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Introduction

Tinnitus is the apparent sensation of sound without definite acoustic stimulation and is defined as a ringing, rumbling or whining sound. Tinnitus represents one of the most common and distressing diagnoses in otology practice. Nevertheless, tinnitus is often underreported since patients do not always seek medical attention. Of those affected, approximately 3–5% are estimated to suffer from severe disabling tinnitus interfering with work, sleep and decreasing the quality of life . The incidence is estimated to range from 2 to 7% in adult population, while in the US population 15 million people consider their tinnitus to be a significant problem . The prevalence in the adults above 55 years is approximately 20–30% in patients. Tinnitus is encountered in different otological diseases. Nevertheless, no apparent cause can be established in 8-10% of patients with normal hearing .

Even though quite a lot of hypotheses have been suggested to clarify the pathology of tinnitus, the precise mechanism is still unknown . A large number of therapies have been used to alleviate the severity of tinnitus, including tinnitus retraining, tinnitus masking, biofeedback therapy, herbal medicines, various drug treatments (intratympanic steroids, vasodilators, vitamins, antihistamines, barbiturates, anesthetics, Ca-channel blockers, antidepressants, anxiolytics, etc.) . However, in most of the cases the results were no different from placebo.

In a recent study, Shim et al. demonstrated that intratympanic (IT) dexamethasone plus alprazolam is the best treatment choice for unilateral acute idiopathic tinnitus within 3 months of development. The authors hypothesized that cochlear injury in early stage is reversible by the action of IT corticoids while alprazolam acts on the initial neural hyperactivity of the central auditory pathways. Since cochlear lesions are reversible for a limited period of time, IT steroids could be effective only within a year. Cochlear restoration allows for the related cessation of neural hyperactivity in the central auditory tract . Melatonin is a hormone produced by the pineal gland, known to be involved in regulating the sleep-wake cycle and has been used with various success rates in tinnitus treatment . Rosenberg et al. firstly demonstrated an improvement in tinnitus with melatonin. Melatonin was more effective than placebo in tinnitus relief and the effect was pronounced in patients with sleep disorders. Megwalu et al. revealed that both tinnitus annoyance and sleep quality improved in patients on melatonin. Hurtuk et al. through a prospective, randomized, double-blind, crossover trial confirmed that melatonin is associated with a statistically significant decrease in tinnitus intensity and improved sleep quality.

The purpose of our study was to determine whether the combination of IT corticosteroid with melatonin could be associated with decreased tinnitus in patients with acute idiopathic tinnitus. We evaluated this hypothesis through a prospective, randomized, controlled, double-blinded trial. As previously suggested , we concentrated only on unilateral tinnitus patients, since the concurrent occurrence of bilateral cochlear lesions is questionable. Moreover, in bilateral tinnitus it is a challenge to assess outcomes only on the side of recent onset.