Reduction of cortical excitability and increase of thalamic activity in a low-frequency rTMS treatment for chronic tinnitus.

Low-frequency repetitive transcranial magnetic stimulation (rTMS) has received increasing attention for the treatment of tinnitus, but its therapeutic mechanisms are unclear. We performed low-frequency rTMS treatment for a patient with chronic tinnitus and examined changes of cortical excitability and cerebral blood flow using paired-pulse TMS and single-photon emission computed tomography. After the rTMS treatment, tinnitus loudness was decreased, cortical excitability was reduced, and blood flow in the thalamus was increased. Our results suggest that low-frequency rTMS treatment reduces tinnitus loudness by an inhibitory effect on the cortical excitability and a remote activation effect on the thalamus through the corticothalamic networks.