Levodopa does not enhance the effect of low-frequency repetitive transcranial magnetic stimulation in tinnitus treatment

Objective: Low-frequency repetitive transcranial magnetic stimulation (rTMS) has shown promise for the treatment of tinnitus. Experimental data from motor cortex stimulation in healthy subjects indicates that the suppressing effect of low-frequency rTMS can be enhanced by dopaminergic receptor activation. Here we investigated whether administration of the dopamine precursor Levodopa before low-frequency rTMS enhances its efficacy in tinnitus treatment.

Study design: 16 patients with chronic tinnitus received 100mg of Levodopa before each session of low frequency rTMS. Results were compared with a matched control group of 16 patients who received the same treatment, but without Levodopa. Treatment outcome was assessed with a standardized tinnitus questionnaire.

Results: Both stimulation protocols resulted in a significant reduction of tinnitus scores after 10 days of stimulation; however, there was no significant difference between the two groups.

Conclusion: Our data suggests that 100mg of Levodopa do not enhance the effect of rTMS in the treatment of tinnitus.