargeted laboratory testing in sudden sensorineural hearing loss. KAS 6-Audiometric follow-up is excluded as a reasonable workup for retrocochlear pathology. Magnetic resonance imaging, computerized tomography scan if magnetic resonance imaging cannot be done, and, secondarily, auditory brainstem response evaluation are the modalities recommended. A time frame for such testing is not specified, nor is it specified which clinician should be ordering this workup; however, it is implied that it would be the general or subspecialty otolaryngologist. KAS 7-The importance of shared decision making is highlighted, and salient points are emphasized. KAS 8-The option for corticosteroid intervention within 2 weeks of symptom onset is emphasized. KAS 9-Changed to KAS 9A and 9B. Hyperbaric oxygen therapy remains an option but only when combined with steroid therapy for either initial treatment (9A) or salvage therapy (9B). The timing of initial therapy is within 2 weeks of onset, and that of salvage therapy is within 1 month of onset of sudden sensorineural hearing loss. KAS 10-Intratympanic steroid therapy for salvage is recommended within 2 to 6 weeks following onset of sudden sensorineural hearing loss. The time to treatment is defined and emphasized. KAS 11-Antioxidants were removed from the list of interventions that the clinical practice guideline recommends against using. KAS 12-Follow-up audiometry at conclusion of treatment and also within 6 months posttreatment is added. KAS 13-This statement on audiologic rehabilitation includes patients who have residual hearing loss and/or tinnitus who may benefit from treatment. Addition of an algorithm outlining KASs Enhanced emphasis on patient education and shared decision making with tools provided to assist in same.

Ocular and cervical vestibular-evoked myogenic potentials in idiopathic sudden sensorineural hearing loss (ISSHL) without vertigo: VEMPs in ISSHL

PURPOSE

Idiopathic sudden sensorineural hearing loss (ISSHL) is a hearing impairment greater than 30 dB at three consecutive frequencies developing in less than 3 days. The aim of this study was to evaluate VEMPs and caloric testing in patients affected by ISSHL without vertigo.

METHODS

We retrospectively evaluated 35 subjects affected by ISSHL. The audio-vestibular investigation consisted of pure-tone and speech audiometry, impedance, bithermal caloric testing, oVEMPs and cVEMPs.

RESULTS

VEMPS were abnormal in 21 patients (60%): cVEMPs in 12 (34.2%) and oVEMPs in 19 (54.2%). 10 patients (28.5%) presented with both c-and oVEMPs altered. Subjects without vestibular involvement showed a significant lower PTA in the affected ear both at admission and at discharge. Recovery rate was significantly higher in group without vestibular involvement.

CONCLUSION

The evaluation of the vestibular system can be useful for predicting the auditory recovery in patients without vertigo also.

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

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

Longitudinal Pure-Tone Threshold Changes in the Same Subjects: Analysis of Factors Affecting Hearing

OBJECTIVES

To investigate the change of hearing threshold over time and analyze factors that could affect hearing, this longitudinal study of pure-tone threshold changes in the same subjects at a 9-year interval was performed.

STUDY DESIGN

Retrospective longitudinal study in a single center (n = 1,978).

METHODS

A total of 1,978 subjects were included; they received pure-tone audiometry at a 9-year interval. The degree of the threshold changes was examined and compared between age groups. The subjects' data, such as the level of cholesterol, were analyzed to find risk factors on hearing.

RESULTS

The average of the threshold changes was 3.35 dB in the 20s to 30s; 4.38 dB in the 30s to 40s; 5.75 dB in the 40s to 50s; 7.21 dB in the 50s to 60s; and 10.00 dB in the 60s to 70s (all P < 0.05). If the low-density lipoprotein cholesterol (LDL-C) was maintained below 100 mg/dl, the difference in the weighted four-frequency average was 5.45 dB, whereas it was 6.15 dB in the subjects whose LDL-C was over 100 mg/dl (P = 0.032, age-adjusted). In current smokers, the thresholds increased more than in never- or ex-smokers (P = 0.026 in the weighted four-frequency average and P = 0.011 at 8,000 Hz, age-adjusted).

CONCLUSION

The degree of the threshold changes exhibited an exponential increase with age. Cessation of smoking is advisable to prevent increased aggravation of hearing. Strict management of the low-density lipoprotein cholesterol may have a positive effect on hearing.

LEVEL OF EVIDENCE

3 Laryngoscope, 129:470-476, 2019.

Neutrophil-to-lymphocyte ratio predicts diagnosis and prognosis of idiopathic sudden sensorineural hearing loss: A systematic review and meta-analysis

BACKGROUND

Chronic inflammation has been regarded as one of the causes of idiopathic sudden sensorineural hearing loss (ISSHL). Several individual studies have reported the association between neutrophil-to-lymphocyte ratio (NLR) and ISSHL. However, the findings have been inconsistent, and these data have not been systematically evaluated. Thus, we conducted this meta-analysis to further explore the predictive value of NLR on formation and prognosis of ISSHL.

METHODS

A comprehensive literature search was performed to identify eligible studies based on PubMed, Embase, Web of Science, and China National Knowledge Infrastructure. The Standardized mean deviation (SMD) with its 95% confidence interval (CI) was applied to be the effect size estimate.

RESULTS

A total 10 papers with 15 retrospective case-control studies, which included 1029 ISSHL patients (the case group) and 1020 healthy people (the control group), were selected for the meta-analysis of the relationship between NLR and onset of ISSHL. The NLR levels in the case group were observed to be higher than the control group (SMD = 1.65, 95% CI = 1.20-2.09, P < .001). The pooled results did not significantly change by the subgroup analyses based on study region, baseline matching, and laterality. Moreover, 9 publications with 12 retrospective cohort studies, which included 590 recovered ISSHL patients and 438 unrecovered ISSHL patients, explored the association between NLR and ISSHL prognosis, and the combined data showed that the NLR value was much higher in unrecovered patients rather than recovered patients (SMD = 1.27, 95% CI: 0.62-1.92, P < .001). The subgroup analyses based on study region, laterality, type of steroid, medication administration, maintenance treatment, follow-up period, and definition of "recovered" further supported these results.

CONCLUSION

The results of this meta-analysis suggest that NLR might be a useful biomarker to determine the onset and prognosis of ISSHL.

Current concepts in the management of idiopathic sudden sensorineural hearing loss

PURPOSE OF REVIEW

The purpose of this manuscript is to review the initial management strategies for idiopathic sudden sensorineural hearing loss, with an emphasis on the role that steroids play in treatment of this condition, and discuss options for auditory rehabilitation of persistent unilateral hearing loss.

RECENT FINDINGS

Recent data suggest that hearing improvement may be greater for patients initially treated with both systemic and intratympanic steroid when compared with those treated with systemic steroids alone. Salvage intratympanic steroids have been shown to confer hearing benefit if initial management fails. The ideal dosing regimen for intratympanic steroids has not been established, but evidence supports that higher dosing strategies are advantageous. Cochlear implantation has emerged as a strategy for auditory rehabilitation of persistent unilateral hearing loss. Recent studies have demonstrated high patient satisfaction, subjective improvement in tinnitus, and objective performance benefit after cochlear implantation for single-sided deafness.

SUMMARY

Patients can be offered steroid therapy in the initial management of idiopathic sudden sensorineural hearing loss, but should be counseled that the efficacy of steroids remains unclear. If patients fail to improve with initial management, salvage intratympanic steroid administration should be considered. If hearing loss persists long term, options for auditory rehabilitation should be discussed.

Rheopheresis in treatment of idiopathic sensorineural sudden hearing loss

Backround

Only few therapeutic options exist for patients with refractory sudden idiopathic sensorineural hearing loss (SISHL). Little is known about the efficacy of second-line therapies. Rheopheresis seems to be an effective therapeutic possibility.

Methods

Between 2012 and 2015, 106 patients with SISHL were enrolled in the study, of whom 52 were refractory to initial treatment. As salvage therapy, these patients were offered either 3 sessions of rheopheresis (33 pts) or intratympanic steroid treatment through MicroWick application (19 pts). Pure tone audiometry was performed at diagnosis, at the 1st month and the 1st year during the follow-up.

Results

Patients in the rheopheretic arm had higher hearing loss than in the MicroWick arm (81% vs. 52%, p = 0.04). In spite of this, there was a significant improvement for patients in the rheopheretic arm (27% of hearing loss reduction, p < 0.001) after the 1st month and this remained unchanged during the 1st year, while no improvement was seen in the MicroWick arm (0% of hearing loss reduction, p = 0.424). We found no predictive factor for steroid-failure in first-line therapy. Older age (p = 0.003), presence of vertigo (p = 0.006) and more profound initial hearing loss (p < 0.001) were identified as negative prognostic markers.

Conclusion

Rheopheresis can be used as a potentially effective and safe salvage therapy for patients with cortico-refractory SISHL.

Prognostic Factors for Recovery from Sudden Sensorineural Hearing Loss: A Retrospective Study

Background and Objectives

This study aimed to investigate prognostic factors in patients with idiopathic sudden sensorineural hearing loss (ISSNHL).

Subjects and Methods

From January 2007 to December 2011, a retrospective chart review identified 494 consecutive patients with ISSNHL. Demographic, audiometric, and clinical data were analyzed using a logistic regression test.

Results

Hearing recovery from ISSNHL was significantly associated with factors such as age, duration from onset of symptoms to commencement of treatment, severity of the initial pure tone threshold, and the treatment method. Intratympanic (IT) steroid administration alone showed a comparable efficiency to oral steroid administration with or without IT steroid injection. In patients who received IT steroid injection, the duration from onset to treatment, severity of initial hearing loss, and sequential IT steroid injection following systemic steroid administration were statistically associated with hearing improvement.

Conclusions

Age, severity of initial pure tone threshold, duration from onset to treatment, initial speech discrimination, and initial pure tone threshold are statistically significant prognostic factors related to hearing improvement in ISSNHL. IT steroid injection as an initial single treatment is comparable to systemic oral steroid administration.

A novel PIK3CD C896T mutation detected in bilateral sudden sensorineural hearing loss using next generation sequencing: An indication of primary immunodeficiency

Objective

To investigate immune-related genetic background in bilateral sudden sensorineural hearing loss (SSNHL).

Case report and methods

The case is a 45-year-old man presenting with a 7-year history of bilateral profound SSNHL. Blood biochemical testing demonstrated increased levels of total cholesterol (5.88 mmol/L). Tests for hepatitis B showed a positive antibody against the hepatitis B core antigen. Complement C3 was below the normal value, and complement C4 and IgG were in the lower range of normal values. CT images showed a normal inner ear and vestibular aqueduct but round window membranous ossification on both sides. A total number of 232 immune-associated genes were sequenced using the next generation sequencing technique.

Results

Mutations were detected in 5 genes, including the phosphoinositide 3-kinase catalytic subunit delta (PIK3CD), caspase recruitment domain-containing protein 9 (CARD9), complement factor H-related (CFHR2), immunoglobulin lambda-like polypeptide 1 Protein (IGLL1), and transmembrane channel-like gene family 8 (TMC8). In the PIK3CD gene, a C896T substitute in exon 7 was detected. This mutation causes primary immunodeficiency and is an autosomal dominant disease.

Conclusion

The PIK3CD C896T mutation responsible for primary immunodeficiency may contribute to the onset of bilateral SSNHL with subsequent rapid progression.