Evaluation of botulinum toxin A in treatment of tinnitus.

OBJECTIVES

The purpose of this study was to evaluate the potential benefit of botulinum toxin A in treatment of tinnitus with a prospective, double-blinded study design.

STUDY DESIGN

Double-blinded, prospective clinical study.

METHODS

Thirty patients with tinnitus were randomly placed into 1 of 2 treatment arms. Patients either received botulinum toxin A (20 to 50 units) or saline injection at the first treatment, and the opposite treatment 4 months later. Prospective data including tinnitus matching test, tinnitus handicap inventory (THI), tinnitus rating scale (TRS), and patient questionnaires were obtained over a 4-month period after each injection.

RESULTS

Twenty-six patients completed both injections and follow-up and were included in data analysis. After botulinum toxin A, subjective tinnitus changes included 7 patients improved, 3 worsened, and 16 unchanged. Following placebo, 2 patients were improved, 7 worsened, and 17 unchanged. Comparison of the treatment and placebo groups was statistically significant (P < 0.005) when including better, worse, and same effects. A significant decrease in THI scores between pretreatment and 4 month postbotulinum toxin A injection (P = 0.0422) was recorded. None of the other comparisons of pretreatment to 1 month, or pretreatment to 4 months were significantly different.

CONCLUSIONS

This small study found improvement in THI scores and patient subjective results after botulinum toxin A injection compared with placebo, suggesting a possible benefit of botulinum toxin A in tinnitus management. Larger studies need to be completed to further evaluate potential benefits of botulinum toxin A in treatment of this difficult problem.