Transcranial magnetic stimulation: potential treatment for tinnitus?

Tinnitus is a common and often severely disabling disorder for which there is no satisfactory treatment. Transcranial magnetic stimulation (TMS) is a new, non-invasive method of modifying the excitability of the cerebral cortex, which has proven effective in auditory hallucinations and other disorders. Some early studies have been published in which TMS has been trialed in the treatment of tinnitus. The aim of the present paper was to examine the literature and consider the potential for TMS as a therapy in tinnitus. A thorough search of the tinnitus and TMS literature was conducted, and all available relevant material was examined. Discussions were held with leaders in both fields. Tinnitus is common and there are no effective treatments. It is frequently associated with deafness, and may be the result of a pathological plastic process, secondary to loss of innervation of the outer hair cells of the cochlea. Neuroimaging studies demonstrate increase blood flow to the primary and secondary auditory cortices, particularly on the left side. Transcranial magnetic stimulation is a non-invasive method of perturbing and inducing change in the cerebral cortex. It uses electromagnetic principles and has been successfully employed in the treatment of other conditions associated with increased activity of the cerebral cortex. A small number of studies have suggested that TMS may be effective in the treatment of tinnitus. There is a good theoretical basis and early research evidence suggesting that TMS may have treatment potential in tinnitus. Further, larger studies are necessary.