**1. Introduction**

Tinnitus is a complex disorder and is presented as a hearing sensation, which is not associated with an external sound stimulus [1]. It probably arises initially in the cochlea and later reaches higher structures of the auditory system where it becomes sometimes very annoying (severe disabling tinnitus—SDT).

One study showed 10 patients with "predominantly cochlear tinnitus" treated using intratympanic dexamethasone injections and described 5 patients with tinnitus control for at least 1 year [2]. They did not use a control group.

The effectiveness of intratympanic dexamethasone injections as a treatment for SDT was studied [3]. A control group was treated with saline solution and a study group with dexamethasone solution, both using intratympanic injections. There was no statistic significant difference between saline and dexamethasone solution regarding tinnitus improvement measured with visual analog scale (VAS). They concluded that intratympanic injections of steroids are not effective for the treatment of chronic SDT.

For acute tinnitus, interventions such as intratympanic AM‐101 (a cochlear N‐methyl‐D‐aspartate receptor antagonist) were tested. However, there is insufficient evidence to support the safety and efficacy of this intervention [4]. A second phase study was carried out, randomized, and placebo controlled using AM‐101 intratympanic injections and concluded that the duration of symptoms affected the cure rate of intratympanic therapy for acute subjective tinnitus [5].

The management of subjective tinnitus associated with idiopathic sudden sensorineural hearing loss (ISSHL) includes oral, intravenous, and/or intratympanic administration of corticosteroids as initial therapy [6]. Intratympanic corticosteroids were effective for the treatment of idiopathic sudden sensorineural hearing loss (ISSHL) in controlled trials when used as primary therapy [7] or as rescue therapy after failure of initial oral steroids therapy [6].

The sudden sensorineural hearing loss (SSHL) is a hearing loss of at least 30 dB at three consecutive frequencies occurring in the period of 3 days or less [8] may occur in frequencies and intensities varying from a mild hearing loss to a total loss of hearing [9, 10].

SSHL is often accompanied by tinnitus and there are few theories trying to explain its mechanism. One of them associates this symptom to a maladaptive attempt at cortical reorganization process due to peripheral deafferentation [7].

Many of these patients with tinnitus and SHL remain with residual buzz even if the treatment for SHL has been effective. The treatment of sudden sensorineural hearing loss is based on its etiology. In idiopathic sudden sensorineural hearing loss (ISSHL), the oral corticosteroids are widely used, although the supporting evidence is weak. Injection intratympanic dexamethasone has been tried in patients with idiopathic sudden sensorineural hearing loss because it provides a high concentration of steroids in the labyrinth in animal models [8]. In addition, there are several advantages to intratympanic treatment. The procedure is well tolerated, relatively easy to perform as outpatient. Most patients understand the concept of intratympanic treatment and easily accept this therapy [3].

The questions we try to ask in this paper are as follows:

