A single trial containing 22 patients, with a low risk of bias was included. This trial found that after 24 months, compared with placebo , the use of intratympanic dexamethasone demonstrated a statistically significant improvement in vertigo as defined by a respective improvement in functional level (90% versus 42%), class (82% versus 57%), change in Dizziness Handicap Inventory scores ( versus ) and mean vertigo subjective improvement (90% versus 57%). The treatment regime described by the authors involved daily injections of dexamethasone solution 4 mg/ml for five consecutive days. These results were clinically significant. No complications were reported.
Clinically, the success rate of Intratympanic steroid therapy in patients with SHL is variable in the literature and the available studies are limited to retrospective and non-controlled prospective ones. In those studies steroids were used in various concentrations, regimens and delivery methods and their effectiveness have not been established due to the lack of randomized controlled trials. There have been some studies in the literature that discussed the effectiveness of Intratympanic steroid therapy as a salvage mode of therapy in patients who failed to respond to oral steroids (Herr & Marzo 2005, Slattery et al 2005).