Concurrent hyperbaric oxygen therapy and intratympanic steroid application as salvage therapy after severe sudden sensorineural hearing loss.

Sudden sensorineural hearing loss (SSNHL) is defined as a loss of hearing of 30 dB or more over at least three contiguous frequencies. Usually, symptoms present unilaterally and suddenly within 24–72 h. Most of the cases are referred to as idiopathic sensorineural hearing loss (ISSNHL) since etiologies remain unclear in the majority of the patients. Sudden SNHL occurs in five to 20 cases per 100,000 per year in the United States 1, 2. A spontaneous recovery can be observed in up to 65% 3 of the patients. The rate of spontaneous recovery was rated between 25 and 89% according to recent publications 4. Different treatment regimens like antioxidants, corticosteroids, vasodilatators, hyperbaric oxygen (HBO), or carbogen therapy 5 have been described. Among these approaches, steroid treatment is the most common. Steroids can be applied systemically (intravenously or orally) or by intratympanic injection. Intratympanic injection of steroids (ITS) is regarded as effective, safe, and well tolerated 6, and was shown to be as sufficient as orally applied steroids 7, 8. Although many studies have reported on the usefulness of steroids, the authors of a recent Cochrane review came to the conclusion that the value of steroids in the treatment of ISSNHL remains unclear 9. For the treatment of ISSNHL, HBOT has been applied over decades either alone or in addition to other medical treatments 10. In combination with HBOT, the overall success rate of ITS was superior when compared to i.v. steroid application 11. However, HBOT in addition to application of a vitamin cocktail and dexamethasone, did not improve chronic ISSNHL in another study 12. Nevertheless, since benefits of HBO in the treatment of ISSNHL were demonstrated 13, the Committee of the Undersea and Hyperbaric Medical Society approved ISSNHL as indication for HBOT 14. These authors claim that best results are achieved when HBOT starts within 2 weeks and is combined with steroid treatment. The combination of HBOT with systemic steroid treatment was especially successful for patients with an initial hearing loss of more than 90 dB 15. Additionally, HBOT resulted in an improvement of thresholds especially in the low frequencies of patients with otherwise therapy‐refractory SSNHL 16. In another study, ITS was compared to HBOT and to a combination of both after unsuccessful systemic corticoid treatment of ISSNHL 17. All three modalities resulted in an improvement of word scores and pure tone audiometry (PTA). However, the highest success was achieved, especially at low frequencies, after the combined use of HBOT and ITS. Despite of the excellent results that can be achieved after treating patients with acute ISSNHL (duration max. 2 weeks) with HBO, data concerning the outcome of HBOT of patients with chronic (>6 months) ISSNHL have not been reported hitherto 18. We therefore present a case study on patients with severe ISSNHL receiving HBOT combined with ITS as salvage treatment after an unsuccessful attempt with systemic steroids application. In most of the cases, the delay between onset of hearing loss and start of the combined therapy was much more than the recommended maximum of 30 days 17.