Background and purpose: Although there are a number of positive reports on the therapeutic effects of repetitive transcranial magnetic stimulation (rTMS) for treatment of tinnitus, there are few details about the duration of treatment effects or the relative efficiency of different rTMS protocols.
Methods: Sixty six patients with chronic tinnitus were divided into four groups, receiving sham rTMS, 1, 10 and 25 Hz rTMS applied each day for 10 days over left temporoparietal cortex. They were followed up at 4 months and 1 year using the tinnitus questionnaire [Tinnitus Handicap Inventory(THI)] and self ratings of annoyance as well as measures of residual inhibition.
Results: A two factor anova revealed a significant 'rTMS' x 'time' interaction indicating that real and sham rTMS had different effects on the THI scale and annoyance of tinnitus (P = 0.026 and 0.046 respectively). After 1 year, the tinnitus was absent in one or both ears of 10 patients who had received real rTMS: one of these was in the 1 Hz group, four patients were in the 10 Hz group and five patients were in the 25 Hz group.
Conclusion: Some patients show a lasting benefit at 1 year after 10 days of rTMS treatment. It appears that treatment at 10 or 25 Hz may be more beneficial than at 1 Hz, although more work is necessary to validate this conclusion.