Should hyperbaric oxygen be added to treatment in idiopathic sudden sensorineural hearing loss? Antiviral treatment of idiopathic sudden sensorineural hearing loss: a prospective, randomized, double-blind clinical trial. Treatment of idiopathic sudden sensorineural hearing loss with antiviral therapy: a prospective, randomized, double-blind clinical trial.
At present, there is still no agreement about the therapy of idiopathic sudden sensorineural hearing loss (ISSHL). Hyperbaric oxygen (HBO) is used in the therapy of ISSHL to increase the partial oxygen pressure and the oxygen concentration in the inner ear and also to improve the blood profile and the microcirculation. In our prospective randomized study, we aimed to investigate the therapeutic effects of HBO therapy in the 1st 2 weeks of the onset of ISSHL. Fifty-one hospitalized patients with confirmed ISSHL who had received therapy were grouped randomly into two groups. Twenty-one patients (group I) received steroids, plasma expander dextrans (rheomacrodex), diazepam, pentoxiphylline and salt restriction, and 30 patients (group II) received the same basic treatment with the addition of HBO therapy. Audiological assessments of the patients were performed before and after the treatment. The hearing gains at frequencies of 250, 500, 1,000, 2,000 and 4,000 Hz were calculated separately. The level of hearing loss at the five frequencies was assessed in three groups at the first visit: equal or below 60 dB, between 61-80 dB and equal or above 81 dB. The average of the mean hearing gains at the five frequencies of the patients according to the age groups in group II was compared. The mean hearing gains at the five frequencies were compared between the two groups, and statistically significant improvement was detected in all the frequencies except at 2,000 Hz in group II. The mean hearing gains in group II were found to be significantly high in patients with initial hearing levels up to 60 dB in comparison to patients with initial hearing levels below 60 dB. When age groups and mean hearing gains were compared, there was no statistically significant difference in group I. In group II, the mean hearing gains were 39.1+/-18.3 dB in patients younger than 50 years and 22.7+/-11.3 dB in patients older than 50 years ( P=0.044). In conclusion, the addition of HBO therapy to conventional treatment modalities significantly improves the outcome of ISSHL, especially at the frequencies of 250, 500, 1,000 and 4,000 Hz and in hearing loss of above 61 dB. Furthermore, HBO therapy was found to be more effective in patients younger than 50 years. A subclinical viral labyrinthitis has been postulated in the literature to elicit Idiopathic Sudden Sensorineural Hearing Loss. An etiological role for the herpes virus family is assumed. Corticosteroids possess a limited beneficial effect on hearing recovery in ISSHL. In this study, the therapeutic value of the antiherpetic drug aciclovir (Zovirax) on hearing recovery in 44 ISSHL patients receiving prednisolone is evaluated in a multicentre clinical trial. The study is designed prospectively, randomized, double-blind and placebo-controlled. Subjective parameters include hearing recovery, a pressure sensation on the affected ear, disequilibrium or vertigo and tinnitus. Audiometric parameters include pure tone and speech audiometry. A one-year follow up is obtained. Both the pressure sensation and disequilibrium or vertigo have a good prognosis, but tinnitus, occurring in most patients, has a poor prognosis. Hearing recovery prognosis depends on the severity of initial hearing loss, and not on vestibular involvement. No beneficial effect from combining aciclovir with prednisolone can be established in ISSHL. A subclinical viral labyrinthitis has been postulated in the literature to elicit idiopathic sudden sensorineural hearing loss (ISSHL). An etiologic role for the herpes family is assumed. Corticosteroids possess a limited beneficial effect on hearing recovery in ISSHL. In this study, we evaluated the therapeutic value of the antiherpetic drug acyclovir (Zovirax) on hearing recovery in 91 patients with ISSHL who received prednisolone in a prospective, randomized, double-blind, placebo-controlled, multicenter trial. The audiometric parameters included pure tone and speech audiometry. Subjective parameters studied included hearing recovery, a pressure sensation in the affected ear, vertigo, and tinnitus. A 1-year follow-up was obtained. Hearing recovery for the whole group averaged about 35 dB and was independent of the severity of the initial hearing loss or vestibular involvement. Speech audiometry improved from 49% to 75%. After 12 months, pressure sensation and vertigo decreased to 15.6% (acyclovir) and 10.3% (placebo) and 12.5% (acyclovir) and 10.7% (placebo), respectively. Tinnitus decreased slightly, to 46.9% (acyclovir) and 55.2% (placebo), in the same period (p > .05 for all parameters). We conclude that no beneficial effect from combining acyclovir with prednisolone can be established in patients with ISSHL.
For people with acute ISSHL, the application of HBOT significantly improved hearing, but the clinical significance remains unclear. We could not assess the effect of HBOT on tinnitus by pooled analysis. In view of the modest number of patients, methodological shortcomings and poor reporting, this result should be interpreted cautiously. An appropriately powered trial is justified to define those patients (if any) who can be expected to derive most benefit from HBOT.
There is no evidence of a beneficial effect of HBOT on chronic ISSHL or tinnitus and we do not recommend the use of HBOT for this purpose.