Intratympanic Injections: An Unsolved Mystery

Abstract

Aims: The aim of this study was to test the effectiveness of intratympanic dexamethasone injections as a treatment for severe disabling tinnitus and also observe its effect on hearing loss if any. Materials and Methods: Thirty patients with severe disabling tinnitus in the age group 20 to 60 years were selected and randomly assigned to receive intratympanic injections of a dexamethasone solution 4 mg/ml (0.5 ml) or isotonic saline (0.5 ml) solution under topical anaesthesia, once per week for 4 weeks using a zero degree endoscope. Improvement in tinnitus was assessed using a visual analog scale, considering 2-point improvement as significant and alteration in hearing if any was noted by pure tone audiometery before and after the therapy. Results: The improvement in tinnitus was not significant, with no alteration in audiometery reports. Conclusions: Intratympanic therapy is an attractive mode of treatment because of its highly targeted delivery, low concentration of the drugs required and a very good patient tolerance. Although there has been no breakthrough in intratympanic therapy for tinnitus or other otological conditions, accessibility to the inner ear through the semipermeable round window membrane holds many promises in the near future.

Intratympanic injection of dexamethasone for controlling subjective idiopathic tinnitus

“…Yilmaz et al [18] studied IT dexamethasone injection in 40 patients with nearly the same inclusion and exclusion criteria and reported no significant changes in average high-frequency and SD% and a significant reduction in PTA, which agreed partially with our results. Our results were in agreement with those of Parelkar et al [12], who reported no change in the hearing levels before and after treatment as per the pure-tone audiogram reports in the patient group. Hamid in his study on Meniere's disease noticed a significant gain in speech discrimination (30-60%) that has been associated with IT dexamethasone perfusion.…”

“…However, Araújo et al [11], in his randomized single-blind study, reported no difference between IT injection of dexamethasone and saline in patients with severe, disabling tinnitus. The same results were reported by Parelkar et al [12] in a recent study.…”

“…Parelkar et al [12] reported that, although IT therapy is a highly efficacious and tempting mode of drug delivery, IT dexamethasone injections are not effective for refractory tinnitus and do not alter the hearing loss; this study was also conducted on patients with severely disabling tinnitus. They also referred the failure of IT injection in a group of patients to the poor round window membrane permeability.…”

Efficacy of intratympanic injection of dexamethasone in the treatment of subjective idiopathic tinnitus

“…The mechanism of action of this therapeutic modality is multifactorial, including antiinformatory effects, a metabolic improving effect, an edema-relieving effect, and suppress the irritated or hypersensitive hair cells in the inner ear, which are believed to cause tinnitus. 10 Pondugula et al pointed at other mechanism of action for IT dexamethazone injection in tinnitus patients, which suggest that steroid perfusion of labyrinthine tissues can affect sodium and fluid transport in vitro studies. 11 The choice of an IT route in the treatment of tinnitus has two advantages: first, high perilymph levels are attained as a result of providing a direct passage through the oval window membrane, and, second, adverse effects of systemic administration of the drug are avoided.…”