Idiopathic Sudden Sensorineural Hearing Loss (ISSNHL), commonly defined as greater than 20 dB of unilateral hearing loss in at least 3 frequencies occurring within 3 days, has a reported incidence of 5 to 20 per 100,000 patients per year. Untreated, it has a recovery rate of 32 to 65%. Although accepted therapy is high-dose prednisone taper (HDPT), recent publications suggest that intratympanic dexamethasone (IT-Dex) therapy may improve hearing recovery.Methods:
This multicenter, double-blinded, placebo-controlled, randomized study seeks to compare hearing results in ISSNHL patients who have received HDPT alone, IT-Dex alone, or IT-Dex and HDPT (combination therapy). Fifty-one patients with a less than 6-week history of ISSNHL were randomized to 1 of 3 arms and followed prospectively. Group A (17 patients) received IT-Dex therapy with placebo taper, whereas Group B (18 patients) were administered HDPT and placebo intratympanic injections. Patients in Group C (16 patients) were administered IT-Dex and HDPT, otherwise known as combination therapy. Injections (IT-Dex/placebo) and audiograms were performed weekly for 3 weeks, and a final audiogram was obtained 4 weeks after the final injection.Results:
Patients receiving combination therapy (IT-Dex + HDPT) in Group C had an average improvement in speech discrimination score of 44 percentage points and a 40-dB improvement in pure-tone average (PTA). Patients in Group C had statistically significant improvements in speech discrimination score compared with Group B patients (HDPT alone; p < 0.05). When defining a significant improvement in PTA as greater than 15 dB, there was a statistically significant difference between the groups in the proportion of patients achieving hearing improvement. Furthermore, the proportion of patients achieving a significant PTA improvement in Group C was statistically greater than patients in Group B (p < 0.02). Logistic regression analysis indicates that patients receiving combination therapy demonstrated better odds of hearing recovery than patients in both of the other groups (p < 0.05), when all 3 groups were adjusted for age, vertigo, initial hearing levels, and time delay between onset of hearing loss and treatment. Lastly, combination therapy patients recovered their hearing more quickly than patients in the other groups (p < 0.05).Conclusion:
The results of this study suggest that ISSNHL patients treated with IT-Dex + HDPT (combination therapy) have a higher likelihood of hearing recovery than those treated with HDPT alone.