Background: Idiopathic sudden sensorineural hearing loss (ISSHL) is a clinical diagnosis characterised by a sudden deafness of cochlear or retrocochlear origin in the absence of a clear precipitating cause. Steroids are commonly prescribed to treat this condition. There is no consensus on their effectiveness.

Objectives: To determine the effectiveness and the side-effect profile of steroids in the treatment of idiopathic sudden sensorineural hearing loss.

Search strategy: We searched the Cochrane Ear, Nose and Throat Disorders Group Specialised Register, the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library Issue 4, 2004), MEDLINE (1966 to December 2004) and EMBASE (1974 to December 2004). Reference lists of all trials were also manually searched.

Selection criteria: We identified all randomised controlled trials (with or without blinding) in which steroids were evaluated in comparison with either no treatment or a placebo. Trials including the use of steroids in combination with another treatment were considered if the comparison control group also received the same other treatment. The full text articles of all the retrieved trials of possible relevance were reviewed by the two authors and the inclusion criteria applied independently. Any differences in opinion about which studies to include in the reviews were resolved by discussion.

Data collection and analysis: Trials were graded for methodological quality using the Cochrane approach. The data extraction was performed in a standardised manner by one author and rechecked by the other author, and where necessary investigators were contacted to obtain the missing information. Meta-analysis was neither possible nor considered appropriate because of the heterogeneity of the populations studied, the differences in steroid formulations, dosages and duration of the treatment. The quality of the result of each study was analysed and reported individually. A narrative overview of the result is presented.

Main results: Only two trials satisfied the inclusion criteria and both were of low methodological quality. One trial showed a lack of effect of oral steroids in hearing improvement compared with the placebo control group. The other trial showed a significant improvement of hearing in 61% of the patients receiving oral steroid and in only 32% of the patients from the control group (combination of placebo treated group and untreated control group). There was no clear evidence presented in the former study about any harmful side effects of the steroids. The latter study declared that no patients suffered from adverse effects from the steroid treatment.

Authors' conclusions: The value of steroids in the treatment of idiopathic sudden sensorineural hearing loss remains unclear since the evidence obtained from randomised controlled trials are contradictory in outcome, in part because the studies are based upon too small a number of patients.