CRD Summary: The review concluded that intratympanic gentamicin appears effective for the control of symptoms of Meniere's disease, regardless of method of delivery, dosing frequency or concentration. There is a likelihood of significant bias in the published studies. Methodological weaknesses in the review, together with the authors' appropriate consideration of the limitations of the included studies, suggest that the findings may not be reliable.

CRD Commentary: The review question was clear in terms of the participants, intervention and outcomes, but was not defined in terms of the study design. Several relevant sources were searched, but no search terms were reported. The search strategy was not reported and can neither be evaluated nor replicated. The restriction to English language studies might have resulted in the loss of some relevant data. No attempts were made to locate unpublished data. The authors indicated the likelihood of publication bias, although this was not formally assessed. Methods were used to minimise reviewer error and bias in the study selection and data extraction processes. Study validity was not assessed, so the results from these studies and any synthesis might not be reliable. The narrative synthesis was appropriate given the heterogeneity of the participants and included studies. Methodological weaknesses in the review, together with the authors' appropriate consideration of the limitations of the included studies, suggest that the findings may not be reliable.