Abstract
Background
This is an update of a Cochrane review first published in The Cochrane Library in Issue 1, 2006 and previously updated in 2009.
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 whether steroids in the treatment of ISSHL a) improve hearing (primary) and b) reduce tinnitus (secondary).
To determine the incidence of significant side effects from the medication.
Search methods
We searched the Cochrane Ear, Nose and Throat Disorders Group Trials Register; the Cochrane Central Register of Controlled Trials (CENTRAL); PubMed; EMBASE; CINAHL; Web of Science; Cambridge Scientific Abstracts; ICTRP and additional sources for published and unpublished trials. The date of the most recent search was 22 April 2013.
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. We considered trials including the use of steroids in combination with another treatment if the comparison control group also received the same other treatment. The two authors reviewed the full-text articles of all the retrieved trials of possible relevance and applied the inclusion criteria independently.
Data collection and analysis
We graded trials for risk of bias using the Cochrane approach. The data extraction was performed in a standardised manner by one author and rechecked by the other author. Where necessary we contacted investigators to obtain the missing information. Meta-analysis was neither possible nor considered appropriate because of the heterogeneity of the populations studied and the differences in steroid formulations, dosages and duration of treatment. We analysed and reported the quality of the results of each study individually. A narrative overview of the results is presented.
Main results
Only three trials, involving 267 participants, satisfied the inclusion criteria and all three studies were at high risk of bias. One trial showed a lack of effect of oral steroids in improving hearing compared with the placebo control group. The second 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). The third trial also showed a lack of effect of oral steroids in improving hearing compared with the placebo control. However, this trial did not follow strict inclusion criteria for participant selection and analysis of data was limited by significant exclusion of participants from the final analysis and lack of participant compliance to the treatment protocol. No clear evidence was presented in two trials about any harmful side effects of the steroids. Only one study declared that no patients suffered from adverse effects of 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 is contradictory in outcome, in part because the studies are based upon too small a number of patients.
Plain language summary
Steroids for the treatment of sudden hearing loss with unknown cause
A sudden onset of hearing loss due to disease of the hearing organs is a medical emergency and requires prompt recognition and treatment. In addition to the hearing impairment, patients may also suffer from symptoms of tinnitus (background ringing noise), a sensation of ear fullness and dizziness. In many instances medical specialists are able to find the cause and treat the hearing impairment. However, in a large proportion of patients, no known cause of the sudden hearing loss can be found. Steroids are commonly used to treat patients with sudden hearing loss of an unknown origin. The specific action of the steroids in the hearing apparatus is uncertain. It is possible that the steroid treatment improves hearing because of its ability to reduce inflammation and oedema (swelling) in the hearing organs. The review of the trials showed a lack of good-quality evidence for the effectiveness of steroids in the treatment of sudden hearing loss of an unknown origin. The quality of the trials was generally low and more research is needed.
