The efficacy and safety of systemic injection of Ginkgo biloba extract, EGb761, in idiopathic sudden sensorineural hearing loss: a randomized placebo-controlled clinical trial

Steroids are currently the most frequently accepted agents for idiopathic sudden sensorineural hearing loss (ISSNHL). However, the therapeutic effect of steroids is not always satisfactory. In this pilot study, we evaluated whether systemic treatment with Ginkgo biloba extract (EGb761) has an additive therapeutic effect in patients receiving a systemic steroid due to ISSNHL. A multicenter, randomized, double-blind clinical trial was performed. Fifty-six patients with ISSNHL were allocated to either EGb761 or placebo. In both groups, methylprednisolone was administered for 14 days. EGb761 was infused intravenously for 5 days in the EGb761 group, while the same amount of normal saline was infused in the placebo group. For the efficacy evaluation, pure-tone audiometry, speech audiometry, tinnitus handicap inventory (THI) and short form-36 health (SF-36) survey outcomes were obtained before administration and on days 3, 5, 14 and 28 of administration. Twenty-four patients in each group completed the study protocol. There was no difference in hearing loss between the two groups before treatment. At day 28, air conduction threshold values in the placebo and EGb761 groups were 34.63 +/- 28.90 and 23.84 +/- 25.42 dB, respectively (p = 0.082). Speech discrimination scores in the placebo and EGb761 groups were 69.17 +/- 40.89 and 87.48 +/- 28.65 %, respectively (p = 0.050). THI and SF-36 scores in the placebo and EGb761 groups were similar. Although a combination of steroid and EGb761 for initial treatment did not show better pure tone threshold, compared with steroid alone, speech discrimination was significantly improved in combination therapy. Further studies will be needed to know if addition of EGb761 actually improves the outcome of ISSNHL treatment.