Evaluation of a "shotgun" regimen for sudden hearing loss

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.

Lesion-specific prognosis by magnetic resonance imaging in sudden sensorineural hearing loss

BACKGROUND

High signals in the inner ear of idiopathic sudden sensorineural hearing loss (ISSNHL) on magnetic resonance imaging (MRI) have been reported, but no quantitative evaluation has yet been done.

OBJECTIVES

To evaluate hearing outcomes and cochlear signal intensities on 3-T heavily T₂-weighted three-dimensional fluid-attenuated inversion recovery magnetic resonance imaging (hT₂W-3D-FLAIR) in patients with ISSNHL.

MATERIALS AND METHODS

Twenty-nine patients with ISSNHL were included. Patients underwent hT₂W-3D-FLAIR with intravenous gadolinium injection and pure tone audiometry (PTA) at initial visits and 3 months later. Signal intensity ratios (SIRs) were measured in the basal or apical-middle turns of the affected cochlea. A statistical analysis of relationships between SIRs and the average hearing levels (HLs) at low (125, 250, and 500 Hz) and high (2, 4, and 8 kHz) tone frequencies was performed.

RESULTS

Hearing improvements at high-tone frequencies in ears with HLs ≥60 dB were significantly worse in those with high SIRs at the basal turns on pre-contrast images. Similarly, hearing improvements at low-tone frequencies in ears with HLs ≥60 dB were significantly worse in those with high SIRs at the apical-middle turns on post-contrast images.

CONCLUSIONS AND SIGNIFICANCE

High SIRs on hT₂W-3D-FLAIR indicate cochlear disturbances with severe ISSNHL and could provide lesion-specific prognostic information.

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.

Efficacy of oral vs. intratympanic corticosteroids in sudden sensorineural hearing loss

BACKGROUND

The current standard treatment for sudden sensorineural hearing loss (SSNHL) comprises of tapered course of oral corticosteroids. Intratympanic steroids are introduced as another modality of treatment, but management of SSNHL continues to be debatable. The present study was designed to evaluate the efficacy of steroids given orally and by the intratympanic route.

METHODS

A prospective, randomized, open-labeled study was conducted involving 42 patients. These were randomly divided into two groups; group I patients received oral prednisone tapered over 14 days, and group II patients were treated with intratympanic methylprednisolone (40 mg/mL). One milliliter of the drug solution containing 40 mg of the drug (40 mg/mL) was injected into the middle ear cavity through the trans-tympanic route. The drug was injected twice a week for 2 weeks. The total duration of the study was 60 days, and hearing outcome was assessed on the basis of change in pure tone average.

RESULTS

An improvement of 18.24±8.72 dB was recorded in group I patients treated with oral prednisone in comparison to 14.68±12.88 dB improvement in group II. Statistically significant improvement in hearing was observed in both groups, but it was not significant when group I and group II were compared.

CONCLUSIONS

The post-treatment outcomes among patients who receive either oral prednisone or intratympanic methylprednisolone within 2 weeks of onset of symptoms were comparable. The outcomes were affected by degree of hearing loss and association of SSNHL with vertigo.

Lack of Association between Inherited Thrombophilic Risk Factors and Idiopathic Sudden Sensorineural Hearing Loss in Italian Patients

Objectives:

We investigated the presence of congenital thrombophilic risk factors in a population of consecutive Italian patients affected by idiopathic sudden sensorineural hearing loss (SSNHL).

Methods:

We investigated 48 patients with idiopathic SSNHL for the presence of congenital thrombophilic risk factors. The factor V Leiden G1691A, the prothrombin G20210A allele, and methylenetetrahydrofolate reductase (MTHFR) C677T genotypes were investigated. Allele frequencies and genotype distribution of all factors found in patients were compared to those of 48 healthy subjects of the same ethnic background by χ2 and odds-ratio analysis. Odds ratios and 95% confidence intervals were calculated for allele and genotype frequencies of all thrombophilia variants. Statistical significance was accepted with a p value of less than .05. We also performed the following blood tests: hemacytometric analysis including platelet count, prothrombin time, activated partial thromboplastin time, fibrinogen, erythrocyte sedimentation rate, C-reactive protein, protein S, protein C, antithrombin III, and activated protein C resistance.

Results:

In our series, we did not find an association between SSNHL and abnormal levels of antithrombin III, protein C, protein S, D-dimer, or fibrinogen; activated protein C resistance; or factor V G1691 A, prothrombin G20210A, or MTHFR C677T mutations.

Conclusions:

At present, the few studies regarding genetic polymorphisms of congenital thrombophilic factors in SSNHL are not conclusive. According to our data, factor V G1691A, prothrombin G20210A, and MTHFR C677T variants should be not considered risk factors for SSNHL. Further large prospective studies are needed to provide currently lacking information and to improve our knowledge in the field before we recommend the determination of genetic polymorphism in SSNHL as routine practice.

Oral steroid regimens for idiopathic sudden sensorineural hearing loss

OBJECTIVE

To determine hearing recovery in patients with idiopathic sudden hearing loss treated with varying amounts of oral steroids.

STUDY DESIGN AND SETTING

A retrospective chart review (n = 75) in a tertiary care clinic examined sudden hearing loss patients treated with 1 60-mg prednisone taper, 1 course of steroid less than a 60-mg taper, or any 2 courses of oral steroid.

RESULTS:

Overall, 35% of the patients recovered a clinically significant amount of hearing. Recovery was associated with immediate treatment (within 2 weeks from onset), better hearing at the onset of treatment, and treatment with the higher dose of prednisone in patients with just 1 additional symptom (dizziness or tinnitus). Patients tended to continue to experience some recovery in hearing up to 4 months after treatment.

CONCLUSION:

Immediate treatment of patients with unilateral idiopathic sudden hearing loss and additional symptoms (dizziness or tinnitus) with a 14-day course of 60 mg prednisone (with taper) is recommended. EBM rating: B-3.

Intratympanic Steroid Treatment in Idiopathic Sudden Sensorineural Hearing Loss: A Control Study

BACKGROUND AND OBJECTIVE: Although systemic steroids in sudden sensorineural hearing loss (SSHL) appears to be the most effective and the most widely accepted treatment today, a significant number of patients do not respond to steroid treatment or they cannot receive steroids for medical reasons. Intratympanic (IT) administration of steroids appears to be an alternative or additional method of management without the side effects of intravenous steroids. The aim of this study is to investigate the effectiveness and safeness of IT administration of steroids in patients who had not responded to IV treatment and to compare treatment efficacy with controls.

STUDY DESIGN AND SETTING: Our study consisted of 37 patients with SSHL who, at the end of 10 days of therapy with intravenous steroids as a 1st line treatment, had pure-tone 4-frequency (0.5, 1, 2, and 4 kHz) average (PTA) of worse than 30 dB or worse than 10 dB from the contralateral ear (defined as failed intravenous treatment). They were randomized into 2 groups, treatment and control. The 19 patients of the treatment group received approximately 0.5 mL sterile aqueous suspension of methylprednisolone acetate in a concentration of 80 mg/2 mL by direct injection. The procedure was carried out 4 times within a 15-day period. An audiogram was performed before each injection and approximately 1.5 months after the last session.

RESULTS: All patients tolerated the procedure well. No perforation or infection was noticed in any of the patients at their last visit. With regard to the 19 patients who received intratympanic treatment, in 9 patients, the PTA threshold improved more than 10 db, in 10 patients there was no change greater than 10 db, and no patients deteriorated more than 10 db. In the control group, none of the patients showed any change greater than 10 db. The difference was statistically significant ( P = 0.002). The treatment group showed an improvement in mean PTA of 14.9 dB, whereas the control group showed a deterioration of 0.8 dB, and this difference also was statistically significant ( P = 0.0005). IT treatment ( P = 0.0001), better post-IV PTA ( P = 0.0008), and absence of vertigo ( P = 0.02) were good predictors of the outcome. In contrast, sex, age, affected ear, days to admission, and pattern of the initial audiogram showed no significant influence on the outcome.

CONCLUSION AND SIGNIFICANCE: IT steroid administration after failed intravenous steroids is a safe and effective treatment in sudden sensorineural hearing loss.

Evaluation of Super-High-Dose Steroid Therapy for Sudden Sensorineural Hearing Loss

OBJECTIVE: To determine the efficacy of a high-dose steroid regimen for patients with sudden sensorineural hearing loss (SSNHL) and to evaluate the relationship between outcome and initial steroid dose.

STUDY DESIGN AND SETTING: We conducted a retrospective study of 112 patients presenting to Saitama Medical Center. Patients received tapering courses of hydrocortisone (HC) with an initial dose of either 1200 mg or 600 mg.

RESULTS: More than 87% of patients had recovery of hearing. When hearing stabilized, there were no significant differences between the 1200 mg and 600 mg groups in terms of hearing outcome ( P > 0.05). However, at completion of treatment, the 1200 mg group exhibited significantly superior complete recovery rate and improvement rate ( P < 0.05).

CONCLUSION: Application of our treatment protocol of a tapered course of 1200 mg HC significantly and rapidly improves recovery outcomes in patients of SSNHL.

EBM rating: C-4

Steroids for idiopathic sudden sensorineural hearing loss

BACKGROUND

This is an update of a Cochrane review first published in The Cochrane Library in Issue 1, 2006 and previously updated in 2009.Idiopathic sudden sensorineural hearing loss (ISSHL) is a clinical diagnosis characterised by a sudden deafness of cochlear or retrocochlear origin in the absence of a clear precipitating cause. Steroids are commonly prescribed to treat this condition. There is no consensus on their effectiveness.

OBJECTIVES

To determine whether steroids in the treatment of ISSHL a) improve hearing (primary) and b) reduce tinnitus (secondary).To determine the incidence of significant side effects from the medication.

SEARCH METHODS

We searched the Cochrane Ear, Nose and Throat Disorders Group Trials Register; the Cochrane Central Register of Controlled Trials (CENTRAL); PubMed; EMBASE; CINAHL; Web of Science; Cambridge Scientific Abstracts; ICTRP and additional sources for published and unpublished trials. The date of the most recent search was 22 April 2013.

SELECTION CRITERIA

We identified all randomised controlled trials (with or without blinding) in which steroids were evaluated in comparison with either no treatment or a placebo. We considered trials including the use of steroids in combination with another treatment if the comparison control group also received the same other treatment. The two authors reviewed the full-text articles of all the retrieved trials of possible relevance and applied the inclusion criteria independently.

DATA COLLECTION AND ANALYSIS

We graded trials for risk of bias using the Cochrane approach. The data extraction was performed in a standardised manner by one author and rechecked by the other author. Where necessary we contacted investigators to obtain the missing information. Meta-analysis was neither possible nor considered appropriate because of the heterogeneity of the populations studied and the differences in steroid formulations, dosages and duration of treatment. We analysed and reported the quality of the results of each study individually. A narrative overview of the results is presented.

MAIN RESULTS

Only three trials, involving 267 participants, satisfied the inclusion criteria and all three studies were at high risk of bias. One trial showed a lack of effect of oral steroids in improving hearing compared with the placebo control group. The second trial showed a significant improvement of hearing in 61% of the patients receiving oral steroid and in only 32% of the patients from the control group (combination of placebo-treated group and untreated control group). The third trial also showed a lack of effect of oral steroids in improving hearing compared with the placebo control. However, this trial did not follow strict inclusion criteria for participant selection and analysis of data was limited by significant exclusion of participants from the final analysis and lack of participant compliance to the treatment protocol. No clear evidence was presented in two trials about any harmful side effects of the steroids. Only one study declared that no patients suffered from adverse effects of the steroid treatment.

AUTHORS' CONCLUSIONS

The value of steroids in the treatment of idiopathic sudden sensorineural hearing loss remains unclear since the evidence obtained from randomised controlled trials is contradictory in outcome, in part because the studies are based upon too small a number of patients.

Treatment Outcome of Additional Dextran to Corticosteroid Therapy on Sudden Deafness

Objective

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

Study Design

Historical cohort study.

Setting

Tertiary teaching hospital.

Subjects and Methods

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

Results

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

Conclusion

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

Noninvasive intratympanic dexamethasone treatment for sudden sensorineural hearing loss

CONCLUSION

Noninvasive intratympanic dexamethasone perfusion (IDP) through the eustachian tube is an effective and safe therapy in cases of sudden sensorineural hearing loss (SSNHL).

OBJECTIVE

To investigate the effectiveness and safety of noninvasive IDP through the eustachian tube in patients with SSNHL.

METHODS

In this prospective study, 74 consecutive patients with SSNHL treated between September 2007 and March 2011 were enrolled: 35 patients fitted the criteria for initial treatment in the study (group I), while 39 patients, who had failed systemic therapy, received salvage treatment (group S). IDP through the eustachian tube was applied four times at 2-day intervals. Pure-tone test and tympanometry were performed before starting treatment, and 24 h and 1 week afterwards.

RESULTS

All patients tolerated the procedure well. No perforation or infection was noticed in any of the patients at their last visit. With regard to the 74 patients who received intratympanic treatment, 80.0% (28 of 35) of the patients in group I and 64.1% (25 of 39) patients in group S had improvement in their hearing ability. Patients with simultaneous symptoms reported that the symptoms were relieved as follows: tinnitus, 73.3% (44/60); vertigo, 76.2% (16/21); and stuffy ear, 81.1% (30/37).

Changes in guinea pig cochlea after transient cochlear ischemia

Perturbation of cochlear microcirculation, that is, ischemia is a major cause of hearing impairment. Earlier studies examined the short-term (≤7 days) effect of cochlear ischemia. This study characterized the long-term (4 weeks) functional and morphological changes in adult guinea pig cochleae subject to transient ischemia by clamping the labyrinthine artery for 0.25-3 h. Notably, cochlear ischemia for over 1 h caused an increase of auditory brainstem response thresholds and loss of high-frequency hearing, basal-turn hair cells, and spiral ganglions. Auditory recovery may be possible after 30-min ischemia. The extent of the functional and morphological changes depended on the ischemia period, and the changes progressed in extent from the apical to the basal turn in an orderly fashion.

Prognosis of patients with idiopathic sudden hearing loss: role of vestibular assessment

Objective:

To evaluate the correlation between caloric and vestibular evoked myogenic potential test results, initial audiogram data, and early hearing recovery, in patients with idiopathic sudden hearing loss.

Materials and methods:

One hundred and four patients with unilateral idiopathic sudden hearing loss underwent complete neurotological evaluation. Results for vestibular evoked myogenic potential and caloric testing were compared with patients' initial and final audiograms.

Results:

Overall, abnormal vestibular evoked myogenic potential responses occurred in 28.8 per cent of patients, whereas abnormal caloric test results occurred in 50 per cent. A statistically significant relationship was found between the type of inner ear lesion and the incidence of profound hearing loss. Moreover, a negative correlation was found between the extent of the inner ear lesion and the likelihood of early recovery.

Conclusion:

In patients with idiopathic sudden hearing loss, the extent of the inner ear lesion tends to correlate with the severity of cochlear damage. Vestibular assessment may be valuable in predicting the final outcome.

Sudden hearing loss

Sudden sensorineural hearing loss is a medical emergency in search of an appropriate treatment. Almost all aspects of this disease process are disputed in the literature. The natural course of the disease process has not been well defined, although spontaneous recovery in a percentage of patients appears well accepted. Little scientific data exist to develop an evidence-based treatment protocol. The more common elements of treatment in the United States include oral steroid therapy, transtympanic steroid therapy, and potentially oral antiviral therapy. Other therapies are used with great frequency, and their potential should not be discounted.

Urografin in the treatment of sudden sensorineural hearing loss

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

Glutathione s-transferase gene polymorphisms in Italian patients with sudden sensorineural hearing loss

HYPOTHESIS

To investigate the association between glutathione S-transferase (GST) gene polymorphisms and sudden sensorineural hearing loss (SSNHL) in a population of consecutive Italian patients. Assuming that reactive oxygen species formation may play a role in inner ear damage, we investigated whether profiles of GSTs antioxidant enzymes M1 and T1 genotypes may be associated with the risk of SSNHL.

STUDY DESIGN

A prospective study in patients with SSNHL.

PATIENTS AND METHODS

We investigated 80 Italian patients with SSNHL for the frequency of GSTT1 and GSTM1 polymorphisms. Genotype distribution of all factors found in patients were compared with those of 80 healthy control subjects of the same ethnic background using chi and odds-ratio analysis. Statistical significance was accepted at a level of p < 0.05.

RESULTS

In our series, the frequencies of GSTM1 and GSTT1 null genotypes did not differ from those of the control subjects.

CONCLUSION

The few studies regarding genetic polymorphisms of GSTs in SSNHL are not conclusive. Further studies are needed to investigate the role of antioxidants including GSTs in SSNHL and to provide the lacking information to improve our knowledge in the field before implementing the use of genetic polymorphism in the SSNHL medicine daily practice.

Vitamin E and vitamin C in the treatment of idiopathic sudden sensorineural hearing loss

CONCLUSION

The results of this study suggest that the administration of vitamin E and vitamin C to patients with idiopathic sudden sensorineural hearing loss (ISSHL) has beneficial effects by reducing the level of reactive oxygen metabolites produced by inner ear ischaemia and reperfusion injury after treatment.

OBJECTIVES

The purpose of this study was to investigate the efficacy of antioxidant vitamin E and vitamin C in the treatment of ISSHL.

PATIENTS AND METHODS

In a retrospective chart review, a total of 87 patients were enrolled who fulfilled the following inclusion criteria: 1) sudden onset of sensorineural hearing loss, 2) cause of hearing loss unknown, 3) hearing loss did not fluctuate, 4) arithmetic mean of hearing levels at 250, 500, 1000, 2000 and 4000 Hz exceeded 40 dB and 5) treatment was started within 14 days from the onset of hearing loss. All the patients were treated with steroids and/or alprostadil. In the study group, patients additionally received vitamin E (tocopherol nicotinate, 600 mg/day) and vitamin C (1200 mg/day) orally.

RESULTS

The hearing gain after therapy was 29.4 dB and the improvement rate was 63.3% in the study group, compared with 18.5 dB and 44.0% in the control group. Significant improvement was seen in the hearing gain and recovery rate in the study group.

In vivo imaging of mammalian cochlear blood flow using fluorescence microendoscopy

AIMS

We sought to develop techniques for visualizing cochlear blood flow in live mammalian subjects using fluorescence microendoscopy.

BACKGROUND

Inner ear microcirculation appears to be intimately involved in cochlear function. Blood velocity measurements suggest that intense sounds can alter cochlear blood flow. Disruption of cochlear blood flow may be a significant cause of hearing impairment, including sudden sensorineural hearing loss. However, inability to image cochlear blood flow in a nondestructive manner has limited investigation of the role of inner ear microcirculation in hearing function. Present techniques for imaging cochlear microcirculation using intravital light microscopy involve extensive perturbations to cochlear structure, precluding application in human patients. The few previous endoscopy studies of the cochlea have suffered from optical resolution insufficient for visualizing cochlear microvasculature. Fluorescence microendoscopy is an emerging minimally invasive imaging modality that provides micron-scale resolution in tissues inaccessible to light microscopy. In this article, we describe the use of fluorescence microendoscopy in live guinea pigs to image capillary blood flow and movements of individual red blood cells within the basal turn of the cochlea.

METHODS

We anesthetized eight adult guinea pigs and accessed the inner ear through the mastoid bulla. After intravenous injection of fluorescein dye, we made a limited cochleostomy and introduced a compound doublet gradient refractive index endoscope probe 1 mm in diameter into the inner ear. We then imaged cochlear blood flow within individual vessels in an epifluorescence configuration using one-photon fluorescence microendoscopy.

RESULTS

We observed single red blood cells passing through individual capillaries in several cochlear structures, including the round window membrane, spiral ligament, osseous spiral lamina, and basilar membrane. Blood flow velocities within inner ear capillaries varied widely, with observed speeds reaching up to approximately 500 microm/s.

CONCLUSION

Fluorescence microendoscopy permits visualization of cochlear microcirculation with micron-scale optical resolution and determination of blood flow velocities through analysis of video sequences.

Impact of prognostic factors on recovery from sudden hearing loss

Objective:

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

Methods:

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

Results:

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

Conclusions:

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

Steroids for idiopathic sudden sensorineural hearing loss

BACKGROUND

Idiopathic sudden sensorineural hearing loss (ISSHL) is a clinical diagnosis characterised by a sudden deafness of cochlear or retrocochlear origin in the absence of a clear precipitating cause. Steroids are commonly prescribed to treat this condition. There is no consensus on their effectiveness.

OBJECTIVES

To determine the effectiveness and the side-effect profile of steroids in the treatment of idiopathic sudden sensorineural hearing loss.

SEARCH STRATEGY

We searched the Cochrane Ear, Nose and Throat Disorders Group Specialised Register, the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library Issue 4, 2004), MEDLINE (1966 to December 2004) and EMBASE (1974 to December 2004). Reference lists of all trials were also manually searched.

SELECTION CRITERIA

We identified all randomised controlled trials (with or without blinding) in which steroids were evaluated in comparison with either no treatment or a placebo. Trials including the use of steroids in combination with another treatment were considered if the comparison control group also received the same other treatment. The full text articles of all the retrieved trials of possible relevance were reviewed by the two authors and the inclusion criteria applied independently. Any differences in opinion about which studies to include in the reviews were resolved by discussion.

DATA COLLECTION AND ANALYSIS

Trials were graded for methodological quality using the Cochrane approach. The data extraction was performed in a standardised manner by one author and rechecked by the other author, and where necessary investigators were contacted to obtain the missing information. Meta-analysis was neither possible nor considered appropriate because of the heterogeneity of the populations studied, the differences in steroid formulations, dosages and duration of the treatment. The quality of the result of each study was analysed and reported individually. A narrative overview of the result is presented.

MAIN RESULTS

Only two trials satisfied the inclusion criteria and both were of low methodological quality. One trial showed a lack of effect of oral steroids in hearing improvement compared with the placebo control group. The other trial showed a significant improvement of hearing in 61% of the patients receiving oral steroid and in only 32% of the patients from the control group (combination of placebo treated group and untreated control group). There was no clear evidence presented in the former study about any harmful side effects of the steroids. The latter study declared that no patients suffered from adverse effects from the steroid treatment.

AUTHORS' CONCLUSIONS

The value of steroids in the treatment of idiopathic sudden sensorineural hearing loss remains unclear since the evidence obtained from randomised controlled trials are contradictory in outcome, in part because the studies are based upon too small a number of patients.

Idiopathic Sudden Sensorineural Hearing Loss Is Not an Otologic Emergency

OBJECTIVE

To investigate whether delay in treatment has any influence on the audiometric outcome at Day 30 in idiopathic sudden sensorineural hearing loss.

STUDY DESIGN

Prospective study.

SETTING

Otorhinolaryngologic emergency center in Paris, France.

PATIENTS

Three hundred forty-seven consecutive cases of sudden sensorineural hearing loss were examined. A neurologic or retrocochlear cause was revealed in 17 cases. Four additional cases were lost for follow-up. Three hundred twenty-six cases of "idiopathic" sensorineural hearing loss seen within 7 days of onset were enrolled and classified by type according to five audiogram shapes: low tone (Type A), flat (Type B), high tone (Type C), cup-shaped (Type D) or total or subtotal (Type E). Because of loss for follow-up, the hearing outcome at 1 month could be evaluated in only 249 cases.

INTERVENTION

All 326 patients were given 1 mg/kg per day corticosteroids intravenously for 6 days and 500 ml mannitol 10% in the subgroup presenting ascending audiometric shape.

MAIN OUTCOME MEASURES

The following parameters were used. The first parameter was hearing recovery (initial PTA-PTA at Day 6 or Day 30). It was considered as complete if final PTA was below 25 dB. The second parameter was incidence of hearing recovery based on the following formula: (initial PTA-PTA on a given test day)/(initial PTA) x 100%. Using regression analysis and ANOVA, the audiometric outcome was analyzed at Day 6 and Day 30 as a function of the day of onset of treatment and of the audiometric type.

RESULTS

Whatever the audiometric type, there was no significant difference in final outcome whether the treatment was started within the first 24 hours or within the first week.

CONCLUSIONS

Delay in initiating treatment does not appear to influence the final degree of hearing loss. Idiopathic sudden sensorineural hearing loss cannot be considered as an otologic emergency.

Usefulness of High Doses of Glucocorticoids and Hyperbaric Oxygen Therapy in Sudden Sensorineural Hearing Loss Treatment

OBJECTIVE

We investigated the effect of pharmacologic (steroids, vasodilators, vitamins, and Betaserc) and hyperbaric oxygen therapy on patients with sudden sensorineural hearing loss.

METHODS

The pharmacologic arm of the study consisted of 52 patients with defined sudden sensorineural hearing loss treated simultaneously in the ENT Department and National Center for Hyperbaric Medicine of the Medical University of Gdansk, Poland, from 1997 to 2000 (Group A). The hyperbaric oxygen therapy consisted of exposure to 100% oxygen at a pressure of 250 kPa for a total of 60 minutes in a multiplace hyperbaric chamber. The control group included 81 patients with defined sudden sensorineural hearing loss treated in the ENT Department, Medical University of Gdansk, from 1980 to 1996 (Group B). Both groups were comparable regarding the age of the patients, season of hearing loss occurrence, tinnitus and vestibular symptom frequency, delay before therapy, and average threshold loss before the start of treatment. The treatment results (hearing gain) were estimated using pure-tone audiometry. We retrospectively analyzed the audiograms of all patients.

RESULTS

Patients from Group A (blood flow-promoting drugs, glucocorticoids in high doses, betahistine, and hyperbaric oxygen therapy) showed significantly better recovery of hearing levels compared with those from Group B (blood flow-promoting drugs and glucocorticoids in low doses) at seven frequencies (500, 1,000, 2,000, 3,000, 4,000, 6,000, and 8,000 Hz) (p < 0.05) and four groups of frequencies (pure-tone average, high-tone average, pure middle-tone average, and overall average) (p < 0.05). Percentage hearing gain in all investigated frequencies was also better in Group A versus Group B, and the differences were statistically significant (p < 0.05).

CONCLUSION

We conclude that hyperbaric oxygen therapy with high doses of glucocorticoids improves the results of conventional sudden sensorineural hearing loss treatment and should be recommended. In addition, the best results are achieved if the treatment is started as early as possible.

Combined treatment of sudden sensorineural hearing loss with steroid, dextran and piracetam: experience with 68 cases

The purpose of this study was to evaluate the effectiveness of our combined treatment regimen and to clarify the possible prognostic factors in sudden sensorineural hearing loss (SSNHL). In a retrospective chart review, the charts of 68 patients who matched the inclusion criteria of this study were evaluated. All patients were treated with a standard regimen including prednisone, dextran and piracetam between January 1998 and December 2001. Initial (at the beginning of therapy) and final (3 weeks after the beginning of therapy) audiograms were compared with respect to hearing improvement. Possible prognostic factors were also evaluated. Overall hearing improvement was determined as 54.4%. Sex was the only determined prognostic factor in this study. Females had a better prognosis. Our treatment regimen had no superiority to the reported spontaneous hearing recovery. Females seem to have a better prognosis.

Antioxidants in treatment of idiopathic sudden hearing loss

OBJECTIVE

Assuming that superoxide anion radicals (O(2)-) may play a role in damage to the inner ear, the authors investigated the possible benefit of vitamin E as an antioxidant in the treatment of idiopathic sudden hearing loss.

STUDY DESIGN

Prospective, double-blind study.

SETTING

The Department of Otolaryngology of Rambam Medical Center serves as a tertiary referral center for a population of 1.2 million people.

PATIENTS

A total of 66 patients, aged 15 to 70 years, with diagnoses of idiopathic sudden hearing loss of less than 7 days' duration during 1998 to 2001, were included in the study. All were treated with bed rest, steroids, magnesium, and carbogen inhalation. The study group received vitamin E in addition.

RESULTS

The recovery rate, calculated as hearing gain divided by the difference in hearing level between the affected and unaffected ear, was better than 75% in 41 of 66 (62.12%) patients. This rate was achieved in 26 (78.78%) patients in the study group treated with vitamin E, compared with 15 (45.45%) patients in the control group.

CONCLUSIONS

Patients treated with the addition of vitamin E achieved better recovery than did the control patients. Further studies should be directed toward a better understanding of the role of antioxidants in idiopathic sudden hearing loss.

Effect of single-drug treatment on idiopathic sudden sensorineural hearing loss

OBJECTIVES

In order to evaluate the effect of a medical administration for the sudden deafness patients, single-drug treatment for idiopathic sudden sensorineural hearing loss (ISSHL) was assessed at multi-centers participating in the Acute Severe Hearing Loss Study Group sponsored by the Ministry of Health, Labor and Welfare of Japan.

METHODS

The subjects consisted of ISSHL patients who were (1) 20 years of age or older, (2) diagnosed within 2 weeks after the onset of hearing loss, (3) showing a mean hearing level of 40-90 dB at five frequencies from 250 to 4000 Hz, (4) previously untreated, and (5) with normal for age in hearing of the opposite ear. The drugs used in this study were ATP, alprostadil, hydrocortisone and amidotrizoate, which were administered intravenously, and beraprost sodium and betamethasone, which were given orally. Two drugs were assigned to each center, one of which was selected according to the code hidden in envelopes and administered for 1 week. The treatment after the single-drug administration was conducted at the discretion of each center. The hearing gain and recovery rate at 1 week after the initiation of single-drug treatment and at 1 month or over when the hearing level was fixed, were evaluated based on the criteria for hearing recovery prepared by the Acute Severe Hearing Loss Study Group.

RESULTS

There was no statistically significant difference in the recovery rate among drugs either at 1 week after the initiation of single-drug treatment or at the time of fixed hearing level. At the time when the hearing level was fixed, a statistically significant difference in the complete recovery rate was detected only between amidotrizoate and beraprost sodium.

CONCLUSION

From these results, we could not find any specific drugs recommended for ISSNHL. In evaluating the effect of the drugs, however, several problems in the clinical trial for ISSHL should be considered.

Acyclovir in the Treatment of Idiopathic Sudden Sensorineural Hearing Loss

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

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

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

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

Prognosis is predicted by early hearing improvement in patients with idiopathic sudden sensorineural hearing loss

The time-course of the recovery of the hearing level after treatment in 90 patients with idiopathic sudden sensorineural hearing loss was examined. The improvement rate calculated relative to the hearing level of the opposite ear was investigated to estimate the hearing recovery. Follow-up audiograms were performed once per week for 1 month after treatment and once per month thereafter. There were two groups that differed with respect to the characteristics of hearing recovery. One group showed an improvement rate of over 50% at 1-2 weeks and a good improvement rate at 3 months after treatment. In the other group, the improvement rate did not reach 50% at 1-2 weeks, and the improvement rate was poor at 3 months after treatment. The patients with improvement rates of over 50% at 1-2 weeks had earlier initial visits and had mild hearing loss, whereas the patients with profound hearing loss had improvement rates under 50% and poor long-term prognosis. We conclude that the improvement rate at 1-2 weeks after treatment predicts the long-term prognosis for recovery of hearing level in patients with sudden sensorineural hearing loss.

Dextran-induced pulmonary edema in patients with sudden deafness

OBJECTIVE

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

PATIENTS

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

RESULTS

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

CONCLUSIONS

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

Magnesium: a new therapy for idiopathic sudden sensorineural hearing loss

OBJECTIVE

To determine whether treatment with Mg(2+) improves the outcome of idiopathic sudden hearing loss and to investigate which variables influence its prognosis.

STUDY DESIGN

Prospective randomized study.

SETTING

Department of Otolaryngology-Head and Neck Surgery, Rambam Medical Center, Haifa, Israel.

PATIENTS

The study group included 133 patients. Sixty patients were treated with carbogen inhalation, and 73 were treated with a combination of carbogen inhalation and intravenous MgSO(4).

RESULTS

The mean improvement rate was 66.4% in the Mg(2+) group and 49.9% in the carbogen group (p < 0.01). Recovery was achieved in 35 patients (48%) in the Mg(2+) group and only in 19 patients (31.6%) in the carbogen group (p < 0.01). Significant improvement was seen in 20 patients (27.4%) in the Mg(2+) group and in 14 patients (23.3%) in the carbogen group. Partial improvement was seen in eight patients (10.9%) in the Mg(2+) group and in 12 patients (20%) in the carbogen group. No improvement was achieved in 10 patients (13.6%) in the Mg(2+) group and in 15 patients (25%) in the carbogen group. Patients with vestibular symptoms had a poorer hearing outcome compared to those without vertigo (p < 0.04). Patients who commenced the treatment 8 days or more after onset had poorer recovery as compared with those who started treatment earlier (p < 0.03), regardless of the treatment regimen. Age, sex, and tinnitus had no significant impact on hearing recovery.

CONCLUSION

We found that Mg(2+) improved hearing recovery in cases of idiopathic sudden hearing loss. Vertigo and treatment delay beyond 8 days were poor prognostic factors for recovery.

Treatment of sudden sensorineural hearing loss with systemic steroids and valacyclovir

OBJECTIVE

To determine if the addition of an antiviral medication to systemic steroids improves recovery in the treatment of idiopathic sudden sensorineural hearing loss.

STUDY DESIGN

Randomized, double-blind, placebo-controlled prospective multicenter clinical trial.

SETTING

The study was administrated from a tertiary care center and clinical research institute; patients were enrolled by otolaryngologists in academic and private practice outpatient settings.

PATIENTS

Inclusion criteria included 1) loss of at least 30 dB in 3 contiguous frequencies over <3 days in patients with previous audiometry, 2) marked loss of hearing in patients with prior subjectively normal hearing and no previous audiometry, with contralateral hearing taken as baseline, and 3) patients seen within 10 days of onset of hearing loss. Pretreatment evaluation included audiometry and complete blood cell count, complete blood chemistry, and fluorescent treponemal antibody absorption test. Auditory brainstem-evoked response or magnetic resonance imaging was recommended.

INTERVENTION

Patients received prednisone (80 mg/d for 4 d, then tapered over 8 d) with placebo or prednisone with valacyclovir (1 g, 3 times a day for 10 days).

MAIN OUTCOME MEASURE

1) Audiometric assessment at presentation, Week 2, and Week 6; 2) Hearing Screening Inventory questionnaire twice weekly for 6 weeks; and 3) acute Short Form-12 questionnaire at presentation and Week 2.

RESULTS

Of 105 subjects enrolled in the study, 84 subjects were evaluable. There were no significant differences between placebo and valacyclovir treatment groups in terms of hearing recovery or symptom recovery on the basis of the Hearing Screening Inventory or Short Form-12 questionnaires. No adverse events were related to the use of valacyclovir.

CONCLUSION

Within the paradigm used in the current study, an antiviral medication did not provide more benefit than steroid alone in the treatment of idiopathic sudden sensorineural hearing loss.

A follow-up study of patients suffering from sudden sensorineural hearing loss

Sudden sensorineural hearing loss (S-SNHL) is a common problem with a high recovery rate. However, little is known of the long-term prognosis of affected patients. The purpose of this follow-up study was to evaluate the long-term hearing results of S-SNHL patients. The sample consisted of 168 patients with S-SNHL treated with carbogen inhalation and/or anticoagulant therapy during the period 1982-89. A questionnaire was sent to these patients, and audiological investigations were carried out in a selection of these patients in 1997. Comparison of the different treatment methods showed that the difference observed in improvement of hearing was statistically significant between the carbogen inhalation and anticoagulant treatment groups. The hearing improvement achieved was stable for, on average, 8 years of follow-up. During the follow-up period, Ménière's disease was diagnosed in only 1 of the 116 patients who answered the questionnaire and no cases of acoustic neurinoma were diagnosed, indicating that establishment of a careful patient history and clinical and audiological investigations are sufficient for the diagnosis of S-SNHL. In general, the hearing improvement achieved in S-SNHL patients is stable during long-term follow-up.

Intratympanic dexamethasone for sudden sensorineural hearing loss: clinical and laboratory evaluation

OBJECTIVE

To discuss the value of intratympanic dexamethasone (IT-DEX) perfusion for sudden sensorineural hearing loss (SSNHL), clinically and in an animal model.

STUDY DESIGN

Retrospective case review of 10 patients with SSNHL treated with IT-DEX. The findings are correlated with this institution's previous findings from a study of IT-DEX in guinea pigs.

SETTING

Ambulatory tertiary otologic referral center.

PATIENTS

Sequential patients with SSNHL who chose IT-DEX treatment.

INTERVENTIONS

Dexamethasone 0.5 mg was injected transtympanically and bathed the round window for 20 minutes. Animal study: 79 ears were randomized into five groups: control, IT-DEX versus intravenous (IV)-DEX, IT-DEX with histamine, IT-DEX with hyaluronic acid, and IT-DEX with dimethylsulfoxide.

MAIN OUTCOME MEASURES

Clinical study: postprocedure audiometry. Animal study: perilymph steroid concentration.

RESULTS

IT-DEX results in significant hearing improvement and in significantly higher perilymph concentration of steroid than IV-DEX.

CONCLUSIONS

IT-DEX is an appropriate treatment option for the treatment of SSNHL. Further study of dosages and frequency of administration is warranted.

Post-irradiation sudden deafness

As in radiation-induced cancer, post-irradiation sudden deafness (PISD) is defined as sudden onset deafness in patients post-irradiation. Fifteen nasopharyngeal carcinoma (NPC) patients with PISD were enrolled in this study. The mean interval from the completion of irradiation to the occurrence of PISD was 12 years. Seven had total deafness, seven had profound hearing loss, and one had moderate hearing loss. Nine out of 15 (60 per cent) patients experienced hearing recovery within three months after treatment. In conclusion, PISD is a late complication in NPC patients post-irradiation. The causative mechanism is theorized as vascular insufficiency.

Corticosteroid pharmacokinetics in the inner ear fluids: an animal study followed by clinical application

OBJECTIVE

Autoimmune disease (e.g., Cogan syndrome) and other inflammatory inner ear diseases may ravage the labyrinth if not treated aggressively with antiinflammatory medication. Corticosteroids are the mainstay of treatment, yet, partly because of the existence of the blood-labyrinthine barrier, the ideal drug, dose, and route of administration are currently unknown.

STUDY DESIGN

In the present study, we established cochlear fluid pharmacokinetic profiles of hydrocortisone, methylprednisolone, and dexamethasone in the guinea pig following oral, intravenous, and topical (intratympanic) administration. High-performance liquid chromatography was used to determine the drug concentrations, and comparisons were made with simultaneous pharmacokinetic profiles from blood and cerebrospinal fluid.

RESULTS

Our findings demonstrated a much higher penetration of all three drugs into the cochlear fluids following topical application as compared with systemic administration, with methylprednisolone showing the best profile.

DISCUSSION

The results suggested that intratympanic administration of corticosteroids might be more efficacious while avoiding high blood levels and therefore the deleterious side effects of systemic use.

CLINICAL APPLICATION

Thirty-seven patients with various inner ear disorders causing sensorineural hearing loss were subsequently treated using intratympanic corticosteroids, 20 with dexamethasone, and 17 with methlyprednisolone. Patients with immune-mediated hearing losses showed the best results, with notable improvement also seen in several cases of a "sudden deafness." No benefit was seen in patients with cochlear hydrops or those with sudden deterioration of a preexisting hearing loss. Three patients developed a transient otitis media related to the treatments, easily controlled with antibiotics. There were no cases of treatment-induced hearing loss and no permanent tympanic membrane perforations.

CONCLUSIONS

Overall injection of intratympanic corticosteroids for the treatment of hearing loss in inner ear disorders appears to be both safe and highly effective for certain disorders. The concept of this technique is supported by animal experimental data. The findings from the present study warrant further clinical application and experimental investigation.

Clinical applications of otoacoustic emissions in sudden hearing loss

Sudden hearing loss (SHL) is a controversial topic for which no definitive practical guidelines exist. Studies employing vasodilators, plasma expanders, anticoagulants, and carbogen inhalations have shown no improvement over the rate of spontaneous recovery. At present, there is insufficient evidence to support medical treatment for SHL, except steroid therapy in selected patients. Distortion product otoacoustic emissions (DPOAEs) are sensitive to cochlear disorders and are absent in ischemic injury to the cochlea, but can persist in cochlear neuritis. In a prospective study of 10 patients who presented to Albany Medical Center from 1995 to 1996, three patients with intact DPOAEs at presentation had an average improvement of 33 dB in the pure-tone average (PTA) of 0.5, 1.0, and 2.0 kHz with steroid therapy, whereas five of seven patients with absent DPOAEs had no improvement in hearing despite steroid therapy in six patients. The presence of DPOAEs may be a useful prognostic factor that positively correlates with recovery from SHL.

Sudden sensorineural hearing loss after general anesthesia for nonotologic surgery

Sudden sensorineural hearing loss (SNHL) is a well-recognized phenomenon that is attributed to a variety of etiologies. Sudden SNHL after cardiopulmonary bypass surgery has been well reported and is thought to be due to microemboli. However, a review of the English literature revealed only 15 cases of SNHL after general anesthesia for nonotologic surgery. Several etiologies for this loss have been suggested, but no proven pathogenesis is yet available. This report adds to the literature three additional cases of sudden SNHL after general anesthesia for nonotologic surgery. The literature is reviewed and proposed mechanisms of injury are discussed.

Sudden sensorineural hearing loss: An update

For many otolaryngologists the management of acute sensorineural hearing loss is an intuitive exercise. The ideas that govern a practice is as important as treating the patients and preventing progression of the disease; this has evolved by retrospective, anecdotal reports and clinical experience rather than through prospective research. To evaluate the current literature on management of such sensorineural hearing loss, a medline search of the topic was carried out and evidence based on recent articles were analysed. The review article discusses the current opinion on the subject including investigations and suggests a management protocol for idiopathic cases.

Sudden deafness: a comparison of anticoagulant therapy and carbogen inhalation therapy

Sudden deafness (SD) is a sudden or rapidly progressive, partial or complete, typically unilateral sensorineural hearing impairment that has no known specific etiologic factor. This study was designed to compare, in a group of 168 consecutive patients with SD, the effect of anticoagulant therapy and carbogen inhalation therapy. Special attention was paid to the shape of the audiogram relative to the clinical outcome and the treatment modality. We found that the configuration of the audiogram of SD patients is prognostic of the outcome, and that patients with a low-frequency-sloping hearing impairment have a better prognosis compared to the patients with a high-sloping loss. Anticoagulant treatment was most effective in low-sloping hearing losses, while carbogen inhalation may be more effective for patients with high-sloping hearing losses.

Sudden bilateral sensorineural hearing loss

Most cases of sudden sensorineural hearing loss (SHL) remain idiopathic, and the majority are unilateral. From 1989 to 1993, 823 patients with sudden SHL were evaluated. Of these, 14 (1.7%) had sudden bilateral SHL. We reviewed the charts of these 14 patients to compare sudden bilateral SHL with sudden unilateral SHL. Usually, bilateral SHL was asymmetric. Most bilateral cases received combined steroid and vasodilator treatment, while unilateral cases were more likely to receive only one of these treatments. By audiological criteria, 67% of bilateral SHL cases improved, while the improvement rate in unilateral SHL was 52%; however, this difference was not statistically significant. In bilateral SHL patients showing improvement, both ears responded. Bilateral SHL patients were older at the onset of hearing loss, had a higher incidence of vascular disease, and were more likely to have positive antinuclear antibody titer. Recognition of similarities and differences between sudden unilateral and bilateral SHL can help in counseling patients.

Current concepts in the diagnosis and treatment of sudden sensorineural hearing loss

Sudden hearing loss (SHL) has been a controversial topic in the literature for the past several decades. Although much theoretical work has been done regarding its diagnosis and treatment, no useful practical guidelines exist for application to current patient management. Many authors have discussed the various treatment protocols available to treat this entity, but only a handful of dated, clinical studies supporting these treatments are available. More recent studies applying treatment protocols including vasodilators, plasma expanders, anti-coagulants, and carbogen inhalations have shown no improvement over the rate of spontaneous recovery without therapy. Except in cases of therapy directed toward known predisposing factors, there is insufficient evidence in the literature to support medical treatment for SHL, although steroid therapy appears to be useful in selected patients. Our own review of 14 patients with SHL is presented. A standard diagnostic and therapeutic approach based on a comprehensive review of the literature is described that can be applied to most patients presenting with SHL.

Investigation of pure-tone hearing levels at a single frequency in sudden deafness

Hearing levels in patients with sudden deafness are commonly discussed in terms of average thresholds at 3 or 5 frequencies, but an investigation of hearing levels at a single frequency is also important. In this paper, pure tone thresholds at 500 Hz and 4,000 Hz were investigated in patients with sudden deafness who came to our clinic within 4 days of onset. Particular attention was paid to the relationship between audiometric types according to the contour of the initial loss and degree of hearing recovery at each frequency. In the group of patients whose initial hearing level at 500 Hz was between 55 and 70 dB, the hearing recovery at 500 Hz in the upward slope type was significantly greater than that in the downward slope type, but in other groups no significant differences in hearing recovery were observed among the different types of initial audiograms. We considered that the hearing recovery at a single frequency was not related to the audiometric type except in the patients with the upward slope type with moderate hearing loss.

Evaluation of hearing recovery in patients with sudden deafness

It is still difficult to evaluate the efficacy of treatment of sudden deafness. Effective methods of therapy have been reported in some studies and other studies have reported spontaneous recovery. In the present study, we assessed the correlation between hearing recovery and various parameters measured during recovery. We used three parameters: hearing gain, relative hearing gain, and recovery rate. We found that the recovery rate during recovery and the parameters measured on the 7th treatment day demonstrated the greatest correlation. The recovery rate on the 7th day of treatment was found to be useful for predicting the final hearing recovery. Comparison of the recovery rate on the 7th day of treatment may be useful for the evaluation of the efficacy of treatment of sudden deafness.

Clinical Correlates of Sudden Auditory-Vestibular Loss in a Cochlear Implant Patient

The precise electrophysiologic mechanism for sudden sensorineural auditory-vestibular loss has yet to be defined. No human models exist for this idiopathic phenomenon. A 67-year-old cochlear implant (CI) patient experienced what could be termed a “typical” acute sudden auditory-vestibular loss. Vestibular and CI electrical psychophysical changes were monitored over a 22-month period. Once the acute vestibular problems diminished, CI electrical parameters returned to near pre-episode levels. Some improvement occurred in rotational chair phase lag and asymmetry. While improving, platform posturography continued to show difficulty performing sensory organization tests V and VI. These clinical findings may imply that ganglion cell and neuronal population are responsible for the auditory findings in sudden auditory-vestibular loss. Secondly, a CI patient may serve as an ideal human model for further study of this phenomenon, should it occur.

Hearing recovery in sudden deafness patients using a modified defibrinogenation therapy

Ninety-eight patients with idiopathic sudden deafness were treated with a modified defibrinogenation (DF) therapy including batroxobin, low molecular dextran, vasodilators and vitamins. Hearing improvement was evaluated with two methods: categorical judgement and improvement rate (%). By categorical judgement, 60 patients (61% of the total) were classified into recovery or good improvement categories. The improvement rate was calculated for each of the 93 patients, and the average value was 64%. Modified DF therapy was effective especially for patients with severe hearing loss of 70-90 dB with flat audiogram. Although serum fibrinogen significantly decreased after batroxobin administration there was no correlation between the concentration of fibrinogen and hearing recovery. When prognostic factors were studied, the interval between the onset of hearing loss and start of treatment, initial hearing level, and the existence of vertigo all had significant correlation with the degree of hearing recovery.

The effect of CO2- and O2-gas mixtures on laser Doppler measured cochlear and skin blood flow in guinea pigs

The effects of carbogen (5% CO2: 95% O2) 10% CO2-in-air and 100% O2 on cochlear blood flow (CBF), skin blood flow (SBP), blood pressure (BP) and arterial blood gases were investigated in the anesthetized, respired or self-respiring guinea pig. In respired animals, CBF and SBF were increased with carbogen and 10% CO2-in-air and decreased with O2. BP was elevated with each gas. In freely breathing animals, only 10% CO2-in-air caused a small increase in CBF; both carbogen and O2 caused CBF to decrease. SPF changes were similar in form, but larger than those seen in respirated subjects. No consistent change in BP was seen during breathing of these mixtures. Arterial PO2 was increased by carbogen and 10% CO2-in-air for both groups. PCO2 increased for both CO2 gas mixtures during forced respiration; but in free-breathing animals PCO2 only increased for 10% CO2-in-air (normal PCO2 values were maintained with carbogen thorough increased breathing rate). The observed changes in CBF were consistent with a balance between a combined vasoconstrictive effect of PO2 and vasodilation effect of PCO2 on cochlear vessels. Analysis of cochlear vascular conductivity (CBF/BP) indicated that vasodilation was significant only with 10% CO2-in-air in respirated animals. In all other conditions the increased CBF apparently reflects the increase profusion pressure associated with respiration of each gas. For clinical purposes, while carbogen does not appear to directly cause vasodilation of cochlear vessels it does lead to an increased oxygenation of the cochlea blood and would appear to avoid the cochlear vasoconstriction caused by 100% O2.