Idiopathic sudden sensorineural hearing loss: Effectiveness of salvage treatment with low-dose intratympanic dexamethasone

Salvage therapy for refractory sudden sensorineural hearing loss (RSSNHL): a systematic review and network meta-analysis

OBJECTIVE

Approximately 30-50% of sudden sensorineural hearing loss (SSNHL) patients show poor response to systemic steroid therapy. Additionally, the most appropriate treatment for patients with refractory sudden sensorineural hearing loss (RSSNHL) is unknown. This study aimed to explore the best treatment for RSSNHL.

DESIGN

Using a frequentist contrast-based model and PRISMA guidelines, this study compared five salvage regimes: intratympanic injection of steroids (ITS), hyperbaric oxygen (HBO) therapy, post auricle steroid injection (PSI), ITS combined with HBO therapy, and continued systemic steroids.

STUDY SAMPLE

We searched the PubMed, EMBASE, Web of Science, and Cochrane Library databases for randomised controlled trials and cohort studies comparing treatment regimens for RSSNHL.

RESULTS

Compared with the control group (no additional treatment), PSI and ITS demonstrated significant improvements. The mean hearing gain was greater after PSI (11.1 dB [95% CI, 4.4-17.9]) than after ITS (7.7 dB [95% CI, 4.8-10.7]). When a restricted definition of RSSNHL was used, the ITS + HBO therapy showed the largest difference in improvement for pure tone average compared with the control group (14.5 dB [95% CI, 4.2-25.0]).

CONCLUSIONS

The administration of either PSI or ITS leads to the greatest therapeutic effect in patients with RSSNHL. However, a consensus on the definition of RSSNHL is needed.

Relevant Research of Inflammatory Cytokines Spectrum in Peripheral Blood of Sudden Hearing Loss

OBJECTIVE

To investigate whether there is a correlation between the inflammatory state and the pathogenesis and clinical features of sudden hearing loss (SHL) by studying the expression of inflammation-related cytokines in the peripheral blood of patients with SHL.

METHODS

In this work, we analyzed the cytokine profiles of 48 analytes in 38 patients with SHL compared to 38 healthy donors using a multiplex immunoassay. This study used appropriate statistical methods to screen for inflammatory cytokines associated with the pathogenesis of SHL, to analyze their network correlation, and to analyze the relationship between clinical features of SHL and inflammatory cytokines.

RESULTS

Several cytokines, including CTACK, Eotaxin, HGF, INF-α2, IFN-β, IL-1β, IL-1ra, IL-2Rα, IL-4, IL-7, IL-8, IL-9, IL-10, IL-12(p40), IL-13, MIG, β-NGF, SCF, and TNF-α, exhibited significantly higher levels in the peripheral blood of the SHL group compared to the control group. An inflammatory network composed of multiple cytokines, including IL-1β, is a risk factor for the development of SHL.

CONCLUSION

This study identified several inflammatory cytokines with elevated expression, which may be linked with the onset of SHL. The results of this study also provide a basis for the theoretical hypothesis of inflammation in SHL.

LEVEL OF EVIDENCE

III Laryngoscope, 2024.

Idiopathic sudden sensorineural hearing loss: effectiveness of salvage treatment with intratympanic dexamethasone or hyperbaric oxygen therapy in addition to systemic steroids

Background

The development of standardized treatments for idiopathic sudden sensorineural hearing loss (ISSNHL) is hampered by uncertainty over the etiology of this disorder. Systemic steroids are historically the primary therapy, with variable hearing outcomes. Over the last two decades, intratympanic steroids (ITS) and hyperbaric oxygen therapy (HBOT) have been proposed as salvage treatments in case of failure of systemic steroids. The present study aims to evaluate the effectiveness of these salvage treatments in addition to systemic steroids.

Methods

We performed a retrospective study on 75 consecutive patients with a diagnosis of ISSNHL who were admitted to the Department of Otorhinolaryngology of our hospital between December 2018 and December 2022. All patients received primary treatment with systemic steroids. In case of slight or no hearing recovery within the 5th day from the beginning of the therapy (T1), a salvage treatment with ITS or HBOT was proposed. Patients were divided into three groups according to the therapy received: systemic steroids (group A), systemic steroids + HBOT (group B), and systemic steroids + ITS (group C). Pure-tone average at 500, 1000, 2000, and 3000 Hz and the mean gain were evaluated at T1 and 3 months after the beginning of the salvage treatment (T2). The hearing recovery was assessed according to the Siegel's criteria.

Results

Sixty-two patients (31 men and 31 women, mean age 56 years) with failure of the primary treatment were definitively enrolled in the study: 34 (54.8%) in group A, 16 (25.8%) in group B, and 12 (19.4%) in group C. The ratio of patients responding to therapy was higher in group A (29.4%) than in groups B (18.75%) and C (16.7%). We did not find any statistically significant difference between groups in terms of mean hearing gain at T2 (17.4 ± 15.4 dB in group A vs. 18.6 ± 21.1 dB in group B and 15.7 ± 14.2 dB in group C, p = 0.9).

Conclusion

In our experience, ITS or HBOT associated with systemic steroids, as salvage treatment, did not show significant improvement in hearing outcomes. The evolution of ISSNHL, regardless of the treatment, remains unpredictable.

Primary versus salvage intratympanic steroid treatment for idiopathic sudden sensorineural hearing loss

Objective

The objective of this research is to compare primary and salvage intratympanic (IT) steroid treatments in terms of hearing outcomes in patients with idiopathic sudden sensorineural hearing loss (ISSNHL).

Methods

The patients were randomized into two (primary and salvage) groups. Both groups received systemic steroid treatment for 2 weeks. The primary group also received IT dexamethasone injection three times during the treatment period, whereas the salvage group received IT dexamethasone injection only if no or slight recovery was noted at the 2-week follow-up. If needed, salvage steroid injection was administered three times during the following 2 weeks. Hearing recovery was analyzed according to the modified American Academy of Otolaryngology-Head and Neck Surgery criteria.

Results

The degrees of hearing improvement at the 3-month follow-up were similar in the two groups. Compared with baseline, the pure-tone average values and speech discrimination scores improved by 38.45 ± 21.95 dB HL and 34.32% ± 30.55%, respectively, in the primary group and 36.80 ± 22.33 dB HL and 31.87% ± 27.88%, respectively, in the salvage group (p = .762 and .659, respectively). In addition, the complete or partial hearing recovery rates were also similar in the primary and salvage groups (67.7% vs. 73.3%, respectively; p = .780). In the salvage group, 18 patients required no IT steroid injection because they recovered after systemic steroid treatment.

Conclusion

Primary and salvage IT steroid treatments for ISSNHL led to similar outcomes. In summary, salvage IT steroid injection is recommended for patients with ISSNHL patients to prevent unnecessary IT injection.

Level of evidence

2.