Long-Term Outcomes of Acute Low-Tone Hearing Loss

Prognosis of Acute Low-Tone Hearing Loss Without Vertigo: A Scoping Review

OBJECTIVE

Despite its relatively high prevalence, our understanding of the natural clinical course of acute low-tone hearing loss (ALHL) without vertigo remains incomplete. The purpose of this study is to summarize the findings of studies that evaluated recovery from hearing loss (HL), recurrence and/or fluctuation of HL, and progression to Meniere's Disease (MD) of patients presenting with ALHL without vertigo.

METHODS

A scoping review of the English literature was performed. On May 14, 2020 and July 6, 2022, MEDLINE, Embase, and Scopus were searched to identify articles related to the prognosis of ALHL. To be included, articles had to present outcomes that were clearly distinguishable for patients with ALHL without vertigo. Two reviewers evaluated articles for inclusion and extracted data. Disagreements were adjudicated by a third reviewer.

RESULTS

Forty-one studies were included. There was extensive heterogeneity between studies in regard to defining ALHL, treatment methods, and time of follow-up. Most of the cohorts (39 out of 40) reported partial or complete recovery of hearing in the majority (>50%) of patients, although reports of recurrence were relatively common. Progression to MD was infrequently reported. Shorter time from onset of symptoms to treatment predicted better hearing outcomes in 6 of 8 studies.

CONCLUSION

The literature suggests that although the majority of patients with ALHL experience hearing improvement, recurrence and/or fluctuation are common, and progression to MD occurs in a minority of patients. Additional trials utilizing standardized inclusion and outcome criteria are needed to determine the ideal treatment for ALHL.

LEVEL OF EVIDENCE

NA Laryngoscope, 133:2457-2469, 2023.

Combination Therapy and Single-Modality Treatment for Acute Low-Tone Hearing Loss: A Meta-Analysis with Trial Sequential Analysis

Acute low-tone hearing loss (ALHL) is a common clinical disease and was first proposed by Abe in 1981 as sensorineural hearing loss confined to low frequencies. The best strategy for initiating medication is still unclear, as the superiority of steroids and diuretics is still debated, and combination therapy might yield additional benefits. However, no study regarding combination therapy has been published. The objective of this study was to evaluate the efficacy of steroid therapy versus combination therapy of diuretics with steroids by conducting a systematic review with a meta-analysis and trial sequential analysis (TSA). Studies enrolling patients with a diagnosis of acute low-tone hearing loss were considered eligible. After searching the PubMed, Cochrane Library, Embase, Scopus and Web of Science databases from inception to 31 December 2021, five studies including 433 patients were enrolled. Overall, the comparison between combination therapy with steroids and diuretics and single-modality treatment with steroids (OR, 1.15; 95% CI, 0.51 to 2.59; p = 0.74; I2 = 34%) and the comparison between combination therapy and treatment with diuretics alone (OR, 1.73; 95% CI, 0.93 to 3.23; p = 0.09; I2 = 5%) showed that combination therapy did not confer significant benefits when compared to single-modality treatments. A trial sequential analysis (TSA) showed conclusive nonsignificant results of the comparison between the combination of steroids and diuretics and a single-modality treatment. In conclusion, we reported that the combination of steroids and diuretics did not yield significant benefits when compared to single-modality treatment with steroids or diuretics. We suggest that treatment should be initiated with steroids or diuretics alone to avoid potential adverse effects.

Recurrent sudden sensorineural hearing loss-A literature review

Objective

Sudden sensorineural hearing loss (SSNHL) is one of the few emergent otologic conditions. Although more than half of all patients would benefit from timely treatment, recurrence occasionally develops unexpectedly. The aim of our study is to evaluate the recurrence rate after SSNHL, and present the prognosis after first-episode and recurrent SSNHL.

Methods

A literature search was conducted of the PubMed and Embase electronic databases.

Results

Seven studies with a total of 3781 patients were included, and 96 patients experienced recurrence. The recurrence rate ranged between 1.4% and 17%. The average time to recurrence was about 2 years in most studies. The majority of the studies reported using systemic steroids for treating first-episode SSNHL, and one study used a plasma expander in patients with recurrent SSNHL. The recovery rate for first-episode patients was 58%-79%, while that for recurrent SSNHL ranged widely, from 21% to 86%. There were no common risk factors for SSNHL recurrence among the studies, although low-frequency hearing loss, the presence of tinnitus during follow-up, and an increased neutrophil-to-lymphocyte ratio and platelet-to-lymphocyte ratio have been proposed.

Conclusion

Understanding the recurrence rate, risk factors, and prognosis after recurrence of SSHNL is crucial for comprehensive medical care; in this respect, further prospective studies with long-term follow-up may be instructive.

Level of Evidence

4.

Optimal First-Line Therapy for Acute Low-Tone Sensorineural Hearing loss

Background and Objectives

We aimed to analyze treatment outcomes following different initial management approaches and confirm treatment regimens for acute low-tone sensorineural hearing loss (ALHL) that would yield the best results.

Subjects and Methods

We retrospectively analyzed the medical records of 106 patients with ALHL who visited a university hospital’s otology clinic from March 2013 to June 2019. Pure-tone averages at the initial visit and at 2 and 4 weeks after the initial visit were evaluated.

Results

Forty-nine patients were enrolled in this study; of them, 41 (83.7%) exhibited complete recovery (CR) at 2 weeks and 43 (87.8%) exhibited CR at 1 month after the initial visit. Regression analysis revealed that CR at 2 weeks after the initial visit was associated with diuretic use [Exp(B): 10.309, 95% confidence interval (CI): 1.007-100]. An initial daily low-dose steroid use was marginally significant [Exp(B): 1.042, 95% CI: 0.997-1.092; p=0.066]. Isolated diuretic use [Exp(B): 25.641, 95% CI: 1.121-90.909; p=0.039] was an independent, good prognostic factor at 1 month after the initial visit. However, other treatment regimens did not affect the final results.

Conclusions

A combination of initial daily administration of ≤30 mg prednisolone plus diuretics was sufficient as the first-line treatment for ALHL. High-dose steroids and salvage intratympanic steroid injections can be applied as a second choice; however, the predicted outcome would not be good in that case.

Magnetic resonance imaging of the endolymphatic space in patients with acute low-tone sensorineural hearing loss

OBJECTIVE

The aim of this study was to measure the volume of the endolymphatic space (ELS) and to investigate prognosis in patients with acute low-tone sensorineural hearing loss (ALHL).

METHODS

A total of 61 ALHL patients participated; 47 were definite while 14 were probable ALHL cases. The definite ALHL patients were classified into three groups: A, "Cure"; B, "No cure"; and C, "Recurrence." Also, nine patients for whom diagnosis changed from ALHL to cochlear Meniere's disease (cMD) without vertigo (ALHL-cMD group). Images of the inner ear fluid space, positive perilymph, and positive endolymph were acquired using a 3T magnetic resonance scanner. Three-dimensional (3D) images were semi-automatically reconstructed using anatomical and tissue information to fuse the 3D images of the inner ear fluid space with the 3D ELS images.

RESULTS

Patients in the no cure group showed a significantly higher ELS/total fluid space (TFS) volume ratio in the affected cochlear region than the patients of the other groups. Additionally, the affected vestibular ELS/TFS volume ratio in the cure group was significantly lower than that in the recurrence group. There were significantly higher cochlear and vestibular ELS/TFS ratios in ALHL-cMD patients than in control subjects.

CONCLUSIONS

These results indicate that the cochlear ELS/TFS volume ratio should be considered when investigating the extent of recovery, while the extended ELS in the vestibule should be considered when investigating cases of recurrence. Thus, our study suggests that the severe extended ELS appeared likely to change to cMD and that the prognostic determination of ALHL is possible.

Sequential versus Combination Treatment Using Steroids and Diuretics for Acute Low-Frequency Sensorineural Hearing Loss: A Noninferiority Trial

OBJECTIVE

Acute low-frequency hearing loss (ALHL) is typically treated with combination therapy, including steroids and diuretics. To avoid unnecessary use of steroids we proposed a method of sequential administration using these two drugs, and compared the efficacy of our protocol with that of existing combination treatments.

METHODS

A prospective, randomized, open-label, single-blind, noninferiority clinical trial was conducted to investigate whether the effectiveness of sequential treatment is noninferior to that of combination treatment for ALHL. Ninety-two patients with ALHL received either steroids and diuretics simultaneously for 2 weeks (combination group), or diuretics for 2 weeks followed by steroids for another 2 weeks if they did not respond to diuretic treatment (sequential group). The primary outcome measure was a change in mean hearing threshold at three frequencies (125, 250, and 500 Hz) at 4 weeks after treatment.

RESULTS

The mean hearing threshold of the low frequencies improved 20.0 and 17.2 dB in the combination and the sequential group, respectively. The 95% lower confidence interval was -8.0 dB and noninferiority was established at p < 0.05. At 4 weeks after treatment, the complete recovery rate was 80.5 and 82.9% in the combination and sequential groups, respectively.

CONCLUSION

This is the first study on ALHL treatment following the establishment of Consolidated Standards of Reporting Trials (CONSORT). The sequential treatment is not inferior to combination treatment for ALHL, and therefore may be a better treatment guideline for ALHL considering that patients receive less steroid exposure and smaller restrictions in diuretic use compared with steroids.

Hearing Outcome of Low-tone Compared to High-tone Sudden Sensorineural Hearing Loss

Introduction  Low-tone sudden sensorineural hearing loss (SSHL) is a well-recognized disease, in which the hearing loss is restricted to low frequencies. In contrast to low-tone SSHL, high-tone SSHL is characterized by high-frequency (4,000, 8,000 Hz) hearing loss and preservation of low-, middle-frequency hearing.

Objective  The objective of this study is to compare the hearing recovery and long-term outcome of low-tone SSHL with those of patients affected by high-tone SSHL in a follow-up of ∼ 3 years.

Methods  The low-tone SSHL and high-tone SSHL groups included 27 and 20 patients, respectively; the patients of both groups were treated with intravenous steroids. Predictive factors (gender, affected side, delay of treatment, follow-up time) were also examined.

Results  Overall, complete hearing recovery was observed in 77.7% of the patients in the low-tone SSHL group and in 15% of the patients in the high-tone SSHL group. In the high-tone SSHL group, a higher proportion of patients reported tinnitus compared with the low-tone SSHL group (13 cases [65%] versus 3 cases [11%]); however, recurrences were more common in the low-tone SSHL (22%, 6 patients) compared with the high-tone SSHL (2 cases [10%]) group. No predictive factor was found to statistically impact on hearing outcome.

Conclusion  After initial therapy, the low-tone SSHL patients have more favorable hearing outcome than high-tone SSHL patients. However, recurrences occurred more frequently in the low-tone SSHL group, while the high-tone SSHL group was more often accompanied by residual symptoms, such as tinnitus.

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

Background and Objectives

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

Subjects and Methods

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

Results

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

Conclusions

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

Short-Term Outcomes of Acute Low-Tone Sensorineural Hearing Loss According to Treatment Modality

BACKGROUND AND OBJECTIVES

We compared improvements in hearing thresholds in acute low-tone sensorineural hearing loss (ALHL) patients after two different treatments: steroid alone and steroid and diuretic combined. We analyzed how the duration between the onset of symptoms and the initiation of treatment affected hearing loss improvement and investigated the relation between presence of vertigo in ALHL patients and ALHL progression to Ménière's disease (MD).

SUBJECTS AND METHODS

We retrospectively analyzed the medical records of 47 ALHL patients aged 21 to 76 years. Patients received either orally administered steroid alone (n=12) or steroid and diuretic combined (n=35). We compared improvements in the two groups' hearing thresholds at three lower frequencies (125, 250, and 500 Hz) after participants had received one month of each respective treatment.

RESULTS

Our two treatments did not show any statistical difference in hearing loss improvement after one month. Forty percent of ALHL patients with vertigo developed MD, which was a significantly higher rate than the 12.5% of ALHL patients without vertigo who developed MD. The shorter duration between the onset of symptoms and the initiation of treatment significantly increased improvement in the sum of lower frequency hearing threshold after one month.

CONCLUSIONS

The current study suggests that steroid and diuretic administered together and steroid alone similarly improve the hearing threshold in ALHL patients after one month. We concluded that patients should initiate ALHL treatment as soon as they experience symptoms. ALHL patients should also be notified of their higher risk of developing MD.